From 1e9f88889f8b7c66dd229299715eed87e734aafa Mon Sep 17 00:00:00 2001
From: Anup Patel <anup.patel@wdc.com>
Date: Sun, 18 Aug 2019 13:14:44 +0530
Subject: lib: Emulate HTIMEDELTA CSR for platforms not having TIME CSR
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>
---
include/sbi/riscv_encoding.h | 4 ++-
include/sbi/sbi_emulate_csr.h | 5 ++--
include/sbi/sbi_timer.h | 8 +++++
lib/sbi/sbi_emulate_csr.c | 70 ++++++++++++++++++++++++++++++++++++-------
lib/sbi/sbi_illegal_insn.c | 5 ++--
lib/sbi/sbi_timer.c | 47 +++++++++++++++++++++++++++++
6 files changed, 122 insertions(+), 17 deletions(-)
diff --git a/include/sbi/riscv_encoding.h b/include/sbi/riscv_encoding.h
index 5aab9d2..902c81a 100644
--- a/include/sbi/riscv_encoding.h
+++ b/include/sbi/riscv_encoding.h
@@ -276,7 +276,9 @@
#define CSR_HSTATUS 0x600
#define CSR_HEDELEG 0x602
#define CSR_HIDELEG 0x603
-#define CSR_HCOUNTERNEN 0x606
+#define CSR_HTIMEDELTA 0x605
+#define CSR_HTIMEDELTAH 0x615
+#define CSR_HCOUNTERNEN 0x606
#define CSR_HGATP 0x680
#define CSR_VSSTATUS 0x200
diff --git a/include/sbi/sbi_emulate_csr.h b/include/sbi/sbi_emulate_csr.h
index 5d1755f..fe357e5 100644
--- a/include/sbi/sbi_emulate_csr.h
+++ b/include/sbi/sbi_emulate_csr.h
@@ -12,12 +12,13 @@
#include <sbi/sbi_types.h>
+struct sbi_trap_regs;
struct sbi_scratch;
-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 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);
#endif
diff --git a/include/sbi/sbi_timer.h b/include/sbi/sbi_timer.h
index e40cce9..c14c8d0 100644
--- a/include/sbi/sbi_timer.h
+++ b/include/sbi/sbi_timer.h
@@ -16,6 +16,14 @@ struct sbi_scratch;
u64 sbi_timer_value(struct sbi_scratch *scratch);
+u64 sbi_timer_virt_value(struct sbi_scratch *scratch);
+
+u64 sbi_timer_get_delta(struct sbi_scratch *scratch);
+
+void sbi_timer_set_delta(struct sbi_scratch *scratch, ulong delta);
+
+void sbi_timer_set_delta_upper(struct sbi_scratch *scratch, ulong delta_upper);
+
void sbi_timer_event_stop(struct sbi_scratch *scratch);
void sbi_timer_event_start(struct sbi_scratch *scratch, u64 next_event);
diff --git a/lib/sbi/sbi_emulate_csr.c b/lib/sbi/sbi_emulate_csr.c
index 791890f..0901ec1 100644
--- a/lib/sbi/sbi_emulate_csr.c
+++ b/lib/sbi/sbi_emulate_csr.c
@@ -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:
+ ret = SBI_ENOTSUPP;
+ break;
+ };
+
+ if (ret)
sbi_dprintf(scratch, "%s: hartid%d: invalid csr_num=0x%x\n",
__func__, hartid, csr_num);
- return SBI_ENOTSUPP;
- };
- return 0;
+ 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:
+ ret = SBI_ENOTSUPP;
+ break;
+ };
+
+ if (ret)
sbi_dprintf(scratch, "%s: hartid%d: invalid csr_num=0x%x\n",
__func__, hartid, csr_num);
- return SBI_ENOTSUPP;
- };
- return 0;
+ return ret;
}
diff --git a/lib/sbi/sbi_illegal_insn.c b/lib/sbi/sbi_illegal_insn.c
