From 23759dc6430428897a36c4d493f611eca55c9481 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Sun, 2 Apr 2006 00:07:39 +0100 Subject: [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 Signed-off-by: Lennert Buytenhek Signed-off-by: Russell King --- include/asm-arm/arch-ixp23xx/memory.h | 17 +++++++++++++++++ include/asm-arm/dma-mapping.h | 22 +++++++++++++++------- include/asm-arm/memory.h | 8 ++++++++ include/asm-arm/pgtable-hwdef.h | 1 + include/asm-arm/pgtable.h | 1 + 5 files changed, 42 insertions(+), 7 deletions(-) (limited to 'include/asm-arm') diff --git a/include/asm-arm/arch-ixp23xx/memory.h b/include/asm-arm/arch-ixp23xx/memory.h index bebcf0aa0d7..6e19f46d54d 100644 --- a/include/asm-arm/arch-ixp23xx/memory.h +++ b/include/asm-arm/arch-ixp23xx/memory.h @@ -28,6 +28,7 @@ * to an address that the kernel can use. */ #ifndef __ASSEMBLY__ +#include #define __virt_to_bus(v) \ ({ unsigned int ret; \ @@ -40,6 +41,22 @@ data = *((volatile int *)IXP23XX_PCI_SDRAM_BAR); \ __phys_to_virt((((b - (data & 0xfffffff0)) + 0x00000000))); }) +/* + * Coherency support. Only supported on A2 CPUs or on A1 + * systems that have the cache coherency workaround. + */ +static inline int __ixp23xx_arch_is_coherent(void) +{ + extern unsigned int processor_id; + + if (((processor_id & 15) >= 2) || machine_is_roadrunner()) + return 1; + + return 0; +} + +#define arch_is_coherent() __ixp23xx_arch_is_coherent() + #endif diff --git a/include/asm-arm/dma-mapping.h b/include/asm-arm/dma-mapping.h index e3e8541ee63..63ca7412a46 100644 --- a/include/asm-arm/dma-mapping.h +++ b/include/asm-arm/dma-mapping.h @@ -47,7 +47,7 @@ static inline int dma_get_cache_alignment(void) static inline int dma_is_consistent(dma_addr_t handle) { - return 0; + return !!arch_is_coherent(); } /* @@ -145,7 +145,9 @@ static inline dma_addr_t dma_map_single(struct device *dev, void *cpu_addr, size_t size, enum dma_data_direction dir) { - consistent_sync(cpu_addr, size, dir); + if (!arch_is_coherent()) + consistent_sync(cpu_addr, size, dir); + return virt_to_dma(dev, (unsigned long)cpu_addr); } #else @@ -255,7 +257,9 @@ dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, sg->dma_address = page_to_dma(dev, sg->page) + sg->offset; virt = page_address(sg->page) + sg->offset; - consistent_sync(virt, sg->length, dir); + + if (!arch_is_coherent()) + consistent_sync(virt, sg->length, dir); } return nents; @@ -310,14 +314,16 @@ static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - consistent_sync((void *)dma_to_virt(dev, handle), size, dir); + if (!arch_is_coherent()) + consistent_sync((void *)dma_to_virt(dev, handle), size, dir); } static inline void dma_sync_single_for_device(struct device *dev, dma_addr_t handle, size_t size, enum dma_data_direction dir) { - consistent_sync((void *)dma_to_virt(dev, handle), size, dir); + if (!arch_is_coherent()) + consistent_sync((void *)dma_to_virt(dev, handle), size, dir); } #else extern void dma_sync_single_for_cpu(struct device*, dma_addr_t, size_t, enum dma_data_direction); @@ -347,7 +353,8 @@ dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nents, for (i = 0; i < nents; i++, sg++) { char *virt = page_address(sg->page) + sg->offset; - consistent_sync(virt, sg->length, dir); + if (!arch_is_coherent()) + consistent_sync(virt, sg->length, dir); } } @@ -359,7 +366,8 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, int nents, for (i = 0; i < nents; i++, sg++) { char *virt = page_address(sg->page) + sg->offset; - consistent_sync(virt, sg->length, dir); + if (!arch_is_coherent()) + consistent_sync(virt, sg->length, dir); } } #else diff --git a/include/asm-arm/memory.h b/include/asm-arm/memory.h index afa5c3ea077..2b3cf69b3ed 100644 --- a/include/asm-arm/memory.h +++ b/include/asm-arm/memory.h @@ -234,6 +234,14 @@ static inline __deprecated void *bus_to_virt(unsigned long x) #define virt_to_dma(dev, addr) (__arch_virt_to_dma(dev, addr)) #endif +/* + * Optional coherency support. Currently used only by selected + * Intel XSC3-based systems. + */ +#ifndef arch_is_coherent +#define arch_is_coherent() 0 +#endif + #endif #include diff --git a/include/asm-arm/pgtable-hwdef.h b/include/asm-arm/pgtable-hwdef.h index 1d033495cc7..1bc1f997bda 100644 --- a/include/asm-arm/pgtable-hwdef.h +++ b/include/asm-arm/pgtable-hwdef.h @@ -73,6 +73,7 @@ #define PTE_EXT_AP_URW_SRW (PTE_EXT_AP1|PTE_EXT_AP0) #define PTE_EXT_TEX(x) ((x) << 6) /* v5 */ #define PTE_EXT_APX (1 << 9) /* v6 */ +#define PTE_EXT_COHERENT (1 << 9) /* XScale3 */ #define PTE_EXT_SHARED (1 << 10) /* v6 */ #define PTE_EXT_NG (1 << 11) /* v6 */ diff --git a/include/asm-arm/pgtable.h b/include/asm-arm/pgtable.h index e595ae24efe..e85c08d78dd 100644 --- a/include/asm-arm/pgtable.h +++ b/include/asm-arm/pgtable.h @@ -156,6 +156,7 @@ extern void __pgd_error(const char *file, int line, unsigned long val); #define L_PTE_WRITE (1 << 5) #define L_PTE_EXEC (1 << 6) #define L_PTE_DIRTY (1 << 7) +#define L_PTE_COHERENT (1 << 9) /* I/O coherent (xsc3) */ #define L_PTE_SHARED (1 << 10) /* shared between CPUs (v6) */ #define L_PTE_ASID (1 << 11) /* non-global (use ASID, v6) */ -- cgit v1.2.3