[PATCH 05/11] lib: sbi: Remove MCOUNTINHIBT hart feature
Atish Patra
atishp at atishpatra.org
Tue May 3 18:56:19 PDT 2022
On Fri, Apr 29, 2022 at 8:52 AM Anup Patel <apatel at ventanamicro.com> wrote:
>
> If a hart implements privileged spec v1.11 (or higher) then we can
> safely assume that mcountinhibit CSR is present and we don't need
> MCOUNTINHIBT as a hart feature.
>
> Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> ---
> include/sbi/sbi_hart.h | 14 ++++++--------
> lib/sbi/sbi_hart.c | 23 ++++++++---------------
> lib/sbi/sbi_pmu.c | 10 +++++-----
> 3 files changed, 19 insertions(+), 28 deletions(-)
>
> diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h
> index 4665a62..bc6b766 100644
> --- a/include/sbi/sbi_hart.h
> +++ b/include/sbi/sbi_hart.h
> @@ -26,20 +26,18 @@ enum sbi_hart_priv_versions {
>
> /** Possible feature flags of a hart */
> enum sbi_hart_features {
> - /** Hart has counter inhibit CSR */
> - SBI_HART_HAS_MCOUNTINHIBIT = (1 << 0),
> /** Hart has sscofpmf extension */
> - SBI_HART_HAS_SSCOFPMF = (1 << 1),
> + SBI_HART_HAS_SSCOFPMF = (1 << 0),
> /** HART has timer csr implementation in hardware */
> - SBI_HART_HAS_TIME = (1 << 2),
> + SBI_HART_HAS_TIME = (1 << 1),
> /** HART has AIA local interrupt CSRs */
> - SBI_HART_HAS_AIA = (1 << 3),
> + SBI_HART_HAS_AIA = (1 << 2),
> /** HART has menvcfg CSR */
> - SBI_HART_HAS_MENVCFG = (1 << 4),
> + SBI_HART_HAS_MENVCFG = (1 << 3),
> /** HART has mstateen CSR **/
> - SBI_HART_HAS_SMSTATEEN = (1 << 5),
> + SBI_HART_HAS_SMSTATEEN = (1 << 4),
> /** HART has SSTC extension implemented in hardware */
> - SBI_HART_HAS_SSTC = (1 << 6),
> + SBI_HART_HAS_SSTC = (1 << 5),
>
> /** Last index of Hart features*/
> SBI_HART_HAS_LAST_FEATURE = SBI_HART_HAS_SSTC,
> diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
> index ed8a061..0fe88cb 100644
> --- a/lib/sbi/sbi_hart.c
> +++ b/lib/sbi/sbi_hart.c
> @@ -70,7 +70,7 @@ static void mstatus_init(struct sbi_scratch *scratch)
> csr_write(CSR_MCOUNTEREN, -1);
>
> /* All programmable counters will start running at runtime after S-mode request */
> - if (sbi_hart_has_feature(scratch, SBI_HART_HAS_MCOUNTINHIBIT))
> + if (sbi_hart_priv_version(scratch) >= SBI_HART_PRIV_VER_1_11)
> csr_write(CSR_MCOUNTINHIBIT, 0xFFFFFFF8);
>
> /**
> @@ -402,9 +402,6 @@ static inline char *sbi_hart_feature_id2string(unsigned long feature)
> return NULL;
>
> switch (feature) {
> - case SBI_HART_HAS_MCOUNTINHIBIT:
> - fstr = "mcountinhibit";
> - break;
> case SBI_HART_HAS_SSCOFPMF:
> fstr = "sscofpmf";
> break;
> @@ -613,26 +610,22 @@ __mhpm_skip:
> if (!trap.cause)
> hfeatures->priv_version = SBI_HART_PRIV_VER_1_10;
>
> - /* Detect if hart supports MCOUNTINHIBIT feature */
> + /* Detect if hart supports Priv v1.11 */
> val = csr_read_allowed(CSR_MCOUNTINHIBIT, (unsigned long)&trap);
> - if (!trap.cause) {
> - csr_write_allowed(CSR_MCOUNTINHIBIT, (unsigned long)&trap, val);
> - if (!trap.cause) {
> - hfeatures->priv_version = SBI_HART_PRIV_VER_1_11;
> - hfeatures->features |= SBI_HART_HAS_MCOUNTINHIBIT;
