[PATCH 2/3] x86/PCI: Export find_cap() to be used in early PCI code

From: Guilherme G. Piccoli
Date: Thu Oct 18 2018 - 14:37:34 EST


This patch exports (and renames) the function find_cap() to be used
in the early PCI quirk code, by the next patch.

This is being moved out from AGP code to generic early-PCI code
since it's not AGP-specific and can be used for any PCI device.
No functional changes intended.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxxxxx>
---
arch/x86/include/asm/pci-direct.h | 1 +
arch/x86/kernel/aperture_64.c | 30 ++----------------------------
arch/x86/pci/early.c | 25 +++++++++++++++++++++++++
3 files changed, 28 insertions(+), 28 deletions(-)

diff --git a/arch/x86/include/asm/pci-direct.h b/arch/x86/include/asm/pci-direct.h
index 94597a3cf3d0..813996305bf5 100644
--- a/arch/x86/include/asm/pci-direct.h
+++ b/arch/x86/include/asm/pci-direct.h
@@ -10,6 +10,7 @@
extern u32 read_pci_config(u8 bus, u8 slot, u8 func, u8 offset);
extern u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset);
extern u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset);
+extern u32 pci_early_find_cap(int bus, int slot, int func, int cap);
extern void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset, u32 val);
extern void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val);
extern void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, u16 val);
diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index 2c4d5ece7456..365fcc37b2a2 100644
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -120,32 +120,6 @@ static u32 __init allocate_aperture(void)
}


-/* Find a PCI capability */
-static u32 __init find_cap(int bus, int slot, int func, int cap)
-{
- int bytes;
- u8 pos;
-
- if (!(read_pci_config_16(bus, slot, func, PCI_STATUS) &
- PCI_STATUS_CAP_LIST))
- return 0;
-
- pos = read_pci_config_byte(bus, slot, func, PCI_CAPABILITY_LIST);
- for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
- u8 id;
-
- pos &= ~3;
- id = read_pci_config_byte(bus, slot, func, pos+PCI_CAP_LIST_ID);
- if (id == 0xff)
- break;
- if (id == cap)
- return pos;
- pos = read_pci_config_byte(bus, slot, func,
- pos+PCI_CAP_LIST_NEXT);
- }
- return 0;
-}
-
/* Read a standard AGPv3 bridge header */
static u32 __init read_agp(int bus, int slot, int func, int cap, u32 *order)
{
@@ -234,8 +208,8 @@ static u32 __init search_agp_bridge(u32 *order, int *valid_agp)
case PCI_CLASS_BRIDGE_HOST:
case PCI_CLASS_BRIDGE_OTHER: /* needed? */
/* AGP bridge? */
- cap = find_cap(bus, slot, func,
- PCI_CAP_ID_AGP);
+ cap = pci_early_find_cap(bus, slot,
+ func, PCI_CAP_ID_AGP);
if (!cap)
break;
*valid_agp = 1;
diff --git a/arch/x86/pci/early.c b/arch/x86/pci/early.c
index f5fc953e5848..f1ba9d781b52 100644
--- a/arch/x86/pci/early.c
+++ b/arch/x86/pci/early.c
@@ -51,6 +51,31 @@ void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, u16 val)
outw(val, 0xcfc + (offset&2));
}

+u32 pci_early_find_cap(int bus, int slot, int func, int cap)
+{
+ int bytes;
+ u8 pos;
+
+ if (!(read_pci_config_16(bus, slot, func, PCI_STATUS) &
+ PCI_STATUS_CAP_LIST))
+ return 0;
+
+ pos = read_pci_config_byte(bus, slot, func, PCI_CAPABILITY_LIST);
+ for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
+ u8 id;
+
+ pos &= ~3;
+ id = read_pci_config_byte(bus, slot, func, pos+PCI_CAP_LIST_ID);
+ if (id == 0xff)
+ break;
+ if (id == cap)
+ return pos;
+ pos = read_pci_config_byte(bus, slot, func,
+ pos+PCI_CAP_LIST_NEXT);
+ }
+ return 0;
+}
+
int early_pci_allowed(void)
{
return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) ==
--
2.19.0