[PATCH v4 0/4] Use drm_clflush* instead of clflush

[PATCH v4 0/4] Use drm_clflush* instead of clflush

[Michael Cheng]

This patch series re-work a few i915 functions to use drm_clflush_virt_range
instead of calling clflush or clflushopt directly. This will prevent errors
when building for non-x86 architectures.

v2: s/PAGE_SIZE/sizeof(value) for Re-work intel_write_status_page and added
more patches to convert additional clflush/clflushopt to use drm_clflush*.
(Michael Cheng)

v3: Drop invalidate_csb_entries and directly invoke drm_clflush_virt_ran 

v4: Remove extra memory barriers

Michael Cheng (4):
  drm/i915/gt: Re-work intel_write_status_page
  drm/i915/gt: Drop invalidate_csb_entries
  drm/i915/gt: Re-work reset_csb
  drm/i915/: Re-work clflush_write32

 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c  |  8 +++-----
 drivers/gpu/drm/i915/gt/intel_engine.h          | 13 ++++---------
 .../drm/i915/gt/intel_execlists_submission.c    | 17 +++++------------
 3 files changed, 12 insertions(+), 26 deletions(-)

-- 
2.25.1

[PATCH v4 1/4] drm/i915/gt: Re-work intel_write_status_page

[Michael Cheng]

Re-work intel_write_status_page to use drm_clflush_virt_range. This
will prevent compiler errors when building for non-x86 architectures.

Signed-off-by: Michael Cheng <michael.cheng@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_engine.h | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine.h b/drivers/gpu/drm/i915/gt/intel_engine.h
index 0e353d8c2bc8..986777c2430d 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine.h
+++ b/drivers/gpu/drm/i915/gt/intel_engine.h
@@ -4,6 +4,7 @@
 
 #include <asm/cacheflush.h>
 #include <drm/drm_util.h>
+#include <drm/drm_cache.h>
 
 #include <linux/hashtable.h>
 #include <linux/irq_work.h>
@@ -143,15 +144,9 @@ intel_write_status_page(struct intel_engine_cs *engine, int reg, u32 value)
 	 * of extra paranoia to try and ensure that the HWS takes the value
 	 * we give and that it doesn't end up trapped inside the CPU!
 	 */
-	if (static_cpu_has(X86_FEATURE_CLFLUSH)) {
-		mb();
-		clflush(&engine->status_page.addr[reg]);
-		engine->status_page.addr[reg] = value;
-		clflush(&engine->status_page.addr[reg]);
-		mb();
-	} else {
-		WRITE_ONCE(engine->status_page.addr[reg], value);
-	}
+	drm_clflush_virt_range(&engine->status_page.addr[reg], sizeof(value));
+	WRITE_ONCE(engine->status_page.addr[reg], value);
+	drm_clflush_virt_range(&engine->status_page.addr[reg], sizeof(value));
 }
 
 /*
-- 
2.25.1

[PATCH v4 2/4] drm/i915/gt: Drop invalidate_csb_entries

[Michael Cheng]

Drop invalidate_csb_entries and directly call drm_clflush_virt_range.
This allows for one less function call, and prevent complier errors when
building for non-x86 architectures.

v2(Michael Cheng): Drop invalidate_csb_entries function and directly
		   invoke drm_clflush_virt_range. Thanks to Tvrtko for the
		   sugguestion.

Signed-off-by: Michael Cheng <michael.cheng@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index 9bb7c863172f..7500c06562da 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -1646,12 +1646,6 @@ cancel_port_requests(struct intel_engine_execlists * const execlists,
 	return inactive;
 }
 
-static void invalidate_csb_entries(const u64 *first, const u64 *last)
-{
-	clflush((void *)first);
-	clflush((void *)last);
-}
-
 /*
  * Starting with Gen12, the status has a new format:
  *
@@ -1999,7 +1993,7 @@ process_csb(struct intel_engine_cs *engine, struct i915_request **inactive)
 	 * the wash as hardware, working or not, will need to do the
 	 * invalidation before.
 	 */
-	invalidate_csb_entries(&buf[0], &buf[num_entries - 1]);
+	drm_clflush_virt_range(&buf[0], num_entries * sizeof(buf[0]));
 
 	/*
 	 * We assume that any event reflects a change in context flow
@@ -2783,8 +2777,8 @@ static void reset_csb_pointers(struct intel_engine_cs *engine)
 