> - }
> - }
> + if (!trap.cause &&
> + (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_10))
> + hfeatures->priv_version = SBI_HART_PRIV_VER_1_11;
>
> /* Detect if hart has menvcfg CSR */
> csr_read_allowed(CSR_MENVCFG, (unsigned long)&trap);
> - if (!trap.cause) {
> + if (!trap.cause &&
> + (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_11)) {
> hfeatures->priv_version = SBI_HART_PRIV_VER_1_12;
> hfeatures->features |= SBI_HART_HAS_MENVCFG;
> }
>
> /* Counter overflow/filtering is not useful without mcounter/inhibit */
> - if (hfeatures->features & SBI_HART_HAS_MCOUNTINHIBIT &&
> - hfeatures->priv_version >= SBI_HART_PRIV_VER_1_12) {
> + if (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_12) {
> /* Detect if hart supports sscofpmf */
> csr_read_allowed(CSR_SCOUNTOVF, (unsigned long)&trap);
> if (!trap.cause)
> diff --git a/lib/sbi/sbi_pmu.c b/lib/sbi/sbi_pmu.c
> index 853229e..386bf4d 100644
> --- a/lib/sbi/sbi_pmu.c
> +++ b/lib/sbi/sbi_pmu.c
> @@ -300,7 +300,7 @@ static int pmu_ctr_start_hw(uint32_t cidx, uint64_t ival, bool ival_update)
> if (cidx > num_hw_ctrs || cidx == 1)
> return SBI_EINVAL;
>
> - if (!sbi_hart_has_feature(scratch, SBI_HART_HAS_MCOUNTINHIBIT))
> + if (sbi_hart_priv_version(scratch) < SBI_HART_PRIV_VER_1_11)
> goto skip_inhibit_update;
>
> /*
> @@ -372,7 +372,7 @@ static int pmu_ctr_stop_hw(uint32_t cidx)
> struct sbi_scratch *scratch = sbi_scratch_thishart_ptr();
> unsigned long mctr_inhbt;
>
> - if (!sbi_hart_has_feature(scratch, SBI_HART_HAS_MCOUNTINHIBIT))
> + if (sbi_hart_priv_version(scratch) < SBI_HART_PRIV_VER_1_11)
> return 0;
>
> mctr_inhbt = csr_read(CSR_MCOUNTINHIBIT);
> @@ -524,7 +524,7 @@ static int pmu_ctr_find_hw(unsigned long cbase, unsigned long cmask, unsigned lo
> !sbi_hart_has_feature(scratch, SBI_HART_HAS_SSCOFPMF))
> return fixed_ctr;
>
> - if (sbi_hart_has_feature(scratch, SBI_HART_HAS_MCOUNTINHIBIT))
> + if (sbi_hart_priv_version(scratch) >= SBI_HART_PRIV_VER_1_11)
> mctr_inhbt = csr_read(CSR_MCOUNTINHIBIT);
> for (i = 0; i < num_hw_events; i++) {
> temp = &hw_event_map[i];
> @@ -551,7 +551,7 @@ static int pmu_ctr_find_hw(unsigned long cbase, unsigned long cmask, unsigned lo
> if (active_events[hartid][cbase] != SBI_PMU_EVENT_IDX_INVALID)
> continue;
> /* If mcountinhibit is supported, the bit must be enabled */
> - if ((sbi_hart_has_feature(scratch, SBI_HART_HAS_MCOUNTINHIBIT)) &&
> + if ((sbi_hart_priv_version(scratch) >= SBI_HART_PRIV_VER_1_11) &&
> !__test_bit(cbase, &mctr_inhbt))
> continue;
> /* We found a valid counter that is not started yet */
> @@ -726,7 +726,7 @@ void sbi_pmu_exit(struct sbi_scratch *scratch)
> {
> u32 hartid = current_hartid();
>
> - if (sbi_hart_has_feature(scratch, SBI_HART_HAS_MCOUNTINHIBIT))
> + if (sbi_hart_priv_version(scratch) >= SBI_HART_PRIV_VER_1_11)
> csr_write(CSR_MCOUNTINHIBIT, 0xFFFFFFF8);
>
> if (sbi_hart_priv_version(scratch) >= SBI_HART_PRIV_VER_1_10)
> --
> 2.34.1
>
Reviewed-by: Atish Patra <atishp at rivosinc.com>
--
Regards,
Atish
More information about the opensbi
mailing list