| Message ID | 20220610202259.3544623-5-ira.weiny@intel.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | CXL: Read CDAT and DSMAS data | expand |
On Fri, 10 Jun 2022, ira.weiny@intel.com wrote: >+++ b/drivers/cxl/cxlmem.h >@@ -191,6 +191,8 @@ struct cxl_endpoint_dvsec_info { > * @component_reg_phys: register base of component registers > * @info: Cached DVSEC information about the device. > * @serial: PCIe Device Serial Number Missing doc: @doe_use_irq: Use interrupt vectors for DOEs over polling. However introducing such flags is not pretty, and this is only used by devm_cxl_pci_create_doe(). Do we really need it? See below. >+ * @doe_mbs: PCI DOE mailbox array >+ * @num_mbs: Number of DOE mailboxes > * @mbox_send: @dev specific transport for transmitting mailbox commands > * > * See section 8.2.9.5.2 Capacity Configuration and Label Storage for >@@ -224,6 +226,10 @@ struct cxl_dev_state { > resource_size_t component_reg_phys; > u64 serial; > >+ bool doe_use_irq; >+ struct pci_doe_mb **doe_mbs; >+ int num_mbs; >+ > int (*mbox_send)(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd); > }; > >diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c >index 5a0ae46d4989..72c7b535f5df 100644 >--- a/drivers/cxl/pci.c >+++ b/drivers/cxl/pci.c >@@ -8,6 +8,7 @@ > #include <linux/mutex.h> > #include <linux/list.h> > #include <linux/pci.h> >+#include <linux/pci-doe.h> > #include <linux/io.h> > #include "cxlmem.h" > #include "cxlpci.h" >@@ -386,6 +387,116 @@ static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type, > return rc; > } > >+static void cxl_pci_free_irq_vectors(void *data) >+{ >+ pci_free_irq_vectors(data); >+} >+ >+static void cxl_doe_destroy_mb(void *ds) >+{ >+ struct cxl_dev_state *cxlds = ds; >+ int i; >+ >+ for (i = 0; i < cxlds->num_mbs; i++) { >+ if (cxlds->doe_mbs[i]) >+ pci_doe_destroy_mb(cxlds->doe_mbs[i]); >+ } >+} >+ >+static void cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) >+{ >+ struct device *dev = cxlds->dev; >+ struct pci_dev *pdev = to_pci_dev(dev); >+ int max_irqs = 0; >+ int off = 0; >+ int rc; >+ >+ /* Account for all the DOE vectors needed */ >+ pci_doe_for_each_off(pdev, off) { >+ int irq = pci_doe_get_irq_num(pdev, off); >+ >+ if (irq < 0) >+ continue; >+ max_irqs = max(max_irqs, irq + 1); >+ } >+ >+ if (!max_irqs) >+ return; >+ >+ cxlds->doe_use_irq = false; Is this unnecessary, it should already be 0 per the devm_kzalloc(). >+ >+ /* >+ * Allocate enough vectors for the DOE's >+ */ >+ rc = pci_alloc_irq_vectors(pdev, max_irqs, max_irqs, PCI_IRQ_MSI | >+ PCI_IRQ_MSIX); >+ if (rc != max_irqs) { >+ pci_err(pdev, "Not enough interrupts; use polling\n"); >+ /* Some got allocated; clean them up */ >+ if (rc > 0) >+ cxl_pci_free_irq_vectors(pdev); >+ return; >+ } >+ >+ rc = devm_add_action_or_reset(dev, cxl_pci_free_irq_vectors, pdev); >+ if (rc) >+ return; >+ >+ cxlds->doe_use_irq = true; >+} >+ >+/** >+ * devm_cxl_pci_create_doe - Scan and set up DOE mailboxes >+ * >+ * @cxlds: The CXL device state >+ */ >+static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds) >+{ >+ struct device *dev = cxlds->dev; >+ struct pci_dev *pdev = to_pci_dev(dev); >+ u16 off = 0; >+ int num_mbs = 0; >+ int rc; >+ >+ pci_doe_for_each_off(pdev, off) >+ num_mbs++; >+ >+ if (!num_mbs) { >+ pci_dbg(pdev, "0 DOE mailbox's found\n"); >+ return; >+ } >+ >+ cxlds->doe_mbs = devm_kcalloc(dev, num_mbs, sizeof(*cxlds->doe_mbs), >+ GFP_KERNEL); >+ if (!cxlds->doe_mbs) >+ return; >+ >+ pci_doe_for_each_off(pdev, off) { >+ struct pci_doe_mb *doe_mb; >+ int irq = -1; >+ >+ if (cxlds->doe_use_irq) >+ irq = pci_doe_get_irq_num(pdev, off); >+ >+ doe_mb = pci_doe_create_mb(pdev, off, irq); >+ if (IS_ERR(doe_mb)) { >+ pci_err(pdev, >+ "Failed to create MB object for MB @ %x\n", >+ off); >+ doe_mb = NULL; >+ } >+ >+ cxlds->doe_mbs[cxlds->num_mbs] = doe_mb; >+ cxlds->num_mbs++; >+ } >+ >+ rc = devm_add_action_or_reset(dev, cxl_doe_destroy_mb, cxlds); >+ if (rc) >+ return; >+ >+ pci_info(pdev, "Configured %d DOE mailbox's\n", cxlds->num_mbs); >+} >+ > static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > { > struct cxl_register_map map; >@@ -434,6 +545,9 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > cxlds->component_reg_phys = cxl_regmap_to_base(pdev, &map); > >+ cxl_alloc_irq_vectors(cxlds); >+ devm_cxl_pci_create_doe(cxlds); Should cxl_alloc_irq_vectors() just be called directly from devm_cxl_pci_create_doe() instead? Also if devm_cxl_pci_create_doe() fails (say ENOMEM), why do we bother continuing the cxl_pci probing? Thanks, Davidlohr ------ diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index ce5b00f3ebcb..44098c785a8b 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -230,7 +230,6 @@ struct cxl_dev_state { resource_size_t component_reg_phys; u64 serial; - bool doe_use_irq; struct pci_doe_mb **doe_mbs; int num_mbs; diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c index 72c7b535f5df..47c3741f7768 100644 --- a/drivers/cxl/pci.c +++ b/drivers/cxl/pci.c @@ -403,7 +403,7 @@ static void cxl_doe_destroy_mb(void *ds) } } -static void cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) +static int cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) { struct device *dev = cxlds->dev; struct pci_dev *pdev = to_pci_dev(dev); @@ -421,9 +421,7 @@ static void cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) } if (!max_irqs) - return; - - cxlds->doe_use_irq = false; + return -ENOMEM; /* * Allocate enough vectors for the DOE's @@ -435,14 +433,10 @@ static void cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) /* Some got allocated; clean them up */ if (rc > 0) cxl_pci_free_irq_vectors(pdev); - return; + return -ENOMEM; } - rc = devm_add_action_or_reset(dev, cxl_pci_free_irq_vectors, pdev); - if (rc) - return; - - cxlds->doe_use_irq = true; + return devm_add_action_or_reset(dev, cxl_pci_free_irq_vectors, pdev); } /** @@ -457,6 +451,10 @@ static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds) u16 off = 0; int num_mbs = 0; int rc; + bool doe_use_irq = false; + + if (cxl_alloc_irq_vectors(cxlds)) + doe_use_irq = true; pci_doe_for_each_off(pdev, off) num_mbs++; @@ -475,7 +473,7 @@ static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds) struct pci_doe_mb *doe_mb; int irq = -1; - if (cxlds->doe_use_irq) + if (doe_use_irq) irq = pci_doe_get_irq_num(pdev, off); doe_mb = pci_doe_create_mb(pdev, off, irq); @@ -545,7 +543,6 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) cxlds->component_reg_phys = cxl_regmap_to_base(pdev, &map); - cxl_alloc_irq_vectors(cxlds); devm_cxl_pci_create_doe(cxlds); rc = cxl_pci_setup_mailbox(cxlds);
On Fri, 17 Jun 2022, Davidlohr Bueso wrote: >@@ -457,6 +451,10 @@ static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds) > u16 off = 0; > int num_mbs = 0; > int rc; >+ bool doe_use_irq = false; >+ >+ if (cxl_alloc_irq_vectors(cxlds)) if (!cxl_alloc_irq_vectors()), that is. >+ doe_use_irq = true;
