@@ -5,4 +5,4 @@
obj-$(CONFIG_PCI_ENDPOINT_CONFIGFS) += pci-ep-cfs.o
obj-$(CONFIG_PCI_ENDPOINT) += pci-epc-core.o pci-epf-core.o\
- pci-epc-mem.o functions/
+ pci-epc-mem.o pci-ep-msi.o functions/
new file mode 100644
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI Endpoint *Controller* (EPC) MSI library
+ *
+ * Copyright (C) 2024 NXP
+ * Author: Frank Li <Frank.Li@nxp.com>
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of_irq.h>
+#include <linux/pci-epc.h>
+#include <linux/pci-epf.h>
+#include <linux/pci-ep-cfs.h>
+#include <linux/pci-ep-msi.h>
+#include <linux/slab.h>
+
+static void pci_epf_write_msi_msg(struct irq_data *d, struct msi_msg *msg)
+{
+ struct msi_desc *desc = irq_data_get_msi_desc(d);
+ struct pci_epf *epf = to_pci_epf(desc->dev);
+
+ if (epf && epf->db_msg && desc->msi_index < epf->num_db)
+ memcpy(&epf->db_msg[desc->msi_index].msg, msg, sizeof(*msg));
+}
+
+static void pci_epf_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
+{
+ arg->desc = desc;
+ arg->hwirq = desc->msi_index;
+}
+
+static int pci_epf_msi_prepare(struct irq_domain *domain, struct device *dev,
+ int nvec, msi_alloc_info_t *arg)
+{
+ struct pci_epf *epf = to_pci_epf(dev);
+ struct msi_domain_info *msi_info;
+ struct pci_epc *epc = epf->epc;
+
+ memset(arg, 0, sizeof(*arg));
+ arg->scratchpad[0].ul = of_msi_map_id(epc->dev.parent, NULL,
+ (epf->func_no << 8) | epf->vfunc_no);
+
+ /*
+ * @domain->msi_domain_info->hwsize contains the size of the device
+ * domain, but vector allocation happens one by one.
+ */
+ msi_info = msi_get_domain_info(domain);
+ if (msi_info->hwsize > nvec)
+ nvec = msi_info->hwsize;
+
+ /* Allocate at least 32 MSIs, and always as a power of 2 */
+ nvec = max_t(int, 32, roundup_pow_of_two(nvec));
+
+ msi_info = msi_get_domain_info(domain->parent);
+ return msi_info->ops->msi_prepare(domain->parent, dev, nvec, arg);
+}
+
+static const struct msi_domain_template pci_epf_msi_template = {
+ .chip = {
+ .name = "EP-MSI",
+ .irq_mask = irq_chip_mask_parent,
+ .irq_unmask = irq_chip_unmask_parent,
+ .irq_write_msi_msg = pci_epf_write_msi_msg,
+ /* The rest is filled in by the MSI parent */
+ },
+
+ .ops = {
+ .msi_prepare = pci_epf_msi_prepare,
+ .set_desc = pci_epf_msi_set_desc,
+ },
+
+ .info = {
+ .bus_token = DOMAIN_BUS_DEVICE_MSI,
+ },
+};
+
+static int pci_epf_device_msi_init_and_alloc_irqs(struct device *dev, unsigned int nvec)
+{
+ struct irq_domain *domain = dev->msi.domain;
+
+ if (!domain)
+ return -EINVAL;
+
+ if (!msi_create_device_irq_domain(dev, MSI_DEFAULT_DOMAIN,
+ &pci_epf_msi_template, nvec, NULL, NULL))
+ return -ENODEV;
+
+ return msi_domain_alloc_irqs_range(dev, MSI_DEFAULT_DOMAIN, 0, nvec - 1);
+}
+
+int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_db)
+{
+ struct pci_epc *epc = epf->epc;
+ struct device *dev = &epf->dev;
+ struct irq_domain *dom;
+ void *msg;
+ u32 rid;
+ int ret;
+ int i;
+
+ rid = (epf->func_no << 8) | epf->vfunc_no;
+ dom = of_msi_map_get_device_domain(epc->dev.parent, rid, DOMAIN_BUS_PLATFORM_MSI);
+ if (!dom) {
+ dev_err(dev, "Can't find msi domain\n");
+ return -EINVAL;
+ }
+
+ dev_set_msi_domain(dev, dom);
+
+ msg = kcalloc(num_db, sizeof(struct pci_epf_doorbell_msg), GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ epf->num_db = num_db;
+ epf->db_msg = msg;
+
+ ret = pci_epf_device_msi_init_and_alloc_irqs(dev, num_db);
+ if (ret) {
+ /*
+ * The pcie_ep DT node has to specify 'msi-parent' for EP
+ * doorbell support to work. Right now only GIC ITS is
+ * supported. If you have GIC ITS and reached this print,
+ * perhaps you are missing 'msi-map' in DT.
+ */
+ dev_err(dev, "Failed to allocate MSI\n");
+ kfree(msg);
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < num_db; i++)
+ epf->db_msg[i].virq = msi_get_virq(dev, i);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pci_epf_alloc_doorbell);
+
+void pci_epf_free_doorbell(struct pci_epf *epf)
+{
+ msi_domain_free_irqs_all(&epf->dev, MSI_DEFAULT_DOMAIN);
+ msi_remove_device_irq_domain(&epf->dev, MSI_DEFAULT_DOMAIN);
+
+ kfree(epf->db_msg);
+ epf->db_msg = NULL;
+ epf->num_db = 0;
+}
+EXPORT_SYMBOL_GPL(pci_epf_free_doorbell);
new file mode 100644
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * PCI Endpoint *Function* side MSI header file
+ *
+ * Copyright (C) 2024 NXP
+ * Author: Frank Li <Frank.Li@nxp.com>
+ */
+
+#ifndef __PCI_EP_MSI__
+#define __PCI_EP_MSI__
+
+int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 nums);
+void pci_epf_free_doorbell(struct pci_epf *epf);
+
+#endif /* __PCI_EP_MSI__ */
@@ -12,6 +12,7 @@
#include <linux/configfs.h>
#include <linux/device.h>
#include <linux/mod_devicetable.h>
+#include <linux/msi.h>
#include <linux/pci.h>
struct pci_epf;
@@ -125,6 +126,17 @@ struct pci_epf_bar {
int flags;
};
+/**
+ * struct pci_epf_doorbell_msg - represents doorbell message
+ * @msi_msg: MSI message
+ * @virq: irq number of this doorbell MSI message
+ * @name: irq name for doorbell interrupt
+ */
+struct pci_epf_doorbell_msg {
+ struct msi_msg msg;
+ int virq;
+};
+
/**
* struct pci_epf - represents the PCI EPF device
* @dev: the PCI EPF device
@@ -152,6 +164,8 @@ struct pci_epf_bar {
* @vfunction_num_map: bitmap to manage virtual function number
* @pci_vepf: list of virtual endpoint functions associated with this function
* @event_ops: Callbacks for capturing the EPC events
+ * @db_msg: data for MSI from RC side
+ * @num_db: number of doorbells
*/
struct pci_epf {
struct device dev;
@@ -182,6 +196,8 @@ struct pci_epf {
unsigned long vfunction_num_map;
struct list_head pci_vepf;
const struct pci_epc_event_ops *event_ops;
+ struct pci_epf_doorbell_msg *db_msg;
+ u16 num_db;
};
/**