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include: Remove ilen member of struct unpriv_trap

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We simplify struct unpriv_trap by removing ilen member. This
can be achieved by ensuring that at all unpriv load/store
instructions are 4 bytes long using GCC assembler option.

Additionally, this also reduces few instructions from unpriv
load/store functions.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
This commit is contained in:
Anup Patel
2019-11-16 16:08:27 +05:30
committed by Anup Patel
parent 215421ca61
commit 838657c052
3 changed files with 32 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
include/sbi/riscv_unpriv.h
View File

@@ -15,7 +15,6 @@
struct sbi_scratch;
struct unpriv_trap {
unsigned long ilen;
unsigned long cause;
unsigned long tval;
};

50
lib/sbi/riscv_unpriv.c
View File

@@ -13,20 +13,22 @@
#include <sbi/sbi_hart.h>
#include <sbi/sbi_scratch.h>
#define DEFINE_UNPRIVILEGED_LOAD_FUNCTION(type, insn, insnlen) \
#define DEFINE_UNPRIVILEGED_LOAD_FUNCTION(type, insn) \
type load_##type(const type *addr, \
struct sbi_scratch *scratch, \
struct unpriv_trap *trap) \
{ \
register ulong __mstatus asm("a2"); \
type val = 0; \
trap->ilen = insnlen; \
trap->cause = 0; \
trap->tval = 0; \
sbi_hart_set_trap_info(scratch, trap); \
asm volatile( \
"csrrs %0, " STR(CSR_MSTATUS) ", %3\n" \
".option push\n" \
".option norvc\n" \
#insn " %1, %2\n" \
".option pop\n" \
"csrw " STR(CSR_MSTATUS) ", %0" \
: "+&r"(__mstatus), "=&r"(val) \
: "m"(*addr), "r"(MSTATUS_MPRV)); \
@@ -34,41 +36,43 @@
return val; \
}
#define DEFINE_UNPRIVILEGED_STORE_FUNCTION(type, insn, insnlen) \
#define DEFINE_UNPRIVILEGED_STORE_FUNCTION(type, insn) \
void store_##type(type *addr, type val, \
struct sbi_scratch *scratch, \
struct unpriv_trap *trap) \
{ \
register ulong __mstatus asm("a3"); \
trap->ilen = insnlen; \
trap->cause = 0; \
trap->tval = 0; \
sbi_hart_set_trap_info(scratch, trap); \
asm volatile( \
"csrrs %0, " STR(CSR_MSTATUS) ", %3\n" \
".option push\n" \
".option norvc\n" \
#insn " %1, %2\n" \
".option pop\n" \
"csrw " STR(CSR_MSTATUS) ", %0" \
: "+&r"(__mstatus) \
: "r"(val), "m"(*addr), "r"(MSTATUS_MPRV)); \
sbi_hart_set_trap_info(scratch, NULL); \
}
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(u8, lbu, 4)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(u16, lhu, 4)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(s8, lb, 4)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(s16, lh, 4)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(s32, lw, 2)
DEFINE_UNPRIVILEGED_STORE_FUNCTION(u8, sb, 4)
DEFINE_UNPRIVILEGED_STORE_FUNCTION(u16, sh, 4)
DEFINE_UNPRIVILEGED_STORE_FUNCTION(u32, sw, 2)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(u8, lbu)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(u16, lhu)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(s8, lb)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(s16, lh)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(s32, lw)
DEFINE_UNPRIVILEGED_STORE_FUNCTION(u8, sb)
DEFINE_UNPRIVILEGED_STORE_FUNCTION(u16, sh)
DEFINE_UNPRIVILEGED_STORE_FUNCTION(u32, sw)
#if __riscv_xlen == 64
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(u32, lwu, 4)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(u64, ld, 2)
DEFINE_UNPRIVILEGED_STORE_FUNCTION(u64, sd, 2)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(ulong, ld, 2)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(u32, lwu)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(u64, ld)
DEFINE_UNPRIVILEGED_STORE_FUNCTION(u64, sd)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(ulong, ld)
#else
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(u32, lw, 2)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(ulong, lw, 2)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(u32, lw)
DEFINE_UNPRIVILEGED_LOAD_FUNCTION(ulong, lw)
u64 load_u64(const u64 *addr,
struct sbi_scratch *scratch, struct unpriv_trap *trap)
@@ -105,7 +109,6 @@ ulong get_insn(ulong mepc, bool virt, struct sbi_scratch *scratch,
ulong rvc_mask = 3, tmp;
#endif
trap->ilen = 4;
trap->cause = 0;
trap->tval = 0;
sbi_hart_set_trap_info(scratch, trap);
@@ -115,20 +118,29 @@ ulong get_insn(ulong mepc, bool virt, struct sbi_scratch *scratch,
#ifndef __riscv_compressed
asm("csrrs %[mstatus], " STR(CSR_MSTATUS) ", %[mprv]\n"
".option push\n"
".option norvc\n"
#if __riscv_xlen == 64
STR(LWU) " %[insn], (%[addr])\n"
#else
STR(LW) " %[insn], (%[addr])\n"
#endif
".option pop\n"
"csrw " STR(CSR_MSTATUS) ", %[mstatus]"
: [mstatus] "+&r"(__mstatus), [insn] "=&r"(val)
: [mprv] "r"(MSTATUS_MPRV | MSTATUS_MXR), [addr] "r"(mepc));
#else
asm("csrrs %[mstatus], " STR(CSR_MSTATUS) ", %[mprv]\n"
".option push\n"
".option norvc\n"
"lhu %[insn], (%[addr])\n"
".option pop\n"
"and %[tmp], %[insn], %[rvc_mask]\n"
"bne %[tmp], %[rvc_mask], 2f\n"
".option push\n"
".option norvc\n"
"lhu %[tmp], 2(%[addr])\n"
".option pop\n"
"sll %[tmp], %[tmp], 16\n"
"add %[insn], %[insn], %[tmp]\n"
"2: csrw " STR(CSR_MSTATUS) ", %[mstatus]"

2
lib/sbi/sbi_trap.c
View File

@@ -262,7 +262,7 @@ void sbi_trap_handler(struct sbi_trap_regs *regs, struct sbi_scratch *scratch)
uptrap = sbi_hart_get_trap_info(scratch);
if ((regs->mstatus & MSTATUS_MPRV) && uptrap) {
rc = 0;
regs->mepc += uptrap->ilen;
regs->mepc += 4;
uptrap->cause = mcause;
uptrap->tval = mtval;
} else {