From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.lezcano@linaro.org (Daniel Lezcano) Date: Mon, 24 Apr 2017 11:18:01 +0200 Subject: [PATCH v3 15/18] arm64: arch_timer: Enable CNTVCT_EL0 trap if workaround is enabled In-Reply-To: <58FDC1F5.3000401@huawei.com> References: <20170404171826.25030-1-marc.zyngier@arm.com> <20170404171826.25030-16-marc.zyngier@arm.com> <58FDB05B.6020108@huawei.com> <95ac3477-436a-22ad-80f4-d4bed6c73e1c@arm.com> <493e2b26-96a2-4b92-fd4b-f6f7d5c89fb5@arm.com> <58FDC1F5.3000401@huawei.com> Message-ID: <20170424091801.GB2137@mai> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Apr 24, 2017 at 05:14:29PM +0800, Hanjun Guo wrote: > On 2017/4/24 16:40, Marc Zyngier wrote: > > On 24/04/17 09:25, Lixiaoping (Timmy) wrote: > >> Hi Marc, > >> > >> Sorry about previous email's confidential info. Please forget it. > >> > >> +#define ESR_ELx_SYS64_ISS_SYS_CNTFRQ (ESR_ELx_SYS64_ISS_SYS_VAL(3, 3, 14, 0, 0) | \ > >> + ESR_ELx_SYS64_ISS_DIR_READ) > >> > >> I think (3, 3, 14, 0, 0) should be (3, 3, 0, 14, 0)? > > Thanks for spotting this. I assumed that the sys_reg() and > > SR_ELx_SYS64_ISS_SYS_VAL() macros took their arguments in the same > > order. That would have been too easy... ;-) > > > > Amended patch below, please let me know if it works for you. > > > > Thanks, > > > > M. > > > > >From 4444c86a97c1a487e12c319fdc197c88631d72b5 Mon Sep 17 00:00:00 2001 > > From: Marc Zyngier > > Date: Mon, 24 Apr 2017 09:04:03 +0100 > > Subject: [PATCH] arm64: Add CNTFRQ_EL0 trap handler > > > > We now trap accesses to CNTVCT_EL0 when the counter is broken > > enough to require the kernel to mediate the access. But it > > turns out that some existing userspace (such as OpenMPI) do > > probe for the counter frequency, leading to an UNDEF exception > > as CNTVCT_EL0 and CNTFRQ_EL0 share the same control bit. > > > > The fix is to handle the exception the same way we do for CNTVCT_EL0. > > > > Fixes: a86bd139f2ae ("arm64: arch_timer: Enable CNTVCT_EL0 trap if workaround is enabled") > > Reported-by: Hanjun Guo > > Signed-off-by: Marc Zyngier > > --- > > I tested this patch and the undefined instruction error is gone, I can > get the FREQ in the user space now, thank you very much for the quick > response. > > Tested-by: Hanjun Guo > Reviewed-by: Hanjun Guo Thanks for providing so quickly a fix and test it. -- Daniel -- Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog