diff options
| author | Andrey Petrov <andrey.petrov@intel.com> | 2016-04-04 16:10:40 -0700 |
|---|---|---|
| committer | Aaron Durbin <adurbin@chromium.org> | 2016-04-13 16:08:09 +0200 |
| commit | 28c78abaf72b591092c7ec586e4e42492f49082e (patch) | |
| tree | 68d5e73a5834fd77cbd1dfcea9ab2b79e99cb82a /src/soc/intel/apollolake | |
| parent | 108cd0e16d072bef918a3edac2a0e2703f47daba (diff) | |
soc/intel/apollolake: Reserve IMRs (Isolated Memory Regions)
Certain security features on the platform use IMRs. Unfortunately
this memory is unusable for OS or firware. This patch marks IMR
regions as unusable.
Change-Id: I4803c41c699a9cb3349de2b7e0910a0a37cf8e59
Signed-off-by: Andrey Petrov <andrey.petrov@intel.com>
Reviewed-on: https://review.coreboot.org/14245
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
Diffstat (limited to 'src/soc/intel/apollolake')
| -rw-r--r-- | src/soc/intel/apollolake/include/soc/northbridge.h | 7 | ||||
| -rw-r--r-- | src/soc/intel/apollolake/northbridge.c | 47 |
2 files changed, 53 insertions, 1 deletions
diff --git a/src/soc/intel/apollolake/include/soc/northbridge.h b/src/soc/intel/apollolake/include/soc/northbridge.h index 4a071cb788..b68bc933e9 100644 --- a/src/soc/intel/apollolake/include/soc/northbridge.h +++ b/src/soc/intel/apollolake/include/soc/northbridge.h @@ -23,4 +23,11 @@ #define TOLUD 0xbc /* Top of Low Used Memory */ #define TOUUD 0xa8 /* Top of Upper Usable DRAM */ +/* IMR registers are found under MCHBAR. */ +#define MCHBAR_IMR0BASE 0x6870 +#define MCHBAR_IMR0MASK 0x6874 +#define MCH_IMR_PITCH 0x20 +#define MCH_NUM_IMRS 20 + + #endif /* _SOC_APOLLOLAKE_NORTHBRIDGE_H_ */ diff --git a/src/soc/intel/apollolake/northbridge.c b/src/soc/intel/apollolake/northbridge.c index 7d29c9ed45..1a46b61ea9 100644 --- a/src/soc/intel/apollolake/northbridge.c +++ b/src/soc/intel/apollolake/northbridge.c @@ -43,6 +43,47 @@ static int mc_add_fixed_mmio_resources(device_t dev, int index) return index; } +static bool is_imr_enabled(uint32_t imr_base_reg) +{ + return !!(imr_base_reg & (1 << 31)); +} + +static void imr_resource(device_t dev, int idx, uint32_t base, uint32_t mask) +{ + uint32_t base_k, size_k; + /* Bits 28:0 encode the base address bits 38:10, hence the KiB unit. */ + base_k = (base & 0x0fffffff); + /* Bits 28:0 encode the AND mask used for comparison, in KiB. */ + size_k = ((~mask & 0x0fffffff) + 1); + /* + * IMRs sit in lower DRAM. Mark them cacheable, otherwise we run + * out of MTRRs. Memory reserved by IMRs is not usable for host + * so mark it reserved. + */ + reserved_ram_resource(dev, idx, base_k, size_k); +} + +static int mc_add_imr_resources(device_t dev, int index) +{ + uint8_t *mchbar; + size_t i, imr_offset; + uint32_t base, mask; + + mchbar = (void *)(ALIGN_DOWN(get_bar(dev, MCHBAR), 32*KiB)); + + for (i = 0; i < MCH_NUM_IMRS; i ++) { + imr_offset = i * MCH_IMR_PITCH; + base = read32(mchbar + imr_offset + MCHBAR_IMR0BASE); + mask = read32(mchbar + imr_offset + MCHBAR_IMR0MASK); + + if (is_imr_enabled(base)) { + imr_resource(dev, index++, base, mask); + } + } + + return index; +} + static int mc_add_dram_resources(device_t dev, int index) { @@ -99,7 +140,11 @@ static void northbridge_read_resources(device_t dev) index = mc_add_fixed_mmio_resources(dev, index); /* Calculate and add DRAM resources. */ - mc_add_dram_resources(dev, index); + index = mc_add_dram_resources(dev, index); + + /* Add the isolated memory ranges (IMRs). */ + mc_add_imr_resources(dev, index); + } static struct device_operations northbridge_ops = { |