From 05ab803d1ad8ac505ade77c6bd3f86b1b4ea0dc4 Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Tue, 27 Feb 2024 22:55:35 -0800 Subject: riscv: Save/restore envcfg CSR during CPU suspend The value of the [ms]envcfg CSR is lost when entering a nonretentive idle state, so the CSR must be rewritten when resuming the CPU. Cc: # v6.7+ Fixes: 43c16d51a19b ("RISC-V: Enable cbo.zero in usermode") Signed-off-by: Samuel Holland Reviewed-by: Conor Dooley Reviewed-by: Andrew Jones Link: https://lore.kernel.org/r/20240228065559.3434837-4-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/suspend.h | 1 + arch/riscv/kernel/suspend.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/arch/riscv/include/asm/suspend.h b/arch/riscv/include/asm/suspend.h index 02f87867389a..491296a335d0 100644 --- a/arch/riscv/include/asm/suspend.h +++ b/arch/riscv/include/asm/suspend.h @@ -14,6 +14,7 @@ struct suspend_context { struct pt_regs regs; /* Saved and restored by high-level functions */ unsigned long scratch; + unsigned long envcfg; unsigned long tvec; unsigned long ie; #ifdef CONFIG_MMU diff --git a/arch/riscv/kernel/suspend.c b/arch/riscv/kernel/suspend.c index 239509367e42..299795341e8a 100644 --- a/arch/riscv/kernel/suspend.c +++ b/arch/riscv/kernel/suspend.c @@ -15,6 +15,8 @@ void suspend_save_csrs(struct suspend_context *context) { context->scratch = csr_read(CSR_SCRATCH); + if (riscv_cpu_has_extension_unlikely(smp_processor_id(), RISCV_ISA_EXT_XLINUXENVCFG)) + context->envcfg = csr_read(CSR_ENVCFG); context->tvec = csr_read(CSR_TVEC); context->ie = csr_read(CSR_IE); @@ -36,6 +38,8 @@ void suspend_save_csrs(struct suspend_context *context) void suspend_restore_csrs(struct suspend_context *context) { csr_write(CSR_SCRATCH, context->scratch); + if (riscv_cpu_has_extension_unlikely(smp_processor_id(), RISCV_ISA_EXT_XLINUXENVCFG)) + csr_write(CSR_ENVCFG, context->envcfg); csr_write(CSR_TVEC, context->tvec); csr_write(CSR_IE, context->ie); -- cgit