x86: Add functions to convert between mtrr size and mask

Rather than repeating the same code in several places, add some
functions which can do the conversion.

Use the cpu_phys_address_size() function to obtain the physical-address
size, since it is more reliable with kvm, where the host CPU may have a
different value from the emulation CPU.

Series-changes: 3
- Add new patch with functions to convert between mtrr size and mask

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/x86/cpu/mtrr.c

@@ -16,6 +16,7 @@
  * since the MTRR registers are sometimes in flux.
  */
 
+#include <cpu.h>
 #include <cpu_func.h>
 #include <log.h>
 #include <sort.h>
@@ -39,6 +40,27 @@ static const char *const mtrr_type_name[MTRR_TYPE_COUNT] = {
 	"Back",
 };
 
+u64 mtrr_to_size(u64 mask)
+{
+	u64 size;
+
+	size = ~mask & ((1ULL << cpu_phys_address_size()) - 1);
+	size |= (1 << 12) - 1;
+	size += 1;
+
+	return size;
+}
+
+u64 mtrr_to_mask(u64 size)
+{
+	u64 mask;
+
+	mask = ~(size - 1);
+	mask &= (1ull << cpu_phys_address_size()) - 1;
+
+	return mask;
+}
+
 /* Prepare to adjust MTRRs */
 void mtrr_open(struct mtrr_state *state, bool do_caches)
 {
@@ -68,11 +90,9 @@ void mtrr_close(struct mtrr_state *state, bool do_caches)
 
 static void set_var_mtrr(uint reg, uint type, uint64_t start, uint64_t size)
 {
-	u64 mask;
+	u64 mask = mtrr_to_mask(size);
 
 	wrmsrl(MTRR_PHYS_BASE_MSR(reg), start | type);
-	mask = ~(size - 1);
-	mask &= (1ULL << CONFIG_CPU_ADDR_BITS) - 1;
 	wrmsrl(MTRR_PHYS_MASK_MSR(reg), mask | MTRR_PHYS_MASK_VALID);
 }
 
@@ -204,8 +224,7 @@ int mtrr_add_request(int type, uint64_t start, uint64_t size)
 	req->size = size;
 	debug("%d: type=%d, %08llx  %08llx\n", gd->arch.mtrr_req_count - 1,
 	      req->type, req->start, req->size);
-	mask = ~(req->size - 1);
-	mask &= (1ULL << CONFIG_CPU_ADDR_BITS) - 1;
+	mask = mtrr_to_mask(req->size);
 	mask |= MTRR_PHYS_MASK_VALID;
 	debug("   %016llx %016llx\n", req->start | req->type, mask);
 
@@ -360,9 +379,7 @@ int mtrr_list(int reg_count, int cpu_select)
 
 		base = info.mtrr[i].base;
 		mask = info.mtrr[i].mask;
-		size = ~mask & ((1ULL << CONFIG_CPU_ADDR_BITS) - 1);
-		size |= (1 << 12) - 1;
-		size += 1;
+		size = mtrr_to_size(mask);
 		valid = mask & MTRR_PHYS_MASK_VALID;
 		type = mtrr_type_name[base & MTRR_BASE_TYPE_MASK];
 		printf("%d   %-5s %-12s %016llx %016llx %016llx\n", i,

arch/x86/include/asm/mtrr.h

@@ -90,6 +90,22 @@ struct mtrr_info {
 	struct mtrr mtrr[MTRR_MAX_COUNT];
 };
 
+/**
+ * mtrr_to_size() - Convert a mask to a size value
+ *
+ * @mask: Value of the mask register
+ * Return: associated size
+ */
+u64 mtrr_to_size(u64 mask);
+
+/**
+ * mtrr_to_mask() - Convert a size to a mask value
+ *
+ * @size: Value of the size register
+ * Return: associated mask, without MTRR_PHYS_MASK_VALID
+ */
+u64 mtrr_to_mask(u64 size);
+
 /**
  * mtrr_open() - Prepare to adjust MTRRs
  *

cmd/x86/mtrr.c

@@ -14,7 +14,7 @@ static int do_mtrr_set(int cpu_select, uint reg, int argc, char *const argv[])
 {
 	const char *typename = argv[0];
 	uint32_t start, size;
-	uint64_t base, mask;
+	u64 base, mask;
 	int type = -1;
 	bool valid;
 	int ret;
@@ -31,8 +31,7 @@ static int do_mtrr_set(int cpu_select, uint reg, int argc, char *const argv[])
 
 	base = start | type;
 	valid = native_read_msr(MTRR_PHYS_MASK_MSR(reg)) & MTRR_PHYS_MASK_VALID;
-	mask = ~((uint64_t)size - 1);
-	mask &= (1ULL << CONFIG_CPU_ADDR_BITS) - 1;
+	mask = mtrr_to_mask(size);
 	if (valid)
 		mask |= MTRR_PHYS_MASK_VALID;