Hi,

I thought I replied to the list, but only replied to the author.

This looks good to me, thanks.
I noted one possible improvement lower, could be added in a later patch.

Reviewed-by: Lancelot Six <[email protected]>

Best,
Lancelot.

On 14/11/2025 20:48, Jay Cornwall wrote:
The trap may be entered with dependency checking disabled.
Wait for dependency counters and save/restore scheduling mode.

v2:

Use ttmp1 instead of ttmp11. ttmp11 is not zero-initialized.
While the trap handler does zero this field before use, a user-mode
second-level trap handler could not rely on this being zero when
using an older kernel mode driver.

v3:

Use ttmp11 primarily but copy to ttmp1 before jumping to the
second level trap handler. ttmp1 is inspectable by a debugger.
Unexpected bits in the unused space may regress existing software.

Signed-off-by: Jay Cornwall <[email protected]>
Cc: Lancelot Six <[email protected]>
---
  .../gpu/drm/amd/amdkfd/cwsr_trap_handler.h    | 62 +++++++++++--------
  .../amd/amdkfd/cwsr_trap_handler_gfx12.asm    | 37 +++++++++++
  2 files changed, 73 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler.h 
b/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler.h
index 0320163b6e74..f98c735b2905 100644
--- a/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler.h
+++ b/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler.h
@@ -3644,14 +3644,18 @@ static const uint32_t cwsr_trap_gfx9_4_3_hex[] = {
  };
static const uint32_t cwsr_trap_gfx12_hex[] = {
-       0xbfa00001, 0xbfa002a2,
-       0xb0804009, 0xb8f8f804,
+       0xbfa00001, 0xbfa002b2,
+       0xb0804009, 0xb8eef81a,
+       0xbf880000, 0xb980081a,
+       0x00000000, 0xb8f8f804,
+       0x9177ff77, 0x0c000000,
+       0x846e9a6e, 0x8c776e77,
        0x9178ff78, 0x00008c00,
        0xb8fbf811, 0x8b6eff78,
        0x00004000, 0xbfa10008,
        0x8b6eff7b, 0x00000080,
        0xbfa20018, 0x8b6ea07b,
-       0xbfa20042, 0xbf830010,
+       0xbfa2004a, 0xbf830010,
        0xb8fbf811, 0xbfa0fffb,
        0x8b6eff7b, 0x00000bd0,
        0xbfa20010, 0xb8eef812,
@@ -3662,28 +3666,32 @@ static const uint32_t cwsr_trap_gfx12_hex[] = {
        0xf0000000, 0xbfa20005,
        0x8b6fff6f, 0x00000200,
        0xbfa20002, 0x8b6ea07b,
-       0xbfa2002c, 0xbefa4d82,
+       0xbfa20034, 0xbefa4d82,
        0xbf8a0000, 0x84fa887a,
        0xbf0d8f7b, 0xbfa10002,
        0x8c7bff7b, 0xffff0000,
-       0xf4601bbd, 0xf8000010,
-       0xbf8a0000, 0x846e976e,
-       0x9177ff77, 0x00800000,
-       0x8c776e77, 0xf4603bbd,
-       0xf8000000, 0xbf8a0000,
-       0xf4603ebd, 0xf8000008,
-       0xbf8a0000, 0x8bee6e6e,
-       0xbfa10001, 0xbe80486e,
-       0x8b6eff6d, 0xf0000000,
-       0xbfa20009, 0xb8eef811,
-       0x8b6eff6e, 0x00000080,
-       0xbfa20007, 0x8c78ff78,
-       0x00004000, 0x80ec886c,
-       0x82ed806d, 0xbfa00002,
-       0x806c846c, 0x826d806d,
-       0x8b6dff6d, 0x0000ffff,
-       0x8bfe7e7e, 0x8bea6a6a,
-       0x85788978, 0xb9783244,
+       0x8b6eff77, 0x0c000000,
+       0x916dff6d, 0x0c000000,
+       0x8c6d6e6d, 0xf4601bbd,
+       0xf8000010, 0xbf8a0000,
