Patrick Georgi (pgeorgi@google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9342
-gerrit
commit 193e607da6f88db1238a8530833b5283820c4933 Author: Julius Werner jwerner@chromium.org Date: Wed Oct 15 18:50:45 2014 -0700
rk3288: Add early SRAM mapping
Solving the DACR bug will mean that XN bits suddenly become enforced on non-LPAE systems, and we will no longer be able to execute out of a region mapped DCACHE_OFF. When we enable the MMU in romstage we are still executing out of SRAM, so we would instantly kill ourselves.
Solve this issue by enabling the MMU earlier (in the bootblock) and mapping the SRAM regions as DCACHE_WRITETHROUGH. They should really be DCACHE_WRITEBACK, but it looks like there might be hardware limitations in the Cortex-A12 cache architecture that prevent us from doing so. Write-through mappings are equivalent to normal non-cacheable on the A12 anyway, and by using this attribute we don't need to introduce a new DCACHE_OFF_BUT_WITHOUT_XN_BIT type in our API. (Also, using normal non-cacheable might still have a slight speed advantage over strongly ordered since it should fetch whole cache lines at once if the processor finds enough accesses it can combine.)
CQ-DEPEND=CL:223783 BUG=chrome-os-partner:32118 TEST=None (depends on follow-up CL)
Change-Id: I1e5127421f82177ca11af892b1539538b379625e Signed-off-by: Patrick Georgi pgeorgi@chromium.org Original-Commit-Id: e7b079f4b6a69449f3c7cc18ef0e1704f2006847 Original-Change-Id: I53e827d95acc2db909f1251de78d65e295eceaa7 Original-Signed-off-by: Julius Werner jwerner@chromium.org Original-Reviewed-on: https://chromium-review.googlesource.com/223782 Original-Reviewed-by: Aaron Durbin adurbin@chromium.org --- src/mainboard/google/veyron_pinky/romstage.c | 18 ++++-------------- src/soc/rockchip/rk3288/bootblock.c | 11 +++++++++++ src/soc/rockchip/rk3288/memlayout.ld | 3 ++- 3 files changed, 17 insertions(+), 15 deletions(-)
diff --git a/src/mainboard/google/veyron_pinky/romstage.c b/src/mainboard/google/veyron_pinky/romstage.c index 1d7812b..6f9b9d1 100644 --- a/src/mainboard/google/veyron_pinky/romstage.c +++ b/src/mainboard/google/veyron_pinky/romstage.c @@ -64,10 +64,6 @@ void main(void) uint64_t base_time = timestamp_get(); start_romstage_time = timestamp_get(); #endif - /* used for MMU and CBMEM setup, in MB */ - u32 dram_start_mb = (uintptr_t)_dram/MiB; - u32 dram_size_mb = CONFIG_DRAM_SIZE_MB; - u32 dram_end_mb = dram_start_mb + dram_size_mb;
console_init();
@@ -80,18 +76,12 @@ void main(void) #if CONFIG_COLLECT_TIMESTAMPS after_dram_time = timestamp_get(); #endif - mmu_init(); - /* Device memory below DRAM is uncached. */ - mmu_config_range(0, dram_start_mb, DCACHE_OFF); - /* DRAM is cached. */ - mmu_config_range(dram_start_mb, dram_size_mb, DCACHE_WRITEBACK); - /* A window for DMA is uncached. */ + + /* Now that DRAM is up, add mappings for it and DMA coherency buffer. */ + mmu_config_range((uintptr_t)_dram/MiB, + CONFIG_DRAM_SIZE_MB, DCACHE_WRITEBACK); mmu_config_range((uintptr_t)_dma_coherent/MiB, _dma_coherent_size/MiB, DCACHE_OFF); - /* The space above DRAM is uncached. */ - if (dram_end_mb < 4096) - mmu_config_range(dram_end_mb, 4096 - dram_end_mb, DCACHE_OFF); - dcache_mmu_enable();
cbmem_initialize_empty();
diff --git a/src/soc/rockchip/rk3288/bootblock.c b/src/soc/rockchip/rk3288/bootblock.c index eec3456..b2f5bd9 100644 --- a/src/soc/rockchip/rk3288/bootblock.c +++ b/src/soc/rockchip/rk3288/bootblock.c @@ -17,10 +17,12 @@ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
+#include <arch/cache.h> #include <arch/io.h> #include <bootblock_common.h> #include <console/console.h> #include <soc/rockchip/rk3288/grf.h> +#include <symbols.h> #include "addressmap.h" #include "timer.h" #include "clock.h" @@ -41,4 +43,13 @@ static void bootblock_cpu_init(void) }
rkclk_init(); + + mmu_init(); + /* Start with a clean slate. */ + mmu_config_range(0, 4096, DCACHE_OFF); + /* SRAM is tightly wedged between registers, need to use subtables. Map + * write-through as equivalent for non-cacheable without XN on A17. */ + mmu_config_range_kb((uintptr_t)_sram/KiB, + _sram_size/KiB, DCACHE_WRITETHROUGH); + dcache_mmu_enable(); } diff --git a/src/soc/rockchip/rk3288/memlayout.ld b/src/soc/rockchip/rk3288/memlayout.ld index 6faec63..2ddb6a6 100644 --- a/src/soc/rockchip/rk3288/memlayout.ld +++ b/src/soc/rockchip/rk3288/memlayout.ld @@ -34,7 +34,8 @@ SECTIONS
SRAM_START(0xFF700000) TTB(0xFF700000, 16K) - BOOTBLOCK(0xFF704004, 16K - 4) + BOOTBLOCK(0xFF704004, 15K - 4) + TTB_SUBTABLES(0xFF707c00, 1K) VBOOT2_WORK(0xFF708000, 16K) OVERLAP_VERSTAGE_ROMSTAGE(0xFF70C000, 40K) PRERAM_CBFS_CACHE(0xFF716000, 4K)
-
Patrick Georgi