diff options
| author | Bin Meng <bmeng.cn@gmail.com> | 2015-01-22 11:29:41 +0800 |
|---|---|---|
| committer | Simon Glass <sjg@chromium.org> | 2015-01-23 17:24:55 -0700 |
| commit | 3b621ccabdccb34891bb58865a9654a09c2b7279 (patch) | |
| tree | 8c9321d4657a4154867bd77d92d4d5dad851dbc3 /arch/x86/cpu/mtrr.c | |
| parent | 49491669065c1c718d8dc0b0ebc151b3d010c17b (diff) | |
x86: Test mtrr support flag before accessing mtrr msr
On some x86 processors (like Intel Quark) the MTRR registers are not
supported. This is reflected by the CPUID (EAX 01H) result EDX[12].
Accessing the MTRR registers on such processors will cause #GP so we
must test the support flag before accessing MTRR MSRs.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Diffstat (limited to 'arch/x86/cpu/mtrr.c')
| -rw-r--r-- | arch/x86/cpu/mtrr.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/cpu/mtrr.c b/arch/x86/cpu/mtrr.c index ac8765f3cf..5d36b3e020 100644 --- a/arch/x86/cpu/mtrr.c +++ b/arch/x86/cpu/mtrr.c @@ -22,6 +22,9 @@ DECLARE_GLOBAL_DATA_PTR; /* Prepare to adjust MTRRs */ void mtrr_open(struct mtrr_state *state) { + if (!gd->arch.has_mtrr) + return; + state->enable_cache = dcache_status(); if (state->enable_cache) @@ -33,6 +36,9 @@ void mtrr_open(struct mtrr_state *state) /* Clean up after adjusting MTRRs, and enable them */ void mtrr_close(struct mtrr_state *state) { + if (!gd->arch.has_mtrr) + return; + wrmsrl(MTRR_DEF_TYPE_MSR, state->deftype | MTRR_DEF_TYPE_EN); if (state->enable_cache) enable_caches(); @@ -45,6 +51,9 @@ int mtrr_commit(bool do_caches) uint64_t mask; int i; + if (!gd->arch.has_mtrr) + return -ENOSYS; + mtrr_open(&state); for (i = 0; i < gd->arch.mtrr_req_count; i++, req++) { mask = ~(req->size - 1); @@ -66,6 +75,9 @@ int mtrr_add_request(int type, uint64_t start, uint64_t size) struct mtrr_request *req; uint64_t mask; + if (!gd->arch.has_mtrr) + return -ENOSYS; + if (gd->arch.mtrr_req_count == MAX_MTRR_REQUESTS) return -ENOSPC; req = &gd->arch.mtrr_req[gd->arch.mtrr_req_count++]; |