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| author | Max Filippov <jcmvbkbc@gmail.com> | 2018-07-11 14:33:41 -0700 |
|---|---|---|
| committer | Max Filippov <jcmvbkbc@gmail.com> | 2018-07-11 15:59:41 -0700 |
| commit | 2cc15e802b250a11ece57ea54f82993cf3430867 (patch) | |
| tree | d67e3892c92e077bebeac05db22765376e8de5c1 /arch/xtensa/include | |
| parent | adbfa4e6f99689511f1079452508d9d22417544c (diff) | |
| download | linux-2cc15e802b250a11ece57ea54f82993cf3430867.tar.gz linux-2cc15e802b250a11ece57ea54f82993cf3430867.tar.bz2 linux-2cc15e802b250a11ece57ea54f82993cf3430867.zip | |
xtensa: platform-specific handling of coherent memory
Memory layout is not fixed for noMMU xtensa configurations. Platforms
that need to use coherent DMA should implement platform_vaddr_* helpers
that check address type (cached/uncached) and convert addresses between
these types.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/include')
| -rw-r--r-- | arch/xtensa/include/asm/kmem_layout.h | 6 | ||||
| -rw-r--r-- | arch/xtensa/include/asm/pgtable.h | 8 | ||||
| -rw-r--r-- | arch/xtensa/include/asm/platform.h | 27 |
3 files changed, 35 insertions, 6 deletions
diff --git a/arch/xtensa/include/asm/kmem_layout.h b/arch/xtensa/include/asm/kmem_layout.h index 2317c835a4db..9c12babc016c 100644 --- a/arch/xtensa/include/asm/kmem_layout.h +++ b/arch/xtensa/include/asm/kmem_layout.h @@ -63,12 +63,6 @@ #error XCHAL_KSEG_PADDR is not properly aligned to XCHAL_KSEG_ALIGNMENT #endif -#else - -#define XCHAL_KSEG_CACHED_VADDR __XTENSA_UL_CONST(0xd0000000) -#define XCHAL_KSEG_BYPASS_VADDR __XTENSA_UL_CONST(0xd8000000) -#define XCHAL_KSEG_SIZE __XTENSA_UL_CONST(0x08000000) - #endif #ifndef CONFIG_KASAN diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h index 38802259978f..29cfe421cf41 100644 --- a/arch/xtensa/include/asm/pgtable.h +++ b/arch/xtensa/include/asm/pgtable.h @@ -66,6 +66,7 @@ #define FIRST_USER_ADDRESS 0UL #define FIRST_USER_PGD_NR (FIRST_USER_ADDRESS >> PGDIR_SHIFT) +#ifdef CONFIG_MMU /* * Virtual memory area. We keep a distance to other memory regions to be * on the safe side. We also use this area for cache aliasing. @@ -80,6 +81,13 @@ #define TLBTEMP_SIZE ICACHE_WAY_SIZE #endif +#else + +#define VMALLOC_START __XTENSA_UL_CONST(0) +#define VMALLOC_END __XTENSA_UL_CONST(0xffffffff) + +#endif + /* * For the Xtensa architecture, the PTE layout is as follows: * diff --git a/arch/xtensa/include/asm/platform.h b/arch/xtensa/include/asm/platform.h index f8fbef67bc5f..560483356a06 100644 --- a/arch/xtensa/include/asm/platform.h +++ b/arch/xtensa/include/asm/platform.h @@ -75,4 +75,31 @@ extern void platform_calibrate_ccount (void); */ void cpu_reset(void) __attribute__((noreturn)); +/* + * Memory caching is platform-dependent in noMMU xtensa configurations. + * The following set of functions should be implemented in platform code + * in order to enable coherent DMA memory operations when CONFIG_MMU is not + * enabled. Default implementations do nothing and issue a warning. + */ + +/* + * Check whether p points to a cached memory. + */ +bool platform_vaddr_cached(const void *p); + +/* + * Check whether p points to an uncached memory. + */ +bool platform_vaddr_uncached(const void *p); + +/* + * Return pointer to an uncached view of the cached sddress p. + */ +void *platform_vaddr_to_uncached(void *p); + +/* + * Return pointer to a cached view of the uncached sddress p. + */ +void *platform_vaddr_to_cached(void *p); + #endif /* _XTENSA_PLATFORM_H */ |