lib: sbi: Detect extensions from the ISA string in DT

Enable access to some extensions through menvcfg and show them in "Boot
HART ISA Extensions" if they are present in the device tree.

Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>

diff --git a/include/sbi/sbi_hart.h b/include/sbi/sbi_hart.h
index 77138232221729d26395fab02d2dc755c2ac0577..47be251d31aa49320b49674fe7f26c28c2cdda22 100644 (file)
--- a/include/sbi/sbi_hart.h
+++ b/include/sbi/sbi_hart.h
@@ -47,6 +47,12 @@ enum sbi_hart_extensions {
        SBI_HART_EXT_SMCNTRPMF,
        /** Hart has Xandespmu extension */
        SBI_HART_EXT_XANDESPMU,
+       /** Hart has Zicboz extension */
+       SBI_HART_EXT_ZICBOZ,
+       /** Hart has Zicbom extension */
+       SBI_HART_EXT_ZICBOM,
+       /** Hart has Svpbmt extension */
+       SBI_HART_EXT_SVPBMT,
 
        /** Maximum index of Hart extension */
        SBI_HART_EXT_MAX,

diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
index 80699fed36f86a5dac01fad4efb5ad9c143af776..46cd55d063cf8d4ee9c7882904ece4e54f8f935b 100644 (file)
--- a/lib/sbi/sbi_hart.c
+++ b/lib/sbi/sbi_hart.c
@@ -112,47 +112,25 @@ static void mstatus_init(struct sbi_scratch *scratch)
                menvcfg_val |= ((uint64_t)csr_read(CSR_MENVCFGH)) << 32;
 #endif
 
-               /*
-                * Set menvcfg.CBZE == 1
-                *
-                * If Zicboz extension is not available then writes to
-                * menvcfg.CBZE will be ignored because it is a WARL field.
-                */
-               menvcfg_val |= ENVCFG_CBZE;
-
-               /*
-                * Set menvcfg.CBCFE == 1
-                *
-                * If Zicbom extension is not available then writes to
-                * menvcfg.CBCFE will be ignored because it is a WARL field.
-                */
-               menvcfg_val |= ENVCFG_CBCFE;
+#define __set_menvcfg_ext(__ext, __bits)                               \
+               if (sbi_hart_has_extension(scratch, __ext))             \
+                       menvcfg_val |= __bits;
 
                /*
-                * Set menvcfg.CBIE == 3
-                *
-                * If Zicbom extension is not available then writes to
-                * menvcfg.CBIE will be ignored because it is a WARL field.
+                * Enable access to extensions if they are present in the
+                * hardware or in the device tree.
                 */
-               menvcfg_val |= ENVCFG_CBIE_INV << ENVCFG_CBIE_SHIFT;
 
-               /*
-                * Set menvcfg.PBMTE == 1 for RV64 or RV128
-                *
-                * If Svpbmt extension is not available then menvcfg.PBMTE
-                * will be read-only zero.
-                */
+               __set_menvcfg_ext(SBI_HART_EXT_ZICBOZ, ENVCFG_CBZE)
+               __set_menvcfg_ext(SBI_HART_EXT_ZICBOM, ENVCFG_CBCFE)
+               __set_menvcfg_ext(SBI_HART_EXT_ZICBOM,
+                                 ENVCFG_CBIE_INV << ENVCFG_CBIE_SHIFT)
 #if __riscv_xlen > 32
-               menvcfg_val |= ENVCFG_PBMTE;
+               __set_menvcfg_ext(SBI_HART_EXT_SVPBMT, ENVCFG_PBMTE)
 #endif
+               __set_menvcfg_ext(SBI_HART_EXT_SSTC, ENVCFG_STCE)
 
-               /*
-                * The spec doesn't explicitly describe the reset value of menvcfg.
-                * Enable access to stimecmp if sstc extension is present in the
-                * hardware.
-                */
-               if (sbi_hart_has_extension(scratch, SBI_HART_EXT_SSTC))
-                       menvcfg_val |= ENVCFG_STCE;
+#undef __set_menvcfg_ext
 
                csr_write(CSR_MENVCFG, menvcfg_val);
 #if __riscv_xlen == 32
@@ -676,6 +654,9 @@ const struct sbi_hart_ext_data sbi_hart_ext[] = {
        __SBI_HART_EXT_DATA(zkr, SBI_HART_EXT_ZKR),
        __SBI_HART_EXT_DATA(smcntrpmf, SBI_HART_EXT_SMCNTRPMF),
        __SBI_HART_EXT_DATA(xandespmu, SBI_HART_EXT_XANDESPMU),
+       __SBI_HART_EXT_DATA(zicboz, SBI_HART_EXT_ZICBOZ),
+       __SBI_HART_EXT_DATA(zicbom, SBI_HART_EXT_ZICBOM),
+       __SBI_HART_EXT_DATA(svpbmt, SBI_HART_EXT_SVPBMT),
 };
 
 /**