On Thu, Feb 11, 2016 at 04:52:24PM -0800, Sean O. Stalley wrote:
> From: Alex Williamson <alex.williamson@xxxxxxxxxx>
>
> Resource flags are exposed to userspace via the sysfs "resource" file.
> lspci reads the sysfs file to determine resource properties.
> Adding this flag allows lspci to distinguish between [virtual]
> and [enhanced] resources.
>
> If the resource is not aligned, userspace could deduce where
> the resource is EA based on the size & address fields.
> However, a flag indicating whether a PCI resource is a traditional BAR
> or BAR equivalent seems like a much simpler solution and works if the
> EA resource is aligned.
>
> Although this patchset only improves lspci, other uses for this
> flag have been identified. For example, vfio makes assumptions
> about alignment and sizing, and runs into problems when attempting
> to emulate a BAR Equivalent EA resource.
>
> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
> Signed-off-by: Sean O. Stalley <sean.stalley@xxxxxxxxx>
I applied this to pci/resource and intend to merge it for v4.7.
> ---
> drivers/pci/pci.c | 2 +-
> include/linux/ioport.h | 7 +++++++
> 2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index d1a7105..8ff678c 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -2229,7 +2229,7 @@ void pci_pm_init(struct pci_dev *dev)
>
> static unsigned long pci_ea_flags(struct pci_dev *dev, u8 prop)
> {
> - unsigned long flags = IORESOURCE_PCI_FIXED;
> + unsigned long flags = IORESOURCE_PCI_FIXED | IORESOURCE_PCI_EA_BEI;
>
> switch (prop) {
> case PCI_EA_P_MEM:
> diff --git a/include/linux/ioport.h b/include/linux/ioport.h
> index 24bea08..88816f9 100644
> --- a/include/linux/ioport.h
> +++ b/include/linux/ioport.h
> @@ -25,7 +25,11 @@ struct resource {
>
> /*
> * IO resources have these defined flags.
> + *
> + * PCI devices expose these flags to userspace in the "resource" sysfs file,
> + * Moving them around could break stuff, so don't do it.
> */
> +
> #define IORESOURCE_BITS 0x000000ff /* Bus-specific bits */
>
> #define IORESOURCE_TYPE_BITS 0x00001f00 /* Resource type */
> @@ -97,6 +101,7 @@ struct resource {
> #define IORESOURCE_IO_SPARSE (1<<2)
>
> /* PCI ROM control bits (IORESOURCE_BITS) */
> +
> #define IORESOURCE_ROM_ENABLE (1<<0) /* ROM is enabled, same as PCI_ROM_ADDRESS_ENABLE */
> #define IORESOURCE_ROM_SHADOW (1<<1) /* ROM is copy at C000:0 */
> #define IORESOURCE_ROM_COPY (1<<2) /* ROM is alloc'd copy, resource field overlaid */
> @@ -105,6 +110,8 @@ struct resource {
> /* PCI control bits. Shares IORESOURCE_BITS with above PCI ROM. */
> #define IORESOURCE_PCI_FIXED (1<<4) /* Do not move resource */
>
> +/* PCI Enhanced Allocation defined BAR equivalent resource */
> +#define IORESOURCE_PCI_EA_BEI (1<<5)
>
> /* helpers to define resources */
> #define DEFINE_RES_NAMED(_start, _size, _name, _flags) \
> --
> 1.9.1
>
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