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path: root/lib/aarch64/cache_helpers.S
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2015-09-14Make generic code work in presence of system cachesAchin Gupta
On the ARMv8 architecture, cache maintenance operations by set/way on the last level of integrated cache do not affect the system cache. This means that such a flush or clean operation could result in the data being pushed out to the system cache rather than main memory. Another CPU could access this data before it enables its data cache or MMU. Such accesses could be serviced from the main memory instead of the system cache. If the data in the sysem cache has not yet been flushed or evicted to main memory then there could be a loss of coherency. The only mechanism to guarantee that the main memory will be updated is to use cache maintenance operations to the PoC by MVA(See section D3.4.11 (System level caches) of ARMv8-A Reference Manual (Issue A.g/ARM DDI0487A.G). This patch removes the reliance of Trusted Firmware on the flush by set/way operation to ensure visibility of data in the main memory. Cache maintenance operations by MVA are now used instead. The following are the broad category of changes: 1. The RW areas of BL2/BL31/BL32 are invalidated by MVA before the C runtime is initialised. This ensures that any stale cache lines at any level of cache are removed. 2. Updates to global data in runtime firmware (BL31) by the primary CPU are made visible to secondary CPUs using a cache clean operation by MVA. 3. Cache maintenance by set/way operations are only used prior to power down. NOTE: NON-UPSTREAM TRUSTED FIRMWARE CODE SHOULD MAKE EQUIVALENT CHANGES IN ORDER TO FUNCTION CORRECTLY ON PLATFORMS WITH SUPPORT FOR SYSTEM CACHES. Fixes ARM-software/tf-issues#205 Change-Id: I64f1b398de0432813a0e0881d70f8337681f6e9a
2015-04-08Add support to indicate size and end of assembly functionsKévin Petit
In order for the symbol table in the ELF file to contain the size of functions written in assembly, it is necessary to report it to the assembler using the .size directive. To fulfil the above requirements, this patch introduces an 'endfunc' macro which contains the .endfunc and .size directives. It also adds a .func directive to the 'func' assembler macro. The .func/.endfunc have been used so the assembler can fail if endfunc is omitted. Fixes ARM-Software/tf-issues#295 Change-Id: If8cb331b03d7f38fe7e3694d4de26f1075b278fc Signed-off-by: Kévin Petit <kevin.petit@arm.com>
2014-10-29Add support for level specific cache maintenance operationsSoby Mathew
This patch adds level specific cache maintenance functions to cache_helpers.S. The new functions 'dcsw_op_levelx', where '1 <= x <= 3', allow to perform cache maintenance by set/way for that particular level of cache. With this patch, functions to support cache maintenance upto level 3 have been implemented since it is the highest cache level for most ARM SoCs. These functions are now utilized in CPU specific power down sequences to implement them as mandated by processor specific technical reference manual. Change-Id: Icd90ce6b51cff5a12863bcda01b93601417fd45c
2014-06-10Make system register functions inline assemblyAndrew Thoelke
Replace the current out-of-line assembler implementations of the system register and system instruction operations with inline assembler. This enables better compiler optimisation and code generation when accessing system registers. Fixes ARM-software/tf-issues#91 Change-Id: I149af3a94e1e5e5140a3e44b9abfc37ba2324476
2014-05-08Merge pull request #58 from athoelke/optimise-cache-flush-v2danh-arm
Optimise data cache clean/invalidate operation v2
2014-05-07Optimise data cache clean/invalidate operationAndrew Thoelke
The data cache clean and invalidate operations dcsw_op_all() and dcsw_op_loius() were implemented to invoke a DSB and ISB barrier for every set/way operation. This adds a substantial performance penalty to an already expensive operation. These functions have been reworked to provide an optimised implementation derived from the code in section D3.4 of the ARMv8 ARM. The helper macro setup_dcsw_op_args has been moved and reworked alongside the implementation. Fixes ARM-software/tf-issues#146 Change-Id: Icd5df57816a83f0a842fce935320a369f7465c7f
2014-05-07Correct usage of data and instruction barriersAndrew Thoelke
The current code does not always use data and instruction barriers as required by the architecture and frequently uses barriers excessively due to their inclusion in all of the write_*() helper functions. Barriers should be used explicitly in assembler or C code when modifying processor state that requires the barriers in order to enable review of correctness of the code. This patch removes the barriers from the helper functions and introduces them as necessary elsewhere in the code. PORTING NOTE: check any port of Trusted Firmware for use of system register helper functions for reliance on the previous barrier behaviour and add explicit barriers as necessary. Fixes ARM-software/tf-issues#92 Change-Id: Ie63e187404ff10e0bdcb39292dd9066cb84c53bf
2014-05-06Reduce deep nesting of header filesDan Handley
Reduce the number of header files included from other header files as much as possible without splitting the files. Use forward declarations where possible. This allows removal of some unnecessary "#ifndef __ASSEMBLY__" statements. Also, review the .c and .S files for which header files really need including and reorder the #include statements alphabetically. Fixes ARM-software/tf-issues#31 Change-Id: Iec92fb976334c77453e010b60bcf56f3be72bd3e
2014-05-06Move include and source files to logical locationsDan Handley
Move almost all system include files to a logical sub-directory under ./include. The only remaining system include directories not under ./include are specific to the platform. Move the corresponding source files to match the include directory structure. Also remove pm.h as it is no longer used. Change-Id: Ie5ea6368ec5fad459f3e8a802ad129135527f0b3