[PATCH 08/11] lib: sbi: Convert hart features into hart extensions
Atish Patra
atishp at atishpatra.org
Tue May 3 19:00:44 PDT 2022
On Fri, Apr 29, 2022 at 8:52 AM Anup Patel <apatel at ventanamicro.com> wrote:
>
> Since past few years, we have been using "hart features" in OpenSBI
> to represent all optionalities and multi-letter extensions defined
> by the RISC-V specifications.
>
> The RISC-V profiles specification has taken a different approach and
> started assigning extension names for all optionalities which did not
> have any extension name previously.
> (Refer, https://github.com/riscv/riscv-profiles/blob/main/profiles.adoc)
>
> Inspired from the RISC-V profiles specification, we convert OpenSBI
> hart features into hart extensions. Going forward, we align the
> extension naming with RISC-V profiles specification. Currently, only
> "time CSR" and "AIA CSR" have not been assigned extension name but
> for everything else we have a name.
>
> Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> ---
> include/sbi/sbi_hart.h | 35 ++++++------
> lib/sbi/sbi_hart.c | 116 +++++++++++++++++++---------------------
> lib/sbi/sbi_init.c | 4 +-
> lib/sbi/sbi_pmu.c | 6 +--
> lib/sbi/sbi_timer.c | 6 +--
> lib/sbi/sbi_trap.c | 4 +-
> lib/utils/fdt/fdt_pmu.c | 2 +-
> 7 files changed, 83 insertions(+), 90 deletions(-)
>
> diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h
> index c985674..8b21fd4 100644
> --- a/include/sbi/sbi_hart.h
> +++ b/include/sbi/sbi_hart.h
> @@ -24,21 +24,21 @@ enum sbi_hart_priv_versions {
> SBI_HART_PRIV_VER_1_12 = 3,
> };
>
> -/** Possible feature flags of a hart */
> -enum sbi_hart_features {
> - /** Hart has sscofpmf extension */
> - SBI_HART_HAS_SSCOFPMF = (1 << 0),
> - /** HART has timer csr implementation in hardware */
> - SBI_HART_HAS_TIME = (1 << 1),
> - /** HART has AIA local interrupt CSRs */
> - SBI_HART_HAS_AIA = (1 << 2),
> - /** HART has mstateen CSR **/
> - SBI_HART_HAS_SMSTATEEN = (1 << 3),
> - /** HART has SSTC extension implemented in hardware */
> - SBI_HART_HAS_SSTC = (1 << 4),
> +/** Possible ISA extensions of a hart */
> +enum sbi_hart_extensions {
> + /** Hart has Sscofpmt extension */
> + SBI_HART_EXT_SSCOFPMF = 0,
> + /** HART has HW time CSR (extension name not available) */
> + SBI_HART_EXT_TIME,
> + /** HART has AIA CSRs (extension name not available) */
> + SBI_HART_EXT_AIA,
> + /** HART has Smstateen CSR **/
> + SBI_HART_EXT_SMSTATEEN,
> + /** HART has Sstc extension */
> + SBI_HART_EXT_SSTC,
>
> - /** Last index of Hart features*/
> - SBI_HART_HAS_LAST_FEATURE = SBI_HART_HAS_SSTC,
> + /** Maximum index of Hart extension */
> + SBI_HART_EXT_MAX,
> };
>
> struct sbi_scratch;
> @@ -63,9 +63,10 @@ int sbi_hart_pmp_configure(struct sbi_scratch *scratch);
> int sbi_hart_priv_version(struct sbi_scratch *scratch);
> void sbi_hart_get_priv_version_str(struct sbi_scratch *scratch,
> char *version_str, int nvstr);
> -bool sbi_hart_has_feature(struct sbi_scratch *scratch, unsigned long feature);
> -void sbi_hart_get_features_str(struct sbi_scratch *scratch,
> - char *features_str, int nfstr);
> +bool sbi_hart_has_extension(struct sbi_scratch *scratch,
> + enum sbi_hart_extensions ext);
