[PATCH v2 08/27] ocxl: Save the device serial number in ocxl_fn

Alastair D'Silva
2019-12-03T03:50:05Z

From: Alastair D'Silva <alastair@d-silva.org>

This patch retrieves the serial number of the card and makes it available
to consumers of the ocxl driver via the ocxl_fn struct.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
---
drivers/misc/ocxl/config.c | 46 ++++++++++++++++++++++++++++++++++++++
include/misc/ocxl.h | 1 +
2 files changed, 47 insertions(+)

diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c
index fb0c3b6f8312..a9203c309365 100644
--- a/drivers/misc/ocxl/config.c
+++ b/drivers/misc/ocxl/config.c
@@ -71,6 +71,51 @@ static int find_dvsec_afu_ctrl(struct pci_dev *dev, u8 afu_idx)
return 0;
}

+/**
+ * Find a related PCI device (function 0)
+ * @device: PCI device to match
+ *
+ * Returns a pointer to the related device, or null if not found
+ */
+static struct pci_dev *get_function_0(struct pci_dev *dev)
+{
+ unsigned int devfn = PCI_DEVFN(PCI_SLOT(dev->devfn), 0); // Look for function 0
+
+ return pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
+ dev->bus->number, devfn);
+}
+
+static void read_serial(struct pci_dev *dev, struct ocxl_fn_config *fn)
+{
+ u32 low, high;
+ int pos;
+
+ pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DSN);
+ if (pos) {
+ pci_read_config_dword(dev, pos + 0x04, &low);
+ pci_read_config_dword(dev, pos + 0x08, &high);
+
+ fn->serial = low | ((u64)high) << 32;
+
+ return;
+ }
+
+ if (PCI_FUNC(dev->devfn) != 0) {
+ struct pci_dev *related = get_function_0(dev);
+
+ if (!related) {
+ fn->serial = 0;
+ return;
+ }
+
+ read_serial(related, fn);
+ pci_dev_put(related);
+ return;
+ }
+
+ fn->serial = 0;
+}
+
static void read_pasid(struct pci_dev *dev, struct ocxl_fn_config *fn)
{
u16 val;
@@ -208,6 +253,7 @@ int ocxl_config_read_function(struct pci_dev *dev, struct ocxl_fn_config *fn)
int rc;

read_pasid(dev, fn);
+ read_serial(dev, fn);

rc = read_dvsec_tl(dev, fn);
if (rc) {
diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h
index 6f7c02f0d5e3..9843051c3c5b 100644
--- a/include/misc/ocxl.h
+++ b/include/misc/ocxl.h
@@ -46,6 +46,7 @@ struct ocxl_fn_config {
int dvsec_afu_info_pos; /* offset of the AFU information DVSEC */
s8 max_pasid_log;
s8 max_afu_index;
+ u64 serial;
};

enum ocxl_endian {
--
2.23.0