[PATCH v2] arm: versatile: enable PCI I/O space
Arnd Bergmann
arnd at arndb.de
Tue Jul 20 17:22:16 EDT 2010
I/O space handling on the versatile platform is currently
broken in multiple ways. Most importantly, the ports do
not get mapped into the virtual address space at all.
Also, there is some amount of confusion between PCI I/O
space and other statically mapped MMIO registers in the
platform code:
* The __io_address() macro that is used to access the
platform register maps to the same __io macro that gets
used for I/O space.
* The IO_SPACE_LIMIT is set to a value that is much larger
than the total available space.
* The I/O resource of the PCI bus is set to the physical
address of the mapping, which is way outside of the
actual I/O space limit as well as the address range that
gets decoded by traditional PCI cards.
* No attempt is made to stay outside of the ISA port range
that some device drivers try access.
* No resource gets requested as a child of ioport_resource,
but an IORESOURCE_IO type mapping gets requested
as a child of iomem_resource.
This patch attempts to correct all of the above. This makes
it possible to use virtio-pci based virtual devices as well
as actual PCI cards including those with legacy ISA port
ranges like VGA.
Some of the issues seem to be duplicated on other platforms.
Signed-off-by: Arnd Bergmann <arnd at arndb.de>
---
Version 2 of this patch adds improvements suggested by Russell.
I chose to define PCIO_BASE directly and to derive the static
mapping from that, because it will allow us to eventually move
to a fixed PCIO_BASE in the virtual mapping of multiplatform kernels.
Tested in qemu with a small patch to enable PCI I/O space for
versatile. Catalin mentioned that I/O space mappings possibly
never worked on the real versatile board, but applying this
patch should still fix real problems, e.g. you no longer
crash the kernel by writing to /dev/port and it makes it
possible to use qemu virtio devices.
Arnd
arch/arm/mach-versatile/core.c | 19 +++----------------
arch/arm/mach-versatile/include/mach/hardware.h | 17 ++++-------------
arch/arm/mach-versatile/include/mach/io.h | 6 ++++--
arch/arm/mach-versatile/pci.c | 18 ++++++++++++++++--
4 files changed, 27 insertions(+), 33 deletions(-)
diff --git a/arch/arm/mach-versatile/core.c b/arch/arm/mach-versatile/core.c
index 3dff864..4b9ad2c 100644
--- a/arch/arm/mach-versatile/core.c
+++ b/arch/arm/mach-versatile/core.c
@@ -200,26 +200,13 @@ static struct map_desc versatile_io_desc[] __initdata = {
.pfn = __phys_to_pfn(VERSATILE_PCI_CFG_BASE),
.length = VERSATILE_PCI_CFG_BASE_SIZE,
.type = MT_DEVICE
- },
-#if 0
- {
- .virtual = VERSATILE_PCI_VIRT_MEM_BASE0,
- .pfn = __phys_to_pfn(VERSATILE_PCI_MEM_BASE0),
- .length = SZ_16M,
- .type = MT_DEVICE
}, {
- .virtual = VERSATILE_PCI_VIRT_MEM_BASE1,
- .pfn = __phys_to_pfn(VERSATILE_PCI_MEM_BASE1),
- .length = SZ_16M,
- .type = MT_DEVICE
- }, {
- .virtual = VERSATILE_PCI_VIRT_MEM_BASE2,
- .pfn = __phys_to_pfn(VERSATILE_PCI_MEM_BASE2),
- .length = SZ_16M,
+ .virtual = (unsigned long)VERSATILE_PCI_VIRT_MEM_BASE0,
+ .pfn = __phys_to_pfn(VERSATILE_PCI_MEM_BASE0),
+ .length = IO_SPACE_LIMIT,
.type = MT_DEVICE
},
#endif
-#endif
};
void __init versatile_map_io(void)
diff --git a/arch/arm/mach-versatile/include/mach/hardware.h b/arch/arm/mach-versatile/include/mach/hardware.h