> +void sbi_hart_get_extensions_str(struct sbi_scratch *scratch,
> + char *extension_str, int nestr);
>
> void __attribute__((noreturn)) sbi_hart_hang(void);
>
> diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
> index fdfb6d9..956d185 100644
> --- a/lib/sbi/sbi_hart.c
> +++ b/lib/sbi/sbi_hart.c
> @@ -29,7 +29,7 @@ void (*sbi_hart_expected_trap)(void) = &__sbi_expected_trap;
>
> struct hart_features {
> int priv_version;
> - unsigned long features;
> + unsigned long extensions;
> unsigned int pmp_count;
> unsigned int pmp_addr_bits;
> unsigned long pmp_gran;
> @@ -83,7 +83,7 @@ static void mstatus_init(struct sbi_scratch *scratch)
> for (cidx = 0; cidx < num_mhpm; cidx++) {
> #if __riscv_xlen == 32
> csr_write_num(CSR_MHPMEVENT3 + cidx, mhpmevent_init_val & 0xFFFFFFFF);
> - if (sbi_hart_has_feature(scratch, SBI_HART_HAS_SSCOFPMF))
> + if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SSCOFPMF))
> csr_write_num(CSR_MHPMEVENT3H + cidx,
> mhpmevent_init_val >> BITS_PER_LONG);
> #else
> @@ -91,7 +91,7 @@ static void mstatus_init(struct sbi_scratch *scratch)
> #endif
> }
>
> - if (sbi_hart_has_feature(scratch, SBI_HART_HAS_SMSTATEEN)) {
> + if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SMSTATEEN)) {
> mstateen_val = csr_read(CSR_MSTATEEN0);
> #if __riscv_xlen == 32
> mstateen_val |= ((uint64_t)csr_read(CSR_MSTATEEN0H)) << 32;
> @@ -99,7 +99,7 @@ static void mstatus_init(struct sbi_scratch *scratch)
> mstateen_val |= SMSTATEEN_STATEN;
> mstateen_val |= SMSTATEEN0_HSENVCFG;
>
> - if (sbi_hart_has_feature(scratch, SBI_HART_HAS_AIA))
> + if (sbi_hart_has_extension(scratch, SBI_HART_EXT_AIA))
> mstateen_val |= (SMSTATEEN0_AIA | SMSTATEEN0_SVSLCT |
> SMSTATEEN0_IMSIC);
> else
> @@ -153,7 +153,7 @@ static void mstatus_init(struct sbi_scratch *scratch)
> * Enable access to stimecmp if sstc extension is present in the
> * hardware.
> */
> - if (sbi_hart_has_feature(scratch, SBI_HART_HAS_SSTC)) {
> + if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SSTC)) {
> #if __riscv_xlen == 32
> unsigned long menvcfgh_val;
> menvcfgh_val = csr_read(CSR_MENVCFGH);
> @@ -207,7 +207,7 @@ static int delegate_traps(struct sbi_scratch *scratch)
>
> /* Send M-mode interrupts and most exceptions to S-mode */
> interrupts = MIP_SSIP | MIP_STIP | MIP_SEIP;
> - if (sbi_hart_has_feature(scratch, SBI_HART_HAS_SSCOFPMF))
> + if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SSCOFPMF))
> interrupts |= MIP_LCOFIP;
>
> exceptions = (1U << CAUSE_MISALIGNED_FETCH) | (1U << CAUSE_BREAKPOINT) |
> @@ -367,102 +367,94 @@ void sbi_hart_get_priv_version_str(struct sbi_scratch *scratch,
> }
>
> /**
> - * Check whether a particular hart feature is available
> + * Check whether a particular hart extension is available
> *
> * @param scratch pointer to the HART scratch space
> - * @param feature the feature to check
> - * @returns true (feature available) or false (feature not available)
> + * @param ext the extension number to check
> + * @returns true (available) or false (not available)
> */
> -bool sbi_hart_has_feature(struct sbi_scratch *scratch, unsigned long feature)
> +bool sbi_hart_has_extension(struct sbi_scratch *scratch,
> + enum sbi_hart_extensions ext)
