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path: root/lib/aarch64/misc_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>
2014-07-28Implement an assert() callable from assembly codeSoby Mathew
The patch implements a macro ASM_ASSERT() which can be invoked from assembly code. When assertion happens, file name and line number of the check is written to the crash console. Fixes ARM-software/tf-issues#95 Change-Id: I6f905a068e1c0fa4f746d723f18df60daaa00a86
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
2014-05-07Remove unused or invalid asm helper functionsAndrew Thoelke
There are a small number of non-EL specific helper functions which are no longer used, and also some unusable helper functions for non-existant registers. This change removes all of these functions. Change-Id: Idd656cef3b59cf5c46fe2be4029d72288b649c24
2014-05-07Replace disable_mmu with assembler versionAndrew Thoelke
disable_mmu() cannot work as a C function as there is no control over data accesses generated by the compiler between disabling and cleaning the data cache. This results in reading stale data from main memory. As assembler version is provided for EL3, and a variant that also disables the instruction cache which is now used by the BL1 exception handling function. Fixes ARM-software/tf-issues#147 Change-Id: I0cf394d2579a125a23c2f2989c2e92ace6ddb1a6
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