APPLIED[AWS-F]: [PATCHv2][AWS-{F, G}] UBUNTU: SAUCE: arm64: Enable PCI write-combine resources under sysfs
Ian May
ian.may at canonical.com
Fri Oct 9 19:00:31 UTC 2020
Applied to aws-focal.
Thanks!
Ian
On 2020-10-07 13:11:20 , Kamal Mostafa wrote:
> From: Clint Sbisa <csbisa at amazon.com>
>
> BugLink: https://bugs.launchpad.net/bugs/1893817
>
> 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 at amazon.com>
> Reference: https://lore.kernel.org/linux-pci/20200831151827.pumm2p54fyj7fz5s@amazon.com/
> Signed-off-by: Kamal Mostafa <kamal at canonical.com>
> Acked-by: Stefan Bader <stefan.bader at canonical.com>
> Acked-by: Andrea Righi <andrea.righi at canonical.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;
> --
> 2.17.1
>
> --
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