> {
> struct hart_features *hfeatures =
> sbi_scratch_offset_ptr(scratch, hart_features_offset);
>
> - if (hfeatures->features & feature)
> + if (hfeatures->extensions & BIT(ext))
> return true;
> else
> return false;
> }
>
> -static unsigned long hart_get_features(struct sbi_scratch *scratch)
> +static inline char *sbi_hart_extension_id2string(int ext)
> {
> - struct hart_features *hfeatures =
> - sbi_scratch_offset_ptr(scratch, hart_features_offset);
> -
> - return hfeatures->features;
> -}
> -
> -static inline char *sbi_hart_feature_id2string(unsigned long feature)
> -{
> - char *fstr = NULL;
> -
> - if (!feature)
> - return NULL;
> + char *estr = NULL;
>
> - switch (feature) {
> - case SBI_HART_HAS_SSCOFPMF:
> - fstr = "sscofpmf";
> + switch (ext) {
> + case SBI_HART_EXT_SSCOFPMF:
> + estr = "sscofpmf";
> break;
> - case SBI_HART_HAS_TIME:
> - fstr = "time";
> + case SBI_HART_EXT_TIME:
> + estr = "time";
> break;
> - case SBI_HART_HAS_AIA:
> - fstr = "aia";
> + case SBI_HART_EXT_AIA:
> + estr = "aia";
> break;
> - case SBI_HART_HAS_SSTC:
> - fstr = "sstc";
> + case SBI_HART_EXT_SSTC:
> + estr = "sstc";
> break;
> - case SBI_HART_HAS_SMSTATEEN:
> - fstr = "smstateen";
> + case SBI_HART_EXT_SMSTATEEN:
> + estr = "smstateen";
> break;
> default:
> break;
> }
>
> - return fstr;
> + return estr;
> }
>
> /**
> - * Get the hart features in string format
> + * Get the hart extensions in string format
> *
> * @param scratch pointer to the HART scratch space
> - * @param features_str pointer to a char array where the features string will be
> - * updated
> - * @param nfstr length of the features_str. The feature string will be truncated
> - * if nfstr is not long enough.
> + * @param extensions_str pointer to a char array where the extensions string
> + * will be updated
> + * @param nestr length of the features_str. The feature string will be
> + * truncated if nestr is not long enough.
> */
> -void sbi_hart_get_features_str(struct sbi_scratch *scratch,
> - char *features_str, int nfstr)
> +void sbi_hart_get_extensions_str(struct sbi_scratch *scratch,
> + char *extensions_str, int nestr)
> {
> - unsigned long features, feat = 1UL;
> + struct hart_features *hfeatures =
> + sbi_scratch_offset_ptr(scratch, hart_features_offset);
> + int offset = 0, ext = 0;
> char *temp;
> - int offset = 0;
>
> - if (!features_str || nfstr <= 0)
> + if (!extensions_str || nestr <= 0)
> return;
> - sbi_memset(features_str, 0, nfstr);
> + sbi_memset(extensions_str, 0, nestr);
>
> - features = hart_get_features(scratch);
> - if (!features)
> + if (!hfeatures->extensions)
> goto done;
>
> do {
> - if (features & feat) {
> - temp = sbi_hart_feature_id2string(feat);
> + if (hfeatures->extensions & BIT(ext)) {
> + temp = sbi_hart_extension_id2string(ext);
> if (temp) {
> - sbi_snprintf(features_str + offset, nfstr,
> + sbi_snprintf(extensions_str + offset,
> + nestr - offset,
> "%s,", temp);
> offset = offset + sbi_strlen(temp) + 1;
> }
> }
> - feat = feat << 1;
> - } while (feat <= SBI_HART_HAS_LAST_FEATURE);
> +
> + ext++;
> + } while (ext <= SBI_HART_EXT_MAX);
>
it should be ext < SBI_HART_EXT_MAX as SBI_HART_EXT_MAX is no longer
the last extension.
