diff options
author | Lennert Buytenhek <buytenh@wantstofly.org> | 2006-04-01 18:07:39 -0500 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-04-01 18:07:39 -0500 |
commit | 23759dc6430428897a36c4d493f611eca55c9481 (patch) | |
tree | c62050927599b36ed223753c35fd737e3c0c6762 /arch/arm/mach-ixp23xx/pci.c | |
parent | d3f4c571b6e596f9d39c596426269006a309d3b8 (diff) |
[ARM] 3439/2: xsc3: add I/O coherency support
Patch from Lennert Buytenhek
This patch adds support for the I/O coherent cache available on the
xsc3. The approach is to provide a simple API to determine whether the
chipset supports coherency by calling arch_is_coherent() and then
setting the appropriate system memory PTE and PMD bits. In addition,
we call this API on dma_alloc_coherent() and dma_map_single() calls.
A generic version exists that will compile out all the coherency-related
code that is not needed on the majority of ARM systems.
Note that we do not check for coherency in the dma_alloc_writecombine()
function as that still requires a special PTE setting. We also don't
touch dma_mmap_coherent() as that is a special ARM-only API that is by
definition only used on non-coherent system.
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-ixp23xx/pci.c')
-rw-r--r-- | arch/arm/mach-ixp23xx/pci.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/mach-ixp23xx/pci.c b/arch/arm/mach-ixp23xx/pci.c index ba6b4367a1d5..ac72f94c5b4d 100644 --- a/arch/arm/mach-ixp23xx/pci.c +++ b/arch/arm/mach-ixp23xx/pci.c | |||
@@ -219,6 +219,12 @@ static void __init ixp23xx_pci_common_init(void) | |||
219 | *IXP23XX_PCI_CPP_ADDR_BITS &= ~(1 << 1); | 219 | *IXP23XX_PCI_CPP_ADDR_BITS &= ~(1 << 1); |
220 | } else { | 220 | } else { |
221 | *IXP23XX_PCI_CPP_ADDR_BITS |= (1 << 1); | 221 | *IXP23XX_PCI_CPP_ADDR_BITS |= (1 << 1); |
222 | |||
223 | /* | ||
224 | * Enable coherency on A2 silicon. | ||
225 | */ | ||
226 | if (arch_is_coherent()) | ||
227 | *IXP23XX_CPP2XSI_CURR_XFER_REG3 &= ~IXP23XX_CPP2XSI_COH_OFF; | ||
222 | } | 228 | } |
223 | } | 229 | } |
224 | 230 | ||