Hello,
the PCI support on Alchemy Au1500 and Au1550 based platforms is actually broken in
the current mips-kernel.
The problem was introduced in 2.6.18.3 with the casting of some 36bit-defines
(PCI memory) in au1000.h to resource_size_t which may be u32 or u64 depending on
the experimental CONFIG_RESOURCES_64BIT.
With unset CONFIG_RESOURCES_64BIT, the pci-memory cannot be accessed because
the ioremap in arch/mips/au1000/common/pci.c already used the truncated
addresses.
With set CONFIG_RESOURCES_64BIT, things get even worse, because PCI-scan
aborts, due to resource conflict: request_resource() in arch/mips/pci/pci.c
fails because the maximum iomem-address is 0xffffffff (32bit) but the
pci-memory-start-address is 0x440000000 (36bit).
To get pci working again, I propose the following patch:
1. remove the resource_size_t-casting from au1000.h again
2. make the casting in arch/mips/au1000/common/pci.c (it's allowed and
necessary here. The 36bit-handling will be done in __fixup_bigphys_addr).
With this patch pci works again like in 2.6.18.2, the gcc-compile warnings
in pci.c are gone and it doesn't depend on CONFIG_EXPERIMENTAL.
Only advantages ;-) Nevertheless, I'm open for your comments or even better
solutions.
Best regards,
Alexander
Signed-off-by: Alexander Bigga <ab@xxxxxxxxxx>
arch/mips/au1000/common/pci.c | 8 ++++----
include/asm-mips/mach-au1x00/au1000.h | 12 ++++++------
2 files changed, 10 insertions(+), 10 deletions(-)
--- linux-2.6.19.1/include/asm-mips/mach-au1x00/au1000.h 2006-12-12 00:38:26.000000000 +0100
+++ linux-2.6.19.1-dev/include/asm-mips/mach-au1x00/au1000.h 2006-12-21 09:58:15.000000000 +0100
@@ -1665,12 +1665,12 @@
* addresses. For PCI IO, it's simpler because we get to do the ioremap
* ourselves and then adjust the device's resources.
*/
-#define Au1500_EXT_CFG ((resource_size_t) 0x600000000ULL)
-#define Au1500_EXT_CFG_TYPE1 ((resource_size_t) 0x680000000ULL)
-#define Au1500_PCI_IO_START ((resource_size_t) 0x500000000ULL)
-#define Au1500_PCI_IO_END ((resource_size_t) 0x5000FFFFFULL)
-#define Au1500_PCI_MEM_START ((resource_size_t) 0x440000000ULL)
-#define Au1500_PCI_MEM_END ((resource_size_t) 0x44FFFFFFFULL)
+#define Au1500_EXT_CFG 0x600000000ULL
+#define Au1500_EXT_CFG_TYPE1 0x680000000ULL
+#define Au1500_PCI_IO_START 0x500000000ULL
+#define Au1500_PCI_IO_END 0x5000FFFFFULL
+#define Au1500_PCI_MEM_START 0x440000000ULL
+#define Au1500_PCI_MEM_END 0x44FFFFFFFULL
#define PCI_IO_START (Au1500_PCI_IO_START + 0x1000)
#define PCI_IO_END (Au1500_PCI_IO_END)
--- linux-2.6.19.1//arch/mips/au1000/common/pci.c 2006-12-12 00:38:26.000000000 +0100
+++ linux-2.6.19.1-dev/arch/mips/au1000/common/pci.c 2006-12-20 20:22:55.000000000 +0100
@@ -39,15 +39,15 @@
/* TBD */
static struct resource pci_io_resource = {
- .start = PCI_IO_START,
- .end = PCI_IO_END,
+ .start = (resource_size_t)PCI_IO_START,
+ .end = (resource_size_t)PCI_IO_END,
.name = "PCI IO space",
.flags = IORESOURCE_IO
};
static struct resource pci_mem_resource = {
- .start = PCI_MEM_START,
- .end = PCI_MEM_END,
+ .start = (resource_size_t)PCI_MEM_START,
+ .end = (resource_size_t)PCI_MEM_END,
.name = "PCI memory space",
.flags = IORESOURCE_MEM
};
--
Alexander Bigga Tel: +49-4321-55956-25
mycable GmbH Fax: +49-4321-55956-10
Gartenstrasse 10
D-24534 Neumuenster eMail: ab@xxxxxxxxxx
