From db674ed450f113518285f410c93abecd93e71a2f Mon Sep 17 00:00:00 2001
From: Sylvain Munaut <tnt@246tNt.com>
Date: Fri, 6 Jan 2006 00:11:36 -0800
Subject: [PATCH] [PATCH] ppc32: Fix MPC52xx configuration space access
This patch takes care of an errata of the MPC5200 by avoiding 32 bits access
in type 1 configuration accesses. All others accesses are still 32 bits wide.
It also adds some mb() since the simple out_be(...) are not sufficient in
this case.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
arch/ppc/syslib/mpc52xx_pci.c | 83 +++++++++++++++++++++++++++++------
1 file changed, 69 insertions(+), 14 deletions(-)
diff --git a/arch/ppc/syslib/mpc52xx_pci.c b/arch/ppc/syslib/mpc52xx_pci.c
index e6cb3e26615ae..2c5e6ddaf2c50 100644
--- a/arch/ppc/syslib/mpc52xx_pci.c
+++ b/arch/ppc/syslib/mpc52xx_pci.c
@@ -24,6 +24,12 @@
#include <asm/machdep.h>
+/* This macro is defined to activate the workaround for the bug
+ 435 of the MPC5200 (L25R). With it activated, we don't do any
+ 32 bits configuration access during type-1 cycles */
+#define MPC5200_BUG_435_WORKAROUND
+
+
static int
mpc52xx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
int offset, int len, u32 *val)
@@ -40,17 +46,39 @@ mpc52xx_pci_read_config(struct pci_bus *bus, unsigned int devfn,
((bus->number - hose->bus_offset) << 16) |
(devfn << 8) |
(offset & 0xfc));
+ mb();
+
+#ifdef MPC5200_BUG_435_WORKAROUND
+ if (bus->number != hose->bus_offset) {
+ switch (len) {
+ case 1:
+ value = in_8(((u8 __iomem *)hose->cfg_data) + (offset & 3));
+ break;
+ case 2:
+ value = in_le16(((u16 __iomem *)hose->cfg_data) + ((offset>>1) & 1));
+ break;
+
+ default:
+ value = in_le16((u16 __iomem *)hose->cfg_data) |
+ (in_le16(((u16 __iomem *)hose->cfg_data) + 1) << 16);
+ break;
+ }
+ }
+ else
+#endif
+ {
+ value = in_le32(hose->cfg_data);
- value = in_le32(hose->cfg_data);
-
- if (len != 4) {
- value >>= ((offset & 0x3) << 3);
- value &= 0xffffffff >> (32 - (len << 3));
+ if (len != 4) {
+ value >>= ((offset & 0x3) << 3);
+ value &= 0xffffffff >> (32 - (len << 3));
+ }
}
*val = value;
out_be32(hose->cfg_addr, 0);
+ mb();
return PCIBIOS_SUCCESSFUL;
}
@@ -71,21 +99,48 @@ mpc52xx_pci_write_config(struct pci_bus *bus, unsigned int devfn,
((bus->number - hose->bus_offset) << 16) |
(devfn << 8) |
(offset & 0xfc));
+ mb();
+
+#ifdef MPC5200_BUG_435_WORKAROUND
+ if (bus->number != hose->bus_offset) {
+ switch (len) {
+ case 1:
+ out_8(((u8 __iomem *)hose->cfg_data) +
+ (offset & 3), val);
+ break;
+ case 2:
+ out_le16(((u16 __iomem *)hose->cfg_data) +
+ ((offset>>1) & 1), val);
+ break;
+
+ default:
+ out_le16((u16 __iomem *)hose->cfg_data,
+ (u16)val);
+ out_le16(((u16 __iomem *)hose->cfg_data) + 1,
+ (u16)(val>>16));
+ break;
+ }
+ }
+ else
+#endif
+ {
+ if (len != 4) {
+ value = in_le32(hose->cfg_data);
- if (len != 4) {
- value = in_le32(hose->cfg_data);
+ offset = (offset & 0x3) << 3;
+ mask = (0xffffffff >> (32 - (len << 3)));
+ mask <<= offset;
- offset = (offset & 0x3) << 3;
- mask = (0xffffffff >> (32 - (len << 3)));
- mask <<= offset;
+ value &= ~mask;
+ val = value | ((val << offset) & mask);
+ }
- value &= ~mask;
- val = value | ((val << offset) & mask);
+ out_le32(hose->cfg_data, val);
}
-
- out_le32(hose->cfg_data, val);
+ mb();
out_be32(hose->cfg_addr, 0);
+ mb();
return PCIBIOS_SUCCESSFUL;
}
--
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