Andrey Petrov (andrey.petrov@intel.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/15453
-gerrit
commit aa79c97f8125715ab85a29d96e6e1065b90203bd Author: Andrey Petrov andrey.petrov@intel.com Date: Mon Jun 27 15:21:26 2016 -0700
WIP: soc/intel/apollolake: Handle CAR sizes other than 1MiB
Since whole L2 (1MiB) is not used, it is possible to shrink CAR size to 768 KiB. Since 768 KiB is not power of two, 2 MTRRs are used to setup it. This is a part of preparation for CQOS enabling.
BUG=chrome-os-partner:51959
Change-Id: I56326a1790df202a0e428e092dd90286c58763c5 Signed-off-by: Andrey Petrov andrey.petrov@intel.com --- src/soc/intel/apollolake/Kconfig | 2 +- src/soc/intel/apollolake/bootblock/cache_as_ram.S | 27 +++++++++++++++++++++++ 2 files changed, 28 insertions(+), 1 deletion(-)
diff --git a/src/soc/intel/apollolake/Kconfig b/src/soc/intel/apollolake/Kconfig index 0745679..3c0b588 100644 --- a/src/soc/intel/apollolake/Kconfig +++ b/src/soc/intel/apollolake/Kconfig @@ -94,7 +94,7 @@ config DCACHE_RAM_BASE
config DCACHE_RAM_SIZE hex "Length in bytes of cache-as-RAM" - default 0x100000 + default 0xc0000 help The size of the cache-as-ram region required during bootblock and/or romstage. diff --git a/src/soc/intel/apollolake/bootblock/cache_as_ram.S b/src/soc/intel/apollolake/bootblock/cache_as_ram.S index 8647206..eee458d 100644 --- a/src/soc/intel/apollolake/bootblock/cache_as_ram.S +++ b/src/soc/intel/apollolake/bootblock/cache_as_ram.S @@ -17,6 +17,7 @@ */
#include <device/pci_def.h> +#include <commonlib/helpers.h> #include <cpu/x86/mtrr.h> #include <cpu/x86/cache.h> #include <cpu/x86/cr.h> @@ -70,6 +71,7 @@ clear_var_mtrr:
post_code(0x24)
+#if ((CONFIG_DCACHE_RAM_SIZE & (CONFIG_DCACHE_RAM_SIZE - 1)) == 0) /* Configure CAR region as write-back (WB) */ mov $MTRR_PHYS_BASE(0), %ecx mov $CONFIG_DCACHE_RAM_BASE, %eax @@ -82,6 +84,31 @@ clear_var_mtrr: mov $~(CONFIG_DCACHE_RAM_SIZE - 1), %eax /* size mask */ or $MTRR_PHYS_MASK_VALID, %eax wrmsr +#elif (CONFIG_DCACHE_RAM_SIZE == 768 * KiB) /* 768 KiB */ + mov $MTRR_PHYS_BASE(0), %ecx + mov $CONFIG_DCACHE_RAM_BASE, %eax + or $MTRR_TYPE_WRBACK, %eax + xor %edx,%edx + wrmsr + + mov $MTRR_PHYS_MASK(0), %ecx + mov $~(512 * KiB - 1), %eax /* size mask */ + or $MTRR_PHYS_MASK_VALID, %eax + wrmsr + + mov $MTRR_PHYS_BASE(1), %ecx + mov $(CONFIG_DCACHE_RAM_BASE + 512 * KiB), %eax + or $MTRR_TYPE_WRBACK, %eax + xor %edx,%edx + wrmsr + + mov $MTRR_PHYS_MASK(1), %ecx + mov $~(0x256 * KiB - 1), %eax /* size mask */ + or $MTRR_PHYS_MASK_VALID, %eax + wrmsr +#else +#error "DCACHE_RAM_SIZE is not power of 2, and we don't know how to handle this value" +#endif
post_code(0x25)