| Message ID | 20191203034655.51561-11-alastair@au1.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add support for OpenCAPI SCM devices | expand |
On Tue, 2019-12-03 at 14:46 +1100, Alastair D'Silva wrote: > From: Alastair D'Silva <alastair@d-silva.org> > > This driver exposes LPC memory on OpenCAPI SCM cards > as an NVDIMM, allowing the existing nvram infrastructure > to be used. > > Namespace metadata is stored on the media itself, so > scm_reserve_metadata() maps 1 section's worth of PMEM storage > at the start to hold this. The rest of the PMEM range is registered > with libnvdimm as an nvdimm. scm_ndctl_config_read/write/size() > provide > callbacks to libnvdimm to access the metadata. > > Signed-off-by: Alastair D'Silva <alastair@d-silva.org> > --- > drivers/nvdimm/Kconfig | 2 + > drivers/nvdimm/Makefile | 2 +- > drivers/nvdimm/ocxl/Kconfig | 15 + > drivers/nvdimm/ocxl/Makefile | 7 + > drivers/nvdimm/ocxl/scm.c | 519 > +++++++++++++++++++++++++++++ > drivers/nvdimm/ocxl/scm_internal.h | 28 ++ > 6 files changed, 572 insertions(+), 1 deletion(-) > create mode 100644 drivers/nvdimm/ocxl/Kconfig > create mode 100644 drivers/nvdimm/ocxl/Makefile > create mode 100644 drivers/nvdimm/ocxl/scm.c > create mode 100644 drivers/nvdimm/ocxl/scm_internal.h > > diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig > index 36af7af6b7cf..d1bab36da61c 100644 > --- a/drivers/nvdimm/Kconfig > +++ b/drivers/nvdimm/Kconfig > @@ -130,4 +130,6 @@ config NVDIMM_TEST_BUILD > core devm_memremap_pages() implementation and other > infrastructure. > > +source "drivers/nvdimm/ocxl/Kconfig" > + > endif > diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile > index 29203f3d3069..e33492128042 100644 > --- a/drivers/nvdimm/Makefile > +++ b/drivers/nvdimm/Makefile > @@ -1,5 +1,5 @@ > # SPDX-License-Identifier: GPL-2.0 > -obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o > +obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o ocxl/ > obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o > obj-$(CONFIG_ND_BTT) += nd_btt.o > obj-$(CONFIG_ND_BLK) += nd_blk.o > diff --git a/drivers/nvdimm/ocxl/Kconfig > b/drivers/nvdimm/ocxl/Kconfig > new file mode 100644 > index 000000000000..24099b300f5e > --- /dev/null > +++ b/drivers/nvdimm/ocxl/Kconfig > @@ -0,0 +1,15 @@ > +# SPDX-License-Identifier: GPL-2.0-only > +if LIBNVDIMM > + > +config OCXL_SCM > + tristate "OpenCAPI Storage Class Memory" > + depends on LIBNVDIMM && PPC_POWERNV && PCI && EEH > + select ZONE_DEVICE > + select OCXL > + help > + Exposes devices that implement the OpenCAPI Storage Class > Memory > + specification as persistent memory regions. > + > + Select N if unsure. > + > +endif > diff --git a/drivers/nvdimm/ocxl/Makefile > b/drivers/nvdimm/ocxl/Makefile > new file mode 100644 > index 000000000000..74a1bd98848e > --- /dev/null > +++ b/drivers/nvdimm/ocxl/Makefile > @@ -0,0 +1,7 @@ > +# SPDX-License-Identifier: GPL-2.0 > + > +ccflags-$(CONFIG_PPC_WERROR) += -Werror > + > +obj-$(CONFIG_OCXL_SCM) += ocxlscm.o > + > +ocxlscm-y := scm.o > diff --git a/drivers/nvdimm/ocxl/scm.c b/drivers/nvdimm/ocxl/scm.c > new file mode 100644 > index 000000000000..571058a9e7b8 > --- /dev/null > +++ b/drivers/nvdimm/ocxl/scm.c > @@ -0,0 +1,519 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +// Copyright 2019 IBM Corp. > + > +/* > + * A driver for Storage Class Memory, connected via OpenCAPI > + */ > + > +#include <linux/module.h> > +#include <misc/ocxl.h> > +#include <linux/ndctl.h> > +#include <linux/mm_types.h> > +#include <linux/memory_hotplug.h> > +#include "scm_internal.h" > + > + > +static const struct pci_device_id scm_pci_tbl[] = { > + { PCI_DEVICE(PCI_VENDOR_ID_IBM, 0x0625), }, > + { } > +}; > + > +MODULE_DEVICE_TABLE(pci, scm_pci_tbl); > + > +#define SCM_NUM_MINORS 256 // Total to reserve > + > +static dev_t scm_dev; > +static struct class *scm_class; > +static struct mutex minors_idr_lock; > +static struct idr minors_idr; > + > +static const struct attribute_group *scm_pmem_attribute_groups[] = { > + &nvdimm_bus_attribute_group, > + NULL, > +}; > + > +static const struct attribute_group > *scm_pmem_region_attribute_groups[] = { > + &nd_region_attribute_group, > + &nd_device_attribute_group, > + &nd_mapping_attribute_group, > + &nd_numa_attribute_group, > + NULL, > +}; > + > +/** > + * scm_ndctl_config_write() - Handle a ND_CMD_SET_CONFIG_DATA > command from ndctl > + * @scm_data: the SCM metadata > + * @command: the incoming data to write > + * Return: 0 on success, negative on failure > + */ > +static int scm_ndctl_config_write(struct scm_data *scm_data, > + struct nd_cmd_set_config_hdr > *command) > +{ > + if (command->in_offset + command->in_length > > SCM_LABEL_AREA_SIZE) > + return -EINVAL; > + > + memcpy_flushcache(scm_data->metadata_addr + command->in_offset, > command->in_buf, > + command->in_length); > + > + return 0; > +} > + > +/** > + * scm_ndctl_config_read() - Handle a ND_CMD_GET_CONFIG_DATA command > from ndctl > + * @scm_data: the SCM metadata > + * @command: the read request > + * Return: 0 on success, negative on failure > + */ > +static int scm_ndctl_config_read(struct scm_data *scm_data, > + struct nd_cmd_get_config_data_hdr > *command) > +{ > + if (command->in_offset + command->in_length > > SCM_LABEL_AREA_SIZE) > + return -EINVAL; > + > + memcpy_mcsafe(command->out_buf, scm_data->metadata_addr + > command->in_offset, > + command->in_length); > + > + return 0; > +} > + > +/** > + * scm_ndctl_config_size() - Handle a ND_CMD_GET_CONFIG_SIZE command > from ndctl > + * @scm_data: the SCM metadata > + * @command: the read request > + * Return: 0 on success, negative on failure > + */ > +static int scm_ndctl_config_size(struct nd_cmd_get_config_size > *command) > +{ > + command->status = 0; > + command->config_size = SCM_LABEL_AREA_SIZE; > + command->max_xfer = PAGE_SIZE; > + > + return 0; > +} > + > +static int scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, > + struct nvdimm *nvdimm, > + unsigned int cmd, void *buf, unsigned int buf_len, > int *cmd_rc) > +{ > + struct scm_data *scm_data = container_of(nd_desc, struct > scm_data, bus_desc); > + > + switch (cmd) { > + case ND_CMD_GET_CONFIG_SIZE: > + *cmd_rc = scm_ndctl_config_size(buf); > + return 0; > + > + case ND_CMD_GET_CONFIG_DATA: > + *cmd_rc = scm_ndctl_config_read(scm_data, buf); > + return 0; > + > + case ND_CMD_SET_CONFIG_DATA: > + *cmd_rc = scm_ndctl_config_write(scm_data, buf); > + return 0; > + > + default: > + return -ENOTTY; > + } > +} > + > +static ssize_t serial_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct nvdimm *nvdimm = to_nvdimm(dev); > + struct scm_data *scm_data = nvdimm_provider_data(nvdimm); > + const struct ocxl_fn_config *config = > ocxl_function_config(scm_data->ocxl_fn); > + > + return sprintf(buf, "0x%llx\n", config->serial); > +} > +static DEVICE_ATTR_RO(serial); > + > +static struct attribute *scm_dimm_attributes[] = { > + &dev_attr_serial.attr, > + NULL, > +}; > + > +static umode_t scm_dimm_attr_visible(struct kobject *kobj, > + struct attribute *a, int n) > +{ > + return a->mode; > +} > + > +static const struct attribute_group scm_dimm_attribute_group = { > + .name = "ocxl", > + .attrs = scm_dimm_attributes, > + .is_visible = scm_dimm_attr_visible, > +}; > + > +static const struct attribute_group *scm_dimm_attribute_groups[] = { > + &nvdimm_attribute_group, > + &nd_device_attribute_group, > + &scm_dimm_attribute_group, > + NULL, > +}; As Aneesh Kumar has pointed out, these attribute groups should be dropped when the following patch is accepted: https://patchwork.kernel.org/patch/11248491/ > + > +/** > + * scm_reserve_metadata() - Reserve space for nvdimm metadata > + * @scm_data: The SCM device data > + * @lpc_mem: The resource representing the LPC memory of the SCM > device > + */ > +static int scm_reserve_metadata(struct scm_data *scm_data, > + struct resource *lpc_mem) > +{ > + scm_data->metadata_addr = devm_memremap(&scm_data->dev, > lpc_mem->start, > + SCM_LABEL_AREA_SIZE, > MEMREMAP_WB); > + if (IS_ERR(scm_data->metadata_addr)) > + return PTR_ERR(scm_data->metadata_addr); > + > + return 0; > +} > + > +/** > + * scm_register_lpc_mem() - Discover persistent memory on a device > and register it with the NVDIMM subsystem > + * @scm_data: The SCM device data > + * Return: 0 on success > + */ > +static int scm_register_lpc_mem(struct scm_data *scm_data) > +{ > + struct nd_region_desc region_desc; > + struct nd_mapping_desc nd_mapping_desc; > + struct resource *lpc_mem; > + const struct ocxl_afu_config *config; > + const struct ocxl_fn_config *fn_config; > + int rc; > + unsigned long nvdimm_cmd_mask = 0; > + unsigned long nvdimm_flags = 0; > + int target_node; > + char serial[16+1]; > + > + // Set up the reserved metadata area > + rc = ocxl_afu_map_lpc_mem(scm_data->ocxl_afu); > + if (rc < 0) > + return rc; > + > + lpc_mem = ocxl_afu_lpc_mem(scm_data->ocxl_afu); > + if (lpc_mem == NULL || lpc_mem->start == 0) > + return -EINVAL; > + > + config = ocxl_afu_config(scm_data->ocxl_afu); > + fn_config = ocxl_function_config(scm_data->ocxl_fn); > + > + rc = scm_reserve_metadata(scm_data, lpc_mem); > + if (rc) > + return rc; > + > + scm_data->bus_desc.attr_groups = scm_pmem_attribute_groups; > + scm_data->bus_desc.provider_name = "ocxl-scm"; > + scm_data->bus_desc.ndctl = scm_ndctl; > + scm_data->bus_desc.module = THIS_MODULE; > + > + scm_data->nvdimm_bus = nvdimm_bus_register(&scm_data->dev, > + &scm_data->bus_desc); > + if (!scm_data->nvdimm_bus) > + return -EINVAL; > + > + scm_data->scm_res.start = (u64)lpc_mem->start + > SCM_LABEL_AREA_SIZE; > + scm_data->scm_res.end = (u64)lpc_mem->start + config- > >lpc_mem_size - 1; > + scm_data->scm_res.name = "SCM persistent memory"; > + > + set_bit(ND_CMD_GET_CONFIG_SIZE, &nvdimm_cmd_mask); > + set_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm_cmd_mask); > + set_bit(ND_CMD_SET_CONFIG_DATA, &nvdimm_cmd_mask); > + > + set_bit(NDD_ALIASING, &nvdimm_flags); > + > + snprintf(serial, sizeof(serial), "%llx", fn_config->serial); > + nd_mapping_desc.nvdimm = nvdimm_create(scm_data->nvdimm_bus, > scm_data, > + scm_dimm_attribute_groups, > + nvdimm_flags, nvdimm_cmd_mask, > + 0, NULL); > + if (!nd_mapping_desc.nvdimm) > + return -ENOMEM; > + > + if (nvdimm_bus_check_dimm_count(scm_data->nvdimm_bus, 1)) > + return -EINVAL; > + > + nd_mapping_desc.start = scm_data->scm_res.start; > + nd_mapping_desc.size = resource_size(&scm_data->scm_res); > + nd_mapping_desc.position = 0; > + > + scm_data->nd_set.cookie1 = fn_config->serial + 1; // allow for > empty serial > + scm_data->nd_set.cookie2 = fn_config->serial + 1; > + > + target_node = of_node_to_nid(scm_data->pdev->dev.of_node); > + > + memset(®ion_desc, 0, sizeof(region_desc)); > + region_desc.res = &scm_data->scm_res; > + region_desc.attr_groups = scm_pmem_region_attribute_groups; > + region_desc.numa_node = NUMA_NO_NODE; > + region_desc.target_node = target_node; > + region_desc.num_mappings = 1; > + region_desc.mapping = &nd_mapping_desc; > + region_desc.nd_set = &scm_data->nd_set; > + > + set_bit(ND_REGION_PAGEMAP, ®ion_desc.flags); > + /* > + * NB: libnvdimm copies the data from ndr_desc into it's own > + * structures so passing a stack pointer is fine. > + */ > + scm_data->nd_region = nvdimm_pmem_region_create(scm_data- > >nvdimm_bus, > + ®ion_desc); > + if (!scm_data->nd_region) > + return -EINVAL; > + > + dev_info(&scm_data->dev, > + "Onlining %lluMB of persistent memory\n", > + nd_mapping_desc.size / SZ_1M); > + > + return 0; > +} > + > +/** > + * allocate_scm_minor() - Allocate a minor number to use for an SCM > device > + * @scm_data: The SCM device to associate the minor with > + * Return: the allocated minor number > + */ > +static int allocate_scm_minor(struct scm_data *scm_data) > +{ > + int minor; > + > + mutex_lock(&minors_idr_lock); > + minor = idr_alloc(&minors_idr, scm_data, 0, SCM_NUM_MINORS, > GFP_KERNEL); > + mutex_unlock(&minors_idr_lock); > + return minor; > +} > + > +static void free_scm_minor(struct scm_data *scm_data) > +{ > + mutex_lock(&minors_idr_lock); > + idr_remove(&minors_idr, MINOR(scm_data->dev.devt)); > + mutex_unlock(&minors_idr_lock); > +} > + > +/** > + * free_scm() - Free all members of an SCM struct > + * @scm_data: the SCM metadata to clear > + */ > +static void free_scm(struct scm_data *scm_data) > +{ > + int rc; > + > + if (scm_data->nvdimm_bus) > + nvdimm_bus_unregister(scm_data->nvdimm_bus); > + > + free_scm_minor(scm_data); > + > + if (scm_data->metadata_addr) > + devm_memunmap(&scm_data->dev, scm_data->metadata_addr); > + > + if (scm_data->ocxl_context) { > + rc = ocxl_context_detach(scm_data->ocxl_context); > + if (rc == -EBUSY) > + dev_warn(&scm_data->dev, "Timeout detaching > ocxl context\n"); > + else > + ocxl_context_free(scm_data->ocxl_context); > + > + } > + > + if (scm_data->ocxl_afu) > + ocxl_afu_put(scm_data->ocxl_afu); > + > + if (scm_data->ocxl_fn) > + ocxl_function_close(scm_data->ocxl_fn); > + > + kfree(scm_data); > +} > + > +/** > + * free_scm_dev - Free an SCM device > + * @dev: The device struct > + */ > +static void free_scm_dev(struct device *dev) > +{ > + struct scm_data *scm_data = container_of(dev, struct scm_data, > dev); > + > + free_scm(scm_data); > +} > + > +/** > + * scm_register - Register an SCM device with the kernel > + * @scm_data: the SCM metadata > + * Return: 0 on success, negative on failure > + */ > +static int scm_register(struct scm_data *scm_data) > +{ > + int rc; > + int minor = allocate_scm_minor(scm_data); > + > + if (minor < 0) > + return minor; > + > + scm_data->dev.release = free_scm_dev; > + rc = dev_set_name(&scm_data->dev, "ocxl-scm%d", minor); > + if (rc < 0) > + return rc; > + > + scm_data->dev.devt = MKDEV(MAJOR(scm_dev), minor); > + scm_data->dev.class = scm_class; > + scm_data->dev.parent = &scm_data->pdev->dev; > + > + rc = device_register(&scm_data->dev); > + return rc; > +} > + > +/** > + * scm_remove() - Free an OpenCAPI Storage Class Memory device > + * @pdev: the PCI device information struct > + */ > +static void scm_remove(struct pci_dev *pdev) > +{ > + if (PCI_FUNC(pdev->devfn) == 0) { > + struct scm_function_0 *scm_func_0 = > pci_get_drvdata(pdev); > + > + if (scm_func_0) { > + ocxl_function_close(scm_func_0->ocxl_fn); > + scm_func_0->ocxl_fn = NULL; > + } > + } else { > + struct scm_data *scm_data = pci_get_drvdata(pdev); > + > + if (scm_data) > + device_unregister(&scm_data->dev); > + } > +} > + > +/** > + * scm_probe_function_0 - Set up function 0 for an OpenCAPI Storage > Class Memory device > + * This is important as it enables templates higher than 0 across > all other functions, > + * which in turn enables higher bandwidth accesses > + * which in turn enables higher bandwidth accesses > + * @pdev: the PCI device information struct > + * Return: 0 on success, negative on failure > + */ > +static int scm_probe_function_0(struct pci_dev *pdev) > +{ > + struct scm_function_0 *scm_func_0 = NULL; > + struct ocxl_fn *fn; > + > + scm_func_0 = kzalloc(sizeof(*scm_func_0), GFP_KERNEL); > + if (!scm_func_0) > + return -ENOMEM; > + > + scm_func_0->pdev = pdev; > + fn = ocxl_function_open(pdev); > + if (IS_ERR(fn)) { > + kfree(scm_func_0); > + dev_err(&pdev->dev, "failed to open OCXL function\n"); > + return PTR_ERR(fn); > + } > + scm_func_0->ocxl_fn = fn; > + > + pci_set_drvdata(pdev, scm_func_0); > + > + return 0; > +} > + > +/** > + * scm_probe - Init an OpenCAPI Storage Class Memory device > + * @pdev: the PCI device information struct > + * @ent: The entry from scm_pci_tbl > + * Return: 0 on success, negative on failure > + */ > +static int scm_probe(struct pci_dev *pdev, const struct > pci_device_id *ent) > +{ > + struct scm_data *scm_data = NULL; > + > + if (PCI_FUNC(pdev->devfn) == 0) > + return scm_probe_function_0(pdev); > + else if (PCI_FUNC(pdev->devfn) != 1) > + return 0; > + > + scm_data = kzalloc(sizeof(*scm_data), GFP_KERNEL); > + if (!scm_data) { > + dev_err(&pdev->dev, "Could not allocate SCM > metadata\n"); > + goto err; > + } > + scm_data->pdev = pdev; > + > + pci_set_drvdata(pdev, scm_data); > + > + scm_data->ocxl_fn = ocxl_function_open(pdev); > + if (IS_ERR(scm_data->ocxl_fn)) { > + kfree(scm_data); > + scm_data = NULL; > + pci_set_drvdata(pdev, NULL); > + dev_err(&pdev->dev, "failed to open OCXL function\n"); > + goto err; > + } > + > + scm_data->ocxl_afu = ocxl_function_fetch_afu(scm_data->ocxl_fn, > 0); > + if (scm_data->ocxl_afu == NULL) { > + dev_err(&pdev->dev, "Could not get OCXL AFU from > function\n"); > + goto err; > + } > + > + ocxl_afu_get(scm_data->ocxl_afu); > + > + if (scm_register(scm_data) < 0) { > + dev_err(&pdev->dev, "Could not register SCM device with > the kernel\n"); > + goto err; > + } > + > + // Resources allocated below here are cleaned up in the release > handler > + > + if (ocxl_context_alloc(&scm_data->ocxl_context, scm_data- > >ocxl_afu, NULL)) { > + dev_err(&pdev->dev, "Could not allocate OCXL > context\n"); > + goto err; > + } > + > + if (ocxl_context_attach(scm_data->ocxl_context, 0, NULL)) { > + dev_err(&pdev->dev, "Could not attach ocxl context\n"); > + goto err; > + } > + > + if (scm_register_lpc_mem(scm_data)) { > + dev_err(&pdev->dev, "Could not register OCXL SCM memory > with libnvdimm\n"); > + goto err; > + } > + > + return 0; > + > +err: > + /* > + * Further cleanup is done in the release handler via > free_scm() > + * This allows us to keep the character device live to handle > IOCTLs to > + * investigate issues if the card has an error > + */ > + > + dev_err(&pdev->dev, > + "Error detected, will not register storage class > memory\n"); > + return -ENXIO; > +} > + > +static struct pci_driver scm_pci_driver = { > + .name = "ocxl-scm", > + .id_table = scm_pci_tbl, > + .probe = scm_probe, > + .remove = scm_remove, > + .shutdown = scm_remove, > +}; > + > +static int __init scm_init(void) > +{ > + int rc = 0; > + > + rc = pci_register_driver(&scm_pci_driver); > + if (rc) > + return rc; > + > + return 0; > +} > + > +static void scm_exit(void) > +{ > + pci_unregister_driver(&scm_pci_driver); > +} > + > +module_init(scm_init); > +module_exit(scm_exit); > + > +MODULE_DESCRIPTION("Storage Class Memory"); > +MODULE_LICENSE("GPL"); > diff --git a/drivers/nvdimm/ocxl/scm_internal.h > b/drivers/nvdimm/ocxl/scm_internal.h > new file mode 100644 > index 000000000000..6340012e0f8a > --- /dev/null > +++ b/drivers/nvdimm/ocxl/scm_internal.h > @@ -0,0 +1,28 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +// Copyright 2019 IBM Corp. > + > +#include <linux/pci.h> > +#include <misc/ocxl.h> > +#include <linux/libnvdimm.h> > +#include <linux/mm.h> > + > +#define SCM_LABEL_AREA_SIZE (1UL << PA_SECTION_SHIFT) > + > +struct scm_function_0 { > + struct pci_dev *pdev; > + struct ocxl_fn *ocxl_fn; > +}; > + > +struct scm_data { > + struct device dev; > + struct pci_dev *pdev; > + struct ocxl_fn *ocxl_fn; > + struct nd_interleave_set nd_set; > + struct nvdimm_bus_descriptor bus_desc; > + struct nvdimm_bus *nvdimm_bus; > + struct ocxl_afu *ocxl_afu; > + struct ocxl_context *ocxl_context; > + void *metadata_addr; > + struct resource scm_res; > + struct nd_region *nd_region; > +};
