@@ -67,6 +67,9 @@ enum sbi_hart_extensions {
SBI_HART_EXT_SVADE,
/** Hart has Svadu extension */
SBI_HART_EXT_SVADU,
+ /** HART has zicfiss & zicfilp extension */
+ SBI_HART_EXT_ZICFILP,
+ SBI_HART_EXT_ZICFISS,
/** Maximum index of Hart extension */
SBI_HART_EXT_MAX,
@@ -680,6 +680,8 @@ const struct sbi_hart_ext_data sbi_hart_ext[] = {
__SBI_HART_EXT_DATA(ssccfg, SBI_HART_EXT_SSCCFG),
__SBI_HART_EXT_DATA(svade, SBI_HART_EXT_SVADE),
__SBI_HART_EXT_DATA(svadu, SBI_HART_EXT_SVADU),
+ __SBI_HART_EXT_DATA(zicfilp, SBI_HART_EXT_ZICFILP),
+ __SBI_HART_EXT_DATA(zicfiss, SBI_HART_EXT_ZICFISS),
};
_Static_assert(SBI_HART_EXT_MAX == array_size(sbi_hart_ext),
@@ -776,6 +778,7 @@ static int hart_detect_features(struct sbi_scratch *scratch)
unsigned long val, oldval;
bool has_zicntr = false;
int rc;
+ bool ssp_exist, elp_exist;
/* If hart features already detected then do nothing */
if (hfeatures->detected)
@@ -933,6 +936,21 @@ __pmp_skip:
/* Save trap based detection of Zicntr */
has_zicntr = sbi_hart_has_extension(scratch, SBI_HART_EXT_ZICNTR);
+ if (hfeatures->priv_version >= SBI_HART_PRIV_VER_1_12) {
+ val = csr_read_allowed(CSR_SSP, (unsigned long)&trap);
+ ssp_exist = trap.cause == 0;
+ if (ssp_exist)
+ __sbi_hart_update_extension(hfeatures,
+ SBI_HART_EXT_ZICFISS, true);
+
+ csr_set(CSR_MSTATUS, MSTATUS_MPELP);
+ val = csr_read_clear(CSR_MSTATUS, MSTATUS_MPELP);
+ elp_exist = val & MSTATUS_MPELP;
+ if (elp_exist)
+ __sbi_hart_update_extension(hfeatures,
+ SBI_HART_EXT_ZICFILP, true);
+ }
+
/* Let platform populate extensions */
rc = sbi_platform_extensions_init(sbi_platform_thishart_ptr(),
hfeatures);
@@ -103,6 +103,7 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs,
const struct sbi_trap_info *trap)
{
ulong hstatus, vsstatus, prev_mode;
+ bool elp = false;
#if __riscv_xlen == 32
bool prev_virt = (regs->mstatusH & MSTATUSH_MPV) ? true : false;
#else
@@ -116,6 +117,17 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs,
if (prev_mode != PRV_S && prev_mode != PRV_U)
return SBI_ENOTSUPP;
+ /* If extension has support for CFI, clear MPELP because redirecting to VS or (H)S */
+ if (sbi_hart_has_extension(sbi_scratch_thishart_ptr(), SBI_HART_EXT_ZICFILP)) {
+#if __riscv_xlen == 32
+ elp = regs->mstatusH & MSTATUSH_MPELP;
+ regs->mstatusH &= ~MSTATUSH_MPELP;
+#else
+ elp = regs->mstatus & MSTATUS_MPELP;
+ regs->mstatus &= ~MSTATUS_MPELP;
+#endif
+ }
+
/* If exceptions came from VS/VU-mode, redirect to VS-mode if
* delegated in hedeleg
*/
@@ -169,6 +181,10 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs,
/* Get VS-mode SSTATUS CSR */
vsstatus = csr_read(CSR_VSSTATUS);
+ /*if elp was set, set it back in vsstatus */
+ if (elp)
+ vsstatus |= MSTATUS_SPELP;
+
/* Set SPP for VS-mode */
vsstatus &= ~SSTATUS_SPP;
if (prev_mode == PRV_S)
@@ -209,6 +225,10 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs,
/* Clear SIE for S-mode */
regs->mstatus &= ~MSTATUS_SIE;
+
+ /* if elp was set, set it back in mstatus */
+ if (elp)
+ regs->mstatus |= MSTATUS_SPELP;
}
return 0;
This patch adds support for zicfilp / zicfiss detection in sbi_hart.c Zicfilp records status of hart's ELP state in *status csr. Missing landing pad sets MPELP in mstatus. When SBI is redirecting back to S/VS/HS, SPELP is set in sstatus/vsstatus. Signed-off-by: Deepak Gupta <debug@rivosinc.com> --- include/sbi/sbi_hart.h | 3 +++ lib/sbi/sbi_hart.c | 18 ++++++++++++++++++ lib/sbi/sbi_trap.c | 20 ++++++++++++++++++++ 3 files changed, 41 insertions(+)