return type1;
}
-/*
- * Check and return the effective type for MTRR-MTRR type overlap.
- * Returns true if the effective type is UNCACHEABLE, else returns false
- */
-static bool check_type_overlap(u8 *prev, u8 *curr)
-{
- *prev = *curr = get_effective_type(*curr, *prev);
-
- return *prev == MTRR_TYPE_UNCACHABLE;
-}
-
-/**
- * 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_variable(u64 start, u64 end, u64 *partial_end,
- int *repeat, u8 *uniform)
-{
- int i;
- u64 base, mask;
- u8 prev_match, curr_match;
-
- *repeat = 0;
- *uniform = 1;
-
- prev_match = MTRR_TYPE_INVALID;
- for (i = 0; i < num_var_ranges; ++i) {
- unsigned short start_state, end_state, inclusive;
-
- if (!(mtrr_state.var_ranges[i].mask_lo & MTRR_PHYSMASK_V))
- continue;
-
- base = (((u64)mtrr_state.var_ranges[i].base_hi) << 32) +
- (mtrr_state.var_ranges[i].base_lo & PAGE_MASK);
- mask = (((u64)mtrr_state.var_ranges[i].mask_hi) << 32) +
- (mtrr_state.var_ranges[i].mask_lo & PAGE_MASK);
-
- start_state = ((start & mask) == (base & mask));
- end_state = ((end & mask) == (base & mask));
- inclusive = ((start < base) && (end > base));
-
- if ((start_state != end_state) || inclusive) {
- /*
- * We have start:end spanning across an MTRR.
- * 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 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);
- else
- *partial_end = base;
-
- if (unlikely(*partial_end <= start)) {
- WARN_ON(1);
- *partial_end = start + PAGE_SIZE;
- }
-
- 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 & MTRR_PHYSBASE_TYPE;
- 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 (prev_match != MTRR_TYPE_INVALID)
- return prev_match;
-
- return mtrr_state.def_type;
-}
-
static void rm_map_entry_at(int idx)
{
cache_map_n--;
mtrr_state_set = 1;
}
+static u8 type_merge(u8 type, u8 new_type, u8 *uniform)
+{
+ u8 effective_type;
+
+ if (type == MTRR_TYPE_INVALID)
+ return new_type;
+
+ effective_type = get_effective_type(type, new_type);
+ if (type != effective_type)
+ *uniform = 0;
+
+ return effective_type;
+}
+
/**
* mtrr_type_lookup - look up memory type in MTRR
*
* 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.
+ * uniform - Set to 1 when the returned MTRR type is valid for the whole
+ * region, set to 0 else.
*/
u8 mtrr_type_lookup(u64 start, u64 end, u8 *uniform)
{
- u8 type, prev_type, is_uniform = 1, dummy;
- int repeat;
- u64 partial_end;
-
- /* Make end inclusive instead of exclusive */
- end--;
+ u8 type = MTRR_TYPE_INVALID;
+ unsigned int i;
- if (!mtrr_state_set)
+ if (!mtrr_state_set) {
+ /* Uniformity is unknown. */
+ *uniform = 0;
return MTRR_TYPE_INVALID;
+ }
+
+ *uniform = 1;
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;
- }
+ for (i = 0; i < cache_map_n && start < end; i++) {
+ /* Region after current map entry? -> continue with next one. */
+ if (start >= cache_map[i].end)
+ continue;
- /*
- * 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);
+ /* Start of region not covered by current map entry? */
+ if (start < cache_map[i].start) {
+ /* At least some part of region has default type. */
+ type = type_merge(type, mtrr_state.def_type, uniform);
+ /* End of region not covered, too? -> lookup done. */
+ if (end <= cache_map[i].start)
+ return type;
+ }
- /*
- * Common path is with repeat = 0.
- * However, we can have cases where [start:end] spans across some
- * MTRR ranges and/or the default type. Do repeated lookups for
- * that case here.
- */
- while (repeat) {
- prev_type = type;
- start = partial_end;
- is_uniform = 0;
- type = mtrr_type_lookup_variable(start, end, &partial_end,
- &repeat, &dummy);
-
- if (check_type_overlap(&prev_type, &type))
- goto out;
+ /* At least part of region covered by map entry. */
+ type = type_merge(type, cache_map[i].type, uniform);
+
+ start = cache_map[i].end;
}
- if (mtrr_tom2 && (start >= (1ULL<<32)) && (end < mtrr_tom2))
- type = MTRR_TYPE_WRBACK;
+ /* End of region past last entry in map? -> use default type. */
+ if (start < end)
+ type = type_merge(type, mtrr_state.def_type, uniform);
-out:
- *uniform = is_uniform;
return type;
}