index e75c13c..d15986a 100644
--- a/lib/sbi/sbi_illegal_insn.c
+++ b/lib/sbi/sbi_illegal_insn.c
@@ -49,8 +49,7 @@ static int system_opcode_insn(ulong insn, u32 hartid, ulong mcause,
return sbi_trap_redirect(regs, scratch,
regs->mepc, mcause, insn);
- if (sbi_emulate_csr_read(csr_num, hartid, regs->mstatus,
- scratch, &csr_val))
+ if (sbi_emulate_csr_read(csr_num, hartid, regs, scratch, &csr_val))
return truly_illegal_insn(insn, hartid, mcause,
regs, scratch);
@@ -80,7 +79,7 @@ static int system_opcode_insn(ulong insn, u32 hartid, ulong mcause,
return truly_illegal_insn(insn, hartid, mcause, regs, scratch);
};
- if (do_write && sbi_emulate_csr_write(csr_num, hartid, regs->mstatus,
+ if (do_write && sbi_emulate_csr_write(csr_num, hartid, regs,
scratch, new_csr_val))
return truly_illegal_insn(insn, hartid, mcause, regs, scratch);
diff --git a/lib/sbi/sbi_timer.c b/lib/sbi/sbi_timer.c
index c58441d..1ba386f 100644
--- a/lib/sbi/sbi_timer.c
+++ b/lib/sbi/sbi_timer.c
@@ -9,9 +9,12 @@
#include <sbi/riscv_asm.h>
#include <sbi/riscv_encoding.h>
+#include <sbi/sbi_error.h>
#include <sbi/sbi_platform.h>
#include <sbi/sbi_timer.h>
+static unsigned long time_delta_off;
+
#if __riscv_xlen == 32
u64 get_ticks(void)
{
@@ -44,6 +47,35 @@ u64 sbi_timer_value(struct sbi_scratch *scratch)
return get_ticks();
}
+u64 sbi_timer_virt_value(struct sbi_scratch *scratch)
+{
+ u64 *time_delta = sbi_scratch_offset_ptr(scratch, time_delta_off);
+
+ return sbi_timer_value(scratch) + *time_delta;
+}
+
+u64 sbi_timer_get_delta(struct sbi_scratch *scratch)
+{
+ u64 *time_delta = sbi_scratch_offset_ptr(scratch, time_delta_off);
+
+ return *time_delta;
+}
+
+void sbi_timer_set_delta(struct sbi_scratch *scratch, ulong delta)
+{
+ u64 *time_delta = sbi_scratch_offset_ptr(scratch, time_delta_off);
+
+ *time_delta = (u64)delta;
+}
+
+void sbi_timer_set_delta_upper(struct sbi_scratch *scratch, ulong delta_upper)
+{
+ u64 *time_delta = sbi_scratch_offset_ptr(scratch, time_delta_off);
+
+ *time_delta &= 0xffffffffULL;
+ *time_delta |= ((u64)delta_upper << 32);
+}
+
void sbi_timer_event_stop(struct sbi_scratch *scratch)
{
sbi_platform_timer_event_stop(sbi_platform_ptr(scratch));
@@ -64,5 +96,20 @@ void sbi_timer_process(struct sbi_scratch *scratch)
int sbi_timer_init(struct sbi_scratch *scratch, bool cold_boot)
{
+ u64 *time_delta;
+
+ if (cold_boot) {
+ time_delta_off = sbi_scratch_alloc_offset(sizeof(*time_delta),
+ "TIME_DELTA");
+ if (!time_delta_off)
+ return SBI_ENOMEM;
+ } else {
+ if (!time_delta_off)
+ return SBI_ENOMEM;
+ }
+
+ time_delta = sbi_scratch_offset_ptr(scratch, time_delta_off);
+ *time_delta = 0;
+
return sbi_platform_timer_init(sbi_platform_ptr(scratch), cold_boot);
}
--
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