 	/* Check that the GPU does indeed update the CSB entries! */
 	memset(execlists->csb_status, -1, (reset_value + 1) * sizeof(u64));
-	invalidate_csb_entries(&execlists->csb_status[0],
-			       &execlists->csb_status[reset_value]);
+	drm_clflush_virt_range(&execlists->csb_status[0],
+				sizeof(&execlists->csb_status[reset_value]));
 
 	/* Once more for luck and our trusty paranoia */
 	ENGINE_WRITE(engine, RING_CONTEXT_STATUS_PTR,
-- 
2.25.1

[PATCH v4 3/4] drm/i915/gt: Re-work reset_csb

[Michael Cheng]

Use drm_clflush_virt_range instead of directly invoking clflush. This
will prevent compiler errors when building for non-x86 architectures.

v2(Michael Cheng): Remove extra clflush

v3(Michael Cheng): Remove memory barrier since drm_clflush_virt_range
		   takes care of it.

Signed-off-by: Michael Cheng <michael.cheng@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_execlists_submission.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index 7500c06562da..22505aa428d9 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -2944,9 +2944,8 @@ reset_csb(struct intel_engine_cs *engine, struct i915_request **inactive)
 {
 	struct intel_engine_execlists * const execlists = &engine->execlists;
 
-	mb(); /* paranoia: read the CSB pointers from after the reset */
-	clflush(execlists->csb_write);
-	mb();
+	drm_clflush_virt_range(execlists->csb_write,
+			sizeof(execlists->csb_write));
 
 	inactive = process_csb(engine, inactive); /* drain preemption events */
 
-- 
2.25.1

[PATCH v4 4/4] drm/i915/: Re-work clflush_write32

[Michael Cheng]

Use drm_clflush_virt_range instead of clflushopt and remove the memory
barrier, since drm_clflush_virt_range takes care of that.

Signed-off-by: Michael Cheng <michael.cheng@intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 498b458fd784..0854276ff7ba 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -1332,10 +1332,8 @@ static void *reloc_vaddr(struct i915_vma *vma,
 static void clflush_write32(u32 *addr, u32 value, unsigned int flushes)
 {
 	if (unlikely(flushes & (CLFLUSH_BEFORE | CLFLUSH_AFTER))) {
-		if (flushes & CLFLUSH_BEFORE) {
-			clflushopt(addr);
-			mb();
-		}
+		if (flushes & CLFLUSH_BEFORE)
+			drm_clflush_virt_range(addr, sizeof(addr));
 
 		*addr = value;
 
@@ -1347,7 +1345,7 @@ static void clflush_write32(u32 *addr, u32 value, unsigned int flushes)
 		 * to ensure ordering of clflush wrt to the system.
 		 */
 		if (flushes & CLFLUSH_AFTER)
-			clflushopt(addr);
+			drm_clflush_virt_range(addr, sizeof(addr));
 	} else
 		*addr = value;
 }
-- 
2.25.1

[PATCH v4 4/4] drm/i915/: Re-work clflush_write32

[Michael Cheng]

Use drm_clflush_virt_range instead of clflushopt and remove the memory
barrier, since drm_clflush_virt_range takes care of that.

Signed-off-by: Michael Cheng <michael.cheng@intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 498b458fd784..0854276ff7ba 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -1332,10 +1332,8 @@ static void *reloc_vaddr(struct i915_vma *vma,
 static void clflush_write32(u32 *addr, u32 value, unsigned int flushes)
 {
 	if (unlikely(flushes & (CLFLUSH_BEFORE | CLFLUSH_AFTER))) {
-		if (flushes & CLFLUSH_BEFORE) {
-			clflushopt(addr);
-			mb();
-		}
+		if (flushes & CLFLUSH_BEFORE)
+			drm_clflush_virt_range(addr, sizeof(addr));
 
 		*addr = value;
 
@@ -1347,7 +1345,7 @@ static void clflush_write32(u32 *addr, u32 value, unsigned int flushes)
 		 * to ensure ordering of clflush wrt to the system.
 		 */
 		if (flushes & CLFLUSH_AFTER)
-			clflushopt(addr);
+			drm_clflush_virt_range(addr, sizeof(addr));
 	} else
 		*addr = value;
 }
-- 
2.25.1