Re: [PATCH v2 08/27] ocxl: Save the device serial number in ocxl_fn
From: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
Date: 2020-02-03 12:53:52
Also in:
linux-mm, lkml, nvdimm
On Tue, 3 Dec 2019 14:46:36 +1100 Alastair D'Silva [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Alastair D'Silva <redacted> 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 <redacted> Acked-by: Frederic Barrat <redacted> Acked-by: Andrew Donnellan <redacted> --- 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; } +/**
Make sure anything you mark as kernel doc with /** is valid kernel-doc.
+ * 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 0Not sure the trailing comment adds much. I'd personally not bother with this wrapper at all and just call the pci functions directly where needed.
quoted hunk ↗ jump to hunk
+ + 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 {