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| author |   Marc Zyngier <marc.zyngier@arm.com> | 2017-07-21 18:15:27 +0100 |
|---|---|---|
| committer |   Will Deacon <will.deacon@arm.com> | 2017-08-01 12:14:06 +0100 |
| commit | c6f97add0f2ac83b98b06dbdda58fa47638ae7b0 (patch) | |
| tree | c8cb6bd8f2298b13a329c0d5c9fb6507614ae783 /arch | |
| parent | Linux 4.13-rc3 (diff) | |
| download | linux-dev-c6f97add0f2ac83b98b06dbdda58fa47638ae7b0.tar.xz linux-dev-c6f97add0f2ac83b98b06dbdda58fa47638ae7b0.zip | |
arm64: Use arch_timer_get_rate when trapping CNTFRQ_EL0
In an ideal world, CNTFRQ_EL0 always contains the timer frequency
for the kernel to use. Sadly, we get quite a few broken systems
where the firmware authors cannot be bothered to program that
register on all CPUs, and rely on DT to provide that frequency.
So when trapping CNTFRQ_EL0, make sure to return the actual rate
(as known by the kernel), and not CNTFRQ_EL0.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/kernel/traps.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index d48f47080213..8a62648848e5 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -523,7 +523,7 @@ static void cntfrq_read_handler(unsigned int esr, struct pt_regs *regs) { int rt = (esr & ESR_ELx_SYS64_ISS_RT_MASK) >> ESR_ELx_SYS64_ISS_RT_SHIFT; - pt_regs_write_reg(regs, rt, read_sysreg(cntfrq_el0)); + pt_regs_write_reg(regs, rt, arch_timer_get_rate()); regs->pc += 4; } |