+       0x846e976e, 0x9177ff77,
+       0x00800000, 0x8c776e77,
+       0xf4603bbd, 0xf8000000,
+       0xbf8a0000, 0xf4603ebd,
+       0xf8000008, 0xbf8a0000,
+       0x8bee6e6e, 0xbfa10001,
+       0xbe80486e, 0x8b6eff6d,
+       0xf0000000, 0xbfa20009,
+       0xb8eef811, 0x8b6eff6e,
+       0x00000080, 0xbfa20007,
+       0x8c78ff78, 0x00004000,
+       0x80ec886c, 0x82ed806d,
+       0xbfa00002, 0x806c846c,
+       0x826d806d, 0x8b6dff6d,
+       0x0000ffff, 0x8bfe7e7e,
+       0x8bea6a6a, 0x85788978,
+       0x936eff77, 0x0002001a,
+       0xb96ef81a, 0xb9783244,
        0xbe804a6c, 0xb8faf802,
        0xbf0d987a, 0xbfa10001,
        0xbfb00000, 0x8b6dff6d,
@@ -3981,7 +3989,7 @@ static const uint32_t cwsr_trap_gfx12_hex[] = {
        0x008ce800, 0x00000000,
        0x807d817d, 0x8070ff70,
        0x00000080, 0xbf0a7b7d,
-       0xbfa2fff7, 0xbfa0016e,
+       0xbfa2fff7, 0xbfa00171,
        0xbef4007e, 0x8b75ff7f,
        0x0000ffff, 0x8c75ff75,
        0x00040000, 0xbef60080,
@@ -4163,12 +4171,14 @@ static const uint32_t cwsr_trap_gfx12_hex[] = {
        0xf8000074, 0xbf8a0000,
        0x8b6dff6d, 0x0000ffff,
        0x8bfe7e7e, 0x8bea6a6a,
-       0xb97af804, 0xbe804ec2,
-       0xbf94fffe, 0xbe804a6c,
+       0x936eff77, 0x0002001a,
+       0xb96ef81a, 0xb97af804,
        0xbe804ec2, 0xbf94fffe,
-       0xbfb10000, 0xbf9f0000,
+       0xbe804a6c, 0xbe804ec2,
+       0xbf94fffe, 0xbfb10000,
        0xbf9f0000, 0xbf9f0000,
        0xbf9f0000, 0xbf9f0000,
+       0xbf9f0000, 0x00000000,
  };
static const uint32_t cwsr_trap_gfx9_5_0_hex[] = {
diff --git a/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler_gfx12.asm 
b/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler_gfx12.asm
index 5a1a1b1f897f..07999b4649de 100644
--- a/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler_gfx12.asm
+++ b/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler_gfx12.asm
@@ -78,9 +78,16 @@ var SQ_WAVE_EXCP_FLAG_PRIV_RESTORE_PART_2_SHIFT      = 
SQ_WAVE_EXCP_FLAG_PRIV_ILLEGAL
  var SQ_WAVE_EXCP_FLAG_PRIV_RESTORE_PART_2_SIZE        = 
SQ_WAVE_EXCP_FLAG_PRIV_HOST_TRAP_SHIFT - 
SQ_WAVE_EXCP_FLAG_PRIV_ILLEGAL_INST_SHIFT
  var SQ_WAVE_EXCP_FLAG_PRIV_RESTORE_PART_3_SHIFT       = 
SQ_WAVE_EXCP_FLAG_PRIV_WAVE_START_SHIFT
  var SQ_WAVE_EXCP_FLAG_PRIV_RESTORE_PART_3_SIZE        = 32 - 
SQ_WAVE_EXCP_FLAG_PRIV_RESTORE_PART_3_SHIFT
+
+var SQ_WAVE_SCHED_MODE_DEP_MODE_SHIFT          = 0
+var SQ_WAVE_SCHED_MODE_DEP_MODE_SIZE           = 2
+
  var BARRIER_STATE_SIGNAL_OFFSET                       = 16
  var BARRIER_STATE_VALID_OFFSET                        = 0
+var TTMP11_SCHED_MODE_SHIFT = 26
+var TTMP11_SCHED_MODE_SIZE                     = 2
+var TTMP11_SCHED_MODE_MASK                     = 0xC000000
  var TTMP11_DEBUG_TRAP_ENABLED_SHIFT           = 23
  var TTMP11_DEBUG_TRAP_ENABLED_MASK            = 0x800000
@@ -160,8 +167,19 @@ L_JUMP_TO_RESTORE:
        s_branch        L_RESTORE
L_SKIP_RESTORE:
+       // Assume most relaxed scheduling mode is set. Save and revert to 
normal mode.
+       s_getreg_b32    ttmp2, hwreg(HW_REG_WAVE_SCHED_MODE)

