From 157e586dc98fcc9c6ec4cefa7d893e3a0992bd1a Mon Sep 17 00:00:00 2001 From: Jay Cornwall Date: Thu, 31 Jan 2019 11:38:18 -0600 Subject: [PATCH] drm/amdkfd: Preserve wave state after instruction fetch MEM_VIOL If instruction fetch fails the wave cannot be halted and returned to the shader without raising MEM_VIOL again. Currently the wave is terminated if this occurs, but this loses information about the cause of the fault. The debugger would prefer the faulting wave state to be context-saved. Poll inside the trap handler until TRAPSTS.SAVECTX indicates context save is ready. Exit the poll loop and complete the remainder of the exception handler, then return to the shader. The next instruction fetch will be from the trap handler and not the faulting PC. Context save will then deschedule the wave and save its state. Signed-off-by: Jay Cornwall Reviewed-by: Felix Kuehling Signed-off-by: Felix Kuehling Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler.h | 10 ++++++---- drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler_gfx9.asm | 10 ++++++++-- 2 files changed, 14 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler.h b/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler.h index ec9a9a99f808..097da0dd3b04 100644 --- a/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler.h +++ b/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler.h @@ -274,15 +274,17 @@ static const uint32_t cwsr_trap_gfx8_hex[] = { static const uint32_t cwsr_trap_gfx9_hex[] = { - 0xbf820001, 0xbf82015d, + 0xbf820001, 0xbf820161, 0xb8f8f802, 0x89788678, 0xb8f1f803, 0x866eff71, - 0x00000400, 0xbf850037, + 0x00000400, 0xbf85003b, 0x866eff71, 0x00000800, 0xbf850003, 0x866eff71, - 0x00000100, 0xbf840008, + 0x00000100, 0xbf84000c, 0x866eff78, 0x00002000, - 0xbf840001, 0xbf810000, + 0xbf840005, 0xbf8e0010, + 0xb8eef803, 0x866eff6e, + 0x00000400, 0xbf84fffb, 0x8778ff78, 0x00002000, 0x80ec886c, 0x82ed806d, 0xb8eef807, 0x866fff6e, diff --git a/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler_gfx9.asm b/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler_gfx9.asm index 0bb9c577b3a2..6a010c9e55de 100644 --- a/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler_gfx9.asm +++ b/drivers/gpu/drm/amd/amdkfd/cwsr_trap_handler_gfx9.asm @@ -266,10 +266,16 @@ if (!EMU_RUN_HACK) L_HALT_WAVE: // If STATUS.HALT is set then this fault must come from SQC instruction fetch. - // We cannot prevent further faults so just terminate the wavefront. + // We cannot prevent further faults. Spin wait until context saved. s_and_b32 ttmp2, s_save_status, SQ_WAVE_STATUS_HALT_MASK s_cbranch_scc0 L_NOT_ALREADY_HALTED - s_endpgm + +L_WAIT_CTX_SAVE: + s_sleep 0x10 + s_getreg_b32 ttmp2, hwreg(HW_REG_TRAPSTS) + s_and_b32 ttmp2, ttmp2, SQ_WAVE_TRAPSTS_SAVECTX_MASK + s_cbranch_scc0 L_WAIT_CTX_SAVE + L_NOT_ALREADY_HALTED: s_or_b32 s_save_status, s_save_status, SQ_WAVE_STATUS_HALT_MASK