[PATCH 01/11] lib: sbi: Detect and print privileged spec version
Anup Patel
anup at brainfault.org
Fri May 6 21:57:59 PDT 2022
On Wed, May 4, 2022 at 7:12 AM Atish Patra <atishp at atishpatra.org> wrote:
>
> On Fri, Apr 29, 2022 at 8:52 AM Anup Patel <apatel at ventanamicro.com> wrote:
> >
> > It is possible to guess privileged spec versions based on the CSRs
> > that where introduced in different privleged spec versions. In future,
>
> /s/privleged/privileged
>
> > if we are not able guess privileged spec version then we can have
> > platform provide it.
> >
> > We add privileged spec version as per-hart feature and try to guess
> > it based on presense of mcounteren, mcountinhibit, and menvcfg CSRs.
> >
>
> /s/presense/presence
>
> > Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> > ---
> > include/sbi/sbi_hart.h | 15 ++++++++++++
> > lib/sbi/sbi_hart.c | 52 +++++++++++++++++++++++++++++++++++++-----
> > lib/sbi/sbi_init.c | 2 ++
> > 3 files changed, 63 insertions(+), 6 deletions(-)
> >
> > diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h
> > index 1d09374..3c37933 100644
> > --- a/include/sbi/sbi_hart.h
> > +++ b/include/sbi/sbi_hart.h
> > @@ -12,6 +12,18 @@
> >
> > #include <sbi/sbi_types.h>
> >
> > +/** Possible privileged specification versions of a hart */
> > +enum sbi_hart_priv_versions {
> > + /** Unknown privileged specification */
> > + SBI_HART_PRIV_VER_UNKNOWN = 0,
> > + /** Privileged specification v1.10 */
> > + SBI_HART_PRIV_VER_1_10 = 1,
> > + /** Privileged specification v1.11 */
> > + SBI_HART_PRIV_VER_1_11 = 2,
> > + /** Privileged specification v1.12 */
> > + SBI_HART_PRIV_VER_1_12 = 3,
> > +};
> > +
> > /** Possible feature flags of a hart */
> > enum sbi_hart_features {
> > /** Hart has S-mode counter enable */
> > @@ -56,6 +68,9 @@ unsigned long sbi_hart_pmp_granularity(struct sbi_scratch *scratch);
> > unsigned int sbi_hart_pmp_addrbits(struct sbi_scratch *scratch);
> > unsigned int sbi_hart_mhpm_bits(struct sbi_scratch *scratch);
> > 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);
> > diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
> > index 229c14a..ed4e631 100644
> > --- a/lib/sbi/sbi_hart.c
> > +++ b/lib/sbi/sbi_hart.c
> > @@ -28,6 +28,7 @@ extern void __sbi_expected_trap_hext(void);
> > void (*sbi_hart_expected_trap)(void) = &__sbi_expected_trap;
> >
> > struct hart_features {
> > + int priv_version;
> > unsigned long features;
> > unsigned int pmp_count;
> > unsigned int pmp_addr_bits;
> > @@ -334,6 +335,39 @@ int sbi_hart_pmp_configure(struct sbi_scratch *scratch)
> > return 0;
> > }
> >
> > +int sbi_hart_priv_version(struct sbi_scratch *scratch)
> > +{
> > + struct hart_features *hfeatures =
> > + sbi_scratch_offset_ptr(scratch, hart_features_offset);
> > +
> > + return hfeatures->priv_version;
> > +}
> > +
> > +void sbi_hart_get_priv_version_str(struct sbi_scratch *scratch,
> > + char *version_str, int nvstr)
> > +{
> > + char *temp;
> > + struct hart_features *hfeatures =
> > + sbi_scratch_offset_ptr(scratch, hart_features_offset);
> > +
> > + switch (hfeatures->priv_version) {
> > + case SBI_HART_PRIV_VER_1_10:
