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lib: Redirect WFI trapped from VS/VU mode to HS-mode

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The WFI will trap as illegal instruction trap when executed
in VS/VU mode so we just forward/redirect it to HS-mode so
that hypervisor can deal with it appropriately.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
This commit is contained in:
Anup Patel
2019-04-05 18:17:11 +05:30
committed by Anup Patel
parent bbeb8e619d
commit a14e7ee82c
2 changed files with 20 additions and 3 deletions
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3
include/sbi/riscv_encoding.h
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@@ -544,6 +544,9 @@
#define INSN_MATCH_C_FSWSP 0xe002
#define INSN_MASK_C_FSWSP 0xe003
#define INSN_MASK_WFI 0xffffff00
#define INSN_MATCH_WFI 0x10500000
#define INSN_LEN(insn) ((((insn) & 0x3) < 0x3) ? 2 : 4)
#if __riscv_xlen == 64

20
lib/sbi/sbi_illegal_insn.c
View File

@@ -36,9 +36,23 @@ static int system_opcode_insn(ulong insn, u32 hartid, ulong mcause,
int csr_num = (u32)insn >> 20;
ulong csr_val, new_csr_val;
if (sbi_emulate_csr_read(csr_num, hartid, regs->mstatus, scratch,
&csr_val))
return truly_illegal_insn(insn, hartid, mcause, regs, scratch);
/*
* WFI always traps as illegal instruction when executed from
* VS/VU mode so we just forward it to HS-mode.
*/
#if __riscv_xlen == 32
if ((regs->mstatusH & MSTATUSH_MPV) &&
#else
if ((regs->mstatus & MSTATUS_MPV) &&
#endif
(insn & INSN_MASK_WFI) == INSN_MATCH_WFI)
return sbi_trap_redirect(regs, scratch,
regs->mepc, mcause, insn);
if (sbi_emulate_csr_read(csr_num, hartid, regs->mstatus,
scratch, &csr_val))
return truly_illegal_insn(insn, hartid, mcause,
regs, scratch);
do_write = rs1_num;
switch (GET_RM(insn)) {