| Message ID | 20240430084241.2009259-1-nylon.chen@sifive.com |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | [1/1] lib: sbi: Add Smrnmi extension detection | expand |
On Tue, Apr 30, 2024 at 2:13 PM Nylon Chen <nylon.chen@sifive.com> wrote: > > Adds detection and initialization of the Smrnmi extension > in the SBI hart initialization code. > > The Smrnmi extension provides resumable non-maskable interrupts (RNMIs) > support. It adds new CSRs (mnscratch, mnepc, mncause, mnstatus) to save > the interrupted context and a new instruction MNRET to resume from the > RNMI handler[1]. > > we need to detect its presence and enable it in the early hart > initialization process, before any traps. > > [1] https://github.com/riscv/riscv-isa-manual/blob/main/src/rnmi.adoc > > Co-developed-by: Zong Li <zong.li@sifive.com> > Signed-off-by: Zong Li <zong.li@sifive.com> > Signed-off-by: Nylon Chen <nylon.chen@sifive.com> > Reviewed-by: Greentime Hu <greentime.hu@sifive.com> > Reviewed-by: Yong-Xuan Wang <yongxuan.wang@sifive.com> > --- > include/sbi/riscv_encoding.h | 10 ++++++++++ > include/sbi/sbi_hart.h | 2 ++ > lib/sbi/sbi_hart.c | 22 ++++++++++++++++++++++ > 3 files changed, 34 insertions(+) > > diff --git a/include/sbi/riscv_encoding.h b/include/sbi/riscv_encoding.h > index d914828..320bb2b 100644 > --- a/include/sbi/riscv_encoding.h > +++ b/include/sbi/riscv_encoding.h > @@ -207,6 +207,10 @@ > > #endif > > +#define MNSTATUS_NMIE (_UL(0x8)) > +#define MNSTATUS_MNPV (_UL(0x80)) > +#define MNSTATUS_MNPP (_UL(0x1800)) > + > #define MHPMEVENT_SSCOF_MASK _ULL(0xFFFF000000000000) > > #define ENVCFG_STCE (_ULL(1) << 63) > @@ -738,6 +742,12 @@ > #define CSR_MSTATEEN3 0x30F > #define CSR_MSTATEEN3H 0x31F > > +/* Smrnmi extension registers */ > +#define CSR_MNSCRATCH 0x740 > +#define CSR_MNEPC 0x741 > +#define CSR_MNCAUSE 0x742 > +#define CSR_MNSTATUS 0x744 > + > /* Machine-Level High-Half CSRs (AIA) */ > #define CSR_MIDELEGH 0x313 > #define CSR_MIEH 0x314 > diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h > index cc78eec..d49d987 100644 > --- a/include/sbi/sbi_hart.h > +++ b/include/sbi/sbi_hart.h > @@ -63,6 +63,8 @@ enum sbi_hart_extensions { > SBI_HART_EXT_SSCSRIND, > /** Hart has Ssccfg extension */ > SBI_HART_EXT_SSCCFG, > + /** Hart has Smrnmi extension */ > + SBI_HART_EXT_SMRNMI, > > /** Maximum index of Hart extension */ > SBI_HART_EXT_MAX, > diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c > index 0e7b5d1..6941a94 100644 > --- a/lib/sbi/sbi_hart.c > +++ b/lib/sbi/sbi_hart.c > @@ -668,6 +668,7 @@ const struct sbi_hart_ext_data sbi_hart_ext[] = { > __SBI_HART_EXT_DATA(smcdeleg, SBI_HART_EXT_SMCDELEG), > __SBI_HART_EXT_DATA(sscsrind, SBI_HART_EXT_SSCSRIND), > __SBI_HART_EXT_DATA(ssccfg, SBI_HART_EXT_SSCCFG), > + __SBI_HART_EXT_DATA(smrnmi, SBI_HART_EXT_SMRNMI), > }; > > _Static_assert(SBI_HART_EXT_MAX == array_size(sbi_hart_ext), > @@ -706,6 +707,20 @@ void sbi_hart_get_extensions_str(struct sbi_scratch *scratch, > sbi_strncpy(extensions_str, "none", nestr); > } > > +static int hart_smrnmi_get_allowed(void) > +{ > + unsigned long val; > + struct sbi_trap_info trap = {0}; > + > + val = csr_read_allowed(CSR_MNSTATUS, (unsigned long)&trap); > + if (!trap.cause) { > + val |= MNSTATUS_NMIE; > + csr_write(CSR_MNSTATUS, val); > + return true; > + } else { > + return false; > + } > + > static unsigned long hart_pmp_get_allowed_addr(void) > { > unsigned