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>
---
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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