[coreboot-gerrit] Patch set updated for coreboot: soc/intel/apollolake: Reserve IMRs (Isolated Memory Regions)
Andrey Petrov (andrey.petrov@intel.com)
gerrit at coreboot.org
Tue Apr 12 22:14:33 CEST 2016
Andrey Petrov (andrey.petrov at intel.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/14245
-gerrit
commit 4dbc78ccbc305983b8929c737952f3d826fb3be7
Author: Andrey Petrov <andrey.petrov at intel.com>
Date: Mon Apr 4 16:10:40 2016 -0700
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 at intel.com>
---
src/soc/intel/apollolake/include/soc/northbridge.h | 7 ++++
src/soc/intel/apollolake/northbridge.c | 43 +++++++++++++++++++++-
2 files changed, 49 insertions(+), 1 deletion(-)
diff --git a/src/soc/intel/apollolake/include/soc/northbridge.h b/src/soc/intel/apollolake/include/soc/northbridge.h
index 4a071cb..b68bc93 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 7d29c9e..6bc00bd 100644
--- a/src/soc/intel/apollolake/northbridge.c
+++ b/src/soc/intel/apollolake/northbridge.c
@@ -43,6 +43,43 @@ 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);
+ /* Cacheable, since IMRs lay in DRAM. Not usable (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 +136,11 @@ 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 = {
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