ira.weiny@ wrote: > From: Ira Weiny <ira.weiny@intel.com> > > DOE mailbox objects will be needed for various mailbox communications > with each memory device. > > Iterate each DOE mailbox capability and create PCI DOE mailbox objects > as found. > > It is not anticipated that this is the final resting place for the > iteration of the DOE devices. The support of ports may drive this code > into the pcie side. In this imagined architecture the CXL port driver > would then query into the PCI device for the DOE mailbox array. > > For now this is good enough for the endpoints and the split is similar > to the envisioned architecture where getting the mailbox array is > separated from the various protocol needs. For example, it is not > anticipated that the CDAT code will need to move because it is only > needed by the cxl_ports. > > Likewise irq's are separated out in a similar design pattern to the > PCIe port driver. But a much simpler irq enabling flag is used and only > DOE interrupts are supported. > > Reviewed-by: Ben Widawsky <bwidawsk@kernel.org> > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > --- > Changes from V9: > Bug fix: ensure DOE mailboxes are iterated before memdev add > Ben Widawsky > Set use_irq to false and just return on error. > Don't return a value from devm_cxl_pci_create_doe() > Skip allocating doe_mb array if there are no mailboxes > Skip requesting irqs if none found. > Ben/Jonathan Cameron > s/num_irqs/max_irqs > > Changes from V8: > Move PCI_DOE selection to CXL_BUS to support future patches > which move queries into the port code. > Remove Auxiliary device arch > Squash the functionality of the auxiliary driver into this > patch. > Split out the irq handling a bit. > > Changes from V7: > Minor code clean ups > Rebased on cxl-pending > > Changes from V6: > Move all the auxiliary device stuff to the CXL layer > > Changes from V5: > Split the CXL specific stuff off from the PCI DOE create > auxiliary device code. > --- > drivers/cxl/Kconfig | 1 + > drivers/cxl/cxlmem.h | 6 +++ > drivers/cxl/pci.c | 114 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 121 insertions(+) > > diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig > index f64e3984689f..7adaaf80b302 100644 > --- a/drivers/cxl/Kconfig > +++ b/drivers/cxl/Kconfig > @@ -2,6 +2,7 @@ > menuconfig CXL_BUS > tristate "CXL (Compute Express Link) Devices Support" > depends on PCI > + select PCI_DOE > help > CXL is a bus that is electrically compatible with PCI Express, but > layers three protocols on that signalling (CXL.io, CXL.cache, and > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > index 60d10ee1e7fc..4d2764b865ab 100644 > --- a/drivers/cxl/cxlmem.h > +++ b/drivers/cxl/cxlmem.h > @@ -191,6 +191,8 @@ struct cxl_endpoint_dvsec_info { > * @component_reg_phys: register base of component registers > * @info: Cached DVSEC information about the device. > * @serial: PCIe Device Serial Number > + * @doe_mbs: PCI DOE mailbox array > + * @num_mbs: Number of DOE mailboxes > * @mbox_send: @dev specific transport for transmitting mailbox commands > * > * See section 8.2.9.5.2 Capacity Configuration and Label Storage for > @@ -224,6 +226,10 @@ struct cxl_dev_state { > resource_size_t component_reg_phys; > u64 serial; > > + bool doe_use_irq; Don't pass temporary state through a long lived data structure. Just pass flag by reference between the functions that want to coordinate this. > + struct pci_doe_mb **doe_mbs; > + int num_mbs; > + > int (*mbox_send)(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd); > }; > > diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c > index 5a0ae46d4989..72c7b535f5df 100644 > --- a/drivers/cxl/pci.c > +++ b/drivers/cxl/pci.c > @@ -8,6 +8,7 @@ > #include <linux/mutex.h> > #include <linux/list.h> > #include <linux/pci.h> > +#include <linux/pci-doe.h> > #include <linux/io.h> > #include "cxlmem.h" > #include "cxlpci.h" > @@ -386,6 +387,116 @@ static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type, > return rc; > } > > +static void cxl_pci_free_irq_vectors(void *data) > +{ > + pci_free_irq_vectors(data); > +} > + > +static void cxl_doe_destroy_mb(void *ds) > +{ > + struct cxl_dev_state *cxlds = ds; > + int i; > + > + for (i = 0; i < cxlds->num_mbs; i++) { > + if (cxlds->doe_mbs[i]) > + pci_doe_destroy_mb(cxlds->doe_mbs[i]); > + } > +} > + > +static void cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) > +{ > + struct device *dev = cxlds->dev; > + struct pci_dev *pdev = to_pci_dev(dev); > + int max_irqs = 0; > + int off = 0; > + int rc; > + > + /* Account for all the DOE vectors needed */ > + pci_doe_for_each_off(pdev, off) { > + int irq = pci_doe_get_irq_num(pdev, off); > + > + if (irq < 0) > + continue; > + max_irqs = max(max_irqs, irq + 1); This seems to assume that different DOEs will get independent vectors. The driver needs to be prepared for DOE instances, Event notifications, and mailbox commands to share a single MSI vector in the worst case. Lets focus on polled mode DOE, or explicitly only support interrupt based operation when no vector sharing is detected. > + } > + > + if (!max_irqs) > + return; > + > + cxlds->doe_use_irq = false; > + > + /* > + * Allocate enough vectors for the DOE's > + */ > + rc = pci_alloc_irq_vectors(pdev, max_irqs, max_irqs, PCI_IRQ_MSI | > + PCI_IRQ_MSIX); > + if (rc != max_irqs) { > + pci_err(pdev, "Not enough interrupts; use polling\n"); > + /* Some got allocated; clean them up */ > + if (rc > 0) > + cxl_pci_free_irq_vectors(pdev); > + return; > + } > + > + rc = devm_add_action_or_reset(dev, cxl_pci_free_irq_vectors, pdev); > + if (rc) > + return; > + > + cxlds->doe_use_irq = true; > +} > + > +/** > + * devm_cxl_pci_create_doe - Scan and set up DOE mailboxes > + * > + * @cxlds: The CXL device state > + */ > +static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds) > +{ > + struct device *dev = cxlds->dev; > + struct pci_dev *pdev = to_pci_dev(dev); > + u16 off = 0; > + int num_mbs = 0; > + int rc; > + > + pci_doe_for_each_off(pdev, off) > + num_mbs++; > + > + if (!num_mbs) { > + pci_dbg(pdev, "0 DOE mailbox's found\n"); > + return; > + } > + > + cxlds->doe_mbs = devm_kcalloc(dev, num_mbs, sizeof(*cxlds->doe_mbs), > + GFP_KERNEL); > + if (!cxlds->doe_mbs) > + return; > + > + pci_doe_for_each_off(pdev, off) { > + struct pci_doe_mb *doe_mb; > + int irq = -1; > + > + if (cxlds->doe_use_irq) > + irq = pci_doe_get_irq_num(pdev, off); > + > + doe_mb = pci_doe_create_mb(pdev, off, irq); > + if (IS_ERR(doe_mb)) { > + pci_err(pdev, > + "Failed to create MB object for MB @ %x\n", > + off); > + doe_mb = NULL; > + } > + > + cxlds->doe_mbs[cxlds->num_mbs] = doe_mb; > + cxlds->num_mbs++; > + } > + > + rc = devm_add_action_or_reset(dev, cxl_doe_destroy_mb, cxlds); > + if (rc) > + return; > + > + pci_info(pdev, "Configured %d DOE mailbox's\n", cxlds->num_mbs); > +} > + > static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > { > struct cxl_register_map map; > @@ -434,6 +545,9 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > cxlds->component_reg_phys = cxl_regmap_to_base(pdev, &map); > > + cxl_alloc_irq_vectors(cxlds); > + devm_cxl_pci_create_doe(cxlds); > + > rc = cxl_pci_setup_mailbox(cxlds); > if (rc) > return rc; > -- > 2.35.1 >
