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cxl: Use pci_find_vsec_capability() to simplify the code

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PCI core add pci_find_vsec_capability() to query VSEC. We can use that
core API to simplify the code.

The only logical change is that pci_find_vsec_capability check the
Vendor ID before finding the VSEC.

PCI spec rev 5.0 says in 7.9.5.2 Vendor-Specific Header:
  VSEC ID - This field is a vendor-defined ID number that indicates the
  nature and format of the VSEC structure
  Software must qualify the Vendor ID before interpreting this field.

Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230804075630.186054-1-wangxiongfeng2@huawei.com
This commit is contained in:
Xiongfeng Wang 2023-08-04 15:56:30 +08:00 committed by Michael Ellerman
parent 6039fcd3fb
commit 0e1cd3d9f8
1 changed files with 1 additions and 10 deletions
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11
drivers/misc/cxl/pci.c
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@ -150,16 +150,7 @@ static inline resource_size_t p2_size(struct pci_dev *dev)
static int find_cxl_vsec(struct pci_dev *dev)
{
int vsec = 0;
u16 val;
while ((vsec = pci_find_next_ext_capability(dev, vsec, PCI_EXT_CAP_ID_VNDR))) {
pci_read_config_word(dev, vsec + 0x4, &val);
if (val == CXL_PCI_VSEC_ID)
return vsec;
}
return 0;
return pci_find_vsec_capability(dev, PCI_VENDOR_ID_IBM, CXL_PCI_VSEC_ID);
}
static void dump_cxl_config_space(struct pci_dev *dev)