diff options
| author | Lennert Buytenhek <buytenh@wantstofly.org> | 2006-04-01 23:07:39 (GMT) |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-04-01 23:07:39 (GMT) |
| commit | 23759dc6430428897a36c4d493f611eca55c9481 (patch) | |
| tree | c62050927599b36ed223753c35fd737e3c0c6762 /arch/arm/mm | |
| parent | d3f4c571b6e596f9d39c596426269006a309d3b8 (diff) | |
| download | linux-23759dc6430428897a36c4d493f611eca55c9481.tar.xz | |
[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/mm')
| -rw-r--r-- | arch/arm/mm/consistent.c | 17 | ||||
| -rw-r--r-- | arch/arm/mm/mm-armv.c | 11 | ||||
| -rw-r--r-- | arch/arm/mm/proc-xsc3.S | 2 |
3 files changed, 29 insertions, 1 deletions
diff --git a/arch/arm/mm/consistent.c b/arch/arm/mm/consistent.c index 8a1bfcd..50e6b6b 100644 --- a/arch/arm/mm/consistent.c +++ b/arch/arm/mm/consistent.c @@ -18,6 +18,7 @@ #include <linux/device.h> #include <linux/dma-mapping.h> +#include <asm/memory.h> #include <asm/cacheflush.h> #include <asm/tlbflush.h> #include <asm/sizes.h> @@ -272,6 +273,17 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, void * dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp) { + if (arch_is_coherent()) { + void *virt; + + virt = kmalloc(size, gfp); + if (!virt) + return NULL; + *handle = virt_to_dma(dev, virt); + + return virt; + } + return __dma_alloc(dev, size, handle, gfp, pgprot_noncached(pgprot_kernel)); } @@ -350,6 +362,11 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr WARN_ON(irqs_disabled()); + if (arch_is_coherent()) { + kfree(cpu_addr); + return; + } + size = PAGE_ALIGN(size); spin_lock_irqsave(&consistent_lock, flags); diff --git a/arch/arm/mm/mm-armv.c b/arch/arm/mm/mm-armv.c index 5e5d05b..f14b2d0 100644 --- a/arch/arm/mm/mm-armv.c +++ b/arch/arm/mm/mm-armv.c @@ -389,6 +389,17 @@ void __init build_mem_type_table(void) kern_pgprot = user_pgprot = cp->pte; /* + * Enable CPU-specific coherency if supported. + * (Only available on XSC3 at the moment.) + */ + if (arch_is_coherent()) { + if (cpu_is_xsc3()) { + mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S; + mem_types[MT_MEMORY].prot_pte |= L_PTE_COHERENT; + } + } + + /* * ARMv6 and above have extended page tables. */ if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) { diff --git a/arch/arm/mm/proc-xsc3.S b/arch/arm/mm/proc-xsc3.S index b9dfce5..80873b3 100644 --- a/arch/arm/mm/proc-xsc3.S +++ b/arch/arm/mm/proc-xsc3.S @@ -371,7 +371,7 @@ ENTRY(cpu_xsc3_switch_mm) ENTRY(cpu_xsc3_set_pte) str r1, [r0], #-2048 @ linux version - bic r2, r1, #0xff0 + bic r2, r1, #0xdf0 @ Keep C, B, coherency bits orr r2, r2, #PTE_TYPE_EXT @ extended page eor r3, r1, #L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_WRITE | L_PTE_DIRTY |