On Fri, Jun 17, 2022 at 01:40:46PM -0700, Davidlohr Bueso wrote: > On Fri, 10 Jun 2022, ira.weiny@intel.com wrote: > > +++ b/drivers/cxl/cxlmem.h > > @@ -191,6 +191,8 @@ struct cxl_endpoint_dvsec_info { > > * @component_reg_phys: register base of component registers > > * @info: Cached DVSEC information about the device. > > * @serial: PCIe Device Serial Number > > Missing doc: > > @doe_use_irq: Use interrupt vectors for DOEs over polling. > > However introducing such flags is not pretty, and this is only used by > devm_cxl_pci_create_doe(). Do we really need it? See below. Yes Dan had the same feedback to get rid of the member. [snip] > > + > > static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > { > > struct cxl_register_map map; > > @@ -434,6 +545,9 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > > > cxlds->component_reg_phys = cxl_regmap_to_base(pdev, &map); > > > > + cxl_alloc_irq_vectors(cxlds); > > + devm_cxl_pci_create_doe(cxlds); > > Should cxl_alloc_irq_vectors() just be called directly from devm_cxl_pci_create_doe() > instead? I was anticipating having to merge cxl_alloc_irq_vectors() with other code which is supporting irq's for other things later on. So I kept the 2 separate. This is also why the use irq flag was in the device state. The irq vector call could have specified to use other types of irq's. But those can be passed directly as Dan suggested. > Also if devm_cxl_pci_create_doe() fails (say ENOMEM), why do we > bother continuing the cxl_pci probing? Because the DOE is only required for CDAT data which is optional at this point. Thanks for the suggested diff below. But I'm going to go with Dan's suggestion to use a flag which is set and passed between the functions. Thanks for the review! Ira > > Thanks, > Davidlohr > > ------ > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > index ce5b00f3ebcb..44098c785a8b 100644 > --- a/drivers/cxl/cxlmem.h > +++ b/drivers/cxl/cxlmem.h > @@ -230,7 +230,6 @@ struct cxl_dev_state { > resource_size_t component_reg_phys; > u64 serial; > > - bool doe_use_irq; > struct pci_doe_mb **doe_mbs; > int num_mbs; > > diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c > index 72c7b535f5df..47c3741f7768 100644 > --- a/drivers/cxl/pci.c > +++ b/drivers/cxl/pci.c > @@ -403,7 +403,7 @@ static void cxl_doe_destroy_mb(void *ds) > } > } > > -static void cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) > +static int cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) > { > struct device *dev = cxlds->dev; > struct pci_dev *pdev = to_pci_dev(dev); > @@ -421,9 +421,7 @@ static void cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) > } > > if (!max_irqs) > - return; > - > - cxlds->doe_use_irq = false; > + return -ENOMEM; > > /* > * Allocate enough vectors for the DOE's > @@ -435,14 +433,10 @@ static void cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) > /* Some got allocated; clean them up */ > if (rc > 0) > cxl_pci_free_irq_vectors(pdev); > - return; > + return -ENOMEM; > } > > - rc = devm_add_action_or_reset(dev, cxl_pci_free_irq_vectors, pdev); > - if (rc) > - return; > - > - cxlds->doe_use_irq = true; > + return devm_add_action_or_reset(dev, cxl_pci_free_irq_vectors, pdev); > } > > /** > @@ -457,6 +451,10 @@ static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds) > u16 off = 0; > int num_mbs = 0; > int rc; > + bool doe_use_irq = false; > + > + if (cxl_alloc_irq_vectors(cxlds)) > + doe_use_irq = true; > > pci_doe_for_each_off(pdev, off) > num_mbs++; > @@ -475,7 +473,7 @@ static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds) > struct pci_doe_mb *doe_mb; > int irq = -1; > > - if (cxlds->doe_use_irq) > + if (doe_use_irq) > irq = pci_doe_get_irq_num(pdev, off); > > doe_mb = pci_doe_create_mb(pdev, off, irq); > @@ -545,7 +543,6 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) > > cxlds->component_reg_phys = cxl_regmap_to_base(pdev, &map); > > - cxl_alloc_irq_vectors(cxlds); > devm_cxl_pci_create_doe(cxlds); > > rc = cxl_pci_setup_mailbox(cxlds);
