return 0;
}
-/*
- * Error/Semi-error returns:
- * 0xFF - when MTRR is not enabled
- * *repeat == 1 implies [start:end] spanned across MTRR range and type returned
- * corresponds only to [start:*partial_end].
- * Caller has to lookup again for [*partial_end:end].
+/**
+ * mtrr_type_lookup_fixed - look up memory type in MTRR fixed entries
+ *
+ * Return the MTRR fixed memory type of 'start'.
+ *
+ * MTRR fixed entries are divided into the following ways:
+ * 0x00000 - 0x7FFFF : This range is divided into eight 64KB sub-ranges
+ * 0x80000 - 0xBFFFF : This range is divided into sixteen 16KB sub-ranges
+ * 0xC0000 - 0xFFFFF : This range is divided into sixty-four 4KB sub-ranges
+ *
+ * Return Values:
+ * MTRR_TYPE_(type) - Matched memory type
+ * MTRR_TYPE_INVALID - Unmatched
+ */
+static u8 mtrr_type_lookup_fixed(u64 start, u64 end)
+{
+ int idx;
+
+ if (start >= 0x100000)
+ return MTRR_TYPE_INVALID;
+
+ /* 0x0 - 0x7FFFF */
+ if (start < 0x80000) {
+ idx = 0;
+ idx += (start >> 16);
+ return mtrr_state.fixed_ranges[idx];
+ /* 0x80000 - 0xBFFFF */
+ } else if (start < 0xC0000) {
+ idx = 1 * 8;
+ idx += ((start - 0x80000) >> 14);
+ return mtrr_state.fixed_ranges[idx];
+ }
+
+ /* 0xC0000 - 0xFFFFF */
+ idx = 3 * 8;
+ idx += ((start - 0xC0000) >> 12);
+ return mtrr_state.fixed_ranges[idx];
+}
+
+/**
+ * mtrr_type_lookup_variable - look up memory type in MTRR variable entries
+ *
+ * Return Value:
+ * MTRR_TYPE_(type) - Matched memory type or default memory type (unmatched)
+ *
+ * Output Arguments:
+ * repeat - Set to 1 when [start:end] spanned across MTRR range and type
+ * returned corresponds only to [start:*partial_end]. Caller has
+ * to lookup again for [*partial_end:end].
+ *
+ * uniform - Set to 1 when an MTRR covers the region uniformly, i.e. the
+ * region is fully covered by a single MTRR entry or the default
+ * type.
*/
-static u8 __mtrr_type_lookup(u64 start, u64 end, u64 *partial_end, int *repeat)
+static u8 mtrr_type_lookup_variable(u64 start, u64 end, u64 *partial_end,
+ int *repeat, u8 *uniform)
{
int i;
u64 base, mask;
u8 prev_match, curr_match;
*repeat = 0;
- if (!mtrr_state_set)
- return 0xFF;
-
- if (!mtrr_state.enabled)
- return 0xFF;
+ *uniform = 1;
- /* Make end inclusive end, instead of exclusive */
+ /* Make end inclusive instead of exclusive */
end--;
- /* Look in fixed ranges. Just return the type as per start */
- if (mtrr_state.have_fixed && (start < 0x100000)) {
- int idx;
-
- if (start < 0x80000) {
- idx = 0;
- idx += (start >> 16);
- return mtrr_state.fixed_ranges[idx];
- } else if (start < 0xC0000) {
- idx = 1 * 8;
- idx += ((start - 0x80000) >> 14);
- return mtrr_state.fixed_ranges[idx];
- } else if (start < 0x1000000) {
- idx = 3 * 8;
- idx += ((start - 0xC0000) >> 12);
- return mtrr_state.fixed_ranges[idx];
- }
- }
-
- /*
- * Look in variable ranges
- * Look of multiple ranges matching this address and pick type
- * as per MTRR precedence
- */
- if (!(mtrr_state.enabled & 2))
- return mtrr_state.def_type;
-
- prev_match = 0xFF;
+ prev_match = MTRR_TYPE_INVALID;
for (i = 0; i < num_var_ranges; ++i) {
- unsigned short start_state, end_state;
+ unsigned short start_state, end_state, inclusive;
if (!(mtrr_state.var_ranges[i].mask_lo & (1 << 11)))
continue;
start_state = ((start & mask) == (base & mask));
end_state = ((end & mask) == (base & mask));
+ inclusive = ((start < base) && (end > base));
- if (start_state != end_state) {
+ if ((start_state != end_state) || inclusive) {
/*
* We have start:end spanning across an MTRR.
- * We split the region into
- * either
- * (start:mtrr_end) (mtrr_end:end)
- * or
- * (start:mtrr_start) (mtrr_start:end)
+ * We split the region into either
+ *
+ * - start_state:1
+ * (start:mtrr_end)(mtrr_end:end)
+ * - end_state:1
+ * (start:mtrr_start)(mtrr_start:end)
+ * - inclusive:1
+ * (start:mtrr_start)(mtrr_start:mtrr_end)(mtrr_end:end)
+ *
* depending on kind of overlap.
