On 28/03/2022 18:25, Matthew Auld wrote:
From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Even though the initial protocontext we load onto HW has the register
cleared, by the time we save it into the default image, BB_OFFSET has
had the enable bit set. Reclear BB_OFFSET for each new context.
Intriguing - is there any impact to this which would require cc: stable?
Regards,
Tvrtko
Testcase: igt/i915_selftests/gt_lrc
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
Signed-off-by: Ramalingam C <ramalingam.c@xxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_engine_regs.h | 1 +
drivers/gpu/drm/i915/gt/intel_lrc.c | 17 +++++++++++++++++
drivers/gpu/drm/i915/gt/selftest_lrc.c | 5 +++++
3 files changed, 23 insertions(+)
diff --git a/drivers/gpu/drm/i915/gt/intel_engine_regs.h b/drivers/gpu/drm/i915/gt/intel_engine_regs.h
index 0bf8b45c9319..d6da3bbf66f8 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_regs.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine_regs.h
@@ -109,6 +109,7 @@
#define RING_SBBSTATE(base) _MMIO((base) + 0x118) /* hsw+ */
#define RING_SBBADDR_UDW(base) _MMIO((base) + 0x11c) /* gen8+ */
#define RING_BBADDR(base) _MMIO((base) + 0x140)
+#define RING_BB_OFFSET(base) _MMIO((base) + 0x158)
#define RING_BBADDR_UDW(base) _MMIO((base) + 0x168) /* gen8+ */
#define CCID(base) _MMIO((base) + 0x180)
#define CCID_EN BIT(0)
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 07bef7128fdb..f673bae97a03 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -662,6 +662,18 @@ static int lrc_ring_mi_mode(const struct intel_engine_cs *engine)
return -1;
}
+static int lrc_ring_bb_offset(const struct intel_engine_cs *engine)
+{
+ if (GRAPHICS_VER_FULL(engine->i915) >= IP_VER(12, 50))
+ return 0x80;
+ else if (GRAPHICS_VER(engine->i915) >= 12)
+ return 0x70;
+ else if (GRAPHICS_VER(engine->i915) >= 9)
+ return 0x64;
+ else
+ return -1;
+}
+
static int lrc_ring_gpr0(const struct intel_engine_cs *engine)
{
if (GRAPHICS_VER_FULL(engine->i915) >= IP_VER(12, 50))
@@ -768,6 +780,7 @@ static void init_common_regs(u32 * const regs,
bool inhibit)
{
u32 ctl;
+ int loc;
ctl = _MASKED_BIT_ENABLE(CTX_CTRL_INHIBIT_SYN_CTX_SWITCH);
ctl |= _MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT);
@@ -779,6 +792,10 @@ static void init_common_regs(u32 * const regs,
regs[CTX_CONTEXT_CONTROL] = ctl;
regs[CTX_TIMESTAMP] = ce->runtime.last;
+
+ loc = lrc_ring_bb_offset(engine);
+ if (loc != -1)
+ regs[loc + 1] = 0;
}
static void init_wa_bb_regs(u32 * const regs,
diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index 21c29d315cc0..13f57c7c4224 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -323,6 +323,11 @@ static int live_lrc_fixed(void *arg)
lrc_ring_cmd_buf_cctl(engine),
"RING_CMD_BUF_CCTL"
},
+ {
+ i915_mmio_reg_offset(RING_BB_OFFSET(engine->mmio_base)),
+ lrc_ring_bb_offset(engine),
+ "RING_BB_OFFSET"
+ },
{ },
}, *t;
u32 *hw;