index 4f8f99a..b4ae7cf 100644
--- a/arch/arm/mach-versatile/include/mach/hardware.h
+++ b/arch/arm/mach-versatile/include/mach/hardware.h
@@ -29,25 +29,16 @@
*/
#define VERSATILE_PCI_VIRT_BASE (void __iomem *)0xe8000000ul
#define VERSATILE_PCI_CFG_VIRT_BASE (void __iomem *)0xe9000000ul
+#define VERSATILE_PCI_VIRT_MEM_BASE0 (void __iomem *)PCIO_BASE
-#if 0
-#define VERSATILE_PCI_VIRT_MEM_BASE0 0xf4000000
-#define VERSATILE_PCI_VIRT_MEM_BASE1 0xf5000000
-#define VERSATILE_PCI_VIRT_MEM_BASE2 0xf6000000
-
-#define PCIO_BASE VERSATILE_PCI_VIRT_MEM_BASE0
-#define PCIMEM_BASE VERSATILE_PCI_VIRT_MEM_BASE1
-#endif
-
-/* CIK guesswork */
-#define PCIBIOS_MIN_IO 0x44000000
+#define PCIBIOS_MIN_IO 0x00001000
#define PCIBIOS_MIN_MEM 0x50000000
#define pcibios_assign_all_busses() 1
-/* macro to get at IO space when running virtually */
+/* macro to get at MMIO space when running virtually */
#define IO_ADDRESS(x) (((x) & 0x0fffffff) + (((x) >> 4) & 0x0f000000) + 0xf0000000)
-#define __io_address(n) __io(IO_ADDRESS(n))
+#define __io_address(n) ((void __iomem *)IO_ADDRESS(n))
#endif
diff --git a/arch/arm/mach-versatile/include/mach/io.h b/arch/arm/mach-versatile/include/mach/io.h
index f067c14..83ef5b6 100644
--- a/arch/arm/mach-versatile/include/mach/io.h
+++ b/arch/arm/mach-versatile/include/mach/io.h
@@ -20,9 +20,11 @@
#ifndef __ASM_ARM_ARCH_IO_H
#define __ASM_ARM_ARCH_IO_H
-#define IO_SPACE_LIMIT 0xffffffff
+#define PCIO_BASE 0xeb000000ul
+#define PCIO_SIZE 0x00100000ul
+#define IO_SPACE_LIMIT (PCIO_SIZE - 1)
-#define __io(a) __typesafe_io(a)
+#define __io(a) (a + PCIO_BASE)
#define __mem_pci(a) (a)
#endif
diff --git a/arch/arm/mach-versatile/pci.c b/arch/arm/mach-versatile/pci.c
index 334f0df..4630ff1 100644
--- a/arch/arm/mach-versatile/pci.c
+++ b/arch/arm/mach-versatile/pci.c
@@ -170,11 +170,18 @@ static struct pci_ops pci_versatile_ops = {
.write = versatile_write_config,
};
+static struct resource io_port = {
+ .name = "PCI",
+ .start = 0,
+ .end = IO_SPACE_LIMIT,
+ .flags = IORESOURCE_IO,
+};
+
static struct resource io_mem = {
.name = "PCI I/O space",
.start = VERSATILE_PCI_MEM_BASE0,
.end = VERSATILE_PCI_MEM_BASE0+VERSATILE_PCI_MEM_BASE0_SIZE-1,
- .flags = IORESOURCE_IO,
+ .flags = IORESOURCE_MEM,
};
static struct resource non_mem = {
@@ -201,6 +208,12 @@ static int __init pci_versatile_setup_resources(struct resource **resource)
"memory region (%d)\n", ret);
goto out;
}
+ ret = request_resource(&ioport_resource, &io_port);
+ if (ret) {
+ printk(KERN_ERR "PCI: unable to allocate I/O "
+ "port region (%d)\n", ret);
+ goto out;
+ }
ret = request_resource(&iomem_resource, &non_mem);
if (ret) {
printk(KERN_ERR "PCI: unable to allocate non-prefetchable "
@@ -219,7 +232,7 @@ static int __init pci_versatile_setup_resources(struct resource **resource)
* bus->resource[1] is the mem resource for this bus
* bus->resource[2] is the prefetch mem resource for this bus
*/
- resource[0] = &io_mem;
+ resource[0] = &io_port;
resource[1] = &non_mem;
resource[2] = &pre_mem;
@@ -250,6 +263,7 @@ int __init pci_versatile_setup(int nr, struct pci_sys_data *sys)
if (nr == 0) {
sys->mem_offset = 0;
+ sys->io_offset = 0;
ret = pci_versatile_setup_resources(sys->resource);
if (ret < 0) {
printk("pci_versatile_setup: resources... oops?\n");
--
1.7.1
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