X-Received: by 10.194.236.196 with SMTP id uw4mr4486656wjc.5.1426282807031; Fri, 13 Mar 2015 14:40:07 -0700 (PDT) X-BeenThere: linux.kernel@googlegroups.com Received: by 10.180.83.9 with SMTP id m9ls236404wiy.16.gmail; Fri, 13 Mar 2015 14:40:02 -0700 (PDT) X-Received: by 10.180.80.132 with SMTP id r4mr4270499wix.4.1426282802048; Fri, 13 Mar 2015 14:40:02 -0700 (PDT) MIME-Version: 1.0 Path: vt8ni24025lbb.0!nntp.google.com!goblin3!goblin2!goblin.stu.neva.ru!aioe.org!bofh.it!news.nic.it!robomod From: Toshi Kani Newsgroups: linux.kernel Subject: [PATCH v3 2/5] mtrr, x86: Fix MTRR lookup to handle inclusive entry Date: Fri, 13 Mar 2015 22:40:01 +0100 Message-ID: References: X-Original-To: ak...@linux-foundation.org, h...@zytor.com, tg...@linutronix.de, mi...@redhat.com X-Mailer: git-send-email 1.9.3 Sender: rob...@news.nic.it List-ID: X-Mailing-List: linux-...@vger.kernel.org Approved: rob...@news.nic.it Lines: 65 Organization: linux.* mail to news gateway X-Original-Cc: linu...@kvack.org, x...@kernel.org, linux-...@vger.kernel.org, dave....@intel.com, Ell...@hp.com, peb...@tiscali.nl, Toshi Kani X-Original-Date: Fri, 13 Mar 2015 15:33:38 -0600 X-Original-Message-ID: <1426282421-25385-3-git...@hp.com> X-Original-References: <1426282421-25385-1-git...@hp.com> X-Original-Sender: linux-ker...@vger.kernel.org When an MTRR entry is inclusive to a requested range, i.e. the start and end of the request are not within the MTRR entry range but the range contains the MTRR entry entirely, __mtrr_type_lookup() ignores such a case because both start_state and end_state are set to zero. This patch fixes the issue by adding a new flag, 'inclusive', to detect the case. This case is then handled in the same way as (!start_state && end_state). Signed-off-by: Toshi Kani --- arch/x86/kernel/cpu/mtrr/generic.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index 7d74f7b..a82e370 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -154,7 +154,7 @@ static u8 __mtrr_type_lookup(u64 start, u64 end, u64 *partial_end, int *repeat) prev_match = 0xFF; 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; @@ -166,15 +166,16 @@ static u8 __mtrr_type_lookup(u64 start, u64 end, u64 *partial_end, int *repeat) 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 or inclusive:1 + * (start:mtrr_start) (mtrr_start: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 @@ -195,7 +196,7 @@ static u8 __mtrr_type_lookup(u64 start, u64 end, u64 *partial_end, int *repeat) *repeat = 1; } - if ((start & mask) != (base & mask)) + if (!start_state) continue; curr_match = mtrr_state.var_ranges[i].base_lo & 0xff; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majo...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/