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lib: Emulate HTIMEDELTA CSR for platforms not having TIME CSR

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For platforms not having TIME CSR, we trap-n-emulate TIME CSR
read/write in OpenSBI. Same rationale applies to HTIMEDELTA CSR
as well so we trap-n-emulate HTIMEDELTA CSR for platforms not
having TIME CSR.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
This commit is contained in:
Anup Patel
2019-08-18 13:14:44 +05:30
committed by Anup Patel
parent 7d4420bd69
commit 1e9f88889f
6 changed files with 124 additions and 19 deletions
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74
lib/sbi/sbi_emulate_csr.c
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@@ -14,16 +14,30 @@
#include <sbi/sbi_emulate_csr.h>
#include <sbi/sbi_error.h>
#include <sbi/sbi_timer.h>
#include <sbi/sbi_trap.h>
int sbi_emulate_csr_read(int csr_num, u32 hartid, ulong mstatus,
int sbi_emulate_csr_read(int csr_num, u32 hartid, struct sbi_trap_regs *regs,
struct sbi_scratch *scratch, ulong *csr_val)
{
int ret = 0;
ulong cen = -1UL;
ulong prev_mode = (regs->mstatus & MSTATUS_MPP) >> MSTATUS_MPP_SHIFT;
#if __riscv_xlen == 32
bool virt = (regs->mstatusH & MSTATUSH_MPV) ? TRUE : FALSE;
#else
bool virt = (regs->mstatus & MSTATUS_MPV) ? TRUE : FALSE;
#endif
if (EXTRACT_FIELD(mstatus, MSTATUS_MPP) == PRV_U)
if (prev_mode == PRV_U)
cen = csr_read(CSR_SCOUNTEREN);
switch (csr_num) {
case CSR_HTIMEDELTA:
if (prev_mode == PRV_S && !virt)
*csr_val = sbi_timer_get_delta(scratch);
else
ret = SBI_ENOTSUPP;
break;
case CSR_CYCLE:
if (!((cen >> (CSR_CYCLE - CSR_CYCLE)) & 1))
return -1;
@@ -32,7 +46,8 @@ int sbi_emulate_csr_read(int csr_num, u32 hartid, ulong mstatus,
case CSR_TIME:
if (!((cen >> (CSR_TIME - CSR_CYCLE)) & 1))
return -1;
*csr_val = sbi_timer_value(scratch);
*csr_val = (virt) ? sbi_timer_virt_value(scratch):
sbi_timer_value(scratch);
break;
case CSR_INSTRET:
if (!((cen >> (CSR_INSTRET - CSR_CYCLE)) & 1))
@@ -50,6 +65,12 @@ int sbi_emulate_csr_read(int csr_num, u32 hartid, ulong mstatus,
*csr_val = csr_read(CSR_MHPMCOUNTER4);
break;
#if __riscv_xlen == 32
case CSR_HTIMEDELTAH:
if (prev_mode == PRV_S && !virt)
*csr_val = sbi_timer_get_delta(scratch) >> 32;
else
ret = SBI_ENOTSUPP;
break;
case CSR_CYCLEH:
if (!((cen >> (CSR_CYCLE - CSR_CYCLE)) & 1))
return -1;
@@ -58,7 +79,8 @@ int sbi_emulate_csr_read(int csr_num, u32 hartid, ulong mstatus,
case CSR_TIMEH:
if (!((cen >> (CSR_TIME - CSR_CYCLE)) & 1))
return -1;
*csr_val = sbi_timer_value(scratch) >> 32;
*csr_val = (virt) ? sbi_timer_virt_value(scratch) >> 32:
sbi_timer_value(scratch) >> 32;
break;
case CSR_INSTRETH:
if (!((cen >> (CSR_INSTRET - CSR_CYCLE)) & 1))
@@ -83,18 +105,35 @@ int sbi_emulate_csr_read(int csr_num, u32 hartid, ulong mstatus,
*csr_val = csr_read(CSR_MHPMEVENT4);
break;
default:
sbi_dprintf(scratch, "%s: hartid%d: invalid csr_num=0x%x\n",
__func__, hartid, csr_num);
return SBI_ENOTSUPP;
ret = SBI_ENOTSUPP;
break;
};
return 0;
if (ret)
sbi_dprintf(scratch, "%s: hartid%d: invalid csr_num=0x%x\n",
__func__, hartid, csr_num);
return ret;
}
int sbi_emulate_csr_write(int csr_num, u32 hartid, ulong mstatus,
int sbi_emulate_csr_write(int csr_num, u32 hartid, struct sbi_trap_regs *regs,
struct sbi_scratch *scratch, ulong csr_val)
{
int ret = 0;
ulong prev_mode = (regs->mstatus & MSTATUS_MPP) >> MSTATUS_MPP_SHIFT;
#if __riscv_xlen == 32
bool virt = (regs->mstatusH & MSTATUSH_MPV) ? TRUE : FALSE;
#else
bool virt = (regs->mstatus & MSTATUS_MPV) ? TRUE : FALSE;
#endif
switch (csr_num) {
case CSR_HTIMEDELTA:
if (prev_mode == PRV_S && !virt)
sbi_timer_set_delta(scratch, csr_val);
else
ret = SBI_ENOTSUPP;
break;
case CSR_CYCLE:
csr_write(CSR_MCYCLE, csr_val);
break;
@@ -108,6 +147,12 @@ int sbi_emulate_csr_write(int csr_num, u32 hartid, ulong mstatus,
csr_write(CSR_MHPMCOUNTER4, csr_val);
break;
#if __riscv_xlen == 32
case CSR_HTIMEDELTAH:
if (prev_mode == PRV_S && !virt)
sbi_timer_set_delta_upper(scratch, csr_val);
else
ret = SBI_ENOTSUPP;
break;
case CSR_CYCLEH:
csr_write(CSR_MCYCLEH, csr_val);
break;
@@ -128,10 +173,13 @@ int sbi_emulate_csr_write(int csr_num, u32 hartid, ulong mstatus,
csr_write(CSR_MHPMEVENT4, csr_val);
break;
default:
sbi_dprintf(scratch, "%s: hartid%d: invalid csr_num=0x%x\n",
__func__, hartid, csr_num);
return SBI_ENOTSUPP;
ret = SBI_ENOTSUPP;
break;
};
return 0;
if (ret)
sbi_dprintf(scratch, "%s: hartid%d: invalid csr_num=0x%x\n",
__func__, hartid, csr_num);
return ret;
}