@@ -546,9 +546,14 @@ CPU_LE( movk x0, #0x30d0, lsl #16 ) // Clear EE and E0E on LE systems
#endif
/* EL2 debug */
+ mrs x0, id_aa64dfr0_el1 // Check ID_AA64DFR0_EL1 PMUVer
+ sbfx x0, x0, #8, #4
+ cmp x0, #1
+ b.lt 4f // Skip if no PMU present
mrs x0, pmcr_el0 // Disable debug access traps
ubfx x0, x0, #11, #5 // to EL2 and allow access to
msr mdcr_el2, x0 // all PMU counters from EL1
+4:
/* Stage-2 translation */
msr vttbr_el2, xzr
@@ -52,3 +52,15 @@
mov \reg, #4 // bytes per word
lsl \reg, \reg, \tmp // actual cache line size
.endm
+
+/*
+ * reset_pmuserenr_el0 - reset PMUSERENR_EL0 if PMUv3 present
+ */
+ .macro reset_pmuserenr_el0, tmpreg
+ mrs \tmpreg, id_aa64dfr0_el1 // Check ID_AA64DFR0_EL1 PMUVer
+ sbfx \tmpreg, \tmpreg, #8, #4
+ cmp \tmpreg, #1 // Skip if no PMU present
+ b.lt 9000f
+ msr pmuserenr_el0, xzr // Disable PMU access from EL0
+9000:
+ .endm
@@ -164,7 +164,7 @@ ENTRY(cpu_do_resume)
*/
ubfx x11, x11, #1, #1
msr oslar_el1, x11
- msr pmuserenr_el0, xzr // Disable PMU access from EL0
+ reset_pmuserenr_el0 x0 // Disable PMU access from EL0
mov x0, x12
dsb nsh // Make sure local tlb invalidation completed
isb
@@ -204,7 +204,7 @@ ENTRY(__cpu_setup)
msr cpacr_el1, x0 // Enable FP/ASIMD
mov x0, #1 << 12 // Reset mdscr_el1 and disable
msr mdscr_el1, x0 // access to the DCC from EL0
- msr pmuserenr_el0, xzr // Disable PMU access from EL0
+ reset_pmuserenr_el0 x0 // Disable PMU access from EL0
/*
* Memory region attributes for LPAE:
*
This is a note to let you know that I have just added a patch titled arm64: kernel: fix architected PMU registers unconditional access to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.8-ckt15. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 29e6631f2a8b333f408e891c5df6c74b8c81c7d4 Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Date: Wed, 13 Jan 2016 14:50:03 +0000 Subject: arm64: kernel: fix architected PMU registers unconditional access commit f436b2ac90a095746beb6729b8ee8ed87c9eaede upstream. The Performance Monitors extension is an optional feature of the AArch64 architecture, therefore, in order to access Performance Monitors registers safely, the kernel should detect the architected PMU unit presence through the ID_AA64DFR0_EL1 register PMUVer field before accessing them. This patch implements a guard by reading the ID_AA64DFR0_EL1 register PMUVer field to detect the architected PMU presence and prevent accessing PMU system registers if the Performance Monitors extension is not implemented in the core. Cc: Peter Maydell <peter.maydell@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Fixes: 60792ad349f3 ("arm64: kernel: enforce pmuserenr_el0 initialization and restore") Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- arch/arm64/kernel/head.S | 5 +++++ arch/arm64/mm/proc-macros.S | 12 ++++++++++++ arch/arm64/mm/proc.S | 4 ++-- 3 files changed, 19 insertions(+), 2 deletions(-) -- 1.9.1