On Tue, 3 Dec 2019 14:46:38 +1100 Alastair D'Silva <alastair@au1.ibm.com> wrote: > From: Alastair D'Silva <alastair@d-silva.org> > > This driver exposes LPC memory on OpenCAPI SCM cards > as an NVDIMM, allowing the existing nvram infrastructure > to be used. > > Namespace metadata is stored on the media itself, so > scm_reserve_metadata() maps 1 section's worth of PMEM storage > at the start to hold this. The rest of the PMEM range is registered > with libnvdimm as an nvdimm. scm_ndctl_config_read/write/size() provide > callbacks to libnvdimm to access the metadata. > > Signed-off-by: Alastair D'Silva <alastair@d-silva.org> Hi Alastair, A few bits and bobs inline. Thanks, Jonathan > --- > drivers/nvdimm/Kconfig | 2 + > drivers/nvdimm/Makefile | 2 +- > drivers/nvdimm/ocxl/Kconfig | 15 + > drivers/nvdimm/ocxl/Makefile | 7 + > drivers/nvdimm/ocxl/scm.c | 519 +++++++++++++++++++++++++++++ > drivers/nvdimm/ocxl/scm_internal.h | 28 ++ > 6 files changed, 572 insertions(+), 1 deletion(-) > create mode 100644 drivers/nvdimm/ocxl/Kconfig > create mode 100644 drivers/nvdimm/ocxl/Makefile > create mode 100644 drivers/nvdimm/ocxl/scm.c > create mode 100644 drivers/nvdimm/ocxl/scm_internal.h > > diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig > index 36af7af6b7cf..d1bab36da61c 100644 > --- a/drivers/nvdimm/Kconfig > +++ b/drivers/nvdimm/Kconfig > @@ -130,4 +130,6 @@ config NVDIMM_TEST_BUILD > core devm_memremap_pages() implementation and other > infrastructure. > > +source "drivers/nvdimm/ocxl/Kconfig" > + > endif > diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile > index 29203f3d3069..e33492128042 100644 > --- a/drivers/nvdimm/Makefile > +++ b/drivers/nvdimm/Makefile > @@ -1,5 +1,5 @@ > # SPDX-License-Identifier: GPL-2.0 > -obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o > +obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o ocxl/ > obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o > obj-$(CONFIG_ND_BTT) += nd_btt.o > obj-$(CONFIG_ND_BLK) += nd_blk.o > diff --git a/drivers/nvdimm/ocxl/Kconfig b/drivers/nvdimm/ocxl/Kconfig > new file mode 100644 > index 000000000000..24099b300f5e > --- /dev/null > +++ b/drivers/nvdimm/ocxl/Kconfig > @@ -0,0 +1,15 @@ > +# SPDX-License-Identifier: GPL-2.0-only > +if LIBNVDIMM > + > +config OCXL_SCM > + tristate "OpenCAPI Storage Class Memory" > + depends on LIBNVDIMM && PPC_POWERNV && PCI && EEH > + select ZONE_DEVICE > + select OCXL > + help > + Exposes devices that implement the OpenCAPI Storage Class Memory > + specification as persistent memory regions. > + > + Select N if unsure. > + > +endif > diff --git a/drivers/nvdimm/ocxl/Makefile b/drivers/nvdimm/ocxl/Makefile > new file mode 100644 > index 000000000000..74a1bd98848e > --- /dev/null > +++ b/drivers/nvdimm/ocxl/Makefile > @@ -0,0 +1,7 @@ > +# SPDX-License-Identifier: GPL-2.0 > + > +ccflags-$(CONFIG_PPC_WERROR) += -Werror > + > +obj-$(CONFIG_OCXL_SCM) += ocxlscm.o > + > +ocxlscm-y := scm.o > diff --git a/drivers/nvdimm/ocxl/scm.c b/drivers/nvdimm/ocxl/scm.c > new file mode 100644 > index 000000000000..571058a9e7b8 > --- /dev/null > +++ b/drivers/nvdimm/ocxl/scm.c > @@ -0,0 +1,519 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +// Copyright 2019 IBM Corp. > + > +/* > + * A driver for Storage Class Memory, connected via OpenCAPI > + */ > + > +#include <linux/module.h> > +#include <misc/ocxl.h> > +#include <linux/ndctl.h> > +#include <linux/mm_types.h> > +#include <linux/memory_hotplug.h> > +#include "scm_internal.h" > + > + > +static const struct pci_device_id scm_pci_tbl[] = { > + { PCI_DEVICE(PCI_VENDOR_ID_IBM, 0x0625), }, > + { } > +}; > + > +MODULE_DEVICE_TABLE(pci, scm_pci_tbl); > + > +#define SCM_NUM_MINORS 256 // Total to reserve > + > +static dev_t scm_dev; > +static struct class *scm_class; > +static struct mutex minors_idr_lock; > +static struct idr minors_idr; > + > +static const struct attribute_group *scm_pmem_attribute_groups[] = { > + &nvdimm_bus_attribute_group, > + NULL, > +}; > + > +static const struct attribute_group *scm_pmem_region_attribute_groups[] = { > + &nd_region_attribute_group, > + &nd_device_attribute_group, > + &nd_mapping_attribute_group, > + &nd_numa_attribute_group, > + NULL, > +}; > + > +/** > + * scm_ndctl_config_write() - Handle a ND_CMD_SET_CONFIG_DATA command from ndctl > + * @scm_data: the SCM metadata > + * @command: the incoming data to write > + * Return: 0 on success, negative on failure > + */ > +static int scm_ndctl_config_write(struct scm_data *scm_data, > + struct nd_cmd_set_config_hdr *command) > +{ > + if (command->in_offset + command->in_length > SCM_LABEL_AREA_SIZE) > + return -EINVAL; > + > + memcpy_flushcache(scm_data->metadata_addr + command->in_offset, command->in_buf, > + command->in_length); > + > + return 0; > +} > + > +/** > + * scm_ndctl_config_read() - Handle a ND_CMD_GET_CONFIG_DATA command from ndctl > + * @scm_data: the SCM metadata > + * @command: the read request > + * Return: 0 on success, negative on failure > + */ > +static int scm_ndctl_config_read(struct scm_data *scm_data, > + struct nd_cmd_get_config_data_hdr *command) > +{ > + if (command->in_offset + command->in_length > SCM_LABEL_AREA_SIZE) > + return -EINVAL; > + > + memcpy_mcsafe(command->out_buf, scm_data->metadata_addr + command->in_offset, > + command->in_length); > + > + return 0; > +} > + > +/** > + * scm_ndctl_config_size() - Handle a ND_CMD_GET_CONFIG_SIZE command from ndctl > + * @scm_data: the SCM metadata > + * @command: the read request > + * Return: 0 on success, negative on failure > + */ > +static int scm_ndctl_config_size(struct nd_cmd_get_config_size *command) > +{ > + command->status = 0; > + command->config_size = SCM_LABEL_AREA_SIZE; > + command->max_xfer = PAGE_SIZE; > + > + return 0; > +} > + > +static int scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, > + struct nvdimm *nvdimm, > + unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc) > +{ > + struct scm_data *scm_data = container_of(nd_desc, struct scm_data, bus_desc); > + > + switch (cmd) { > + case ND_CMD_GET_CONFIG_SIZE: > + *cmd_rc = scm_ndctl_config_size(buf); > + return 0; > + > + case ND_CMD_GET_CONFIG_DATA: > + *cmd_rc = scm_ndctl_config_read(scm_data, buf); > + return 0; > + > + case ND_CMD_SET_CONFIG_DATA: > + *cmd_rc = scm_ndctl_config_write(scm_data, buf); > + return 0; > + > + default: > + return -ENOTTY; > + } > +} > + > +static ssize_t serial_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct nvdimm *nvdimm = to_nvdimm(dev); > + struct scm_data *scm_data = nvdimm_provider_data(nvdimm); > + const struct ocxl_fn_config *config = ocxl_function_config(scm_data->ocxl_fn); > + > + return sprintf(buf, "0x%llx\n", config->serial); > +} > +static DEVICE_ATTR_RO(serial); > + > +static struct attribute *scm_dimm_attributes[] = { > + &dev_attr_serial.attr, > + NULL, > +}; > + > +static umode_t scm_dimm_attr_visible(struct kobject *kobj, > + struct attribute *a, int n) > +{ > + return a->mode; > +} > + > +static const struct attribute_group scm_dimm_attribute_group = { > + .name = "ocxl", > + .attrs = scm_dimm_attributes, > + .is_visible = scm_dimm_attr_visible, > +}; > + > +static const struct attribute_group *scm_dimm_attribute_groups[] = { > + &nvdimm_attribute_group, > + &nd_device_attribute_group, > + &scm_dimm_attribute_group, > + NULL, > +}; > + > +/** > + * scm_reserve_metadata() - Reserve space for nvdimm metadata > + * @scm_data: The SCM device data > + * @lpc_mem: The resource representing the LPC memory of the SCM device > + */ > +static int scm_reserve_metadata(struct scm_data *scm_data, > + struct resource *lpc_mem) > +{ > + scm_data->metadata_addr = devm_memremap(&scm_data->dev, lpc_mem->start, > + SCM_LABEL_AREA_SIZE, MEMREMAP_WB); > + if (IS_ERR(scm_data->metadata_addr)) > + return PTR_ERR(scm_data->metadata_addr); > + > + return 0; > +} > + > +/** > + * scm_register_lpc_mem() - Discover persistent memory on a device and register it with the NVDIMM subsystem > + * @scm_data: The SCM device data > + * Return: 0 on success > + */ > +static int scm_register_lpc_mem(struct scm_data *scm_data) > +{ > + struct nd_region_desc region_desc; > + struct nd_mapping_desc nd_mapping_desc; > + struct resource *lpc_mem; > + const struct ocxl_afu_config *config; > + const struct ocxl_fn_config *fn_config; > + int rc; > + unsigned long nvdimm_cmd_mask = 0; > + unsigned long nvdimm_flags = 0; > + int target_node; > + char serial[16+1]; > + > + // Set up the reserved metadata area > + rc = ocxl_afu_map_lpc_mem(scm_data->ocxl_afu); > + if (rc < 0) > + return rc; > + > + lpc_mem = ocxl_afu_lpc_mem(scm_data->ocxl_afu); > + if (lpc_mem == NULL || lpc_mem->start == 0) > + return -EINVAL; > + > + config = ocxl_afu_config(scm_data->ocxl_afu); > + fn_config = ocxl_function_config(scm_data->ocxl_fn); > + > + rc = scm_reserve_metadata(scm_data, lpc_mem); > + if (rc) > + return rc; > + > + scm_data->bus_desc.attr_groups = scm_pmem_attribute_groups; > + scm_data->bus_desc.provider_name = "ocxl-scm"; > + scm_data->bus_desc.ndctl = scm_ndctl; > + scm_data->bus_desc.module = THIS_MODULE; > + > + scm_data->nvdimm_bus = nvdimm_bus_register(&scm_data->dev, > + &scm_data->bus_desc); odd alignment. > + if (!scm_data->nvdimm_bus) > + return -EINVAL; > + > + scm_data->scm_res.start = (u64)lpc_mem->start + SCM_LABEL_AREA_SIZE; > + scm_data->scm_res.end = (u64)lpc_mem->start + config->lpc_mem_size - 1; > + scm_data->scm_res.name = "SCM persistent