lib: sbi: Remove MENVCFG hart feature

If a hart implements privileged spec v1.12 (or higher) then we can
safely assume that menvcfg CSR is present and we don't need MENVCFG
as a hart feature.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>

diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h
index bc6b766..c985674 100644 (file)
--- a/include/sbi/sbi_hart.h
+++ b/include/sbi/sbi_hart.h
@@ -32,12 +32,10 @@ enum sbi_hart_features {
        SBI_HART_HAS_TIME = (1 << 1),
        /** HART has AIA local interrupt CSRs */
        SBI_HART_HAS_AIA = (1 << 2),
-       /** HART has menvcfg CSR */
-       SBI_HART_HAS_MENVCFG = (1 << 3),
        /** HART has mstateen CSR **/
-       SBI_HART_HAS_SMSTATEEN = (1 << 4),
+       SBI_HART_HAS_SMSTATEEN = (1 << 3),
        /** HART has SSTC extension implemented in hardware */
-       SBI_HART_HAS_SSTC = (1 << 5),
+       SBI_HART_HAS_SSTC = (1 << 4),
 
        /** 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 0fe88cb..5ee5ddd 100644 (file)
--- a/lib/sbi/sbi_hart.c
+++ b/lib/sbi/sbi_hart.c
@@ -97,10 +97,8 @@ static void mstatus_init(struct sbi_scratch *scratch)
                mstateen_val |= ((uint64_t)csr_read(CSR_MSTATEEN0H)) << 32;
 #endif
                mstateen_val |= SMSTATEEN_STATEN;
-               if (sbi_hart_has_feature(scratch, SBI_HART_HAS_MENVCFG))
-                       mstateen_val |= SMSTATEEN0_HSENVCFG;
-               else
-                       mstateen_val &= ~SMSTATEEN0_HSENVCFG;
+               mstateen_val |= SMSTATEEN0_HSENVCFG;
+
                if (sbi_hart_has_feature(scratch, SBI_HART_HAS_AIA))
                        mstateen_val |= (SMSTATEEN0_AIA | SMSTATEEN0_SVSLCT |
                                        SMSTATEEN0_IMSIC);
@@ -113,7 +111,7 @@ static void mstatus_init(struct sbi_scratch *scratch)
 #endif
        }
 
-       if (sbi_hart_has_feature(scratch, SBI_HART_HAS_MENVCFG)) {
+       if (sbi_hart_priv_version(scratch) >= SBI_HART_PRIV_VER_1_12) {
                menvcfg_val = csr_read(CSR_MENVCFG);
 
                /*
@@ -413,9 +411,6 @@ static inline char *sbi_hart_feature_id2string(unsigned long feature)
        case SBI_HART_HAS_SSTC:
                fstr = "sstc";
                break;
-       case SBI_HART_HAS_MENVCFG:
-               fstr = "menvcfg";
-               break;
        case SBI_HART_HAS_SMSTATEEN:
                fstr = "smstateen";
                break;
@@ -616,13 +611,11 @@ __mhpm_skip:
            (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_10))
                hfeatures->priv_version = SBI_HART_PRIV_VER_1_11;
 
-       /* Detect if hart has menvcfg CSR */
+       /* Detect if hart supports Priv v1.12 */
        csr_read_allowed(CSR_MENVCFG, (unsigned long)&trap);
        if (!trap.cause &&
-           (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_11)) {
+           (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->priv_version >= SBI_HART_PRIV_VER_1_12) {
@@ -644,20 +637,19 @@ __mhpm_skip:
        hfeatures->features |= SBI_HART_HAS_AIA;
 __aia_skip:
 
-       /**
-        * Detect if hart supports stimecmp CSR(Sstc extension) and menvcfg is
-        * implemented.
-        */
-       if (hfeatures->features & SBI_HART_HAS_MENVCFG) {
+       /* 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;
        }
 
        /* Detect if hart supports mstateen CSRs */
-       val = csr_read_allowed(CSR_MSTATEEN0, (unsigned long)&trap);
-       if (!trap.cause)
-               hfeatures->features |= SBI_HART_HAS_SMSTATEEN;
+       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;
+       }
 
        return;
 }