Unverified Commit 05ab803d authored by Samuel Holland's avatar Samuel Holland Committed by Palmer Dabbelt
Browse files

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: <stable@vger.kernel.org> # v6.7+
Fixes: 43c16d51 ("RISC-V: Enable cbo.zero in usermode")
Signed-off-by: default avatarSamuel Holland <samuel.holland@sifive.com>
Reviewed-by: default avatarConor Dooley <conor.dooley@microchip.com>
Reviewed-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240228065559.3434837-4-samuel.holland@sifive.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 4774848f

arch/riscv/include/asm/suspend.h

+1 −0
Original line number Diff line number Diff line
@@ -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

arch/riscv/kernel/suspend.c

+4 −0
Original line number Diff line number Diff line
@@ -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);