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Message-Id: <1458175619-32206-3-git-send-email-toshi.kani@hpe.com>
Date: Wed, 16 Mar 2016 18:46:57 -0600
From: Toshi Kani <toshi.kani@....com>
To: mingo@...nel.org, bp@...e.de, hpa@...or.com, tglx@...utronix.de
Cc: mcgrof@...e.com, jgross@...e.com, paul.gortmaker@...driver.com,
konrad.wilk@...cle.com, elliott@....com, x86@...nel.org,
xen-devel@...ts.xenproject.org, linux-kernel@...r.kernel.org,
Toshi Kani <toshi.kani@....com>
Subject: [PATCH v2 4/6] x86/mtrr: Fix PAT init handling when MTRR MSR is disabled
get_mtrr_state() calls pat_init() on BSP even if MTRR is disabled
by its MSR. This causes pat_init() to be called on BSP only since
APs do not call pat_init() when MTRR is disabled. This inconsistency
between BSP and APs leads undefined behavior.
Move BSP's PAT init code from get_mtrr_state() to mtrr_bp_pat_init().
Change mtrr_bp_init() to call mtrr_bp_pat_init() if MTRR is enabled.
This keeps BSP's calling condition to pat_init() consistent with AP's,
mtrr_ap_init() and mtrr_aps_init().
Signed-off-by: Toshi Kani <toshi.kani@....com>
Cc: Borislav Petkov <bp@...e.de>
Cc: Luis R. Rodriguez <mcgrof@...e.com>
Cc: Juergen Gross <jgross@...e.com>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
---
arch/x86/kernel/cpu/mtrr/generic.c | 24 ++++++++++++++----------
arch/x86/kernel/cpu/mtrr/main.c | 3 +++
arch/x86/kernel/cpu/mtrr/mtrr.h | 1 +
3 files changed, 18 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index fcbcb2f..a9d2e54 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -444,11 +444,24 @@ static void __init print_mtrr_state(void)
pr_debug("TOM2: %016llx aka %lldM\n", mtrr_tom2, mtrr_tom2>>20);
}
+/* PAT setup for BP. We need to go through sync steps here */
+void __init mtrr_bp_pat_init(void)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ prepare_set();
+
+ pat_init();
+
+ post_set();
+ local_irq_restore(flags);
+}
+
/* Grab all of the MTRR state for this CPU into *state */
bool __init get_mtrr_state(void)
{
struct mtrr_var_range *vrs;
- unsigned long flags;
unsigned lo, dummy;
unsigned int i;
@@ -481,15 +494,6 @@ bool __init get_mtrr_state(void)
mtrr_state_set = 1;
- /* PAT setup for BP. We need to go through sync steps here */
- local_irq_save(flags);
- prepare_set();
-
- pat_init();
-
- post_set();
- local_irq_restore(flags);
-
return !!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED);
}
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 2d7d8d7..6186ff4 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -752,6 +752,9 @@ void __init mtrr_bp_init(void)
/* BIOS may override */
__mtrr_enabled = get_mtrr_state();
+ if (mtrr_enabled())
+ mtrr_bp_pat_init();
+
if (mtrr_cleanup(phys_addr)) {
changed_by_mtrr_cleanup = 1;
mtrr_if->set_all();
diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.h b/arch/x86/kernel/cpu/mtrr/mtrr.h
index 951884d..6c7ced0 100644
--- a/arch/x86/kernel/cpu/mtrr/mtrr.h
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.h
@@ -52,6 +52,7 @@ void set_mtrr_prepare_save(struct set_mtrr_context *ctxt);
void fill_mtrr_var_range(unsigned int index,
u32 base_lo, u32 base_hi, u32 mask_lo, u32 mask_hi);
bool get_mtrr_state(void);
+void mtrr_bp_pat_init(void);
extern void set_mtrr_ops(const struct mtrr_ops *ops);
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