On Fri, Jun 17, 2022 at 04:44:27PM -0700, Dan Williams wrote: > ira.weiny@ wrote: [snip] > > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > > index 60d10ee1e7fc..4d2764b865ab 100644 > > --- a/drivers/cxl/cxlmem.h > > +++ b/drivers/cxl/cxlmem.h > > @@ -191,6 +191,8 @@ struct cxl_endpoint_dvsec_info { > > * @component_reg_phys: register base of component registers > > * @info: Cached DVSEC information about the device. > > * @serial: PCIe Device Serial Number > > + * @doe_mbs: PCI DOE mailbox array > > + * @num_mbs: Number of DOE mailboxes > > * @mbox_send: @dev specific transport for transmitting mailbox commands > > * > > * See section 8.2.9.5.2 Capacity Configuration and Label Storage for > > @@ -224,6 +226,10 @@ struct cxl_dev_state { > > resource_size_t component_reg_phys; > > u64 serial; > > > > + bool doe_use_irq; > > Don't pass temporary state through a long lived data structure. Just > pass flag by reference between the functions that want to coordinate > this. Done. [snip] > > + > > +static void cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) > > +{ > > + struct device *dev = cxlds->dev; > > + struct pci_dev *pdev = to_pci_dev(dev); > > + int max_irqs = 0; > > + int off = 0; > > + int rc; > > + > > + /* Account for all the DOE vectors needed */ > > + pci_doe_for_each_off(pdev, off) { > > + int irq = pci_doe_get_irq_num(pdev, off); > > + > > + if (irq < 0) > > + continue; > > + max_irqs = max(max_irqs, irq + 1); > > This seems to assume that different DOEs will get independent vectors. > The driver needs to be prepared for DOE instances, Event notifications, > and mailbox commands to share a single MSI vector in the worst case. > Lets focus on polled mode DOE, or explicitly only support interrupt > based operation when no vector sharing is detected. > Ok I see now. I was under the impression they had to be unique. Do you think it is sufficient to check in this loop for duplicates and bail if any are shared? Ira
In subject, I assume you mean the plural "mailboxes", not the possessive "mailbox's". On Fri, Jun 10, 2022 at 01:22:55PM -0700, ira.weiny@intel.com wrote: > From: Ira Weiny <ira.weiny@intel.com> > > DOE mailbox objects will be needed for various mailbox communications > with each memory device. > > Iterate each DOE mailbox capability and create PCI DOE mailbox objects > as found. > > It is not anticipated that this is the final resting place for the > iteration of the DOE devices. The support of ports may drive this code > into the pcie side. In this imagined architecture the CXL port driver s/pcie/PCIe/ to match other usage below. > would then query into the PCI device for the DOE mailbox array. > > For now this is good enough for the endpoints and the split is similar > to the envisioned architecture where getting the mailbox array is > separated from the various protocol needs. For example, it is not > anticipated that the CDAT code will need to move because it is only > needed by the cxl_ports. > > Likewise irq's are separated out in a similar design pattern to the > PCIe port driver. But a much simpler irq enabling flag is used and only > DOE interrupts are supported. I don't know what the convention is or will be for drivers/cxl. In drivers/pci, we favor "IRQ" over "irq" in English text to go along with PCI, DOE, CDAT, etc. Also makes "IRQs" intelligible where "irq's" looks a little funny because the usage isn't possessive and "irqs" isn't obviously a word or an acronym. Bjorn