- * Return the type for first region and a pointer to
- * the start of second region so that caller will
- * lookup again on the second region.
- * Note: This way we handle multiple overlaps as well.
+ *
+ * Return the type of the first region and a pointer
+ * to the start of next region so that caller will be
+ * advised to lookup again after having adjusted start
+ * and end.
+ *
+ * Note: This way we handle overlaps with multiple
+ * entries and the default type properly.
*/
if (start_state)
*partial_end = base + get_mtrr_size(mask);
end = *partial_end - 1; /* end is inclusive */
*repeat = 1;
+ *uniform = 0;
}
if ((start & mask) != (base & mask))
continue;
curr_match = mtrr_state.var_ranges[i].base_lo & 0xff;
- if (prev_match == 0xFF) {
+ if (prev_match == MTRR_TYPE_INVALID) {
prev_match = curr_match;
continue;
}
+ *uniform = 0;
if (check_type_overlap(&prev_match, &curr_match))
return curr_match;
}
- if (mtrr_tom2) {
- if (start >= (1ULL<<32) && (end < mtrr_tom2))
- return MTRR_TYPE_WRBACK;
- }
-
- if (prev_match != 0xFF)
+ if (prev_match != MTRR_TYPE_INVALID)
return prev_match;
return mtrr_state.def_type;
}
-/*
- * Returns the effective MTRR type for the region
- * Error return:
- * 0xFF - when MTRR is not enabled
+/**
+ * mtrr_type_lookup - look up memory type in MTRR
+ *
+ * Return Values:
+ * MTRR_TYPE_(type) - The effective MTRR type for the region
+ * MTRR_TYPE_INVALID - MTRR is disabled
+ *
+ * Output Argument:
+ * uniform - Set to 1 when an MTRR covers the region uniformly, i.e. the
+ * region is fully covered by a single MTRR entry or the default
+ * type.
*/
-u8 mtrr_type_lookup(u64 start, u64 end)
+u8 mtrr_type_lookup(u64 start, u64 end, u8 *uniform)
{
- u8 type, prev_type;
+ u8 type, prev_type, is_uniform = 1, dummy;
int repeat;
u64 partial_end;
- type = __mtrr_type_lookup(start, end, &partial_end, &repeat);
+ if (!mtrr_state_set)
+ return MTRR_TYPE_INVALID;
+
+ if (!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED))
+ return MTRR_TYPE_INVALID;
+
+ /*
+ * Look up the fixed ranges first, which take priority over
+ * the variable ranges.
+ */
+ if ((start < 0x100000) &&
+ (mtrr_state.have_fixed) &&
+ (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) {
+ is_uniform = 0;
+ type = mtrr_type_lookup_fixed(start, end);
+ goto out;
+ }
+
+ /*
+ * Look up the variable ranges. Look of multiple ranges matching
+ * this address and pick type as per MTRR precedence.
+ */
+ type = mtrr_type_lookup_variable(start, end, &partial_end,
+ &repeat, &is_uniform);
/*
* Common path is with repeat = 0.
* However, we can have cases where [start:end] spans across some
- * MTRR range. Do repeated lookups for that case here.
+ * MTRR ranges and/or the default type. Do repeated lookups for
+ * that case here.
*/
while (repeat) {
prev_type = type;
start = partial_end;
- type = __mtrr_type_lookup(start, end, &partial_end, &repeat);
+ is_uniform = 0;
+ type = mtrr_type_lookup_variable(start, end, &partial_end,
+ &repeat, &dummy);
if (check_type_overlap(&prev_type, &type))
- return type;
+ goto out;
}
+ if (mtrr_tom2 && (start >= (1ULL<<32)) && (end < mtrr_tom2))
+ type = MTRR_TYPE_WRBACK;
+
+out:
+ *uniform = is_uniform;
return type;
}
mtrr_attrib_to_str(mtrr_state.def_type));
if (mtrr_state.have_fixed) {
pr_debug("MTRR fixed ranges %sabled:\n",
- mtrr_state.enabled & 1 ? "en" : "dis");
+ ((mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED) &&
+ (mtrr_state.enabled & MTRR_STATE_MTRR_FIXED_ENABLED)) ?
+ "en" : "dis");
print_fixed(0x00000, 0x10000, mtrr_state.fixed_ranges + 0);
for (i = 0; i < 2; ++i)
print_fixed(0x80000 + i * 0x20000, 0x04000,
print_fixed_last();
}
pr_debug("MTRR variable ranges %sabled:\n",
- mtrr_state.enabled & 2 ? "en" : "dis");
+ mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED ? "en" : "dis");
high_width = (__ffs64(size_or_mask) - (32 - PAGE_SHIFT) + 3) / 4;
for (i = 0; i < num_var_ranges; ++i) {
}
/* Grab all of the MTRR state for this CPU into *state */
-void __init get_mtrr_state(void)
+bool __init get_mtrr_state(void)
{
struct mtrr_var_range *vrs;
unsigned long flags;
post_set();
local_irq_restore(flags);
+
+ return !!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED);
}
/* Some BIOS's are messed up and don't set all MTRRs the same! */
Code Review / kvmfornfv.git / blobdiff