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author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-05-15 10:26:50 -0400 |
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committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-05-15 10:26:50 -0400 |
commit | 12e04ffcd93b25dfd726d46338c2ee7d23de556e (patch) | |
tree | f91479a62805619168994fd3ee55e3ffa23fc24e /arch/arm/include/asm/cacheflush.h | |
parent | 9eff37a8713939f218ab8bf0dc93f1d67af7b8b4 (diff) | |
parent | f722406faae2d073cc1d01063d1123c35425939e (diff) |
Merge tag 'v3.10-rc1' into stable/for-linus-3.10
Linux 3.10-rc1
* tag 'v3.10-rc1': (12273 commits)
Linux 3.10-rc1
[SCSI] qla2xxx: Update firmware link in Kconfig file.
[SCSI] iscsi class, qla4xxx: fix sess/conn refcounting when find fns are used
[SCSI] sas: unify the pointlessly separated enums sas_dev_type and sas_device_type
[SCSI] pm80xx: thermal, sas controller config and error handling update
[SCSI] pm80xx: NCQ error handling changes
[SCSI] pm80xx: WWN Modification for PM8081/88/89 controllers
[SCSI] pm80xx: Changed module name and debug messages update
[SCSI] pm80xx: Firmware flash memory free fix, with addition of new memory region for it
[SCSI] pm80xx: SPC new firmware changes for device id 0x8081 alone
[SCSI] pm80xx: Added SPCv/ve specific hardware functionalities and relevant changes in common files
[SCSI] pm80xx: MSI-X implementation for using 64 interrupts
[SCSI] pm80xx: Updated common functions common for SPC and SPCv/ve
[SCSI] pm80xx: Multiple inbound/outbound queue configuration
[SCSI] pm80xx: Added SPCv/ve specific ids, variables and modify for SPC
[SCSI] lpfc: fix up Kconfig dependencies
[SCSI] Handle MLQUEUE busy response in scsi_send_eh_cmnd
dm cache: set config value
dm cache: move config fns
dm thin: generate event when metadata threshold passed
...
Diffstat (limited to 'arch/arm/include/asm/cacheflush.h')
-rw-r--r-- | arch/arm/include/asm/cacheflush.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h index e1489c54cd1..bff71388e72 100644 --- a/arch/arm/include/asm/cacheflush.h +++ b/arch/arm/include/asm/cacheflush.h @@ -363,4 +363,79 @@ static inline void flush_cache_vunmap(unsigned long start, unsigned long end) flush_cache_all(); } +/* + * Memory synchronization helpers for mixed cached vs non cached accesses. + * + * Some synchronization algorithms have to set states in memory with the + * cache enabled or disabled depending on the code path. It is crucial + * to always ensure proper cache maintenance to update main memory right + * away in that case. + * + * Any cached write must be followed by a cache clean operation. + * Any cached read must be preceded by a cache invalidate operation. + * Yet, in the read case, a cache flush i.e. atomic clean+invalidate + * operation is needed to avoid discarding possible concurrent writes to the + * accessed memory. + * + * Also, in order to prevent a cached writer from interfering with an + * adjacent non-cached writer, each state variable must be located to + * a separate cache line. + */ + +/* + * This needs to be >= the max cache writeback size of all + * supported platforms included in the current kernel configuration. + * This is used to align state variables to their own cache lines. + */ +#define __CACHE_WRITEBACK_ORDER 6 /* guessed from existing platforms */ +#define __CACHE_WRITEBACK_GRANULE (1 << __CACHE_WRITEBACK_ORDER) + +/* + * There is no __cpuc_clean_dcache_area but we use it anyway for + * code intent clarity, and alias it to __cpuc_flush_dcache_area. + */ +#define __cpuc_clean_dcache_area __cpuc_flush_dcache_area + +/* + * Ensure preceding writes to *p by this CPU are visible to + * subsequent reads by other CPUs: + */ +static inline void __sync_cache_range_w(volatile void *p, size_t size) +{ + char *_p = (char *)p; + + __cpuc_clean_dcache_area(_p, size); + outer_clean_range(__pa(_p), __pa(_p + size)); +} + +/* + * Ensure preceding writes to *p by other CPUs are visible to + * subsequent reads by this CPU. We must be careful not to + * discard data simultaneously written by another CPU, hence the + * usage of flush rather than invalidate operations. + */ +static inline void __sync_cache_range_r(volatile void *p, size_t size) +{ + char *_p = (char *)p; + +#ifdef CONFIG_OUTER_CACHE + if (outer_cache.flush_range) { + /* + * Ensure dirty data migrated from other CPUs into our cache + * are cleaned out safely before the outer cache is cleaned: + */ + __cpuc_clean_dcache_area(_p, size); + + /* Clean and invalidate stale data for *p from outer ... */ + outer_flush_range(__pa(_p), __pa(_p + size)); + } +#endif + + /* ... and inner cache: */ + __cpuc_flush_dcache_area(_p, size); +} + +#define sync_cache_w(ptr) __sync_cache_range_w(ptr, sizeof *(ptr)) +#define sync_cache_r(ptr) __sync_cache_range_r(ptr, sizeof *(ptr)) + #endif |