From mboxrd@z Thu Jan 1 00:00:00 1970 From: rmk+kernel@arm.linux.org.uk (Russell King) Date: Fri, 28 Mar 2014 15:14:50 +0000 Subject: [PATCH 06/75] ARM: outer cache: add documentation of outer cache functions In-Reply-To: <20140328151249.GJ7528@n2100.arm.linux.org.uk> References: <20140328151249.GJ7528@n2100.arm.linux.org.uk> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Add some documentation to cover the outer cache functions so that their requirements can be better understood. Of particular note are the flush_all() and disable() methods which must not be called except in very specific circumstances. Signed-off-by: Russell King --- arch/arm/include/asm/outercache.h | 48 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/outercache.h b/arch/arm/include/asm/outercache.h index 0e4420858990..bd80540fe8b9 100644 --- a/arch/arm/include/asm/outercache.h +++ b/arch/arm/include/asm/outercache.h @@ -39,35 +39,75 @@ struct outer_cache_fns { extern struct outer_cache_fns outer_cache; #ifdef CONFIG_OUTER_CACHE - +/** + * outer_inv_range: invalidate range of outer cache lines + * @start: starting physical address, inclusive + * @end: end physical address, exclusive + */ static inline void outer_inv_range(phys_addr_t start, phys_addr_t end) { if (outer_cache.inv_range) outer_cache.inv_range(start, end); } + +/** + * outer_clean_range: clean dirty outer cache lines + * @start: starting physical address, inclusive + * @end: end physical address, exclusive + */ static inline void outer_clean_range(phys_addr_t start, phys_addr_t end) { if (outer_cache.clean_range) outer_cache.clean_range(start, end); } + +/** + * outer_flush_range: clean and invalidate outer cache lines + * @start: starting physical address, inclusive + * @end: end physical address, exclusive + */ static inline void outer_flush_range(phys_addr_t start, phys_addr_t end) { if (outer_cache.flush_range) outer_cache.flush_range(start, end); } +/** + * outer_flush_all: clean and invalidate all cache lines in the outer cache + * + * Note: depending on implementation, this may not be atomic - it must + * only be called with interrupts disabled and no other active outer + * cache masters. + * + * It is intended that this function is only used by implementations + * needing to override the outer_cache.disable() method due to security. + * (Some implementations perform this as a clean followed by an invalidate.) + */ static inline void outer_flush_all(void) { if (outer_cache.flush_all) outer_cache.flush_all(); } +/** + * outer_disable: clean, invalidate and disable the outer cache + * + * Disable the outer cache, ensuring that any data contained in the outer + * cache is pushed out to lower levels of system memory. The note and + * conditions above concerning outer_flush_all() applies here. + */ static inline void outer_disable(void) { if (outer_cache.disable) outer_cache.disable(); } +/** + * outer_resume: restore the cache configuration and re-enable outer cache + * + * Restore any configuration that the cache had when previously enabled, + * and re-enable the outer cache. + */ static inline void outer_resume(void) { if (outer_cache.resume) @@ -89,6 +129,12 @@ static inline void outer_resume(void) { } #endif #ifdef CONFIG_OUTER_CACHE_SYNC +/** + * outer_sync: perform a sync point for outer cache + * + * Ensure that all outer cache operations are complete and any store + * buffers are drained. + */ static inline void outer_sync(void) { if (outer_cache.sync) -- 1.8.3.1