On Tue, Jun 21, 2022 at 11:29:35AM -0700, Ira wrote: > On Fri, Jun 17, 2022 at 04:44:27PM -0700, Dan Williams wrote: > > ira.weiny@ wrote: > > [snip] > > > > diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h > > > index 60d10ee1e7fc..4d2764b865ab 100644 > > > --- a/drivers/cxl/cxlmem.h > > > +++ b/drivers/cxl/cxlmem.h > > > @@ -191,6 +191,8 @@ struct cxl_endpoint_dvsec_info { > > > * @component_reg_phys: register base of component registers > > > * @info: Cached DVSEC information about the device. > > > * @serial: PCIe Device Serial Number > > > + * @doe_mbs: PCI DOE mailbox array > > > + * @num_mbs: Number of DOE mailboxes > > > * @mbox_send: @dev specific transport for transmitting mailbox commands > > > * > > > * See section 8.2.9.5.2 Capacity Configuration and Label Storage for > > > @@ -224,6 +226,10 @@ struct cxl_dev_state { > > > resource_size_t component_reg_phys; > > > u64 serial; > > > > > > + bool doe_use_irq; > > > > Don't pass temporary state through a long lived data structure. Just > > pass flag by reference between the functions that want to coordinate > > this. > > Done. > > [snip] > > > > + > > > +static void cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) > > > +{ > > > + struct device *dev = cxlds->dev; > > > + struct pci_dev *pdev = to_pci_dev(dev); > > > + int max_irqs = 0; > > > + int off = 0; > > > + int rc; > > > + > > > + /* Account for all the DOE vectors needed */ > > > + pci_doe_for_each_off(pdev, off) { > > > + int irq = pci_doe_get_irq_num(pdev, off); > > > + > > > + if (irq < 0) > > > + continue; > > > + max_irqs = max(max_irqs, irq + 1); > > > > This seems to assume that different DOEs will get independent vectors. > > The driver needs to be prepared for DOE instances, Event notifications, > > and mailbox commands to share a single MSI vector in the worst case. > > Lets focus on polled mode DOE, or explicitly only support interrupt > > based operation when no vector sharing is detected. > > > > Ok I see now. I was under the impression they had to be unique. > > Do you think it is sufficient to check in this loop for duplicates and bail if > any are shared? I'm still removing the irq code from the CXL layer but I had to look a bit deeper at this for my own knowledge. I don't think shared interrupt numbers is a problem because the pci_request_irq() used within pci_doe_create_mb() specifies IRQF_SHARED. drivers/pci/irq.c: int pci_request_irq(struct pci_dev *dev, unsigned int nr, irq_handler_t handler, irq_handler_t thread_fn, void *dev_id, const char *fmt, ...) { ... unsigned long irqflags = IRQF_SHARED; ... So I think this would work even with share vectors, right? Regardless, setting up the CXL/PCI IRQs is a bit of a mess. So I'm still going to remove the IRQ code in the CXL layer. But I think it is safe to leave the IRQ code in the pci/doe.c layer for others to use. Ira
diff --git a/drivers/cxl/Kconfig b/drivers/cxl/Kconfig index f64e3984689f..7adaaf80b302 100644 --- a/drivers/cxl/Kconfig +++ b/drivers/cxl/Kconfig @@ -2,6 +2,7 @@ menuconfig CXL_BUS tristate "CXL (Compute Express Link) Devices Support" depends on PCI + select PCI_DOE help CXL is a bus that is electrically compatible with PCI Express, but layers three protocols on that signalling (CXL.io, CXL.cache, and diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h index 60d10ee1e7fc..4d2764b865ab 100644 --- a/drivers/cxl/cxlmem.h +++ b/drivers/cxl/cxlmem.h @@ -191,6 +191,8 @@ struct cxl_endpoint_dvsec_info { * @component_reg_phys: register base of component registers * @info: Cached DVSEC information about the device. * @serial: PCIe Device Serial Number + * @doe_mbs: PCI DOE mailbox array + * @num_mbs: Number of DOE mailboxes * @mbox_send: @dev specific transport for transmitting mailbox commands * * See section 8.2.9.5.2 Capacity Configuration and Label Storage for @@ -224,6 +226,10 @@ struct cxl_dev_state { resource_size_t component_reg_phys; u64 serial; + bool doe_use_irq; + struct pci_doe_mb **doe_mbs; + int num_mbs; + int (*mbox_send)(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd); }; diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c index 5a0ae46d4989..72c7b535f5df 100644 --- a/drivers/cxl/pci.c +++ b/drivers/cxl/pci.c @@ -8,6 +8,7 @@ #include <linux/mutex.h> #include <linux/list.h> #include <linux/pci.h> +#include <linux/pci-doe.h> #include <linux/io.h> #include "cxlmem.h" #include "cxlpci.h" @@ -386,6 +387,116 @@ static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type, return rc; } +static void cxl_pci_free_irq_vectors(void *data) +{ + pci_free_irq_vectors(data); +} + +static void cxl_doe_destroy_mb(void *ds) +{ + struct cxl_dev_state *cxlds = ds; + int i; + + for (i = 0; i < cxlds->num_mbs; i++) { + if (cxlds->doe_mbs[i]) + pci_doe_destroy_mb(cxlds->doe_mbs[i]); + } +} + +static void cxl_alloc_irq_vectors(struct cxl_dev_state *cxlds) +{ + struct device *dev = cxlds->dev; + struct pci_dev *pdev = to_pci_dev(dev); + int max_irqs = 0; + int off = 0; + int rc; + + /* Account for all the DOE vectors needed */ + pci_doe_for_each_off(pdev, off) { + int irq = pci_doe_get_irq_num(pdev, off); + + if (irq < 0) + continue; + max_irqs = max(max_irqs, irq + 1); + } + + if (!max_irqs) + return; + + cxlds->doe_use_irq = false; + + /* + * Allocate enough vectors for the DOE's + */ + rc = pci_alloc_irq_vectors(pdev, max_irqs, max_irqs, PCI_IRQ_MSI | + PCI_IRQ_MSIX); + if (rc != max_irqs) { + pci_err(pdev, "Not enough interrupts; use polling\n"); + /* Some got allocated; clean them up */ + if (rc > 0) + cxl_pci_free_irq_vectors(pdev); + return; + } + + rc = devm_add_action_or_reset(dev, cxl_pci_free_irq_vectors, pdev); + if (rc) + return; + + cxlds->doe_use_irq = true; +} + +/** + * devm_cxl_pci_create_doe - Scan and set up DOE mailboxes + * + * @cxlds: The CXL device state + */ +static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds) +{ + struct device *dev = cxlds->dev; + struct pci_dev *pdev = to_pci_dev(dev); + u16 off = 0; + int num_mbs = 0; + int rc; + + pci_doe_for_each_off(pdev, off) + num_mbs++; + + if (!num_mbs) { + pci_dbg(pdev, "0 DOE mailbox's found\n"); + return; + } + + cxlds->doe_mbs = devm_kcalloc(dev, num_mbs, sizeof(*cxlds->doe_mbs), + GFP_KERNEL); + if (!cxlds->doe_mbs) + return; + + pci_doe_for_each_off(pdev, off) { + struct pci_doe_mb *doe_mb; + int irq = -1; + + if (cxlds->doe_use_irq) + irq = pci_doe_get_irq_num(pdev, off); + + doe_mb = pci_doe_create_mb(pdev, off, irq); + if (IS_ERR(doe_mb)) { + pci_err(pdev, + "Failed to create MB object for MB @ %x\n", + off); + doe_mb = NULL; + } + + cxlds->doe_mbs[cxlds->num_mbs] = doe_mb; + cxlds->num_mbs++; + } + + rc = devm_add_action_or_reset(dev, cxl_doe_destroy_mb, cxlds); + if (rc) + return; + + pci_info(pdev, "Configured %d DOE mailbox's\n", cxlds->num_mbs); +} + static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) { struct cxl_register_map map; @@ -434,6 +545,9 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) cxlds->component_reg_phys = cxl_regmap_to_base(pdev, &map); + cxl_alloc_irq_vectors(cxlds); + devm_cxl_pci_create_doe(cxlds); + rc = cxl_pci_setup_mailbox(cxlds); if (rc) return rc;