From b9a4b713f88c111628d3b35d8a695de88ff39ecd Mon Sep 17 00:00:00 2001 From: Gabe Black Date: Sat, 1 Mar 2014 03:27:00 -0800 Subject: nyan: nyan_big: Mark the address range covering the SRAM as cachable. The SRAM is very likely faster than going all the way out to DRAM for data, but I don't think it's part of the cores themselves and won't be as fast as the L1 caches. Enabling caching for this region reduces the time it takes to get to the payload by about 75% when serial output is disabled and the main part of display init is commented out. BUG=chrome-os-partner:25467 TEST=Built and booted on nyan. BRANCH=None Original-Change-Id: I7ff26dea9d50e7d9a76e598e5654488481286b35 Original-Signed-off-by: Gabe Black Original-Reviewed-on: https://chromium-review.googlesource.com/188459 Original-Reviewed-by: Tom Warren Original-Reviewed-by: Hung-Te Lin Original-Reviewed-by: Julius Werner Original-Tested-by: Gabe Black Original-Commit-Queue: Gabe Black (cherry picked from commit ac8b9b30490d511ca1b207af6845d50e08ac130f) Signed-off-by: Marc Jones Change-Id: If79dcd1b116f30b778788ba4fd45d362ff5d8e6e Reviewed-on: http://review.coreboot.org/7407 Tested-by: build bot (Jenkins) Reviewed-by: David Hendricks --- src/mainboard/google/nyan/romstage.c | 6 ++++++ src/mainboard/google/nyan_big/romstage.c | 6 ++++++ 2 files changed, 12 insertions(+) diff --git a/src/mainboard/google/nyan/romstage.c b/src/mainboard/google/nyan/romstage.c index 28827c8d5f..175eb6fc3e 100644 --- a/src/mainboard/google/nyan/romstage.c +++ b/src/mainboard/google/nyan/romstage.c @@ -89,10 +89,16 @@ static void __attribute__((noinline)) romstage(void) u32 dram_size = dram_end - dram_start; mmu_init(); + /* Device memory below DRAM is uncached. */ mmu_config_range(0, dram_start, DCACHE_OFF); + /* SRAM is cached. Round the size up to 2MB, the LPAE page size. */ + mmu_config_range(0x40000000 >> 20, 2, DCACHE_WRITEBACK); + /* DRAM is cached. */ mmu_config_range(dram_start, dram_size, DCACHE_WRITEBACK); + /* A window for DMA is uncached. */ mmu_config_range(CONFIG_DRAM_DMA_START >> 20, CONFIG_DRAM_DMA_SIZE >> 20, DCACHE_OFF); + /* The space above DRAM is uncached. */ if (dram_end < 4096) mmu_config_range(dram_end, 4096 - dram_end, DCACHE_OFF); mmu_disable_range(0, 1); diff --git a/src/mainboard/google/nyan_big/romstage.c b/src/mainboard/google/nyan_big/romstage.c index 0fbe316882..51f5a49264 100644 --- a/src/mainboard/google/nyan_big/romstage.c +++ b/src/mainboard/google/nyan_big/romstage.c @@ -89,10 +89,16 @@ static void __attribute__((noinline)) romstage(void) u32 dram_size = dram_end - dram_start; mmu_init(); + /* Device memory below DRAM is uncached. */ mmu_config_range(0, dram_start, DCACHE_OFF); + /* SRAM is cached. Round the size up to 2MB, the LPAE page size. */ + mmu_config_range(0x40000000 >> 20, 2, DCACHE_WRITEBACK); + /* DRAM is cached. */ mmu_config_range(dram_start, dram_size, DCACHE_WRITEBACK); + /* A window for DMA is uncached. */ mmu_config_range(CONFIG_DRAM_DMA_START >> 20, CONFIG_DRAM_DMA_SIZE >> 20, DCACHE_OFF); + /* The space above DRAM is uncached. */ if (dram_end < 4096) mmu_config_range(dram_end, 4096 - dram_end, DCACHE_OFF); mmu_disable_range(0, 1); -- cgit v1.2.3