[PATCH] arm64: Add architecture support for PCI

On Tue, Feb 04, 2014 at 08:44:36AM +0000, Arnd Bergmann wrote:

On Monday 03 February 2014 21:36:58 Liviu Dudau wrote:

quoted

On Mon, Feb 03, 2014 at 08:05:56PM +0000, Arnd Bergmann wrote:

quoted

2 MB was a compromise on arm32 to allow up to 32 PCI host bridges but not
take up too much virtual space. On arm64 it should be at least as big.
Could be more than that, although I don't see a reason why it should be,
unless we expect to see systems with tons of host bridges, or buses
that exceed 64KB of I/O space.

I will increase the size to 2MB for v2.

Thinking about this some more, I'd go a little higher. In case of
pci_mv, we already register a 1MB region for one logical host
(which has multiple I/O spaces behind an emulated bridge), so
going to 16MB or more would let us handle multiple 1MB windows
for some amount of future proofing.

Maybe Catalin can assign us some virtual address space to use,
with the constraints that it should be 16MB or more in an
area that doesn't require additional kernel page table pages.

See below, 16MB and could be extended further if needed.

------------>8--------------------

From 00521f109ac8a2589c9089a5feaaaa1be7f26108 Mon Sep 17 00:00:00 2001

From: Catalin Marinas <catalin.marinas@arm.com>
Date: Tue, 4 Feb 2014 16:37:59 +0000
Subject: [PATCH] arm64: Extend the PCI I/O space to 16MB

The patch moves the PCI I/O space (currently at 64K) before the
earlyprintk mapping and extends it to 16MB.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
 Documentation/arm64/memory.txt | 16 ++++++++++------
 arch/arm64/include/asm/io.h    |  2 +-
 2 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/Documentation/arm64/memory.txt b/Documentation/arm64/memory.txt
index 5e054bfe4dde..85e24c4f215c 100644
--- a/Documentation/arm64/memory.txt
+++ b/Documentation/arm64/memory.txt

@@ -35,11 +35,13 @@ ffffffbc00000000	ffffffbdffffffff	   8GB		vmemmap
 
 ffffffbe00000000	ffffffbffbbfffff	  ~8GB		[guard, future vmmemap]
 
-ffffffbffbc00000	ffffffbffbdfffff	   2MB		earlyprintk device
+ffffffbffa000000	ffffffbffaffffff	  16MB		PCI I/O space
+
+ffffffbffb000000	ffffffbffbbfffff	  12MB		[guard]
 
-ffffffbffbe00000	ffffffbffbe0ffff	  64KB		PCI I/O space
+ffffffbffbc00000	ffffffbffbdfffff	   2MB		earlyprintk device
 
-ffffffbffbe10000	ffffffbcffffffff	  ~2MB		[guard]
+ffffffbffbe00000	ffffffbffbffffff	   2MB		[guard]
 
 ffffffbffc000000	ffffffbfffffffff	  64MB		modules
 

@@ -60,11 +62,13 @@ fffffdfc00000000	fffffdfdffffffff	   8GB		vmemmap
 
 fffffdfe00000000	fffffdfffbbfffff	  ~8GB		[guard, future vmmemap]
 
-fffffdfffbc00000	fffffdfffbdfffff	   2MB		earlyprintk device
+fffffdfffa000000	fffffdfffaffffff	  16MB		PCI I/O space
+
+fffffdfffb000000	fffffdfffbbfffff	  12MB		[guard]
 
-fffffdfffbe00000	fffffdfffbe0ffff	  64KB		PCI I/O space
+fffffdfffbc00000	fffffdfffbdfffff	   2MB		earlyprintk device
 
-fffffdfffbe10000	fffffdfffbffffff	  ~2MB		[guard]
+fffffdfffbe00000	fffffdfffbffffff	   2MB		[guard]
 
 fffffdfffc000000	fffffdffffffffff	  64MB		modules
 

diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index 4cc813eddacb..7846a6bb0833 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h

@@ -121,7 +121,7 @@ static inline u64 __raw_readq(const volatile void __iomem *addr)
  *  I/O port access primitives.
  */
 #define IO_SPACE_LIMIT		0xffff
-#define PCI_IOBASE		((void __iomem *)(MODULES_VADDR - SZ_2M))
+#define PCI_IOBASE		((void __iomem *)(MODULES_VADDR - SZ_32M))
 
 static inline u8 inb(unsigned long addr)
 {