long val = 0; > @@ -775,6 +790,13 @@ static int hart_detect_features(struct sbi_scratch *scratch) > hfeatures->mhpm_mask = 0; > hfeatures->priv_version = SBI_HART_PRIV_VER_UNKNOWN; > > + /* > + * Detect Resumable Non-Maskable Interrupts > + * If it exists we must enable it before all traps. > + */ > + if (hart_smrnmi_get_allowed()) > + __sbi_hart_update_extension(hfeatures, SBI_HART_EXT_SMRNMI, true); > + No need to detect Smrnmi using trap. The ISA string parsing is sufficient. Also, enabling mnstatus.NMIE should be done in mstatus_init() only when SBI_HART_EXT_SMRNMI is available. > #define __check_hpm_csr(__csr, __mask) \ > oldval = csr_read_allowed(__csr, (ulong)&trap); \ > if (!trap.cause) { \ > -- > 2.34.1 > > > -- > opensbi mailing list > opensbi@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/opensbi Regards, Anup
diff --git a/include/sbi/riscv_encoding.h b/include/sbi/riscv_encoding.h index d914828..320bb2b 100644 --- a/include/sbi/riscv_encoding.h +++ b/include/sbi/riscv_encoding.h @@ -207,6 +207,10 @@ #endif +#define MNSTATUS_NMIE (_UL(0x8)) +#define MNSTATUS_MNPV (_UL(0x80)) +#define MNSTATUS_MNPP (_UL(0x1800)) + #define MHPMEVENT_SSCOF_MASK _ULL(0xFFFF000000000000) #define ENVCFG_STCE (_ULL(1) << 63) @@ -738,6 +742,12 @@ #define CSR_MSTATEEN3 0x30F #define CSR_MSTATEEN3H 0x31F +/* Smrnmi extension registers */ +#define CSR_MNSCRATCH 0x740 +#define CSR_MNEPC 0x741 +#define CSR_MNCAUSE 0x742 +#define CSR_MNSTATUS 0x744 + /* Machine-Level High-Half CSRs (AIA) */ #define CSR_MIDELEGH 0x313 #define CSR_MIEH 0x314 diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h index cc78eec..d49d987 100644 --- a/include/sbi/sbi_hart.h +++ b/include/sbi/sbi_hart.h @@ -63,6 +63,8 @@ enum sbi_hart_extensions { SBI_HART_EXT_SSCSRIND, /** Hart has Ssccfg extension */ SBI_HART_EXT_SSCCFG, + /** Hart has Smrnmi extension */ + SBI_HART_EXT_SMRNMI, /** Maximum index of Hart extension */ SBI_HART_EXT_MAX, diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c index 0e7b5d1..6941a94 100644 --- a/lib/sbi/sbi_hart.c +++ b/lib/sbi/sbi_hart.c @@ -668,6 +668,7 @@ const struct sbi_hart_ext_data sbi_hart_ext[] = { __SBI_HART_EXT_DATA(smcdeleg, SBI_HART_EXT_SMCDELEG), __SBI_HART_EXT_DATA(sscsrind, SBI_HART_EXT_SSCSRIND), __SBI_HART_EXT_DATA(ssccfg, SBI_HART_EXT_SSCCFG), + __SBI_HART_EXT_DATA(smrnmi, SBI_HART_EXT_SMRNMI), }; _Static_assert(SBI_HART_EXT_MAX == array_size(sbi_hart_ext), @@ -706,6 +707,20 @@ void sbi_hart_get_extensions_str(struct sbi_scratch *scratch, sbi_strncpy(extensions_str, "none", nestr); } +static int hart_smrnmi_get_allowed(void) +{ + unsigned long val; + struct sbi_trap_info trap = {0}; + + val = csr_read_allowed(CSR_MNSTATUS, (unsigned long)&trap); + if (!trap.cause) { + val |= MNSTATUS_NMIE; + csr_write(CSR_MNSTATUS, val); + return true; + } else { + return false; + } + static unsigned long hart_pmp_get_allowed_addr(void) { unsigned long val = 0; @@ -775,6 +790,13 @@ static int hart_detect_features(struct sbi_scratch *scratch) hfeatures->mhpm_mask = 0; hfeatures->priv_version = SBI_HART_PRIV_VER_UNKNOWN; + /* + * Detect Resumable Non-Maskable Interrupts + * If it exists we must enable it before all traps. + */ + if (hart_smrnmi_get_allowed()) + __sbi_hart_update_extension(hfeatures, SBI_HART_EXT_SMRNMI, true); + #define __check_hpm_csr(__csr, __mask) \ oldval = csr_read_allowed(__csr, (ulong)&trap); \ if (!trap.cause) { \