memory"; > + > + set_bit(ND_CMD_GET_CONFIG_SIZE, &nvdimm_cmd_mask); > + set_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm_cmd_mask); > + set_bit(ND_CMD_SET_CONFIG_DATA, &nvdimm_cmd_mask); > + > + set_bit(NDD_ALIASING, &nvdimm_flags); > + > + snprintf(serial, sizeof(serial), "%llx", fn_config->serial); > + nd_mapping_desc.nvdimm = nvdimm_create(scm_data->nvdimm_bus, scm_data, > + scm_dimm_attribute_groups, > + nvdimm_flags, nvdimm_cmd_mask, > + 0, NULL); > + if (!nd_mapping_desc.nvdimm) > + return -ENOMEM; > + > + if (nvdimm_bus_check_dimm_count(scm_data->nvdimm_bus, 1)) > + return -EINVAL; > + > + nd_mapping_desc.start = scm_data->scm_res.start; > + nd_mapping_desc.size = resource_size(&scm_data->scm_res); > + nd_mapping_desc.position = 0; > + > + scm_data->nd_set.cookie1 = fn_config->serial + 1; // allow for empty serial > + scm_data->nd_set.cookie2 = fn_config->serial + 1; > + > + target_node = of_node_to_nid(scm_data->pdev->dev.of_node); > + > + memset(®ion_desc, 0, sizeof(region_desc)); > + region_desc.res = &scm_data->scm_res; > + region_desc.attr_groups = scm_pmem_region_attribute_groups; > + region_desc.numa_node = NUMA_NO_NODE; > + region_desc.target_node = target_node; > + region_desc.num_mappings = 1; > + region_desc.mapping = &nd_mapping_desc; > + region_desc.nd_set = &scm_data->nd_set; > + > + set_bit(ND_REGION_PAGEMAP, ®ion_desc.flags); > + /* > + * NB: libnvdimm copies the data from ndr_desc into it's own > + * structures so passing a stack pointer is fine. > + */ > + scm_data->nd_region = nvdimm_pmem_region_create(scm_data->nvdimm_bus, > + ®ion_desc); > + if (!scm_data->nd_region) > + return -EINVAL; > + > + dev_info(&scm_data->dev, > + "Onlining %lluMB of persistent memory\n", > + nd_mapping_desc.size / SZ_1M); > + > + return 0; > +} > + > +/** > + * allocate_scm_minor() - Allocate a minor number to use for an SCM device > + * @scm_data: The SCM device to associate the minor with > + * Return: the allocated minor number > + */ > +static int allocate_scm_minor(struct scm_data *scm_data) > +{ > + int minor; > + > + mutex_lock(&minors_idr_lock); > + minor = idr_alloc(&minors_idr, scm_data, 0, SCM_NUM_MINORS, GFP_KERNEL); > + mutex_unlock(&minors_idr_lock); > + return minor; > +} > + > +static void free_scm_minor(struct scm_data *scm_data) > +{ > + mutex_lock(&minors_idr_lock); > + idr_remove(&minors_idr, MINOR(scm_data->dev.devt)); > + mutex_unlock(&minors_idr_lock); > +} > + > +/** > + * free_scm() - Free all members of an SCM struct > + * @scm_data: the SCM metadata to clear > + */ > +static void free_scm(struct scm_data *scm_data) > +{ > + int rc; > + > + if (scm_data->nvdimm_bus) > + nvdimm_bus_unregister(scm_data->nvdimm_bus); > + > + free_scm_minor(scm_data); > + > + if (scm_data->metadata_addr) > + devm_memunmap(&scm_data->dev, scm_data->metadata_addr); > + > + if (scm_data->ocxl_context) { > + rc = ocxl_context_detach(scm_data->ocxl_context); > + if (rc == -EBUSY) > + dev_warn(&scm_data->dev, "Timeout detaching ocxl context\n"); > + else > + ocxl_context_free(scm_data->ocxl_context); > + > + } > + > + if (scm_data->ocxl_afu) > + ocxl_afu_put(scm_data->ocxl_afu); > + > + if (scm_data->ocxl_fn) > + ocxl_function_close(scm_data->ocxl_fn); > + > + kfree(scm_data); > +} > + > +/** > + * free_scm_dev - Free an SCM device > + * @dev: The device struct > + */ > +static void free_scm_dev(struct device *dev) > +{ > + struct scm_data *scm_data = container_of(dev, struct scm_data, dev); > + > + free_scm(scm_data); > +} > + > +/** > + * scm_register - Register an SCM device with the kernel > + * @scm_data: the SCM metadata > + * Return: 0 on success, negative on failure > + */ > +static int scm_register(struct scm_data *scm_data) > +{ > + int rc; > + int minor = allocate_scm_minor(scm_data); > + > + if (minor < 0) > + return minor; > + > + scm_data->dev.release = free_scm_dev; > + rc = dev_set_name(&scm_data->dev, "ocxl-scm%d", minor); > + if (rc < 0) > + return rc; > + > + scm_data->dev.devt = MKDEV(MAJOR(scm_dev), minor); > + scm_data->dev.class = scm_class; > + scm_data->dev.parent = &scm_data->pdev->dev; > + > + rc = device_register(&scm_data->dev); > + return rc; return device_register(&scm_data->dev); Assuming nothing else is added inbetween in later patches... If it is then ignore this one. > +} > + > +/** > + * scm_remove() - Free an OpenCAPI Storage Class Memory device > + * @pdev: the PCI device information struct > + */ > +static void scm_remove(struct pci_dev *pdev) > +{ > + if (PCI_FUNC(pdev->devfn) == 0) { > + struct scm_function_0 *scm_func_0 = pci_get_drvdata(pdev); > + > + if (scm_func_0) { > + ocxl_function_close(scm_func_0->ocxl_fn); > + scm_func_0->ocxl_fn = NULL; > + } > + } else { > + struct scm_data *scm_data = pci_get_drvdata(pdev); > + > + if (scm_data) > + device_unregister(&scm_data->dev); > + } > +} > + > +/** > + * scm_probe_function_0 - Set up function 0 for an OpenCAPI Storage Class Memory device Overly long line + not consistent on () after function name. IIRC either () or not is fine, but should be consistent in a gven file. > + * This is important as it enables templates higher than 0 across all other functions, > + * which in turn enables higher bandwidth accesses > + * which in turn enables higher bandwidth accesses Repeated line. > + * @pdev: the PCI device information struct > + * Return: 0 on success, negative on failure > + */ > +static int scm_probe_function_0(struct pci_dev *pdev) > +{ > + struct scm_function_0 *scm_func_0 = NULL; > + struct ocxl_fn *fn; > + > + scm_func_0 = kzalloc(sizeof(*scm_func_0), GFP_KERNEL); > + if (!scm_func_0) > + return -ENOMEM; > + > + scm_func_0->pdev = pdev; > + fn = ocxl_function_open(pdev); > + if (IS_ERR(fn)) { > + kfree(scm_func_0); > + dev_err(&pdev->dev, "failed to open OCXL function\n"); > + return PTR_ERR(fn); > + } > + scm_func_0->ocxl_fn = fn; > + > + pci_set_drvdata(pdev, scm_func_0); > + > + return 0; > +} > + > +/** > + * scm_probe - Init an OpenCAPI Storage Class Memory device > + * @pdev: the PCI device information struct > + * @ent: The entry from scm_pci_tbl > + * Return: 0 on success, negative on failure > + */ > +static int scm_probe(struct pci_dev *pdev, const struct pci_device_id *ent) > +{ > + struct scm_data *scm_data = NULL; Always set in paths that use it. > + > + if (PCI_FUNC(pdev->devfn) == 0) > + return scm_probe_function_0(pdev); > + else if (PCI_FUNC(pdev->devfn) != 1) > + return 0; > + > + scm_data = kzalloc(sizeof(*scm_data), GFP_KERNEL); > + if (!scm_data) { > + dev_err(&pdev->dev, "Could not allocate SCM metadata\n"); > + goto err; > + } > + scm_data->pdev = pdev; > + > + pci_set_drvdata(pdev, scm_data); > + > + scm_data->ocxl_fn = ocxl_function_open(pdev); > + if (IS_ERR(scm_data->ocxl_fn)) { > + kfree(scm_data); > + scm_data = NULL; Doesn't seem like scm_data is used anywhere in the rror path.. > + pci_set_drvdata(pdev, NULL); > + dev_err(&pdev->dev, "failed to open OCXL function\n"); > + goto err; > + } > + > + scm_data->ocxl_afu = ocxl_function_fetch_afu(scm_data->ocxl_fn, 0); > + if (scm_data->ocxl_afu == NULL) { > + dev_err(&pdev->dev, "Could not get OCXL AFU from function\n"); > + goto err; The comment below suggests to me that free_scm will only be called if we succeed in scm_register? If so isn't there more error handling to be done until that happens? > + } > + > + ocxl_afu_get(scm_data->ocxl_afu); > + > + if (scm_register(scm_data) < 0) { > + dev_err(&pdev->dev, "Could not register SCM device with the kernel\n"); > + goto err; > + } > + > + // Resources allocated below here are cleaned up in the release handler > + > + if (ocxl_context_alloc(&scm_data->ocxl_context, scm_data->ocxl_afu, NULL)) { > + dev_err(&pdev->dev, "Could not allocate OCXL context\n"); > + goto err; > + } > + > + if (ocxl_context_attach(scm_data->ocxl_context, 0, NULL)) { > + dev_err(&pdev->dev, "Could not attach ocxl context\n"); > + goto err; > + } > + > + if (scm_register_lpc_mem(scm_data)) { > + dev_err(&pdev->dev, "Could not register OCXL SCM memory with libnvdimm\n"); > + goto err; > + } > + > + return 0; > + > +err: > + /* > + * Further cleanup is done in the release handler via free_scm() > + * This allows us to keep the character device live to handle IOCTLs to > + * investigate issues if the card has an error > + */ > + > + dev_err(&pdev->dev, > + "Error detected, will not register storage class memory\n"); > + return -ENXIO; Probably better to return more specific errors from the various error paths. -ENOMEM etc. > +} > + > +static struct pci_driver scm_pci_driver = { > + .name = "ocxl-scm", > + .id_table = scm_pci_tbl, > + .probe = scm_probe, > + .remove = scm_remove, > + .shutdown = scm_remove, > +}; > + > +static int __init scm_init(void) > +{ > + int rc = 0; > + > + rc = pci_register_driver(&scm_pci_driver); > + if (rc) > + return rc; > + > + return 0; > +} > + > +static void scm_exit(void) > +{ > + pci_unregister_driver(&scm_pci_driver); > +} > + > +module_init(scm_init); > +module_exit(scm_exit); > + > +MODULE_DESCRIPTION("Storage Class Memory"); > +MODULE_LICENSE("GPL"); > diff --git a/drivers/nvdimm/ocxl/scm_internal.h b/drivers/nvdimm/ocxl/scm_internal.h > new file mode 100644 > index 000000000000..6340012e0f8a > --- /dev/null > +++ b/drivers/nvdimm/ocxl/scm_internal.h > @@ -0,0 +1,28 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +// Copyright 2019 IBM Corp. > + > +#include <linux/pci.h> > +#include <misc/ocxl.h> > +#include <linux/libnvdimm.h> > +#include <linux/mm.h> > + > +#define SCM_LABEL_AREA_SIZE (1UL << PA_SECTION_SHIFT) > + > +struct scm_function_0 { > + struct pci_dev *pdev; > + struct ocxl_fn *ocxl_fn; > +}; > + > +struct scm_data { > + struct device dev; > + struct pci_dev *pdev; > + struct ocxl_fn *ocxl_fn; > + struct nd_interleave_set nd_set; > + struct nvdimm_bus_descriptor bus_desc; > + struct nvdimm_bus *nvdimm_bus; > + struct ocxl_afu *ocxl_afu; > + struct ocxl_context *ocxl_context; > + void *metadata_addr; > + struct resource scm_res; > + struct nd_region *nd_region; > +};
