From: Subbaraya Sundeep <sbhatta@xxxxxxxxxxx>
As per the spec - ECN_Enhanced_Allocation_23_Oct_2014_Final
and section 6.9.1.2, EA capability contains fixed secondary
and subordinate bus numbers for type 1 functions.
This patch adds support to read the fixed bus numbers
from EA capability for bridge.
Signed-off-by: Subbaraya Sundeep <sbhatta@xxxxxxxxxxx>
---
v3:
As per Bjorn's suggestion placed EA stuff in pci_ea_init and
captured bus numbers in pci_dev
v2:
None just added Sean
drivers/pci/pci.c | 10 ++++++++--
include/linux/pci.h | 4 ++++
include/uapi/linux/pci_regs.h | 4 ++++
3 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index c25acac..484b63e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -2909,6 +2909,7 @@ void pci_ea_init(struct pci_dev *dev)
u8 num_ent;
int offset;
int i;
+ u32 dw;
/* find PCI EA capability in list */
ea = pci_find_capability(dev, PCI_CAP_ID_EA);
@@ -2922,9 +2923,14 @@ void pci_ea_init(struct pci_dev *dev)
offset = ea + PCI_EA_FIRST_ENT;
- /* Skip DWORD 2 for type 1 functions */
- if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE)
+ /* Note fixed bus numbers for type 1 functions */
+ if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
+ pci_read_config_dword(dev, offset, &dw);
+ dev->fixed_sec_busnr = dw & PCI_EA_FIXED_SEC_BUS;
+ dev->fixed_sub_busnr = (dw & PCI_EA_FIXED_SUB_BUS) >>
+ PCI_EA_FIXED_SUB_SHIFT;
offset += 4;
+ }
/* parse each EA entry */
for (i = 0; i < num_ent; ++i)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 65f1d8c..3e9a3ae 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -459,6 +459,10 @@ struct pci_dev {
char *driver_override; /* Driver name to force a match */
unsigned long priv_flags; /* Private flags for the PCI driver */
+
+ /* bus numbers from EA capability if this device is a bridge */
+ u8 fixed_sec_busnr; /* Fixed Secondary Bus number */
+ u8 fixed_sub_busnr; /* Fixed Subordinate Bus number */
};
static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index e1e9888..51e9ac0 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -372,6 +372,10 @@
#define PCI_EA_FIRST_ENT_BRIDGE 8 /* First EA Entry for Bridges */
#define PCI_EA_ES 0x00000007 /* Entry Size */
#define PCI_EA_BEI 0x000000f0 /* BAR Equivalent Indicator */
+/* Fixed Secondary and Subordinate bus numbers in EA for Bridge */
+#define PCI_EA_FIXED_SEC_BUS 0xff
+#define PCI_EA_FIXED_SUB_BUS 0xff00
+#define PCI_EA_FIXED_SUB_SHIFT 8
/* 0-5 map to BARs 0-5 respectively */
#define PCI_EA_BEI_BAR0 0
#define PCI_EA_BEI_BAR5 5
--
1.8.3.1
