- 10 5月, 2013 4 次提交
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由 Vineet Gupta 提交于
Enforce congruency of userspace shared mappings Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
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由 Vineet Gupta 提交于
Fix the one zillion warnings Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
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由 Vineet Gupta 提交于
This is the meat of the series which prevents any dcache alias creation by always keeping the U and K mapping of a page congruent. If a mapping already exists, and other tries to access the page, prev one is flushed to physical page (wback+inv) Essentially flush_dcache_page()/copy_user_highpage() create K-mapping of a page, but try to defer flushing, unless U-mapping exist. When page is actually mapped to userspace, update_mmu_cache() flushes the K-mapping (in certain cases this can be optimised out) Additonally flush_cache_mm(), flush_cache_range(), flush_cache_page() handle the puring of stale userspace mappings on exit/munmap... flush_anon_page() handles the existing U-mapping for anon page before kernel reads it via the GUP path. Note that while not complete, this is enough to boot a simple dynamically linked Busybox based rootfs Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
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由 Vineet Gupta 提交于
This preps the low level dcache flush helpers to take vaddr argument in addition to the existing paddr to properly flush the VIPT dcache Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
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- 07 5月, 2013 3 次提交
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由 Vineet Gupta 提交于
flush_dcache_page( ) is MM hook to ensure that a page has consistent views between kernel and userspace. Thus it is called when * kernel writes to a page which at some later point could get mapped to userspace (so kernel mapping needs to be flushed-n-inv) * kernel is about to read from a page with possible userspace mappings (so userspace mappings needs to be made coherent with kernel ones) However for Non aliasing VIPT dcache, any userspace mapping will always be congruent to kernel mapping. Thus d-cache need need not be flushed at all (or delayed indefinitely). The only reason it does need to be flushed is when mapping code pages. Since icache doesn't snoop dcache, those dirty dcache lines need to be written back to memory and icache line invalidated so that icache lines fetch will get the right data. Decent gains on LMBench fork/exec/sh and File I/O micro-benchmarks. (1) FPGA @ 80 MHZ Processor, Processes - times in microseconds - smaller is better ------------------------------------------------------------------------------ Host OS Mhz null null open slct sig sig fork exec sh call I/O stat clos TCP inst hndl proc proc proc --------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- 3.9-rc6-a Linux 3.9.0-r 80 4.79 8.72 66.7 116. 239. 8.39 30.4 4798 14.K 34.K 3.9-rc6-b Linux 3.9.0-r 80 4.79 8.62 65.4 111. 239. 8.35 29.0 3995 12.K 30.K 3.9-rc7-c Linux 3.9.0-r 80 4.79 9.00 66.1 106. 239. 8.61 30.4 2858 10.K 24.K ^^^^ ^^^^ ^^^ File & VM system latencies in microseconds - smaller is better ------------------------------------------------------------------------------- Host OS 0K File 10K File Mmap Prot Page 100fd Create Delete Create Delete Latency Fault Fault selct --------- ------------- ------ ------ ------ ------ ------- ----- ------- ----- 3.9-rc6-a Linux 3.9.0-r 317.8 204.2 1122.3 375.1 3522.0 4.288 20.7 126.8 3.9-rc6-b Linux 3.9.0-r 298.7 223.0 1141.6 367.8 3531.0 4.866 20.9 126.4 3.9-rc7-c Linux 3.9.0-r 278.4 179.2 862.1 339.3 3705.0 3.223 20.3 126.6 ^^^^^ ^^^^^ ^^^^^ ^^^^ (2) Customer Silicon @ 500 MHz (166 MHz mem) ------------------------------------------------------------------------------ Host OS Mhz null null open slct sig sig fork exec sh call I/O stat clos TCP inst hndl proc proc proc --------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- abilis-ba Linux 3.9.0-r 497 0.71 1.38 4.58 12.0 35.5 1.40 3.89 2070 5525 13.K abilis-ca Linux 3.9.0-r 497 0.71 1.40 4.61 11.8 35.6 1.37 3.92 1411 4317 10.K ^^^^ ^^^^ ^^^ Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
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由 Vineet Gupta 提交于
Now that we have same helper used for all icache invalidates (i.e. vaddr+paddr based exact line invalidate), consolidate the open coded calls into one place. Also rename flush_icache_range_vaddr => __sync_icache_dcache Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
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由 Vineet Gupta 提交于
ARC icache doesn't snoop dcache thus executable pages need to be made coherent before mapping into userspace in flush_icache_page(). However ARC700 CDU (hardware cache flush module) requires both vaddr (index in cache) as well as paddr (tag match) to correctly identify a line in the VIPT cache. A typical ARC700 SoC has aliasing icache, thus the paddr only based flush_icache_page() API couldn't be implemented efficiently. It had to loop thru all possible alias indexes and perform the invalidate operation (ofcourse the cache op would only succeed at the index(es) where tag matches - typically only 1, but the cost of visiting all the cache-bins needs to paid nevertheless). Turns out however that the vaddr (along with paddr) is available in update_mmu_cache() hence better suits ARC icache flush semantics. With both vaddr+paddr, exactly one flush operation per line is done. Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
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- 16 2月, 2013 1 次提交
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由 Vineet Gupta 提交于
* ARC700 has VIPT L1 Caches * Caches don't snoop and are not coherent * Given the PAGE_SIZE and Cache associativity, we don't support aliasing D$ configurations (yet), but do allow aliasing I$ configs Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
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