diff options
| author | Zhen Lei <thunder.leizhen@huawei.com> | 2021-07-13 15:22:36 +0800 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2021-08-20 17:10:43 -0500 |
| commit | ca32b5310a1a3835f81f498367f1bb7450c8b67b (patch) | |
| tree | 02d05e9e64789543dbc1d82e4f6b97d0057c744f /include/linux/pci.h | |
| parent | a67462fc9de8b958d6a2c2c34d0195733a8c61a6 (diff) | |
PCI: Optimize pci_resource_len() to reduce kernel size
pci_resource_end() can be 0 only when pci_resource_start() is 0.
Otherwise, it is definitely an error. In this case, pci_resource_len()
should be regarded as 0. Therefore, determining whether
pci_resource_start() and pci_resource_end() are both 0 can be reduced to
determining only whether pci_resource_end() is 0.
Although only one condition judgment is reduced, the macro function
pci_resource_len() is widely referenced in the kernel. I used defconfig to
compile the latest kernel on X86, and its binary code size was reduced by
about 3KB.
Before:
[ 2] .rela.text RELA 0000000000000000 093bfcb0
0000000001a67168 0000000000000018 I 68 1 8
After:
[ 2] .rela.text RELA 0000000000000000 093bfcb0
0000000001a66598 0000000000000018 I 68 1 8
Link: https://lore.kernel.org/r/20210713072236.3043-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'include/linux/pci.h')
| -rw-r--r-- | include/linux/pci.h | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/include/linux/pci.h b/include/linux/pci.h index 540b377ca8f6..23ef1a15eb5d 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1881,9 +1881,7 @@ int pci_iobar_pfn(struct pci_dev *pdev, int bar, struct vm_area_struct *vma); #define pci_resource_end(dev, bar) ((dev)->resource[(bar)].end) #define pci_resource_flags(dev, bar) ((dev)->resource[(bar)].flags) #define pci_resource_len(dev,bar) \ - ((pci_resource_start((dev), (bar)) == 0 && \ - pci_resource_end((dev), (bar)) == \ - pci_resource_start((dev), (bar))) ? 0 : \ + ((pci_resource_end((dev), (bar)) == 0) ? 0 : \ \ (pci_resource_end((dev), (bar)) - \ pci_resource_start((dev), (bar)) + 1)) |