Re: [PATCH 1/1] of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses
From: Rob Herring <robh+dt@kernel.org>
Date: 2021-04-15 19:00:10
Also in:
linux-devicetree, linux-pci, lkml
+PPC and PCI lists On Thu, Apr 15, 2021 at 1:01 PM Leonardo Bras [off-list ref] wrote:
Many other resource flag parsers already add this flag when the input has bits 24 & 25 set, so update this one to do the same.
Many others? Looks like sparc and powerpc to me. Those would be the ones I worry about breaking. Sparc doesn't use of/address.c so it's fine. Powerpc version of the flags code was only fixed in 2019, so I don't think powerpc will care either. I noticed both sparc and powerpc set PCI_BASE_ADDRESS_MEM_TYPE_64 in the flags. AFAICT, that's not set anywhere outside of arch code. So never for riscv, arm and arm64 at least. That leads me to pci_std_update_resource() which is where the PCI code sets BARs and just copies the flags in PCI_BASE_ADDRESS_MEM_MASK ignoring IORESOURCE_* flags. So it seems like 64-bit is still not handled and neither is prefetch.
quoted hunk
Some devices (like virtio-net) have more than one memory resource (like MMIO32 and MMIO64) and without this flag it would be needed to verify the address range to know which one is which. Signed-off-by: Leonardo Bras <redacted> --- drivers/of/address.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)diff --git a/drivers/of/address.c b/drivers/of/address.c index 73ddf2540f3f..dc7147843783 100644 --- a/drivers/of/address.c +++ b/drivers/of/address.c@@ -116,9 +116,12 @@ static unsigned int of_bus_pci_get_flags(const __be32 *addr) flags |= IORESOURCE_IO; break; case 0x02: /* 32 bits */ - case 0x03: /* 64 bits */ flags |= IORESOURCE_MEM; break; + + case 0x03: /* 64 bits */ + flags |= IORESOURCE_MEM | IORESOURCE_MEM_64; + break; } if (w & 0x40000000) flags |= IORESOURCE_PREFETCH; --2.30.2