| Message ID | 20200821155154.umharcbew46hkhuq@amazon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Enable PCI write-combine resources under sysfs | expand |
On Fri, Aug 21, 2020 at 03:51:54PM +0000, Clint Sbisa wrote: > Using write-combine is crucial for performance of PCI devices where > significant amounts of transactions go over PCI BARs. > > arm64 supports write-combine PCI mappings, so the appropriate define > has been added which will expose write-combine mappings under sysfs > for prefetchable PCI resources. > > Signed-off-by: Clint Sbisa <csbisa@amazon.com> > --- > arch/arm64/include/asm/pci.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h > index 70b323cf8300..b33ca260e3c9 100644 > --- a/arch/arm64/include/asm/pci.h > +++ b/arch/arm64/include/asm/pci.h > @@ -17,6 +17,7 @@ > #define pcibios_assign_all_busses() \ > (pci_has_flag(PCI_REASSIGN_ALL_BUS)) > > +#define arch_can_pci_mmap_wc() 1 > #define ARCH_GENERIC_PCI_MMAP_RESOURCE 1 > > extern int isa_dma_bridge_buggy; > -- > 2.23.3 > Ping. Let me know if any more info is needed. Clint
On Fri, Aug 21, 2020 at 03:51:54PM +0000, Clint Sbisa wrote: > Using write-combine is crucial for performance of PCI devices where > significant amounts of transactions go over PCI BARs. > > arm64 supports write-combine PCI mappings, so the appropriate define > has been added which will expose write-combine mappings under sysfs > for prefetchable PCI resources. > > Signed-off-by: Clint Sbisa <csbisa@amazon.com> > --- > arch/arm64/include/asm/pci.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h > index 70b323cf8300..b33ca260e3c9 100644 > --- a/arch/arm64/include/asm/pci.h > +++ b/arch/arm64/include/asm/pci.h > @@ -17,6 +17,7 @@ > #define pcibios_assign_all_busses() \ > (pci_has_flag(PCI_REASSIGN_ALL_BUS)) > > +#define arch_can_pci_mmap_wc() 1 > #define ARCH_GENERIC_PCI_MMAP_RESOURCE 1 > > extern int isa_dma_bridge_buggy; > -- > 2.23.3 > Please disregard this submission, I'm resubmitting it to more appropriate maintainers than what was suggested by the get_maintainer script. Clint
diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h index 70b323cf8300..b33ca260e3c9 100644 --- a/arch/arm64/include/asm/pci.h +++ b/arch/arm64/include/asm/pci.h @@ -17,6 +17,7 @@ #define pcibios_assign_all_busses() \ (pci_has_flag(PCI_REASSIGN_ALL_BUS)) +#define arch_can_pci_mmap_wc() 1 #define ARCH_GENERIC_PCI_MMAP_RESOURCE 1 extern int isa_dma_bridge_buggy;
Using write-combine is crucial for performance of PCI devices where significant amounts of transactions go over PCI BARs. arm64 supports write-combine PCI mappings, so the appropriate define has been added which will expose write-combine mappings under sysfs for prefetchable PCI resources. Signed-off-by: Clint Sbisa <csbisa@amazon.com> --- arch/arm64/include/asm/pci.h | 1 + 1 file changed, 1 insertion(+)