On Mon, 2020-02-03 at 13:20 +0000, Jonathan Cameron wrote: > On Tue, 3 Dec 2019 14:46:38 +1100 > Alastair D'Silva <alastair@au1.ibm.com> wrote: > > > From: Alastair D'Silva <alastair@d-silva.org> > > > > This driver exposes LPC memory on OpenCAPI SCM cards > > as an NVDIMM, allowing the existing nvram infrastructure > > to be used. > > > > Namespace metadata is stored on the media itself, so > > scm_reserve_metadata() maps 1 section's worth of PMEM storage > > at the start to hold this. The rest of the PMEM range is registered > > with libnvdimm as an nvdimm. scm_ndctl_config_read/write/size() > > provide > > callbacks to libnvdimm to access the metadata. > > > > Signed-off-by: Alastair D'Silva <alastair@d-silva.org> > Hi Alastair, > > A few bits and bobs inline. > > Thanks, > > Jonathan > > > --- > > drivers/nvdimm/Kconfig | 2 + > > drivers/nvdimm/Makefile | 2 +- > > drivers/nvdimm/ocxl/Kconfig | 15 + > > drivers/nvdimm/ocxl/Makefile | 7 + > > drivers/nvdimm/ocxl/scm.c | 519 > > +++++++++++++++++++++++++++++ > > drivers/nvdimm/ocxl/scm_internal.h | 28 ++ > > 6 files changed, 572 insertions(+), 1 deletion(-) > > create mode 100644 drivers/nvdimm/ocxl/Kconfig > > create mode 100644 drivers/nvdimm/ocxl/Makefile > > create mode 100644 drivers/nvdimm/ocxl/scm.c > > create mode 100644 drivers/nvdimm/ocxl/scm_internal.h > > > > diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig > > index 36af7af6b7cf..d1bab36da61c 100644 > > --- a/drivers/nvdimm/Kconfig > > +++ b/drivers/nvdimm/Kconfig > > @@ -130,4 +130,6 @@ config NVDIMM_TEST_BUILD > > core devm_memremap_pages() implementation and other > > infrastructure. > > > > +source "drivers/nvdimm/ocxl/Kconfig" > > + > > endif > > diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile > > index 29203f3d3069..e33492128042 100644 > > --- a/drivers/nvdimm/Makefile > > +++ b/drivers/nvdimm/Makefile > > @@ -1,5 +1,5 @@ > > # SPDX-License-Identifier: GPL-2.0 > > -obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o > > +obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o ocxl/ > > obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o > > obj-$(CONFIG_ND_BTT) += nd_btt.o > > obj-$(CONFIG_ND_BLK) += nd_blk.o > > diff --git a/drivers/nvdimm/ocxl/Kconfig > > b/drivers/nvdimm/ocxl/Kconfig > > new file mode 100644 > > index 000000000000..24099b300f5e > > --- /dev/null > > +++ b/drivers/nvdimm/ocxl/Kconfig > > @@ -0,0 +1,15 @@ > > +# SPDX-License-Identifier: GPL-2.0-only > > +if LIBNVDIMM > > + > > +config OCXL_SCM > > + tristate "OpenCAPI Storage Class Memory" > > + depends on LIBNVDIMM && PPC_POWERNV && PCI && EEH > > + select ZONE_DEVICE > > + select OCXL > > + help > > + Exposes devices that implement the OpenCAPI Storage Class > > Memory > > + specification as persistent memory regions. > > + > > + Select N if unsure. > > + > > +endif > > diff --git a/drivers/nvdimm/ocxl/Makefile > > b/drivers/nvdimm/ocxl/Makefile > > new file mode 100644 > > index 000000000000..74a1bd98848e > > --- /dev/null > > +++ b/drivers/nvdimm/ocxl/Makefile > > @@ -0,0 +1,7 @@ > > +# SPDX-License-Identifier: GPL-2.0 > > + > > +ccflags-$(CONFIG_PPC_WERROR) += -Werror > > + > > +obj-$(CONFIG_OCXL_SCM) += ocxlscm.o > > + > > +ocxlscm-y := scm.o > > diff --git a/drivers/nvdimm/ocxl/scm.c b/drivers/nvdimm/ocxl/scm.c > > new file mode 100644 > > index 000000000000..571058a9e7b8 > > --- /dev/null > > +++ b/drivers/nvdimm/ocxl/scm.c > > @@ -0,0 +1,519 @@ > > +// SPDX-License-Identifier: GPL-2.0+ > > +// Copyright 2019 IBM Corp. > > + > > +/* > > + * A driver for Storage Class Memory, connected via OpenCAPI > > + */ > > + > > +#include <linux/module.h> > > +#include <misc/ocxl.h> > > +#include <linux/ndctl.h> > > +#include <linux/mm_types.h> > > +#include <linux/memory_hotplug.h> > > +#include "scm_internal.h" > > + > > + > > +static const struct pci_device_id scm_pci_tbl[] = { > > + { PCI_DEVICE(PCI_VENDOR_ID_IBM, 0x0625), }, > > + { } > > +}; > > + > > +MODULE_DEVICE_TABLE(pci, scm_pci_tbl); > > + > > +#define SCM_NUM_MINORS 256 // Total to reserve > > + > > +static dev_t scm_dev; > > +static struct class *scm_class; > > +static struct mutex minors_idr_lock; > > +static struct idr minors_idr; > > + > > +static const struct attribute_group *scm_pmem_attribute_groups[] = > > { > > + &nvdimm_bus_attribute_group, > > + NULL, > > +}; > > + > > +static const struct attribute_group > > *scm_pmem_region_attribute_groups[] = { > > + &nd_region_attribute_group, > > + &nd_device_attribute_group, > > + &nd_mapping_attribute_group, > > + &nd_numa_attribute_group, > > + NULL, > > +}; > > + > > +/** > > + * scm_ndctl_config_write() - Handle a ND_CMD_SET_CONFIG_DATA > > command from ndctl > > + * @scm_data: the SCM metadata > > + * @command: the incoming data to write > > + * Return: 0 on success, negative on failure > > + */ > > +static int scm_ndctl_config_write(struct scm_data *scm_data, > > + struct nd_cmd_set_config_hdr > > *command) > > +{ > > + if (command->in_offset + command->in_length > > > SCM_LABEL_AREA_SIZE) > > + return -EINVAL; > > + > > + memcpy_flushcache(scm_data->metadata_addr + command->in_offset, > > command->in_buf, > > + command->in_length); > > + > > + return 0; > > +} > > + > > +/** > > + * scm_ndctl_config_read() - Handle a ND_CMD_GET_CONFIG_DATA > > command from ndctl > > + * @scm_data: the SCM metadata > > + * @command: the read request > > + * Return: 0 on success, negative on failure > > + */ > > +static int scm_ndctl_config_read(struct scm_data *scm_data, > > + struct nd_cmd_get_config_data_hdr > > *command) > > +{ > > + if (command->in_offset + command->in_length > > > SCM_LABEL_AREA_SIZE) > > + return -EINVAL; > > + > > + memcpy_mcsafe(command->out_buf, scm_data->metadata_addr + > > command->in_offset, > > + command->in_length); > > + > > + return 0; > > +} > > + > > +/** > > + * scm_ndctl_config_size() - Handle a ND_CMD_GET_CONFIG_SIZE > > command from ndctl > > + * @scm_data: the SCM metadata > > + * @command: the read request > > + * Return: 0 on success, negative on failure > > + */ > > +static int scm_ndctl_config_size(struct nd_cmd_get_config_size > > *command) > > +{ > > + command->status = 0; > > + command->config_size = SCM_LABEL_AREA_SIZE; > > + command->max_xfer = PAGE_SIZE; > > + > > + return 0; > > +} > > + > > +static int scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, > > + struct nvdimm *nvdimm, > > + unsigned int cmd, void *buf, unsigned int buf_len, > > int *cmd_rc) > > +{ > > + struct scm_data *scm_data = container_of(nd_desc, struct > > scm_data, bus_desc); > > + > > + switch (cmd) { > > + case ND_CMD_GET_CONFIG_SIZE: > > + *cmd_rc = scm_ndctl_config_size(buf); > > + return 0; > > + > > + case ND_CMD_GET_CONFIG_DATA: > > + *cmd_rc = scm_ndctl_config_read(scm_data, buf); > > + return 0; > > + > > + case ND_CMD_SET_CONFIG_DATA: > > + *cmd_rc = scm_ndctl_config_write(scm_data, buf); > > + return 0; > > + > > + default: > > + return -ENOTTY; > > + } > > +} > > + > > +static ssize_t serial_show(struct device *dev, > > + struct device_attribute *attr, char *buf) > > +{ > > + struct nvdimm *nvdimm = to_nvdimm(dev); > > + struct scm_data *scm_data = nvdimm_provider_data(nvdimm); > > + const struct ocxl_fn_config *config = > > ocxl_function_config(scm_data->ocxl_fn); > > + > > + return sprintf(buf, "0x%llx\n", config->serial); > > +} > > +static DEVICE_ATTR_RO(serial); > > + > > +static struct attribute *scm_dimm_attributes[] = { > > + &dev_attr_serial.attr, > > + NULL, > > +}; > > + > > +static umode_t scm_dimm_attr_visible(struct kobject *kobj, > > + struct attribute *a, int n) > > +{ > > + return a->mode; > > +} > > + > > +static const struct attribute_group scm_dimm_attribute_group = { > > + .name = "ocxl", > > + .attrs = scm_dimm_attributes, > > + .is_visible = scm_dimm_attr_visible, > > +}; > > + > > +static const struct attribute_group *scm_dimm_attribute_groups[] = > > { > > + &nvdimm_attribute_group, > > + &nd_device_attribute_group, > > + &scm_dimm_attribute_group, > > + NULL, > > +}; > > + > > +/** > > + * scm_reserve_metadata() - Reserve space for nvdimm metadata > > + * @scm_data: The SCM device data > > + * @lpc_mem: The resource representing the LPC memory of the SCM > > device > > + */ > > +static int scm_reserve_metadata(struct scm_data *scm_data, > > + struct resource *lpc_mem) > > +{ > > + scm_data->metadata_addr = devm_memremap(&scm_data->dev, > > lpc_mem->start, > > + SCM_LABEL_AREA_SIZE, > > MEMREMAP_WB); > > + if (IS_ERR(scm_data->metadata_addr)) > > + return PTR_ERR(scm_data->metadata_addr); > > + > > + return 0; > > +} > > + > > +/** > > + * scm_register_lpc_mem() - Discover persistent memory on a device > > and register it with the NVDIMM subsystem > > + * @scm_data: The SCM device data > > + * Return: 0 on success > > + */ > > +static int scm_register_lpc_mem(struct scm_data *scm_data) > > +{ > > + struct nd_region_desc region_desc; > > + struct nd_mapping_desc nd_mapping_desc; > > + struct resource *lpc_mem; > > + const struct ocxl_afu_config *config; > > + const struct ocxl_fn_config *fn_config; > > + int