> > + temp = "v1.10";
> > + break;
> > + case SBI_HART_PRIV_VER_1_11:
> > + temp = "v1.11";
> > + break;
> > + case SBI_HART_PRIV_VER_1_12:
> > + temp = "v1.12";
> > + break;
> > + default:
> > + temp = "unknown";
> > + break;
> > + }
> > +
> > + sbi_snprintf(version_str, nvstr, "%s", temp);
> > +}
> > +
> > /**
> > * Check whether a particular hart feature is available
> > *
> > @@ -583,6 +617,7 @@ __mhpm_skip:
> > /* Detect if hart supports SCOUNTEREN feature */
> > val = csr_read_allowed(CSR_SCOUNTEREN, (unsigned long)&trap);
> > if (!trap.cause) {
> > + hfeatures->priv_version = SBI_HART_PRIV_VER_1_10;
> > csr_write_allowed(CSR_SCOUNTEREN, (unsigned long)&trap, val);
> > if (!trap.cause)
> > hfeatures->features |= SBI_HART_HAS_SCOUNTEREN;
> > @@ -591,6 +626,7 @@ __mhpm_skip:
> > /* Detect if hart supports MCOUNTEREN feature */
> > val = csr_read_allowed(CSR_MCOUNTEREN, (unsigned long)&trap);
> > if (!trap.cause) {
> > + hfeatures->priv_version = SBI_HART_PRIV_VER_1_10;
> > csr_write_allowed(CSR_MCOUNTEREN, (unsigned long)&trap, val);
> > if (!trap.cause)
> > hfeatures->features |= SBI_HART_HAS_MCOUNTEREN;
> > @@ -600,8 +636,17 @@ __mhpm_skip:
> > val = csr_read_allowed(CSR_MCOUNTINHIBIT, (unsigned long)&trap);
> > if (!trap.cause) {
> > csr_write_allowed(CSR_MCOUNTINHIBIT, (unsigned long)&trap, val);
> > - if (!trap.cause)
> > + if (!trap.cause) {
> > + hfeatures->priv_version = SBI_HART_PRIV_VER_1_11;
> > hfeatures->features |= SBI_HART_HAS_MCOUNTINHIBIT;
> > + }
> > + }
> > +
> > + /* Detect if hart has menvcfg CSR */
> > + csr_read_allowed(CSR_MENVCFG, (unsigned long)&trap);
> > + if (!trap.cause) {
> > + hfeatures->priv_version = SBI_HART_PRIV_VER_1_12;
> > + hfeatures->features |= SBI_HART_HAS_MENVCFG;
> > }
> >
> > /* Counter overflow/filtering is not useful without mcounter/inhibit */
> > @@ -625,11 +670,6 @@ __mhpm_skip:
> > hfeatures->features |= SBI_HART_HAS_AIA;
> > __aia_skip:
> >
> > - /* Detect if hart has menvcfg CSR */
> > - csr_read_allowed(CSR_MENVCFG, (unsigned long)&trap);
> > - if (!trap.cause)
> > - hfeatures->features |= SBI_HART_HAS_MENVCFG;
> > -
> > /**
> > * Detect if hart supports stimecmp CSR(Sstc extension) and menvcfg is
> > * implemented.
> > diff --git a/lib/sbi/sbi_init.c b/lib/sbi/sbi_init.c
> > index 2b9e5ae..660b11f 100644
> > --- a/lib/sbi/sbi_init.c
> > +++ b/lib/sbi/sbi_init.c
> > @@ -139,6 +139,8 @@ static void sbi_boot_print_hart(struct sbi_scratch *scratch, u32 hartid)
> > /* Boot HART details */
> > sbi_printf("Boot HART ID : %u\n", hartid);
> > sbi_printf("Boot HART Domain : %s\n", dom->name);
> > + sbi_hart_get_priv_version_str(scratch, str, sizeof(str));
> > + sbi_printf("Boot HART Priv Version : %s\n", str);
> > misa_string(xlen, str, sizeof(str));
> > sbi_printf("Boot HART ISA : %s\n", str);
> > sbi_hart_get_features_str(scratch, str, sizeof(str));
> > --
> > 2.34.1
> >
>
> Reviewed-by: Atish Patra <atishp at rivosinc.com>
I have taken care of the typos at the time of merging this patch.
Applied this patch to the riscv/opensbi repo
Regards,
Anup
>
> --
> Regards,
> Atish
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