On 9/23/2021 1:26 PM, Ben Widawsky wrote:
Add pci_find_dvsec_capability to locate a Designated Vendor-Specific
Extended Capability with the specified DVSEC ID.
The Designated Vendor-Specific Extended Capability (DVSEC) allows one or
more vendor specific capabilities that aren't tied to the vendor ID of
the PCI component.
DVSEC is critical for both the Compute Express Link (CXL) driver as well
as the driver for OpenCAPI coherent accelerator (OCXL).
Cc: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: linux-pci@xxxxxxxxxxxxxxx
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Cc: Andrew Donnellan <ajd@xxxxxxxxxxxxx>
Cc: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
Reviewed-by: Frederic Barrat <fbarrat@xxxxxxxxxxxxx>
Signed-off-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
Applied the interface for the perf uncore driver as below. The interface
works properly.
Tested-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
From ebb69ba386dca91fb372522b13af9feb84adcbc0 Mon Sep 17 00:00:00 2001
From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Date: Thu, 23 Sep 2021 13:59:24 -0700
Subject: [PATCH] perf/x86/intel/uncore: Use pci core's DVSEC functionality
Apply standard interface pci_find_dvsec_capability for perf uncore
driver and remove unused macros.
Reduce maintenance burden of DVSEC query implementation.
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
---
arch/x86/events/intel/uncore_discovery.c | 41
+++++++++++++++-----------------
arch/x86/events/intel/uncore_discovery.h | 6 -----
2 files changed, 19 insertions(+), 28 deletions(-)
diff --git a/arch/x86/events/intel/uncore_discovery.c
b/arch/x86/events/intel/uncore_discovery.c
index 3049c64..f8ea092 100644
--- a/arch/x86/events/intel/uncore_discovery.c
+++ b/arch/x86/events/intel/uncore_discovery.c
@@ -21,7 +21,7 @@ static bool has_generic_discovery_table(void)
return false;
/* A discovery table device has the unique capability ID. */
- dvsec = pci_find_next_ext_capability(dev, 0, UNCORE_EXT_CAP_ID_DISCOVERY);
+ dvsec = pci_find_next_ext_capability(dev, 0, PCI_EXT_CAP_ID_DVSEC);
pci_dev_put(dev);
if (dvsec)
return true;
@@ -260,7 +260,7 @@ static int parse_discovery_table(struct pci_dev
*dev, int die,
bool intel_uncore_has_discovery_tables(void)
{
- u32 device, val, entry_id, bar_offset;
+ u32 device, val, bar_offset;
int die, dvsec = 0, ret = true;
struct pci_dev *dev = NULL;
bool parsed = false;
@@ -275,27 +275,24 @@ bool intel_uncore_has_discovery_tables(void)
* the discovery table devices.
*/
while ((dev = pci_get_device(PCI_VENDOR_ID_INTEL, device, dev)) !=
NULL) {
- while ((dvsec = pci_find_next_ext_capability(dev, dvsec,
UNCORE_EXT_CAP_ID_DISCOVERY))) {
- pci_read_config_dword(dev, dvsec + UNCORE_DISCOVERY_DVSEC_OFFSET, &val);
- entry_id = val & UNCORE_DISCOVERY_DVSEC_ID_MASK;
- if (entry_id != UNCORE_DISCOVERY_DVSEC_ID_PMON)
- continue;
-
- pci_read_config_dword(dev, dvsec + UNCORE_DISCOVERY_DVSEC2_OFFSET,
&val);
-
- if (val & ~UNCORE_DISCOVERY_DVSEC2_BIR_MASK) {
- ret = false;
- goto err;
- }
- bar_offset = UNCORE_DISCOVERY_BIR_BASE +
- (val & UNCORE_DISCOVERY_DVSEC2_BIR_MASK) *
UNCORE_DISCOVERY_BIR_STEP;
-
