| Message ID | 1443518829-19744-1-git-send-email-ian.campbell@citrix.com |
|---|---|
| State | Accepted |
| Delegated to: | Tom Rini |
| Headers | show |
On Tue, Sep 29, 2015 at 10:27:09AM +0100, Ian Campbell wrote: > We run 4 Arndale boards in our automated test framework, they have > been running quite happily for quite some time using a Debian Wheezy > userspace. > > However when upgrading to a Debian Jessie we started seeing frequent > segmentation faults from gcc when building the kernel, to the extent > that it is unable to successfully build the kernel twice in a row, and > often fails on the first attempt. > > Searching around I found https://bugs.launchpad.net/arndale/+bug/1081417 > which pointed towards http://www.spinics.net/lists/kvm-arm/msg03723.html > and CPU Errata 773022 and 774769. > > This errata needs to be applied to all processors in an SMP system, > meaning that the usual strategy of applying them in > arch/arm/cpu/armv7/start.S is not appropriate (since that applies to > the boot processor only). Instead we apply these errata in the secure > monitor which is code that is traversed by all processors as they are > brought up. > > The net affect on Arndale is that ACTLR changes from 0x40 to > 0x2000042. I ran 17 kernel compile iterations overnight with no > segfaults. > > Runtime testing was done on our v2014.10 based branch and forward > ported (with only minimal and trivial contextual conflicts) to current > master, where it has been build tested only. > > I suppose in theory these errata apply to any Exynos5250 based boards, > but Arndale is the only one I have access to and I have therefore > chosen to be conservative and only apply it there. > > Also, reorder CONFIG_ARM_ERRATA_794072 in README to make the list > numerically sorted. > > Signed-off-by: Ian Campbell <ian.campbell@citrix.com> Applied to u-boot/master, thanks!
diff --git a/README b/README index a13705a..f8546cf 100644 --- a/README +++ b/README @@ -681,8 +681,10 @@ The following options need to be configured: CONFIG_ARM_ERRATA_742230 CONFIG_ARM_ERRATA_743622 CONFIG_ARM_ERRATA_751472 - CONFIG_ARM_ERRATA_794072 CONFIG_ARM_ERRATA_761320 + CONFIG_ARM_ERRATA_773022 + CONFIG_ARM_ERRATA_774769 + CONFIG_ARM_ERRATA_794072 If set, the workarounds for these ARM errata are applied early during U-Boot startup. Note that these options force the diff --git a/arch/arm/cpu/armv7/nonsec_virt.S b/arch/arm/cpu/armv7/nonsec_virt.S index 30d81db..31d1c9e 100644 --- a/arch/arm/cpu/armv7/nonsec_virt.S +++ b/arch/arm/cpu/armv7/nonsec_virt.S @@ -53,6 +53,20 @@ _secure_monitor: bl psci_arch_init #endif +#ifdef CONFIG_ARM_ERRATA_773022 + mrc p15, 0, r5, c1, c0, 1 + orr r5, r5, #(1 << 1) + mcr p15, 0, r5, c1, c0, 1 + isb +#endif + +#ifdef CONFIG_ARM_ERRATA_774769 + mrc p15, 0, r5, c1, c0, 1 + orr r5, r5, #(1 << 25) + mcr p15, 0, r5, c1, c0, 1 + isb +#endif + mrc p15, 0, r5, c1, c1, 0 @ read SCR bic r5, r5, #0x4a @ clear IRQ, EA, nET bits orr r5, r5, #0x31 @ enable NS, AW, FW bits diff --git a/include/configs/arndale.h b/include/configs/arndale.h index 437a745..b08f341 100644 --- a/include/configs/arndale.h +++ b/include/configs/arndale.h @@ -49,6 +49,10 @@ /* The PERIPHBASE in the CBAR register is wrong on the Arndale, so override it */ #define CONFIG_ARM_GIC_BASE_ADDRESS 0x10480000 +/* CPU Errata */ +#define CONFIG_ARM_ERRATA_773022 +#define CONFIG_ARM_ERRATA_774769 + /* Power */ #define CONFIG_POWER #define CONFIG_POWER_I2C
We run 4 Arndale boards in our automated test framework, they have been running quite happily for quite some time using a Debian Wheezy userspace. However when upgrading to a Debian Jessie we started seeing frequent segmentation faults from gcc when building the kernel, to the extent that it is unable to successfully build the kernel twice in a row, and often fails on the first attempt. Searching around I found https://bugs.launchpad.net/arndale/+bug/1081417 which pointed towards http://www.spinics.net/lists/kvm-arm/msg03723.html and CPU Errata 773022 and 774769. This errata needs to be applied to all processors in an SMP system, meaning that the usual strategy of applying them in arch/arm/cpu/armv7/start.S is not appropriate (since that applies to the boot processor only). Instead we apply these errata in the secure monitor which is code that is traversed by all processors as they are brought up. The net affect on Arndale is that ACTLR changes from 0x40 to 0x2000042. I ran 17 kernel compile iterations overnight with no segfaults. Runtime testing was done on our v2014.10 based branch and forward ported (with only minimal and trivial contextual conflicts) to current master, where it has been build tested only. I suppose in theory these errata apply to any Exynos5250 based boards, but Arndale is the only one I have access to and I have therefore chosen to be conservative and only apply it there. Also, reorder CONFIG_ARM_ERRATA_794072 in README to make the list numerically sorted. Signed-off-by: Ian Campbell <ian.campbell@citrix.com> --- Our v2014.10 based branch: http://xenbits.xen.org/gitweb/?p=people/ianc/osstest/u-boot.git;a=shortlog;h=refs/heads/arndale --- README | 4 +++- arch/arm/cpu/armv7/nonsec_virt.S | 14 ++++++++++++++ include/configs/arndale.h | 4 ++++ 3 files changed, 21 insertions(+), 1 deletion(-)