rc; > > + unsigned long nvdimm_cmd_mask = 0; > > + unsigned long nvdimm_flags = 0; > > + int target_node; > > + char serial[16+1]; > > + > > + // Set up the reserved metadata area > > + rc = ocxl_afu_map_lpc_mem(scm_data->ocxl_afu); > > + if (rc < 0) > > + return rc; > > + > > + lpc_mem = ocxl_afu_lpc_mem(scm_data->ocxl_afu); > > + if (lpc_mem == NULL || lpc_mem->start == 0) > > + return -EINVAL; > > + > > + config = ocxl_afu_config(scm_data->ocxl_afu); > > + fn_config = ocxl_function_config(scm_data->ocxl_fn); > > + > > + rc = scm_reserve_metadata(scm_data, lpc_mem); > > + if (rc) > > + return rc; > > + > > + scm_data->bus_desc.attr_groups = scm_pmem_attribute_groups; > > + scm_data->bus_desc.provider_name = "ocxl-scm"; > > + scm_data->bus_desc.ndctl = scm_ndctl; > > + scm_data->bus_desc.module = THIS_MODULE; > > + > > + scm_data->nvdimm_bus = nvdimm_bus_register(&scm_data->dev, > > + &scm_data->bus_desc); > > odd alignment. Ok > > > + if (!scm_data->nvdimm_bus) > > + return -EINVAL; > > + > > + scm_data->scm_res.start = (u64)lpc_mem->start + > > SCM_LABEL_AREA_SIZE; > > + scm_data->scm_res.end = (u64)lpc_mem->start + config- > > >lpc_mem_size - 1; > > + scm_data->scm_res.name = "SCM persistent memory"; > > + > > + set_bit(ND_CMD_GET_CONFIG_SIZE, &nvdimm_cmd_mask); > > + set_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm_cmd_mask); > > + set_bit(ND_CMD_SET_CONFIG_DATA, &nvdimm_cmd_mask); > > + > > + set_bit(NDD_ALIASING, &nvdimm_flags); > > + > > + snprintf(serial, sizeof(serial), "%llx", fn_config->serial); > > + nd_mapping_desc.nvdimm = nvdimm_create(scm_data->nvdimm_bus, > > scm_data, > > + scm_dimm_attribute_groups, > > + nvdimm_flags, nvdimm_cmd_mask, > > + 0, NULL); > > + if (!nd_mapping_desc.nvdimm) > > + return -ENOMEM; > > + > > + if (nvdimm_bus_check_dimm_count(scm_data->nvdimm_bus, 1)) > > + return -EINVAL; > > + > > + nd_mapping_desc.start = scm_data->scm_res.start; > > + nd_mapping_desc.size = resource_size(&scm_data->scm_res); > > + nd_mapping_desc.position = 0; > > + > > + scm_data->nd_set.cookie1 = fn_config->serial + 1; // allow for > > empty serial > > + scm_data->nd_set.cookie2 = fn_config->serial + 1; > > + > > + target_node = of_node_to_nid(scm_data->pdev->dev.of_node); > > + > > + memset(®ion_desc, 0, sizeof(region_desc)); > > + region_desc.res = &scm_data->scm_res; > > + region_desc.attr_groups = scm_pmem_region_attribute_groups; > > + region_desc.numa_node = NUMA_NO_NODE; > > + region_desc.target_node = target_node; > > + region_desc.num_mappings = 1; > > + region_desc.mapping = &nd_mapping_desc; > > + region_desc.nd_set = &scm_data->nd_set; > > + > > + set_bit(ND_REGION_PAGEMAP, ®ion_desc.flags); > > + /* > > + * NB: libnvdimm copies the data from ndr_desc into it's own > > + * structures so passing a stack pointer is fine. > > + */ > > + scm_data->nd_region = nvdimm_pmem_region_create(scm_data- > > >nvdimm_bus, > > + ®ion_desc); > > + if (!scm_data->nd_region) > > + return -EINVAL; > > + > > + dev_info(&scm_data->dev, > > + "Onlining %lluMB of persistent memory\n", > > + nd_mapping_desc.size / SZ_1M); > > + > > + return 0; > > +} > > + > > +/** > > + * allocate_scm_minor() - Allocate a minor number to use for an > > SCM device > > + * @scm_data: The SCM device to associate the minor with > > + * Return: the allocated minor number > > + */ > > +static int allocate_scm_minor(struct scm_data *scm_data) > > +{ > > + int minor; > > + > > + mutex_lock(&minors_idr_lock); > > + minor = idr_alloc(&minors_idr, scm_data, 0, SCM_NUM_MINORS, > > GFP_KERNEL); > > + mutex_unlock(&minors_idr_lock); > > + return minor; > > +} > > + > > +static void free_scm_minor(struct scm_data *scm_data) > > +{ > > + mutex_lock(&minors_idr_lock); > > + idr_remove(&minors_idr, MINOR(scm_data->dev.devt)); > > + mutex_unlock(&minors_idr_lock); > > +} > > + > > +/** > > + * free_scm() - Free all members of an SCM struct > > + * @scm_data: the SCM metadata to clear > > + */ > > +static void free_scm(struct scm_data *scm_data) > > +{ > > + int rc; > > + > > + if (scm_data->nvdimm_bus) > > + nvdimm_bus_unregister(scm_data->nvdimm_bus); > > + > > + free_scm_minor(scm_data); > > + > > + if (scm_data->metadata_addr) > > + devm_memunmap(&scm_data->dev, scm_data->metadata_addr); > > + > > + if (scm_data->ocxl_context) { > > + rc = ocxl_context_detach(scm_data->ocxl_context); > > + if (rc == -EBUSY) > > + dev_warn(&scm_data->dev, "Timeout detaching > > ocxl context\n"); > > + else > > + ocxl_context_free(scm_data->ocxl_context); > > + > > + } > > + > > + if (scm_data->ocxl_afu) > > + ocxl_afu_put(scm_data->ocxl_afu); > > + > > + if (scm_data->ocxl_fn) > > + ocxl_function_close(scm_data->ocxl_fn); > > + > > + kfree(scm_data); > > +} > > + > > +/** > > + * free_scm_dev - Free an SCM device > > + * @dev: The device struct > > + */ > > +static void free_scm_dev(struct device *dev) > > +{ > > + struct scm_data *scm_data = container_of(dev, struct scm_data, > > dev); > > + > > + free_scm(scm_data); > > +} > > + > > +/** > > + * scm_register - Register an SCM device with the kernel > > + * @scm_data: the SCM metadata > > + * Return: 0 on success, negative on failure > > + */ > > +static int scm_register(struct scm_data *scm_data) > > +{ > > + int rc; > > + int minor = allocate_scm_minor(scm_data); > > + > > + if (minor < 0) > > + return minor; > > + > > + scm_data->dev.release = free_scm_dev; > > + rc = dev_set_name(&scm_data->dev, "ocxl-scm%d", minor); > > + if (rc < 0) > > + return rc; > > + > > + scm_data->dev.devt = MKDEV(MAJOR(scm_dev), minor); > > + scm_data->dev.class = scm_class; > > + scm_data->dev.parent = &scm_data->pdev->dev; > > + > > + rc = device_register(&scm_data->dev); > > + return rc; > return device_register(&scm_data->dev); > > Assuming nothing else is added inbetween in later patches... > If it is then ignore this one. > Ok > > +} > > + > > +/** > > + * scm_remove() - Free an OpenCAPI Storage Class Memory device > > + * @pdev: the PCI device information struct > > + */ > > +static void scm_remove(struct pci_dev *pdev) > > +{ > > + if (PCI_FUNC(pdev->devfn) == 0) { > > + struct scm_function_0 *scm_func_0 = > > pci_get_drvdata(pdev); > > + > > + if (scm_func_0) { > > + ocxl_function_close(scm_func_0->ocxl_fn); > > + scm_func_0->ocxl_fn = NULL; > > + } > > + } else { > > + struct scm_data *scm_data = pci_get_drvdata(pdev); > > + > > + if (scm_data) > > + device_unregister(&scm_data->dev); > > + } > > +} > > + > > +/** > > + * scm_probe_function_0 - Set up function 0 for an OpenCAPI > > Storage Class Memory device > Overly long line + not consistent on () after function name. > > IIRC either () or not is fine, but should be consistent in a gven > file. Ok > > > + * This is important as it enables templates higher than 0 across > > all other functions, > > + * which in turn enables higher bandwidth accesses > > + * which in turn enables higher bandwidth accesses > > Repeated line. Ok > > > + * @pdev: the PCI device information struct > > + * Return: 0 on success, negative on failure > > + */ > > +static int scm_probe_function_0(struct pci_dev *pdev) > > +{ > > + struct scm_function_0 *scm_func_0 = NULL; > > + struct ocxl_fn *fn; > > + > > + scm_func_0 = kzalloc(sizeof(*scm_func_0), GFP_KERNEL); > > + if (!scm_func_0) > > + return -ENOMEM; > > + > > + scm_func_0->pdev = pdev; > > + fn = ocxl_function_open(pdev); > > + if (IS_ERR(fn)) { > > + kfree(scm_func_0); > > + dev_err(&pdev->dev, "failed to open OCXL function\n"); > > + return PTR_ERR(fn); > > + } > > + scm_func_0->ocxl_fn = fn; > > + > > + pci_set_drvdata(pdev, scm_func_0); > > + > > + return 0; > > +} > > + > > +/** > > + * scm_probe - Init an OpenCAPI Storage Class Memory device > > + * @pdev: the PCI device information struct > > + * @ent: The entry from scm_pci_tbl > > + * Return: 0 on success, negative on failure > > + */ > > +static int scm_probe(struct pci_dev *pdev, const struct > > pci_device_id *ent) > > +{ > > + struct scm_data *scm_data = NULL; > > Always set in paths that use it. Ok > > > + > > + if (PCI_FUNC(pdev->devfn) == 0) > > + return scm_probe_function_0(pdev); > > + else if (PCI_FUNC(pdev->devfn) != 1) > > + return 0; > > + > > + scm_data = kzalloc(sizeof(*scm_data), GFP_KERNEL); > > + if (!scm_data) { > > + dev_err(&pdev->dev, "Could not allocate SCM > > metadata\n"); > > + goto err; > > + } > > + scm_data->pdev = pdev; > > + > > + pci_set_drvdata(pdev, scm_data); > > + > > + scm_data->ocxl_fn = ocxl_function_open(pdev); > > + if (IS_ERR(scm_data->ocxl_fn)) { > > + kfree(scm_data); > > + scm_data = NULL; > > Doesn't seem like scm_data is used anywhere in the rror path.. Ok > > > + pci_set_drvdata(pdev, NULL); > > + dev_err(&pdev->dev, "failed to open OCXL function\n"); > > + goto err; > > + } > > + > > + scm_data->ocxl_afu = ocxl_function_fetch_afu(scm_data->ocxl_fn, > > 0); > > + if (scm_data->ocxl_afu == NULL) { > > + dev_err(&pdev->dev, "Could not get OCXL AFU from > > function\n"); > > + goto err; > > The comment below suggests to me that free_scm will only be called if > we succeed > in scm_register? If so isn't there more error handling to be done > until that > happens? > I've moved that comment up - once device_register has been called (even if the call fails), the free handler should always be called via device_put. > > + } > > + > > + ocxl_afu_get(scm_data->ocxl_afu); > > + > > + if (scm_register(scm_data) < 0) { > > + dev_err(&pdev->dev, "Could not register SCM device with > > the kernel\n"); > > + goto err; > > + } > > + > > + // Resources allocated below here are cleaned up in the release > > handler > > + > > + if (ocxl_context_alloc(&scm_data->ocxl_context, scm_data- > > >ocxl_afu, NULL)) { > > + dev_err(&pdev->dev, "Could not allocate OCXL > > context\n"); > > + goto err; > > + } > > + > > + if (ocxl_context_attach(scm_data->ocxl_context, 0, NULL)) { > > + dev_err(&pdev->dev, "Could not attach ocxl context\n"); > > + goto err; > > + } > > + > > + if (scm_register_lpc_mem(scm_data)) { > > + dev_err(&pdev->dev, "Could not register OCXL SCM memory > > with libnvdimm\n"); > > + goto err; > > + } > > + > > + return 0; > > + > > +err: > > + /* > > + * Further cleanup is done in the release handler via > > free_scm() > > + * This allows us to keep the character device live to handle > > IOCTLs to > > + * investigate issues if the card has an error > > + */ > > + > > + dev_err(&pdev->dev, > > + "Error detected, will not register storage class > > memory\n"); > > + return -ENXIO; > > Probably better to return more specific errors from the various error > paths. > -ENOMEM etc. > I've updated the code to propogate errors up from the calls. > > > +} > > + > > +static struct pci_driver scm_pci_driver = { > > + .name = "ocxl-scm", > > + .id_table = scm_pci_tbl, > > + .probe = scm_probe, > > + .remove = scm_remove, > > + .shutdown = scm_remove, > > +}; > > + > > +static int __init scm_init(void) > > +{ > > + int rc = 0; > > + > > + rc = pci_register_driver(&scm_pci_driver); > > + if (rc) > > + return rc; > > + > > + return 0; > > +} > > + > > +static void scm_exit(void) > > +{ > > + pci_unregister_driver(&scm_pci_driver); > > +} > > + > > +module_init(scm_init); > > +module_exit(scm_exit); > > + > > +MODULE_DESCRIPTION("Storage Class Memory"); > > +MODULE_LICENSE("GPL"); > > diff --git a/drivers/nvdimm/ocxl/scm_internal.h > > b/drivers/nvdimm/ocxl/scm_internal.h > > new file mode 100644 > > index 000000000000..6340012e0f8a > > --- /dev/null > > +++ b/drivers/nvdimm/ocxl/scm_internal.h > > @@ -0,0 +1,28 @@ > > +// SPDX-License-Identifier: GPL-2.0+ > > +// Copyright 2019 IBM Corp. > > + > > +#include <linux/pci.h> > > +#include <misc/ocxl.h> > > +#include <linux/libnvdimm.h> > > +#include <linux/mm.h> > > + > > +#define SCM_LABEL_AREA_SIZE (1UL << PA_SECTION_SHIFT) > > + > > +struct scm_function_0 { > > + struct pci_dev *pdev; > > + struct ocxl_fn *ocxl_fn; > > +}; > > + > > +struct scm_data { > > + struct device dev; > > + struct pci_dev *pdev; > > + struct ocxl_fn *ocxl_fn; > > + struct nd_interleave_set nd_set; > > + struct nvdimm_bus_descriptor bus_desc; > > + struct nvdimm_bus *nvdimm_bus; > > + struct ocxl_afu *ocxl_afu; > > + struct ocxl_context *ocxl_context; > > + void *metadata_addr; > > + struct resource scm_res; > > + struct nd_region *nd_region; > > +};
diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig index 36af7af6b7cf..d1bab36da61c 100644 --- a/drivers/nvdimm/Kconfig +++ b/drivers/nvdimm/Kconfig @@ -130,4 +130,6 @@ config NVDIMM_TEST_BUILD core devm_memremap_pages() implementation and other infrastructure. +source "drivers/nvdimm/ocxl/Kconfig" + endif diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile index 29203f3d3069..e33492128042 100644 --- a/drivers/nvdimm/Makefile +++ b/drivers/nvdimm/Makefile @@ -1,5 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o +obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o ocxl/ obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o obj-$(CONFIG_ND_BTT) += nd_btt.o obj-$(CONFIG_ND_BLK) += nd_blk.o diff --git a/drivers/nvdimm/ocxl/Kconfig b/drivers/nvdimm/ocxl/Kconfig new file mode 100644 index 000000000000..24099b300f5e --- /dev/null +++ b/drivers/nvdimm/ocxl/Kconfig @@ -0,0 +1,15 @@ +# SPDX-License-Identifier: GPL-2.0-only +if LIBNVDIMM + +config OCXL_SCM + tristate "OpenCAPI Storage Class Memory" + depends on LIBNVDIMM && PPC_POWERNV && PCI && EEH + select ZONE_DEVICE + select OCXL + help + Exposes devices that implement the OpenCAPI Storage Class Memory + specification as persistent memory regions. + + Select N if unsure. + +endif diff --git a/drivers/nvdimm/ocxl/Makefile b/drivers/nvdimm/ocxl/Makefile new file mode 100644 index 000000000000..74a1bd98848e --- /dev/null +++ b/drivers/nvdimm/ocxl/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0 + +ccflags-$(CONFIG_PPC_WERROR) += -Werror + +obj-$(CONFIG_OCXL_SCM) += ocxlscm.o + +ocxlscm-y := scm.o diff --git a/drivers/nvdimm/ocxl/scm.c b/drivers/nvdimm/ocxl/scm.c new file mode 100644 index 000000000000..571058a9e7b8 --- /dev/null +++ b/drivers/nvdimm/ocxl/scm.c @@ -0,0 +1,519 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Copyright 2019 IBM Corp. + +/* + * A driver for Storage Class Memory, connected via OpenCAPI + */ + +#include <linux/module.h> +#include <misc/ocxl.h> +#include <linux/ndctl.h> +#include <linux/mm_types.h> +#include <linux/memory_hotplug.h> +#include "scm_internal.h" + + +static const struct pci_device_id scm_pci_tbl[] = { + { PCI_DEVICE(PCI_VENDOR_ID_IBM, 0x0625), }, + { } +}; + +MODULE_DEVICE_TABLE(pci, scm_pci_tbl); + +#define SCM_NUM_MINORS 256 // Total to reserve + +static dev_t scm_dev; +static struct class *scm_class; +static struct mutex minors_idr_lock; +static struct idr minors_idr; + +static const struct attribute_group *scm_pmem_attribute_groups[] = { + &nvdimm_bus_attribute_group, + NULL, +}; + +static const struct attribute_group *scm_pmem_region_attribute_groups[] = { + &nd_region_attribute_group, + &nd_device_attribute_group, + &nd_mapping_attribute_group, + &nd_numa_attribute_group, + NULL, +}; + +/** + * scm_ndctl_config_write() - Handle a ND_CMD_SET_CONFIG_DATA command from ndctl + * @scm_data: the SCM metadata + * @command: the incoming data to write + * Return: 0 on success, negative on failure + */ +static int scm_ndctl_config_write(struct scm_data *scm_data, + struct nd_cmd_set_config_hdr *command) +{ + if (command->in_offset + command->in_length > SCM_LABEL_AREA_SIZE) + return -EINVAL; + + memcpy_flushcache(scm_data->metadata_addr + command->in_offset, command->in_buf, + command->in_length); + + return 0; +} + +/** + * scm_ndctl_config_read() - Handle a ND_CMD_GET_CONFIG_DATA command from ndctl + * @scm_data: the SCM metadata + * @command: the read request + * Return: 0 on success, negative on failure + */ +static int scm_ndctl_config_read(struct scm_data *scm_data, + struct nd_cmd_get_config_data_hdr *command) +{ + if (command->in_offset + command->in_length > SCM_LABEL_AREA_SIZE) + return -EINVAL; + + memcpy_mcsafe(command->out_buf, scm_data->metadata_addr + command->in_offset, + command->in_length); + + return 0; +} + +/** + * scm_ndctl_config_size() - Handle a ND_CMD_GET_CONFIG_SIZE command from ndctl + * @scm_data: the SCM metadata + * @command: the read request + * Return: 0 on success, negative on failure + */ +static int scm_ndctl_config_size(struct nd_cmd_get_config_size *command) +{ + command->status = 0; + command->config_size = SCM_LABEL_AREA_SIZE; + command->max_xfer = PAGE_SIZE; + + return 0; +} + +static int scm_ndctl(struct nvdimm_bus_descriptor *nd_desc, + struct nvdimm *nvdimm, + unsigned int cmd, void *buf, unsigned int buf_len, int *cmd_rc) +{ + struct scm_data *scm_data = container_of(nd_desc, struct scm_data, bus_desc); + + switch (cmd) { + case ND_CMD_GET_CONFIG_SIZE: + *cmd_rc = scm_ndctl_config_size(buf); + return 0; + + case ND_CMD_GET_CONFIG_DATA: + *cmd_rc = scm_ndctl_config_read(scm_data, buf); + return 0; + + case ND_CMD_SET_CONFIG_DATA: + *cmd_rc = scm_ndctl_config_write(scm_data, buf); + return 0; + + default: + return -ENOTTY; + } +} + +static ssize_t serial_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct nvdimm *nvdimm = to_nvdimm(dev); + struct scm_data *scm_data = nvdimm_provider_data(nvdimm); + const struct ocxl_fn_config *config = ocxl_function_config(scm_data->ocxl_fn); + + return sprintf(buf, "0x%llx\n", config->serial); +} +static DEVICE_ATTR_RO(serial); + +static struct attribute *scm_dimm_attributes[] = { + &dev_attr_serial.attr, + NULL, +}; + +static umode_t scm_dimm_attr_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + return a->mode; +} + +static const struct attribute_group scm_dimm_attribute_group = { + .name = "ocxl", + .attrs = scm_dimm_attributes, + .is_visible = scm_dimm_attr_visible, +}; + +static const struct attribute_group *scm_dimm_attribute_groups[] = { + &nvdimm_attribute_group, + &nd_device_attribute_group, + &scm_dimm_attribute_group, + NULL, +}; + +/** + * scm_reserve_metadata() - Reserve space for nvdimm metadata + * @scm_data: The SCM device data + * @lpc_mem: The resource representing the LPC memory of the SCM device + */ +static int scm_reserve_metadata(struct scm_data *scm_data, + struct resource *lpc_mem) +{ + scm_data->metadata_addr = devm_memremap(&scm_data->dev, lpc_mem->start, + SCM_LABEL_AREA_SIZE, MEMREMAP_WB); + if (IS_ERR(scm_data->metadata_addr)) + return PTR_ERR(scm_data->metadata_addr); + + return 0; +} + +/** + * scm_register_lpc_mem() - Discover persistent memory on a device and register it with the NVDIMM subsystem + * @scm_data: The SCM device data + * Return: 0 on success + */ +static int scm_register_lpc_mem(struct scm_data *scm_data) +{ + struct nd_region_desc region_desc; + struct nd_mapping_desc nd_mapping_desc; + struct resource *lpc_mem; + const struct ocxl_afu_config *config; + const struct ocxl_fn_config *fn_config; + int rc; + unsigned long nvdimm_cmd_mask = 0; + unsigned long nvdimm_flags = 0; + int target_node; + char serial[16+1]; + + // Set up the reserved metadata area + rc = ocxl_afu_map_lpc_mem(scm_data->ocxl_afu); + if (rc < 