> done:
> if (offset)
> - features_str[offset - 1] = '\0';
> + extensions_str[offset - 1] = '\0';
> else
> - sbi_strncpy(features_str, "none", nfstr);
> + sbi_strncpy(extensions_str, "none", nestr);
> }
>
> static unsigned long hart_pmp_get_allowed_addr(void)
> @@ -523,7 +515,7 @@ static void hart_detect_features(struct sbi_scratch *scratch)
>
> /* Reset hart features */
> hfeatures = sbi_scratch_offset_ptr(scratch, hart_features_offset);
> - hfeatures->features = 0;
> + hfeatures->extensions = 0;
> hfeatures->pmp_count = 0;
> hfeatures->mhpm_count = 0;
>
> @@ -623,31 +615,31 @@ __mhpm_skip:
> /* Detect if hart supports sscofpmf */
> csr_read_allowed(CSR_SCOUNTOVF, (unsigned long)&trap);
> if (!trap.cause)
> - hfeatures->features |= SBI_HART_HAS_SSCOFPMF;
> + hfeatures->extensions |= BIT(SBI_HART_EXT_SSCOFPMF);
> }
>
> /* Detect if hart supports time CSR */
> csr_read_allowed(CSR_TIME, (unsigned long)&trap);
> if (!trap.cause)
> - hfeatures->features |= SBI_HART_HAS_TIME;
> + hfeatures->extensions |= BIT(SBI_HART_EXT_TIME);
>
> /* Detect if hart has AIA local interrupt CSRs */
> csr_read_allowed(CSR_MTOPI, (unsigned long)&trap);
> if (!trap.cause)
> - hfeatures->features |= SBI_HART_HAS_AIA;
> + hfeatures->extensions |= BIT(SBI_HART_EXT_AIA);
>
> /* Detect if hart supports stimecmp CSR(Sstc extension) */
> if (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_12) {
> csr_read_allowed(CSR_STIMECMP, (unsigned long)&trap);
> if (!trap.cause)
> - hfeatures->features |= SBI_HART_HAS_SSTC;
> + hfeatures->extensions |= BIT(SBI_HART_EXT_SSTC);
> }
>
> /* Detect if hart supports mstateen CSRs */
> if (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_12) {
> val = csr_read_allowed(CSR_MSTATEEN0, (unsigned long)&trap);
> if (!trap.cause)
> - hfeatures->features |= SBI_HART_HAS_SMSTATEEN;
> + hfeatures->extensions |= BIT(SBI_HART_EXT_SMSTATEEN);
> }
>
> return;
> diff --git a/lib/sbi/sbi_init.c b/lib/sbi/sbi_init.c
> index c4def58..d57efa7 100644
> --- a/lib/sbi/sbi_init.c
> +++ b/lib/sbi/sbi_init.c
> @@ -143,8 +143,8 @@ static void sbi_boot_print_hart(struct sbi_scratch *scratch, u32 hartid)
> sbi_printf("Boot HART Priv Version : %s\n", str);
> misa_string(xlen, str, sizeof(str));
> sbi_printf("Boot HART Base ISA : %s\n", str);
> - sbi_hart_get_features_str(scratch, str, sizeof(str));
> - sbi_printf("Boot HART Features : %s\n", str);
> + sbi_hart_get_extensions_str(scratch, str, sizeof(str));
> + sbi_printf("Boot HART ISA Extensions : %s\n", str);
> sbi_printf("Boot HART PMP Count : %d\n",
> sbi_hart_pmp_count(scratch));
> sbi_printf("Boot HART PMP Granularity : %lu\n",
> diff --git a/lib/sbi/sbi_pmu.c b/lib/sbi/sbi_pmu.c
> index 386bf4d..b60799e 100644
> --- a/lib/sbi/sbi_pmu.c
> +++ b/lib/sbi/sbi_pmu.c
> @@ -313,7 +313,7 @@ static int pmu_ctr_start_hw(uint32_t cidx, uint64_t ival, bool ival_update)
>
> __clear_bit(cidx, &mctr_inhbt);
>
> - if (sbi_hart_has_feature(scratch, SBI_HART_HAS_SSCOFPMF))
> + if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SSCOFPMF))
> pmu_ctr_enable_irq_hw(cidx);
> csr_write(CSR_MCOUNTINHIBIT, mctr_inhbt);
>
> @@ -474,7 +474,7 @@ static int pmu_update_hw_mhpmevent(struct sbi_pmu_hw_event *hw_evt, int ctr_idx,
> * Always set the OVF bit(disable interrupts) and inhibit counting of
> * events in M-mode. The OVF bit should be enabled during the start call.
