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riscv/debug: Add support for steppoint

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Steppoint can be implemented by icount(instruction count)
from RISC-V debug extension, but it may not implemented in all RISC-V cores.

Unfortunately, the currently supported RISC-V cores do not implement it.

Signed-off-by: Huang Qi <huangqi3@xiaomi.com>
This commit is contained in:
Huang Qi 2024-07-31 15:56:51 +08:00 committed by Xiang Xiao
parent fe45d8aace
commit 6ea3bc1217
1 changed files with 117 additions and 81 deletions
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198
arch/risc-v/src/common/riscv_debug.c
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@ -78,12 +78,12 @@
* Private Type
****************************************************************************/
/* Trigger Match Control, from version 0.13.2.
/* Represent the tdata1 register, from the RISC-V Debug Specification 0.13.2
* Read https://riscv.org/wp-content/uploads/2019/03/riscv-debug-release.pdf
* for more information
*/
union mcontrol
union tdata1
{
uintptr_t reg;
struct
@ -109,7 +109,21 @@ union mcontrol
uintptr_t maskmax : 6;
uintptr_t dmode : 1;
uintptr_t type : 4;
};
} match;
struct
{
uintptr_t action: 6;
uintptr_t u : 1;
uintptr_t s : 1;
uintptr_t reserved0 : 1;
uintptr_t m : 1;
uintptr_t count : 14;
uintptr_t hit : 1;
uintptr_t reserved1 : sizeof(uintptr_t) * 8 - 30;
uintptr_t dmode : 1;
uintptr_t type : 4;
} icount;
};
struct riscv_debug_trigger
@ -190,7 +204,7 @@ static int riscv_debug_handler(int irq, void *context, void *arg)
static int riscv_debug_init(void)
{
union mcontrol mc;
union tdata1 reg;
/* Attach the debug exception handler */
@ -223,22 +237,23 @@ static int riscv_debug_init(void)
WRITE_CSR(CSR_TSELECT, 0);
mc.reg = READ_CSR(CSR_TDATA1);
reg.reg = READ_CSR(CSR_TDATA1);
/* REVISIT: NAPOT match is supported and tested on
* QEMU and ESP32C3, prefer to use it.
*/
mc.match = MATCH_TYPE_TOPBITS;
reg.match.type = TRIGGER_TYPE_ADDRESS_DATA;
reg.match.match = MATCH_TYPE_TOPBITS;
/* Write it to tdata1 and read back
* to check if the NAPOT is supported
*/
WRITE_CSR(CSR_TDATA1, mc.reg);
mc.reg = READ_CSR(CSR_TDATA1);
WRITE_CSR(CSR_TDATA1, reg.reg);
reg.reg = READ_CSR(CSR_TDATA1);
if (mc.match == MATCH_TYPE_TOPBITS)
if (reg.match.match == MATCH_TYPE_TOPBITS)
{
g_support_napot = true;
}
@ -256,6 +271,74 @@ static int riscv_debug_init(void)
return 0;
}
/****************************************************************************
* Name: riscv_debug_setup_match
****************************************************************************/
static uintptr_t riscv_debug_setup_match(int type, void *addr, size_t size)
{
union tdata1 reg;
uintptr_t addr_napot;
if (type == DEBUGPOINT_BREAKPOINT)
{
reg.match.execute = 1;
}
else if (type == DEBUGPOINT_WATCHPOINT_RO)
{
reg.match.load = 1;
}
else if (type == DEBUGPOINT_WATCHPOINT_WO)
{
reg.match.store = 1;
}
else if (type == DEBUGPOINT_WATCHPOINT_RW)
{
reg.match.load = 1;
reg.match.store = 1;
}
reg.match.type = TRIGGER_TYPE_ADDRESS_DATA;
reg.match.m = 1;
reg.match.u = 1;
reg.match.hit = 0;
reg.match.dmode = DMODE_TYPE_BOTH;
reg.match.action = ACTION_TYPE_EXCEPTION;
/* From RISC-V Debug Specification:
* tdata1(mcontrol) match = 0 : Exact byte match
*
* tdata1(mcontrol) match = 1 : NAPOT (Naturally Aligned Power-Of-Two):
*
* Examples for understanding how to calculate match pattern to tdata2:
*
* nnnn...nnnnn 1-byte Exact byte match
* nnnn...nnnn0 2-byte NAPOT range
* nnnn...nnn01 4-byte NAPOT range
* nnnn...nn011 8-byte NAPOT range
* nnnn...n0111 16-byte NAPOT range
* nnnn...01111 32-byte NAPOT range
* ...
* n011...11111 2^31 byte NAPOT range
* where n are bits from original address
*/
if (size > 1 && g_support_napot)
{
reg.match.match = MATCH_TYPE_TOPBITS;
addr_napot = ((uintptr_t)addr & ~(size - 1)) |
((size - 1) >> 1);
WRITE_CSR(CSR_TDATA2, addr_napot);
}
else
{
reg.match.match = MATCH_TYPE_EQUAL;
WRITE_CSR(CSR_TDATA2, (uintptr_t)addr);
}
return reg.reg;
}
/****************************************************************************
* Public Functions
****************************************************************************/
@ -268,9 +351,8 @@ int up_debugpoint_add(int type, void *addr, size_t size,
debug_callback_t callback, void *arg)
{
int slot;
union mcontrol mc;
union tdata1 reg;
int ret = OK;
uintptr_t addr_napot;
/* Initialize the debug module if it is not initialized yet */
@ -297,77 +379,31 @@ int up_debugpoint_add(int type, void *addr, size_t size,
WRITE_CSR(CSR_TSELECT, slot);
/* Fetch the current setting from tdata1 */
mc.reg = READ_CSR(CSR_TDATA1);
/* Configure trigger */
mc.m = 1;
mc.u = 1;
mc.hit = 0;
mc.dmode = DMODE_TYPE_BOTH;
mc.action = ACTION_TYPE_EXCEPTION;
mc.execute = 0;
mc.load = 0;
mc.store = 0;
if (type == DEBUGPOINT_BREAKPOINT)
switch (type)
{
mc.execute = 1;
}
else if (type == DEBUGPOINT_WATCHPOINT_RO)
{
mc.load = 1;
}
else if (type == DEBUGPOINT_WATCHPOINT_WO)
{
mc.store = 1;
}
else if (type == DEBUGPOINT_WATCHPOINT_RW)
{
mc.load = 1;
mc.store = 1;
}
else
{
/* DEBUGPOINT_STEPPOINT is not supported since current test platform
* such as QEMU don't implemented yet.
*/
case DEBUGPOINT_STEPPOINT:
/* NOTICE: STEPPOINT implemented but not tested since no such
* hardware that implemented icount is available.
*/
return -ENOTSUP;
}
/* From RISC-V Debug Specification:
* tdata1(mcontrol) match = 0 : Exact byte match
*
* tdata1(mcontrol) match = 1 : NAPOT (Naturally Aligned Power-Of-Two):
*
* Examples for understanding how to calculate match pattern to tdata2:
*
* nnnn...nnnnn 1-byte Exact byte match
* nnnn...nnnn0 2-byte NAPOT range
* nnnn...nnn01 4-byte NAPOT range
* nnnn...nn011 8-byte NAPOT range
* nnnn...n0111 16-byte NAPOT range
* nnnn...01111 32-byte NAPOT range
* ...
* n011...11111 2^31 byte NAPOT range
* where n are bits from original address
*/
if (size > 1 && g_support_napot)
{
mc.match = MATCH_TYPE_TOPBITS;
addr_napot = ((uintptr_t)addr & ~(size - 1)) |
((size - 1) >> 1);
WRITE_CSR(CSR_TDATA2, addr_napot);
}
else
{
mc.match = MATCH_TYPE_EQUAL;
WRITE_CSR(CSR_TDATA2, (uintptr_t)addr);
reg.reg = 0;
reg.icount.type = TRIGGER_TYPE_ICOUNT;
reg.icount.dmode = DMODE_TYPE_BOTH;
reg.icount.count = 1;
reg.icount.hit = 0;
reg.icount.m = 1;
reg.icount.s = 1;
reg.icount.u = 1;
reg.icount.action = ACTION_TYPE_EXCEPTION;
break;
case DEBUGPOINT_BREAKPOINT:
case DEBUGPOINT_WATCHPOINT_RO:
case DEBUGPOINT_WATCHPOINT_RW:
case DEBUGPOINT_WATCHPOINT_WO:
reg.reg = riscv_debug_setup_match(type, addr, size);
break;
default:
return -EINVAL;
}
/* Register the callback and arg */
@ -377,7 +413,7 @@ int up_debugpoint_add(int type, void *addr, size_t size,
g_trigger_map[slot].size = size;
g_trigger_map[slot].callback = callback;
g_trigger_map[slot].arg = arg;
WRITE_CSR(CSR_TDATA1, mc.reg);
WRITE_CSR(CSR_TDATA1, reg.reg);
return 0;
}