From Smstateen extension: the values of the [h/s]stateen CSRs will be lost when entering a non-retentive idle state. Therefore, these CSRs values need to be restored to ensure that the corresponding functionality remains enabled.
Signed-off-by: Max Hsu max.hsu@sifive.com --- arch/riscv/include/asm/suspend.h | 6 ++++++ arch/riscv/kernel/suspend.c | 18 ++++++++++++++++++ 2 files changed, 24 insertions(+)
diff --git a/arch/riscv/include/asm/suspend.h b/arch/riscv/include/asm/suspend.h index 4718096fa5e3..2ecace073869 100644 --- a/arch/riscv/include/asm/suspend.h +++ b/arch/riscv/include/asm/suspend.h @@ -17,6 +17,12 @@ struct suspend_context { unsigned long envcfg; unsigned long tvec; unsigned long ie; +#if __riscv_xlen < 64 + unsigned long hstateen0h; +#endif + unsigned long hstateen0; + unsigned long sstateen0; + #ifdef CONFIG_MMU unsigned long satp; #endif diff --git a/arch/riscv/kernel/suspend.c b/arch/riscv/kernel/suspend.c index 8a327b485b90..a086da222872 100644 --- a/arch/riscv/kernel/suspend.c +++ b/arch/riscv/kernel/suspend.c @@ -19,6 +19,15 @@ void suspend_save_csrs(struct suspend_context *context) context->envcfg = csr_read(CSR_ENVCFG); context->tvec = csr_read(CSR_TVEC); context->ie = csr_read(CSR_IE); + if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN)) { + if (riscv_has_extension_unlikely(RISCV_ISA_EXT_h)) { +#if __riscv_xlen < 64 + context->hstateen0h = csr_read(CSR_HSTATEEN0H); +#endif + context->hstateen0 = csr_read(CSR_HSTATEEN0); + } + context->sstateen0 = csr_read(CSR_SSTATEEN0); + }
/* * No need to save/restore IP CSR (i.e. MIP or SIP) because: @@ -42,6 +51,15 @@ void suspend_restore_csrs(struct suspend_context *context) csr_write(CSR_ENVCFG, context->envcfg); csr_write(CSR_TVEC, context->tvec); csr_write(CSR_IE, context->ie); + if (riscv_has_extension_unlikely(RISCV_ISA_EXT_SMSTATEEN)) { + if (riscv_has_extension_unlikely(RISCV_ISA_EXT_h)) { +#if __riscv_xlen < 64 + csr_write(CSR_HSTATEEN0H, context->hstateen0h); +#endif + csr_write(CSR_HSTATEEN0, context->hstateen0); + } + csr_write(CSR_SSTATEEN0, context->sstateen0); + }
#ifdef CONFIG_MMU csr_write(CSR_SATP, context->satp);