- die = get_device_die_id(dev);
- if (die < 0)
- continue;
-
- parse_discovery_table(dev, die, bar_offset, &parsed);
+ dvsec = pci_find_dvsec_capability(dev, PCI_VENDOR_ID_INTEL,
UNCORE_DISCOVERY_DVSEC_ID_PMON);
+ if (!dvsec)
+ continue;
+
+ pci_read_config_dword(dev, dvsec + UNCORE_DISCOVERY_DVSEC2_OFFSET, &val);
+
+ if (val & ~UNCORE_DISCOVERY_DVSEC2_BIR_MASK) {
+ ret = false;
+ goto err;
}
+ bar_offset = UNCORE_DISCOVERY_BIR_BASE +
+ (val & UNCORE_DISCOVERY_DVSEC2_BIR_MASK) *
UNCORE_DISCOVERY_BIR_STEP;
+
+ die = get_device_die_id(dev);
+ if (die < 0)
+ continue;
+
+ parse_discovery_table(dev, die, bar_offset, &parsed);
}
/* None of the discovery tables are available */
diff --git a/arch/x86/events/intel/uncore_discovery.h
b/arch/x86/events/intel/uncore_discovery.h
index 6d735611..84d56e5 100644
--- a/arch/x86/events/intel/uncore_discovery.h
+++ b/arch/x86/events/intel/uncore_discovery.h
@@ -2,12 +2,6 @@
/* Generic device ID of a discovery table device */
#define UNCORE_DISCOVERY_TABLE_DEVICE 0x09a7
-/* Capability ID for a discovery table device */
-#define UNCORE_EXT_CAP_ID_DISCOVERY 0x23
-/* First DVSEC offset */
-#define UNCORE_DISCOVERY_DVSEC_OFFSET 0x8
-/* Mask of the supported discovery entry type */
-#define UNCORE_DISCOVERY_DVSEC_ID_MASK 0xffff
/* PMON discovery entry type ID */
#define UNCORE_DISCOVERY_DVSEC_ID_PMON 0x1
/* Second DVSEC offset */
--
2.7.4
Thanks,
Kan
---
drivers/pci/pci.c | 32 ++++++++++++++++++++++++++++++++
include/linux/pci.h | 1 +
2 files changed, 33 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ce2ab62b64cf..94ac86ff28b0 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -732,6 +732,38 @@ u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap)
}
EXPORT_SYMBOL_GPL(pci_find_vsec_capability);
+/**
+ * pci_find_dvsec_capability - Find DVSEC for vendor
+ * @dev: PCI device to query
+ * @vendor: Vendor ID to match for the DVSEC
+ * @dvsec: Designated Vendor-specific capability ID
+ *
+ * If DVSEC has Vendor ID @vendor and DVSEC ID @dvsec return the capability
+ * offset in config space; otherwise return 0.
+ */
+u16 pci_find_dvsec_capability(struct pci_dev *dev, u16 vendor, u16 dvsec)
+{
+ int pos;
+
+ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DVSEC);
+ if (!pos)
+ return 0;
+
+ while (pos) {
+ u16 v, id;
+
+ pci_read_config_word(dev, pos + PCI_DVSEC_HEADER1, &v);
+ pci_read_config_word(dev, pos + PCI_DVSEC_HEADER2, &id);
+ if (vendor == v && dvsec == id)
+ return pos;
+
+ pos = pci_find_next_ext_capability(dev, pos, PCI_EXT_CAP_ID_DVSEC);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pci_find_dvsec_capability);
+
/**
* pci_find_parent_resource - return resource region of parent bus of given
* region
diff --git a/include/linux/pci.h b/include/linux/pci.h
index cd8aa6fce204..c93ccfa4571b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1130,6 +1130,7 @@ u16 pci_find_ext_capability(struct pci_dev *dev, int cap);
u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 pos, int cap);
struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap);
+u16 pci_find_dvsec_capability(struct pci_dev *dev, u16 vendor, u16 dvsec);
u64 pci_get_dsn(struct pci_dev *dev);
