lib: sbi: Improve the code of privilege mode and extensions detection

We can enhance the code by creating 2 unified interface with macro  for
privilege mode and extensions detection, which relies on supported
privilege modes and CSRs.

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

diff --git a/lib/sbi/sbi_hart.c b/lib/sbi/sbi_hart.c
index 6acff378bbf1292e3f3f6f1e1c9aa8f2d2d03966..2739005266eb4d1deaf80d372dc45509464755b1 100644 (file)
--- a/lib/sbi/sbi_hart.c
+++ b/lib/sbi/sbi_hart.c
@@ -807,6 +807,7 @@ static int hart_detect_features(struct sbi_scratch *scratch)
        sbi_memset(hfeatures->extensions, 0, sizeof(hfeatures->extensions));
        hfeatures->pmp_count = 0;
        hfeatures->mhpm_mask = 0;
+       hfeatures->priv_version = SBI_HART_PRIV_VER_UNKNOWN;
 
 #define __check_hpm_csr(__csr, __mask)                                           \
        oldval = csr_read_allowed(__csr, (ulong)&trap);                   \
@@ -899,67 +900,54 @@ __pmp_skip:
 #undef __check_csr_2
 #undef __check_csr
 
-       /* Detect if hart supports Priv v1.10 */
-       val = csr_read_allowed(CSR_MCOUNTEREN, (unsigned long)&trap);
-       if (!trap.cause)
-               hfeatures->priv_version = SBI_HART_PRIV_VER_1_10;
 
-       /* Detect if hart supports Priv v1.11 */
-       val = csr_read_allowed(CSR_MCOUNTINHIBIT, (unsigned long)&trap);
-       if (!trap.cause &&
-           (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_10))
-               hfeatures->priv_version = SBI_HART_PRIV_VER_1_11;
+#define __check_priv(__csr, __base_priv, __priv)                       \
+       val = csr_read_allowed(__csr, (ulong)&trap);                    \
+       if (!trap.cause && (hfeatures->priv_version >= __base_priv)) {  \
+               hfeatures->priv_version = __priv;                       \
+       }
 
+       /* Detect if hart supports Priv v1.10 */
+       __check_priv(CSR_MCOUNTEREN,
+                    SBI_HART_PRIV_VER_UNKNOWN, SBI_HART_PRIV_VER_1_10);
+       /* Detect if hart supports Priv v1.11 */
+       __check_priv(CSR_MCOUNTINHIBIT,
+                    SBI_HART_PRIV_VER_1_10, SBI_HART_PRIV_VER_1_11);
        /* 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_12;
+       __check_priv(CSR_MENVCFG,
+                    SBI_HART_PRIV_VER_1_11, SBI_HART_PRIV_VER_1_12);
 
-       /* Counter overflow/filtering is not useful without mcounter/inhibit */
-       if (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_11) {
-               /* Detect if hart supports sscofpmf */
-               csr_read_allowed(CSR_SCOUNTOVF, (unsigned long)&trap);
-               if (!trap.cause)
-                       __sbi_hart_update_extension(hfeatures,
-                                       SBI_HART_EXT_SSCOFPMF, true);
+#undef __check_priv_csr
+
+#define __check_ext_csr(__base_priv, __csr, __ext)                     \
+       if (hfeatures->priv_version >= __base_priv) {                   \
+               csr_read_allowed(__csr, (ulong)&trap);                  \
+               if (!trap.cause)                                        \
+                       __sbi_hart_update_extension(hfeatures,          \
+                                                   __ext, true);       \
        }
 
+       /* Counter overflow/filtering is not useful without mcounter/inhibit */
+       /* Detect if hart supports sscofpmf */
+       __check_ext_csr(SBI_HART_PRIV_VER_1_11,
+                       CSR_SCOUNTOVF, SBI_HART_EXT_SSCOFPMF);
        /* Detect if hart supports time CSR */
-       csr_read_allowed(CSR_TIME, (unsigned long)&trap);
-       if (!trap.cause)
-               __sbi_hart_update_extension(hfeatures,
-                                       SBI_HART_EXT_ZICNTR, true);
-
+       __check_ext_csr(SBI_HART_PRIV_VER_UNKNOWN,
+                       CSR_TIME, SBI_HART_EXT_ZICNTR);
        /* Detect if hart has AIA local interrupt CSRs */
-       csr_read_allowed(CSR_MTOPI, (unsigned long)&trap);
-       if (!trap.cause)
-               __sbi_hart_update_extension(hfeatures,
-                                       SBI_HART_EXT_SMAIA, true);
-
+       __check_ext_csr(SBI_HART_PRIV_VER_UNKNOWN,
+                       CSR_MTOPI, SBI_HART_EXT_SMAIA);
        /* 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)
-                       __sbi_hart_update_extension(hfeatures,
-                                       SBI_HART_EXT_SSTC, true);
-       }
-
+       __check_ext_csr(SBI_HART_PRIV_VER_1_12,
+                       CSR_STIMECMP, SBI_HART_EXT_SSTC);
        /* Detect if hart supports mstateen CSRs */
-       if (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_12) {
-               val = csr_read_allowed(CSR_MSTATEEN0, (unsigned long)&trap);
-               if (!trap.cause)
-                       __sbi_hart_update_extension(hfeatures,
-                                       SBI_HART_EXT_SMSTATEEN, true);
-       }
-
+       __check_ext_csr(SBI_HART_PRIV_VER_1_12,
+                       CSR_MSTATEEN0, SBI_HART_EXT_SMSTATEEN);
        /* Detect if hart supports smcntrpmf */
-       if (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_12) {
-               csr_read_allowed(CSR_MCYCLECFG, (unsigned long)&trap);
-               if (!trap.cause)
-                       __sbi_hart_update_extension(hfeatures,
-                                       SBI_HART_EXT_SMCNTRPMF, true);
-       }
+       __check_ext_csr(SBI_HART_PRIV_VER_1_12,
+                       CSR_MCYCLECFG, SBI_HART_EXT_SMCNTRPMF);
+
+#undef __check_ext_csr
 
        /* Let platform populate extensions */
        rc = sbi_platform_extensions_init(sbi_platform_thishart_ptr(),