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| author | Russell King <rmk+kernel@armlinux.org.uk> | 2018-10-15 18:32:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-10-18 10:16:26 +0300 |
| commit | 510155b2d95b3561ec214a16fa9e28ce10d0d9c7 (patch) | |
| tree | 163232b0c3eddf081d343c52237f78799e66f87c /arch/arm/mm/proc-v7-bugs.c | |
| parent | 5ab8c6e8879c3eee7d70714b630a4770ff8a2678 (diff) | |
| download | linux-510155b2d95b3561ec214a16fa9e28ce10d0d9c7.tar.xz | |
ARM: spectre-v2: add firmware based hardening
Commit 10115105cb3aa17b5da1cb726ae8dd5f6854bd93 upstream.
Add firmware based hardening for cores that require more complex
handling in firmware.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: David A. Long <dave.long@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/mm/proc-v7-bugs.c')
| -rw-r--r-- | arch/arm/mm/proc-v7-bugs.c | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/arch/arm/mm/proc-v7-bugs.c b/arch/arm/mm/proc-v7-bugs.c index 85a2e3d6263c..da25a38e1897 100644 --- a/arch/arm/mm/proc-v7-bugs.c +++ b/arch/arm/mm/proc-v7-bugs.c @@ -1,14 +1,20 @@ // SPDX-License-Identifier: GPL-2.0 +#include <linux/arm-smccc.h> #include <linux/kernel.h> +#include <linux/psci.h> #include <linux/smp.h> #include <asm/cp15.h> #include <asm/cputype.h> +#include <asm/proc-fns.h> #include <asm/system_misc.h> #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR DEFINE_PER_CPU(harden_branch_predictor_fn_t, harden_branch_predictor_fn); +extern void cpu_v7_smc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm); +extern void cpu_v7_hvc_switch_mm(phys_addr_t pgd_phys, struct mm_struct *mm); + static void harden_branch_predictor_bpiall(void) { write_sysreg(0, BPIALL); @@ -19,6 +25,16 @@ static void harden_branch_predictor_iciallu(void) write_sysreg(0, ICIALLU); } +static void __maybe_unused call_smc_arch_workaround_1(void) +{ + arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL); +} + +static void __maybe_unused call_hvc_arch_workaround_1(void) +{ + arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_1, NULL); +} + static void cpu_v7_spectre_init(void) { const char *spectre_v2_method = NULL; @@ -45,7 +61,51 @@ static void cpu_v7_spectre_init(void) harden_branch_predictor_iciallu; spectre_v2_method = "ICIALLU"; break; + +#ifdef CONFIG_ARM_PSCI + default: + /* Other ARM CPUs require no workaround */ + if (read_cpuid_implementor() == ARM_CPU_IMP_ARM) + break; + /* fallthrough */ + /* Cortex A57/A72 require firmware workaround */ + case ARM_CPU_PART_CORTEX_A57: + case ARM_CPU_PART_CORTEX_A72: { + struct arm_smccc_res res; + + if (psci_ops.smccc_version == SMCCC_VERSION_1_0) + break; + + switch (psci_ops.conduit) { + case PSCI_CONDUIT_HVC: + arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, + ARM_SMCCC_ARCH_WORKAROUND_1, &res); + if ((int)res.a0 != 0) + break; + per_cpu(harden_branch_predictor_fn, cpu) = + call_hvc_arch_workaround_1; + processor.switch_mm = cpu_v7_hvc_switch_mm; + spectre_v2_method = "hypervisor"; + break; + + case PSCI_CONDUIT_SMC: + arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, + ARM_SMCCC_ARCH_WORKAROUND_1, &res); + if ((int)res.a0 != 0) + break; + per_cpu(harden_branch_predictor_fn, cpu) = + call_smc_arch_workaround_1; + processor.switch_mm = cpu_v7_smc_switch_mm; + spectre_v2_method = "firmware"; + break; + + default: + break; + } } +#endif + } + if (spectre_v2_method) pr_info("CPU%u: Spectre v2: using %s workaround\n", smp_processor_id(), spectre_v2_method); |