> */
> - if (sbi_hart_has_feature(scratch, SBI_HART_HAS_SSCOFPMF))
> + if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SSCOFPMF))
> mhpmevent_val = (mhpmevent_val & ~MHPMEVENT_SSCOF_MASK) |
> MHPMEVENT_MINH | MHPMEVENT_OF;
>
> @@ -521,7 +521,7 @@ static int pmu_ctr_find_hw(unsigned long cbase, unsigned long cmask, unsigned lo
> */
> fixed_ctr = pmu_ctr_find_fixed_fw(event_idx);
> if (fixed_ctr >= 0 &&
> - !sbi_hart_has_feature(scratch, SBI_HART_HAS_SSCOFPMF))
> + !sbi_hart_has_extension(scratch, SBI_HART_EXT_SSCOFPMF))
> return fixed_ctr;
>
> if (sbi_hart_priv_version(scratch) >= SBI_HART_PRIV_VER_1_11)
> diff --git a/lib/sbi/sbi_timer.c b/lib/sbi/sbi_timer.c
> index bf0f375..353886f 100644
> --- a/lib/sbi/sbi_timer.c
> +++ b/lib/sbi/sbi_timer.c
> @@ -129,7 +129,7 @@ void sbi_timer_event_start(u64 next_event)
> * Update the stimecmp directly if available. This allows
> * the older software to leverage sstc extension on newer hardware.
> */
> - if (sbi_hart_has_feature(sbi_scratch_thishart_ptr(), SBI_HART_HAS_SSTC)) {
> + if (sbi_hart_has_extension(sbi_scratch_thishart_ptr(), SBI_HART_EXT_SSTC)) {
> #if __riscv_xlen == 32
> csr_write(CSR_STIMECMP, next_event & 0xFFFFFFFF);
> csr_write(CSR_STIMECMPH, next_event >> 32);
> @@ -151,7 +151,7 @@ void sbi_timer_process(void)
> * directly without M-mode come in between. This function should
> * only invoked if M-mode programs the timer for its own purpose.
> */
> - if (!sbi_hart_has_feature(sbi_scratch_thishart_ptr(), SBI_HART_HAS_SSTC))
> + if (!sbi_hart_has_extension(sbi_scratch_thishart_ptr(), SBI_HART_EXT_SSTC))
> csr_set(CSR_MIP, MIP_STIP);
> }
>
> @@ -180,7 +180,7 @@ int sbi_timer_init(struct sbi_scratch *scratch, bool cold_boot)
> if (!time_delta_off)
> return SBI_ENOMEM;
>
> - if (sbi_hart_has_feature(scratch, SBI_HART_HAS_TIME))
> + if (sbi_hart_has_extension(scratch, SBI_HART_EXT_TIME))
> get_time_val = get_ticks;
> } else {
> if (!time_delta_off)
> diff --git a/lib/sbi/sbi_trap.c b/lib/sbi/sbi_trap.c
> index 86bab6d..2c509e5 100644
> --- a/lib/sbi/sbi_trap.c
> +++ b/lib/sbi/sbi_trap.c
> @@ -272,8 +272,8 @@ struct sbi_trap_regs *sbi_trap_handler(struct sbi_trap_regs *regs)
> }
>
> if (mcause & (1UL << (__riscv_xlen - 1))) {
> - if (sbi_hart_has_feature(sbi_scratch_thishart_ptr(),
> - SBI_HART_HAS_AIA))
> + if (sbi_hart_has_extension(sbi_scratch_thishart_ptr(),
> + SBI_HART_EXT_AIA))
> rc = sbi_trap_aia_irq(regs, mcause);
> else
> rc = sbi_trap_nonaia_irq(regs, mcause);
> diff --git a/lib/utils/fdt/fdt_pmu.c b/lib/utils/fdt/fdt_pmu.c
> index a2b048f..8ba6b08 100644
> --- a/lib/utils/fdt/fdt_pmu.c
> +++ b/lib/utils/fdt/fdt_pmu.c
> @@ -53,7 +53,7 @@ int fdt_pmu_fixup(void *fdt)
> fdt_delprop(fdt, pmu_offset, "riscv,event-to-mhpmcounters");
> fdt_delprop(fdt, pmu_offset, "riscv,event-to-mhpmevent");
> fdt_delprop(fdt, pmu_offset, "riscv,raw-event-to-mhpmcounters");
> - if (!sbi_hart_has_feature(scratch, SBI_HART_HAS_SSCOFPMF))
> + if (!sbi_hart_has_extension(scratch, SBI_HART_EXT_SSCOFPMF))
> fdt_delprop(fdt, pmu_offset, "interrupts-extended");
>
> return 0;
> --
> 2.34.1
>
Other than that, LGTM.
Reviewed-by: Atish Patra <atishp at rivosinc.com>
--
Regards,
Atish
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