diff options
| author | Anup Patel <anup.patel@wdc.com> | 2019-04-15 11:53:31 +0530 |
|---|---|---|
| committer | Anup Patel <anup@brainfault.org> | 2019-09-30 15:29:37 +0530 |
| commit | bbeb8e619d1cc528d2d56531512d6ea406f9738b (patch) | |
| tree | 564a440550380b8fe3f5320ccf9c49739a158ae2 /lib/sbi/sbi_trap.c | |
| parent | 1a5614e971cf44e08342c2b1639fa3be544b0202 (diff) | |
lib: Extend sbi_trap_redirect() for hypervisor extension
When hypervisor extension is available, we can get traps from VS/VU
modes. We should be able to force redirect some of these traps to
HS-mode. In other words, we should be able forward traps from VS/VU
mode to HS-mode using sbi_trap_redirect() hence this patch.
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Diffstat (limited to 'lib/sbi/sbi_trap.c')
| -rw-r--r-- | lib/sbi/sbi_trap.c | 125 |
1 files changed, 102 insertions, 23 deletions
diff --git a/lib/sbi/sbi_trap.c b/lib/sbi/sbi_trap.c index 82f7b65..93a0404 100644 --- a/lib/sbi/sbi_trap.c +++ b/lib/sbi/sbi_trap.c @@ -79,41 +79,119 @@ static void __noreturn sbi_trap_error(const char *msg, int rc, u32 hartid, int sbi_trap_redirect(struct sbi_trap_regs *regs, struct sbi_scratch *scratch, ulong epc, ulong cause, ulong tval) { - ulong new_mstatus, prev_mode; + ulong hstatus, vsstatus, prev_mode; +#if __riscv_xlen == 32 + bool prev_virt = (regs->mstatusH & MSTATUSH_MPV) ? TRUE : FALSE; + bool prev_stage2 = (regs->mstatusH & MSTATUSH_MTL) ? TRUE : FALSE; +#else + bool prev_virt = (regs->mstatus & MSTATUS_MPV) ? TRUE : FALSE; + bool prev_stage2 = (regs->mstatus & MSTATUS_MTL) ? TRUE : FALSE; +#endif + /* By default, we redirect to HS-mode */ + bool next_virt = FALSE; /* Sanity check on previous mode */ prev_mode = (regs->mstatus & MSTATUS_MPP) >> MSTATUS_MPP_SHIFT; if (prev_mode != PRV_S && prev_mode != PRV_U) return SBI_ENOTSUPP; - /* Update S-mode exception info */ - csr_write(CSR_STVAL, tval); - csr_write(CSR_SEPC, epc); - csr_write(CSR_SCAUSE, cause); + /* For certain exceptions from VS/VU-mode we redirect to VS-mode */ + if (misa_extension('H') && prev_virt && !prev_stage2) { + switch (cause) { + case CAUSE_FETCH_PAGE_FAULT: + case CAUSE_LOAD_PAGE_FAULT: + case CAUSE_STORE_PAGE_FAULT: + next_virt = TRUE; + break; + default: + break; + }; + } + + /* Update MSTATUS MPV and MTL bits */ +#if __riscv_xlen == 32 + regs->mstatusH &= ~MSTATUSH_MPV; + regs->mstatusH |= (next_virt) ? MSTATUSH_MPV : 0UL; + regs->mstatusH &= ~MSTATUSH_MTL; +#else + regs->mstatus &= ~MSTATUS_MPV; + regs->mstatus |= (next_virt) ? MSTATUS_MPV : 0UL; + regs->mstatus &= ~MSTATUS_MTL; +#endif + + /* Update HSTATUS for VS/VU-mode to HS-mode transition */ + if (misa_extension('H') && prev_virt && !next_virt) { + /* Update HSTATUS SP2P, SP2V, SPV, and STL bits */ + hstatus = csr_read(CSR_HSTATUS); + hstatus &= ~HSTATUS_SP2P; + hstatus |= (regs->mstatus & MSTATUS_SPP) ? HSTATUS_SP2P : 0; + hstatus &= ~HSTATUS_SP2V; + hstatus |= (hstatus & HSTATUS_SPV) ? HSTATUS_SP2V : 0; + hstatus &= ~HSTATUS_SPV; + hstatus |= (prev_virt) ? HSTATUS_SPV : 0; + hstatus &= ~HSTATUS_STL; + hstatus |= (prev_stage2) ? HSTATUS_STL : 0; + csr_write(CSR_HSTATUS, hstatus); + } - /* Set MEPC to S-mode exception vector base */ - regs->mepc = csr_read(CSR_STVEC); + /* Update exception related CSRs */ + if (next_virt) { + /* Update VS-mode exception info */ + csr_write(CSR_VSTVAL, tval); + csr_write(CSR_VSEPC, epc); + csr_write(CSR_VSCAUSE, cause); - /* Initial value of new MSTATUS */ - new_mstatus = regs->mstatus; + /* Set MEPC to VS-mode exception vector base */ + regs->mepc = csr_read(CSR_VSTVEC); - /* Clear MPP, SPP, SPIE, and SIE */ - new_mstatus &= - ~(MSTATUS_MPP | MSTATUS_SPP | MSTATUS_SPIE | MSTATUS_SIE); + /* Set MPP to VS-mode */ + regs->mstatus &= ~MSTATUS_MPP; + regs->mstatus |= (PRV_S << MSTATUS_MPP_SHIFT); - /* Set SPP */ - if (prev_mode == PRV_S) - new_mstatus |= (1UL << MSTATUS_SPP_SHIFT); + /* Get VS-mode SSTATUS CSR */ + vsstatus = csr_read(CSR_VSSTATUS); - /* Set SPIE */ - if (regs->mstatus & MSTATUS_SIE) - new_mstatus |= (1UL << MSTATUS_SPIE_SHIFT); + /* Set SPP for VS-mode */ + vsstatus &= ~SSTATUS_SPP; + if (prev_mode == PRV_S) + vsstatus |= (1UL << SSTATUS_SPP_SHIFT); - /* Set MPP */ - new_mstatus |= (PRV_S << MSTATUS_MPP_SHIFT); + /* Set SPIE for VS-mode */ + vsstatus &= ~SSTATUS_SPIE; + if (vsstatus & SSTATUS_SIE) + vsstatus |= (1UL << SSTATUS_SPIE_SHIFT); - /* Set new value in MSTATUS */ - regs->mstatus = new_mstatus; + /* Clear SIE for VS-mode */ + vsstatus &= ~SSTATUS_SIE; + + /* Update VS-mode SSTATUS CSR */ + csr_write(CSR_VSSTATUS, vsstatus); + } else { + /* Update S-mode exception info */ + csr_write(CSR_STVAL, tval); + csr_write(CSR_SEPC, epc); + csr_write(CSR_SCAUSE, cause); + + /* Set MEPC to S-mode exception vector base */ + regs->mepc = csr_read(CSR_STVEC); + + /* Set MPP to S-mode */ + regs->mstatus &= ~MSTATUS_MPP; + regs->mstatus |= (PRV_S << MSTATUS_MPP_SHIFT); + + /* Set SPP for S-mode*/ + regs->mstatus &= ~MSTATUS_SPP; + if (prev_mode == PRV_S) + regs->mstatus |= (1UL << MSTATUS_SPP_SHIFT); + + /* Set SPIE for S-mode */ + regs->mstatus &= ~MSTATUS_SPIE; + if (regs->mstatus & MSTATUS_SIE) + regs->mstatus |= (1UL << MSTATUS_SPIE_SHIFT); + + /* Clear SIE for S-mode */ + regs->mstatus &= ~MSTATUS_SIE; + } return 0; } @@ -195,7 +273,8 @@ void sbi_trap_handler(struct sbi_trap_regs *regs, struct sbi_scratch *scratch) break; default: /* If the trap came from S or U mode, redirect it there */ - rc = sbi_trap_redirect(regs, scratch, regs->mepc, mcause, mtval); + rc = sbi_trap_redirect(regs, scratch, regs->mepc, + mcause, mtval); break; }; |