diff options
| author | Atish Patra <atish.patra@wdc.com> | 2021-11-08 21:52:58 +0300 |
|---|---|---|
| committer | Anup Patel <anup@brainfault.org> | 2021-11-11 15:12:59 +0300 |
| commit | 867c65360df283f056afa963ad8333e9c1eb21bb (patch) | |
| tree | 9757f8fb87e66a09d195ec18bc57e44882db94ed | |
| parent | 7084ad9f4281eecd7a7f66cecfd7d9cff8d452ad (diff) | |
| download | opensbi-867c65360df283f056afa963ad8333e9c1eb21bb.tar.xz | |
lib: sbi: Detect Sscofpmf extension at run time
Sscofpmf ISA extension introduces PMU counter overflow and filtering support.
It introduces a read only `scountovf` csr that can be used to detect if
a hart supports this extension at runtime. However, this feature is only
useful if the hart already supports mcounteren and mcountinhibit.
Add a dynamic detection mechanism and boot time print message if sscofpmf
is present.
Reviewed-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
| -rw-r--r-- | include/sbi/sbi_hart.h | 4 | ||||
| -rw-r--r-- | lib/sbi/sbi_hart.c | 12 |
2 files changed, 15 insertions, 1 deletions
diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h index 0c18ef9..d2db9d6 100644 --- a/include/sbi/sbi_hart.h +++ b/include/sbi/sbi_hart.h @@ -20,8 +20,10 @@ enum sbi_hart_features { SBI_HART_HAS_MCOUNTEREN = (1 << 1), /** Hart has counter inhibit CSR */ SBI_HART_HAS_MCOUNTINHIBIT = (1 << 2), + /** Hart has sscofpmf extension */ + SBI_HART_HAS_SSCOFPMF = (1 << 3), /** HART has timer csr implementation in hardware */ - SBI_HART_HAS_TIME = (1 << 3), + SBI_HART_HAS_TIME = (1 << 4), /** Last index of Hart features*/ SBI_HART_HAS_LAST_FEATURE = SBI_HART_HAS_TIME, diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c index 8eb0c38..7f31bb7 100644 --- a/lib/sbi/sbi_hart.c +++ b/lib/sbi/sbi_hart.c @@ -281,6 +281,9 @@ static inline char *sbi_hart_feature_id2string(unsigned long feature) case SBI_HART_HAS_MCOUNTINHIBIT: fstr = "mcountinhibit"; break; + case SBI_HART_HAS_SSCOFPMF: + fstr = "sscofpmf"; + break; case SBI_HART_HAS_TIME: fstr = "time"; break; @@ -490,6 +493,15 @@ __mhpm_skip: hfeatures->features |= SBI_HART_HAS_MCOUNTINHIBIT; } + /* Counter overflow/filtering is not useful without mcounter/inhibit */ + if (hfeatures->features & SBI_HART_HAS_MCOUNTINHIBIT && + hfeatures->features & SBI_HART_HAS_MCOUNTEREN) { + /* Detect if hart supports sscofpmf */ + csr_read_allowed(CSR_SCOUNTOVF, (unsigned long)&trap); + if (!trap.cause) + hfeatures->features |= SBI_HART_HAS_SSCOFPMF; + } + /* Detect if hart supports time CSR */ csr_read_allowed(CSR_TIME, (unsigned long)&trap); if (!trap.cause) |