drm/i915/perf: Add OA unit support for Gen 8+

Enables access to OA unit metrics for BDW, CHV, SKL and BXT which all
share (more-or-less) the same OA unit design.

Of particular note in comparison to Haswell: some OA unit HW config
state has become per-context state and as a consequence it is somewhat
more complicated to manage synchronous state changes from the cpu while
there's no guarantee of what context (if any) is currently actively
running on the gpu.

The periodic sampling frequency which can be particularly useful for
system-wide analysis (as opposed to command stream synchronised
MI_REPORT_PERF_COUNT commands) is perhaps the most surprising state to
have become per-context save and restored (while the OABUFFER
destination is still a shared, system-wide resource).

This support for gen8+ takes care to consider a number of timing
challenges involved in synchronously updating per-context state
primarily by programming all config state from the cpu and updating all
current and saved contexts synchronously while the OA unit is still
disabled.

The driver intentionally avoids depending on command streamer
programming to update OA state considering the lack of synchronization
between the automatic loading of OACTXCONTROL state (that includes the
periodic sampling state and enable state) on context restore and the
parsing of any general purpose BB the driver can control. I.e. this
implementation is careful to avoid the possibility of a context restore
temporarily enabling any out-of-date periodic sampling state. In
addition to the risk of transiently-out-of-date state being loaded
automatically; there are also internal HW latencies involved in the
loading of MUX configurations which would be difficult to account for
from the command streamer (and we only want to enable the unit when once
the MUX configuration is complete).

Since the Gen8+ OA unit design no longer supports clock gating the unit
off for a single given context (which effectively stopped any progress
of counters while any other context was running) and instead supports
tagging OA reports with a context ID for filtering on the CPU, it means
we can no longer hide the system-wide progress of counters from a
non-privileged application only interested in metrics for its own
context. Although we could theoretically try and subtract the progress
of other contexts before forwarding reports via read() we aren't in a
position to filter reports captured via MI_REPORT_PERF_COUNT commands.
As a result, for Gen8+, we always require the
dev.i915.perf_stream_paranoid to be unset for any access to OA metrics
if not root.

v5: Drain submitted requests when enabling metric set to ensure no
    lite-restore erases the context image we just updated (Lionel)

v6: In addition to drain, switch to kernel context & update all
    context in place (Chris)

v7: Add missing mutex_unlock() if switching to kernel context fails
    (Matthew)

v8: Simplify OA period/flex-eu-counters programming by using the
    batchbuffer instead of modifying ctx-image (Lionel)

v9: Back to updating the context image (due to erroneous testing,
    batchbuffer programming the OA unit doesn't actually work)
    (Lionel)
    Pin context before updating context image (Chris)
    Drop MMIO programming now that we switch to a kernel context with
    right values in initial context image (Chris)

v10: Just pin_map the contexts we want to modify or let the
     configuration happen on first use (Chris)

v11: Update kernel context OA config through the batchbuffer rather
     than on the fly ctx-image update (Lionel)

v12: Rework OA context registers update again by swithing away from
     user contexts and reconfiguring the kernel context through the
     batchbuffer and updating all the other contexts' context image.
     Also take care to lock slice/subslice configuration when OA is
     on. (Lionel)

v13: Request rpcs updates on all engine when updating the OA config
     (Lionel)

v14: Drop any kind of rpcs management now that we monitor sseu
     configuration changes in a later patch (Lionel)
     Remove usleep after programming the NOA configs on Gen8+, this
     doesn't seem to be needed (Lionel)

v15: Respect coding style for block comments (Chris)

v16: Add missing i915_add_request() in case we fail to emit OA
     configuration (Matthew)

Signed-off-by: Robert Bragg <robert@sixbynine.org>
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com> \o/
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 88e4707f571d..bd535f12db18 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -656,6 +656,12 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 
 #define GEN8_OACTXID _MMIO(0x2364)
 
+#define GEN8_OA_DEBUG _MMIO(0x2B04)
+#define  GEN9_OA_DEBUG_DISABLE_CLK_RATIO_REPORTS    (1<<5)
+#define  GEN9_OA_DEBUG_INCLUDE_CLK_RATIO	    (1<<6)
+#define  GEN9_OA_DEBUG_DISABLE_GO_1_0_REPORTS	    (1<<2)
+#define  GEN9_OA_DEBUG_DISABLE_CTX_SWITCH_REPORTS   (1<<1)
+
 #define GEN8_OACONTROL _MMIO(0x2B00)
 #define  GEN8_OA_REPORT_FORMAT_A12	    (0<<2)
 #define  GEN8_OA_REPORT_FORMAT_A12_B8_C8    (2<<2)
@@ -677,6 +683,7 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define  GEN7_OABUFFER_STOP_RESUME_ENABLE   (1<<1)
 #define  GEN7_OABUFFER_RESUME		    (1<<0)
 
+#define GEN8_OABUFFER_UDW _MMIO(0x23b4)
 #define GEN8_OABUFFER _MMIO(0x2b14)
 
 #define GEN7_OASTATUS1 _MMIO(0x2364)
@@ -695,7 +702,9 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define  GEN8_OASTATUS_REPORT_LOST	    (1<<0)
 
 #define GEN8_OAHEADPTR _MMIO(0x2B0C)
+#define GEN8_OAHEADPTR_MASK    0xffffffc0
 #define GEN8_OATAILPTR _MMIO(0x2B10)
+#define GEN8_OATAILPTR_MASK    0xffffffc0
 
 #define OABUFFER_SIZE_128K  (0<<3)
 #define OABUFFER_SIZE_256K  (1<<3)
@@ -708,7 +717,17 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 
 #define OA_MEM_SELECT_GGTT  (1<<0)
 
+/*
+ * Flexible, Aggregate EU Counter Registers.
+ * Note: these aren't contiguous
+ */
 #define EU_PERF_CNTL0	    _MMIO(0xe458)
+#define EU_PERF_CNTL1	    _MMIO(0xe558)
+#define EU_PERF_CNTL2	    _MMIO(0xe658)
+#define EU_PERF_CNTL3	    _MMIO(0xe758)
+#define EU_PERF_CNTL4	    _MMIO(0xe45c)
+#define EU_PERF_CNTL5	    _MMIO(0xe55c)
+#define EU_PERF_CNTL6	    _MMIO(0xe65c)
 
 #define GDT_CHICKEN_BITS    _MMIO(0x9840)
 #define GT_NOA_ENABLE	    0x00000080
@@ -2494,6 +2513,9 @@ enum skl_disp_power_wells {
 #define   GEN8_RC_SEMA_IDLE_MSG_DISABLE	(1 << 12)
 #define   GEN8_FF_DOP_CLOCK_GATE_DISABLE	(1<<10)
 
+#define GEN6_RCS_PWR_FSM _MMIO(0x22ac)
+#define GEN9_RCS_FE_FSM2 _MMIO(0x22a4)
+
 /* Fuse readout registers for GT */
 #define CHV_FUSE_GT			_MMIO(VLV_DISPLAY_BASE + 0x2168)
 #define   CHV_FGT_DISABLE_SS0		(1 << 10)