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authorVincenzo Frascino <vincenzo.frascino@arm.com>2021-03-15 13:20:11 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2021-04-11 10:55:30 +0100
commitf3b7deef8dcaf84fd659108ae300626ea5420f87 (patch)
tree78e07172909ac4406713dbd9e31b182e475ac759 /arch/arm64/kernel
parent1e28eed17697bcf343c6743f0028cc3b5dd88bf0 (diff)
arm64: mte: Add asynchronous mode support
MTE provides an asynchronous mode for detecting tag exceptions. In particular instead of triggering a fault the arm64 core updates a register which is checked by the kernel after the asynchronous tag check fault has occurred. Add support for MTE asynchronous mode. The exception handling mechanism will be added with a future patch. Note: KASAN HW activates async mode via kasan.mode kernel parameter. The default mode is set to synchronous. The code that verifies the status of TFSR_EL1 will be added with a future patch. Cc: Will Deacon <will@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Andrey Konovalov <andreyknvl@google.com> Acked-by: Andrey Konovalov <andreyknvl@google.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Link: https://lore.kernel.org/r/20210315132019.33202-2-vincenzo.frascino@arm.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel')
-rw-r--r--arch/arm64/kernel/mte.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index b3c70a612c7a..fa755cf94e01 100644
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -107,11 +107,23 @@ void mte_init_tags(u64 max_tag)
write_sysreg_s(SYS_GCR_EL1_RRND | gcr_kernel_excl, SYS_GCR_EL1);
}
-void mte_enable_kernel(void)
+static inline void __mte_enable_kernel(const char *mode, unsigned long tcf)
{
/* Enable MTE Sync Mode for EL1. */
- sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, SCTLR_ELx_TCF_SYNC);
+ sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, tcf);
isb();
+
+ pr_info_once("MTE: enabled in %s mode at EL1\n", mode);
+}
+
+void mte_enable_kernel_sync(void)
+{
+ __mte_enable_kernel("synchronous", SCTLR_ELx_TCF_SYNC);
+}
+
+void mte_enable_kernel_async(void)
+{
+ __mte_enable_kernel("asynchronous", SCTLR_ELx_TCF_ASYNC);
}
void mte_set_report_once(bool state)