0) + return rc; + + lpc_mem = ocxl_afu_lpc_mem(scm_data->ocxl_afu); + if (lpc_mem == NULL || lpc_mem->start == 0) + return -EINVAL; + + config = ocxl_afu_config(scm_data->ocxl_afu); + fn_config = ocxl_function_config(scm_data->ocxl_fn); + + rc = scm_reserve_metadata(scm_data, lpc_mem); + if (rc) + return rc; + + scm_data->bus_desc.attr_groups = scm_pmem_attribute_groups; + scm_data->bus_desc.provider_name = "ocxl-scm"; + scm_data->bus_desc.ndctl = scm_ndctl; + scm_data->bus_desc.module = THIS_MODULE; + + scm_data->nvdimm_bus = nvdimm_bus_register(&scm_data->dev, + &scm_data->bus_desc); + if (!scm_data->nvdimm_bus) + return -EINVAL; + + scm_data->scm_res.start = (u64)lpc_mem->start + SCM_LABEL_AREA_SIZE; + scm_data->scm_res.end = (u64)lpc_mem->start + config->lpc_mem_size - 1; + scm_data->scm_res.name = "SCM persistent memory"; + + set_bit(ND_CMD_GET_CONFIG_SIZE, &nvdimm_cmd_mask); + set_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm_cmd_mask); + set_bit(ND_CMD_SET_CONFIG_DATA, &nvdimm_cmd_mask); + + set_bit(NDD_ALIASING, &nvdimm_flags); + + snprintf(serial, sizeof(serial), "%llx", fn_config->serial); + nd_mapping_desc.nvdimm = nvdimm_create(scm_data->nvdimm_bus, scm_data, + scm_dimm_attribute_groups, + nvdimm_flags, nvdimm_cmd_mask, + 0, NULL); + if (!nd_mapping_desc.nvdimm) + return -ENOMEM; + + if (nvdimm_bus_check_dimm_count(scm_data->nvdimm_bus, 1)) + return -EINVAL; + + nd_mapping_desc.start = scm_data->scm_res.start; + nd_mapping_desc.size = resource_size(&scm_data->scm_res); + nd_mapping_desc.position = 0; + + scm_data->nd_set.cookie1 = fn_config->serial + 1; // allow for empty serial + scm_data->nd_set.cookie2 = fn_config->serial + 1; + + target_node = of_node_to_nid(scm_data->pdev->dev.of_node); + + memset(®ion_desc, 0, sizeof(region_desc)); + region_desc.res = &scm_data->scm_res; + region_desc.attr_groups = scm_pmem_region_attribute_groups; + region_desc.numa_node = NUMA_NO_NODE; + region_desc.target_node = target_node; + region_desc.num_mappings = 1; + region_desc.mapping = &nd_mapping_desc; + region_desc.nd_set = &scm_data->nd_set; + + set_bit(ND_REGION_PAGEMAP, ®ion_desc.flags); + /* + * NB: libnvdimm copies the data from ndr_desc into it's own + * structures so passing a stack pointer is fine. + */ + scm_data->nd_region = nvdimm_pmem_region_create(scm_data->nvdimm_bus, + ®ion_desc); + if (!scm_data->nd_region) + return -EINVAL; + + dev_info(&scm_data->dev, + "Onlining %lluMB of persistent memory\n", + nd_mapping_desc.size / SZ_1M); + + return 0; +} + +/** + * allocate_scm_minor() - Allocate a minor number to use for an SCM device + * @scm_data: The SCM device to associate the minor with + * Return: the allocated minor number + */ +static int allocate_scm_minor(struct scm_data *scm_data) +{ + int minor; + + mutex_lock(&minors_idr_lock); + minor = idr_alloc(&minors_idr, scm_data, 0, SCM_NUM_MINORS, GFP_KERNEL); + mutex_unlock(&minors_idr_lock); + return minor; +} + +static void free_scm_minor(struct scm_data *scm_data) +{ + mutex_lock(&minors_idr_lock); + idr_remove(&minors_idr, MINOR(scm_data->dev.devt)); + mutex_unlock(&minors_idr_lock); +} + +/** + * free_scm() - Free all members of an SCM struct + * @scm_data: the SCM metadata to clear + */ +static void free_scm(struct scm_data *scm_data) +{ + int rc; + + if (scm_data->nvdimm_bus) + nvdimm_bus_unregister(scm_data->nvdimm_bus); + + free_scm_minor(scm_data); + + if (scm_data->metadata_addr) + devm_memunmap(&scm_data->dev, scm_data->metadata_addr); + + if (scm_data->ocxl_context) { + rc = ocxl_context_detach(scm_data->ocxl_context); + if (rc == -EBUSY) + dev_warn(&scm_data->dev, "Timeout detaching ocxl context\n"); + else + ocxl_context_free(scm_data->ocxl_context); + + } + + if (scm_data->ocxl_afu) + ocxl_afu_put(scm_data->ocxl_afu); + + if (scm_data->ocxl_fn) + ocxl_function_close(scm_data->ocxl_fn); + + kfree(scm_data); +} + +/** + * free_scm_dev - Free an SCM device + * @dev: The device struct + */ +static void free_scm_dev(struct device *dev) +{ + struct scm_data *scm_data = container_of(dev, struct scm_data, dev); + + free_scm(scm_data); +} + +/** + * scm_register - Register an SCM device with the kernel + * @scm_data: the SCM metadata + * Return: 0 on success, negative on failure + */ +static int scm_register(struct scm_data *scm_data) +{ + int rc; + int minor = allocate_scm_minor(scm_data); + + if (minor < 0) + return minor; + + scm_data->dev.release = free_scm_dev; + rc = dev_set_name(&scm_data->dev, "ocxl-scm%d", minor); + if (rc < 0) + return rc; + + scm_data->dev.devt = MKDEV(MAJOR(scm_dev), minor); + scm_data->dev.class = scm_class; + scm_data->dev.parent = &scm_data->pdev->dev; + + rc = device_register(&scm_data->dev); + return rc; +} + +/** + * scm_remove() - Free an OpenCAPI Storage Class Memory device + * @pdev: the PCI device information struct + */ +static void scm_remove(struct pci_dev *pdev) +{ + if (PCI_FUNC(pdev->devfn) == 0) { + struct scm_function_0 *scm_func_0 = pci_get_drvdata(pdev); + + if (scm_func_0) { + ocxl_function_close(scm_func_0->ocxl_fn); + scm_func_0->ocxl_fn = NULL; + } + } else { + struct scm_data *scm_data = pci_get_drvdata(pdev); + + if (scm_data) + device_unregister(&scm_data->dev); + } +} + +/** + * scm_probe_function_0 - Set up function 0 for an OpenCAPI Storage Class Memory device + * This is important as it enables templates higher than 0 across all other functions, + * which in turn enables higher bandwidth accesses + * which in turn enables higher bandwidth accesses + * @pdev: the PCI device information struct + * Return: 0 on success, negative on failure + */ +static int scm_probe_function_0(struct pci_dev *pdev) +{ + struct scm_function_0 *scm_func_0 = NULL; + struct ocxl_fn *fn; + + scm_func_0 = kzalloc(sizeof(*scm_func_0), GFP_KERNEL); + if (!scm_func_0) + return -ENOMEM; + + scm_func_0->pdev = pdev; + fn = ocxl_function_open(pdev); + if (IS_ERR(fn)) { + kfree(scm_func_0); + dev_err(&pdev->dev, "failed to open OCXL function\n"); + return PTR_ERR(fn); + } + scm_func_0->ocxl_fn = fn; + + pci_set_drvdata(pdev, scm_func_0); + + return 0; +} + +/** + * scm_probe - Init an OpenCAPI Storage Class Memory device + * @pdev: the PCI device information struct + * @ent: The entry from scm_pci_tbl + * Return: 0 on success, negative on failure + */ +static int scm_probe(struct pci_dev *pdev, const struct pci_device_id *ent) +{ + struct scm_data *scm_data = NULL; + + if (PCI_FUNC(pdev->devfn) == 0) + return scm_probe_function_0(pdev); + else if (PCI_FUNC(pdev->devfn) != 1) + return 0; + + scm_data = kzalloc(sizeof(*scm_data), GFP_KERNEL); + if (!scm_data) { + dev_err(&pdev->dev, "Could not allocate SCM metadata\n"); + goto err; + } + scm_data->pdev = pdev; + + pci_set_drvdata(pdev, scm_data); + + scm_data->ocxl_fn = ocxl_function_open(pdev); + if (IS_ERR(scm_data->ocxl_fn)) { + kfree(scm_data); + scm_data = NULL; + pci_set_drvdata(pdev, NULL); + dev_err(&pdev->dev, "failed to open OCXL function\n"); + goto err; + } + + scm_data->ocxl_afu = ocxl_function_fetch_afu(scm_data->ocxl_fn, 0); + if (scm_data->ocxl_afu == NULL) { + dev_err(&pdev->dev, "Could not get OCXL AFU from function\n"); + goto err; + } + + ocxl_afu_get(scm_data->ocxl_afu); + + if (scm_register(scm_data) < 0) { + dev_err(&pdev->dev, "Could not register SCM device with the kernel\n"); + goto err; + } + + // Resources allocated below here are cleaned up in the release handler + + if (ocxl_context_alloc(&scm_data->ocxl_context, scm_data->ocxl_afu, NULL)) { + dev_err(&pdev->dev, "Could not allocate OCXL context\n"); + goto err; + } + + if (ocxl_context_attach(scm_data->ocxl_context, 0, NULL)) { + dev_err(&pdev->dev, "Could not attach ocxl context\n"); + goto err; + } + + if (scm_register_lpc_mem(scm_data)) { + dev_err(&pdev->dev, "Could not register OCXL SCM memory with libnvdimm\n"); + goto err; + } + + return 0; + +err: + /* + * Further cleanup is done in the release handler via free_scm() + * This allows us to keep the character device live to handle IOCTLs to + * investigate issues if the card has an error + */ + + dev_err(&pdev->dev, + "Error detected, will not register storage class memory\n"); + return -ENXIO; +} + +static struct pci_driver scm_pci_driver = { + .name = "ocxl-scm", + .id_table = scm_pci_tbl, + .probe = scm_probe, + .remove = scm_remove, + .shutdown = scm_remove, +}; + +static int __init scm_init(void) +{ + int rc = 0; + + rc = pci_register_driver(&scm_pci_driver); + if (rc) + return rc; + + return 0; +} + +static void scm_exit(void) +{ + pci_unregister_driver(&scm_pci_driver); +} + +module_init(scm_init); +module_exit(scm_exit); + +MODULE_DESCRIPTION("Storage Class Memory"); +MODULE_LICENSE("GPL"); diff --git a/drivers/nvdimm/ocxl/scm_internal.h b/drivers/nvdimm/ocxl/scm_internal.h new file mode 100644 index 000000000000..6340012e0f8a --- /dev/null +++ b/drivers/nvdimm/ocxl/scm_internal.h @@ -0,0 +1,28 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Copyright 2019 IBM Corp. + +#include <linux/pci.h> +#include <misc/ocxl.h> +#include <linux/libnvdimm.h> +#include <linux/mm.h> + +#define SCM_LABEL_AREA_SIZE (1UL << PA_SECTION_SHIFT) + +struct scm_function_0 { + struct pci_dev *pdev; + struct ocxl_fn *ocxl_fn; +}; + +struct scm_data { + struct device dev; + struct pci_dev *pdev; + struct ocxl_fn *ocxl_fn; + struct nd_interleave_set nd_set; + struct nvdimm_bus_descriptor bus_desc; + struct nvdimm_bus *nvdimm_bus; + struct ocxl_afu *ocxl_afu; + struct ocxl_context *ocxl_context; + void *metadata_addr; + struct resource scm_res; + struct nd_region *nd_region; +};