On Mon, Feb 03, 2014 at 06:58:56PM +0000, Arnd Bergmann wrote:
On Monday 03 February 2014 18:43:48 Liviu Dudau wrote:
diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h index 4cc813e..ce5bad2 100644 --- a/arch/arm64/include/asm/io.h +++ b/arch/arm64/include/asm/io.h @@ -120,9 +120,13 @@ static inline u64 __raw_readq(const volatile void __iomem *addr) /*
- I/O port access primitives.
*/ +#define arch_has_dev_port() (0)
Why not?
Maybe I got it the wrong way around, but the comment in include/linux/io.h says:
/* * Some systems do not have legacy ISA devices. * /dev/port is not a valid interface on these systems. * So for those archs, <asm/io.h> should define the following symbol. */
So ... defining it should mean no legacy ISA devices, right?
#define IO_SPACE_LIMIT 0xffff
You probably want to increase this a bit, to allow multiple host bridges to have their own I/O space.
OK, but to what size?
#define PCI_IOBASE ((void __iomem *)(MODULES_VADDR - SZ_2M))
And modify this location: There is no particular reason to have the I/O space mapped exactly 2MB below the loadable modules, as virtual address space is essentially free.
Will talk with Catalin about where to place this.
+#define ioport_map(port, nr) (PCI_IOBASE + ((port) & IO_SPACE_LIMIT)) +#define ioport_unmap(addr)
inline functions?
Will do, thanks!
static inline u8 inb(unsigned long addr) { return readb(addr + PCI_IOBASE); diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h new file mode 100644 index 0000000..dd084a3 --- /dev/null +++ b/arch/arm64/include/asm/pci.h @@ -0,0 +1,35 @@ +#ifndef __ASM_PCI_H +#define __ASM_PCI_H +#ifdef __KERNEL__
+#include <linux/types.h> +#include <linux/slab.h> +#include <linux/dma-mapping.h>
+#include <asm/io.h> +#include <asm-generic/pci-bridge.h> +#include <asm-generic/pci-dma-compat.h>
+#define PCIBIOS_MIN_IO 0 +#define PCIBIOS_MIN_MEM 0
PCIBIOS_MIN_IO is normally set to 0x1000, to stay out of the ISA range.
:) No ISA support! (Die ISA, die!!)
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c new file mode 100644 index 0000000..7b652cf --- /dev/null +++ b/arch/arm64/kernel/pci.c @@ -0,0 +1,112 @@
None of this looks really arm64 specific, nor should it be. I think we should try a little harder to move this as a default implementation into common code, even if we start out by having all architectures override it.
Agree. This is the RFC version. I didn't dare to post a patch with fixes for all architectures. :)
+int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr) +{
- BUG_ON(offset + SZ_64K - 1 > IO_SPACE_LIMIT);
- return ioremap_page_range((unsigned long)PCI_IOBASE + offset,
(unsigned long)PCI_IOBASE + offset + SZ_64K,phys_addr,__pgprot(PROT_DEVICE_nGnRE));+}
Not sure if we want to treat this one as architecture specific though. It certainly won't be portable to x86, but it could be shared with a couple of others. We may also want to redesign the interface. I've been thinking we could make this function allocate space in the Linux virtual I/O space aperture, and pass two resources into it (physical I/O aperture and bus I/O range), and get the actual io_offset as the return value, or a negative error number.
Not sure I completely follow your idea.
That way, you could have an arbitrary number of host bridges in the system and each one gets a share of the virtual aperture until it's full.
One still needs to fix the pci_request_region use that checks against ioport_resource. But it is an interesting idea.
Arnd
Thanks for reviewing this patch!
Liviu