Could be hwreg(HW_REG_WAVE_SCHED_MODE, 0, 2)

+       s_wait_alu      0
+       s_setreg_imm32_b32      hwreg(HW_REG_WAVE_SCHED_MODE, \
+               SQ_WAVE_SCHED_MODE_DEP_MODE_SHIFT, 
SQ_WAVE_SCHED_MODE_DEP_MODE_SIZE), 0
+
        s_getreg_b32    s_save_state_priv, hwreg(HW_REG_WAVE_STATE_PRIV)        
//save STATUS since we will change SCC
+ // Save SCHED_MODE[1:0] into ttmp11[27:26].
+       s_andn2_b32     ttmp11, ttmp11, TTMP11_SCHED_MODE_MASK
+       s_lshl_b32      ttmp2, ttmp2, TTMP11_SCHED_MODE_SHIFT
+       s_or_b32        ttmp11, ttmp11, ttmp2
+
        // Clear SPI_PRIO: do not save with elevated priority.
        // Clear ECC_ERR: prevents SQC store and triggers FATAL_HALT if 
setreg'd.
        s_andn2_b32     s_save_state_priv, s_save_state_priv, 
SQ_WAVE_STATE_PRIV_ALWAYS_CLEAR_MASK
@@ -238,6 +256,13 @@ L_FETCH_2ND_TRAP:
        s_cbranch_scc0  L_NO_SIGN_EXTEND_TMA
        s_or_b32        ttmp15, ttmp15, 0xFFFF0000
  L_NO_SIGN_EXTEND_TMA:
+#if ASIC_FAMILY == CHIP_GFX12
+       // Move SCHED_MODE[1:0] from ttmp11 to unused bits in ttmp1[27:26] 
(return PC_HI).
+       // The second-level trap will restore from ttmp1 for backwards 
compatibility.
+       s_and_b32       ttmp2, ttmp11, TTMP11_SCHED_MODE_MASK
+       s_andn2_b32     ttmp1, ttmp1, TTMP11_SCHED_MODE_MASK
+       s_or_b32        ttmp1, ttmp1, ttmp2
+#endif
s_load_dword ttmp2, [ttmp14, ttmp15], 0x10 scope:SCOPE_SYS // debug trap enabled flag
        s_wait_idle
@@ -287,6 +312,10 @@ L_EXIT_TRAP:
        // STATE_PRIV.BARRIER_COMPLETE may have changed since we read it.
        // Only restore fields which the trap handler changes.
        s_lshr_b32      s_save_state_priv, s_save_state_priv, 
SQ_WAVE_STATE_PRIV_SCC_SHIFT
+
+       // Assume relaxed scheduling mode after this point.
+       restore_sched_mode(ttmp2)
+
        s_setreg_b32    hwreg(HW_REG_WAVE_STATE_PRIV, 
SQ_WAVE_STATE_PRIV_SCC_SHIFT, \
                SQ_WAVE_STATE_PRIV_POISON_ERR_SHIFT - 
SQ_WAVE_STATE_PRIV_SCC_SHIFT + 1), s_save_state_priv
@@ -1043,6 +1072,9 @@ L_SKIP_BARRIER_RESTORE:
        s_and_b64       exec, exec, exec                                        
// Restore STATUS.EXECZ, not writable by s_setreg_b32
        s_and_b64       vcc, vcc, vcc                                           
// Restore STATUS.VCCZ, not writable by s_setreg_b32
+ // Assume relaxed scheduling mode after this point.
+       restore_sched_mode(s_restore_tmp)
+
        s_setreg_b32    hwreg(HW_REG_WAVE_STATE_PRIV), s_restore_state_priv     
// SCC is included, which is changed by previous salu
// Make barrier and LDS state visible to all waves in the group.
@@ -1134,3 +1166,8 @@ function valu_sgpr_hazard
        end
  #endif
  end
+
+function restore_sched_mode(s_tmp)
+       s_bfe_u32       s_tmp, ttmp11, (TTMP11_SCHED_MODE_SHIFT | 
(TTMP11_SCHED_MODE_SIZE << 0x10))
+       s_setreg_b32    hwreg(HW_REG_WAVE_SCHED_MODE), s_tmp
+end

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