[PATCH v6 0/6] Use drm_clflush* instead of clflush

[PATCH v6 0/6] 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                                                
                                                                                 
v5: s/cache_clflush_range/drm_clflush_virt_range  

v6: Fix up "Drop invalidate_csb_entries" to use correct parameters. Also
added in arm64 support for drm_clflush_virt_range.

Michael Cheng (6):
  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
  drm/i915/gt: replace cache_clflush_range
  drm: Add arch arm64 for drm_clflush_virt_range

 drivers/gpu/drm/drm_cache.c                   |  4 ++++
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    |  8 +++-----
 drivers/gpu/drm/i915/gt/gen8_ppgtt.c          | 12 ++++++------
 drivers/gpu/drm/i915/gt/intel_engine.h        | 13 ++++---------
 .../drm/i915/gt/intel_execlists_submission.c  | 19 ++++++-------------
 drivers/gpu/drm/i915/gt/intel_gtt.c           |  2 +-
 drivers/gpu/drm/i915/gt/intel_ppgtt.c         |  2 +-
 .../gpu/drm/i915/gt/uc/intel_guc_submission.c |  2 +-
 8 files changed, 26 insertions(+), 36 deletions(-)

-- 
2.25.1

[PATCH v6 1/6] 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 v6 2/6] 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.

v3(Michael Cheng): Use correct parameters for drm_clflush_virt_range.
		   Thanks to Tvrtko for pointing this out.

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..28f2581d3046 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],
+		execlists->csb_size * sizeof(execlists->csb_status[0]));
 
 	/* Once more for luck and our trusty paranoia */
 	ENGINE_WRITE(engine, RING_CONTEXT_STATUS_PTR,
-- 
2.25.1

[PATCH v6 3/6] 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 28f2581d3046..cc561cfae808 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 v6 4/6] 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 v6 5/6] drm/i915/gt: replace cache_clflush_range

[Michael Cheng]

Replace all occurance of cache_clflush_range with
drm_clflush_virt_range. This will prevent compile errors on non-x86
platforms.

Signed-off-by: Michael Cheng <michael.cheng@intel.com>
---
 drivers/gpu/drm/i915/gt/gen8_ppgtt.c                 | 12 ++++++------
 drivers/gpu/drm/i915/gt/intel_execlists_submission.c |  2 +-
 drivers/gpu/drm/i915/gt/intel_gtt.c                  |  2 +-
 drivers/gpu/drm/i915/gt/intel_ppgtt.c                |  2 +-
 drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c    |  2 +-
 5 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
index c43e724afa9f..d0999e92621b 100644
--- a/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
+++ b/drivers/gpu/drm/i915/gt/gen8_ppgtt.c
@@ -444,11 +444,11 @@ gen8_ppgtt_insert_pte(struct i915_ppgtt *ppgtt,
 				pd = pdp->entry[gen8_pd_index(idx, 2)];
 			}
 
-			clflush_cache_range(vaddr, PAGE_SIZE);
+			drm_clflush_virt_range(vaddr, PAGE_SIZE);
 			vaddr = px_vaddr(i915_pt_entry(pd, gen8_pd_index(idx, 1)));
 		}
 	} while (1);
-	clflush_cache_range(vaddr, PAGE_SIZE);
+	drm_clflush_virt_range(vaddr, PAGE_SIZE);
 
 	return idx;
 }
@@ -532,7 +532,7 @@ static void gen8_ppgtt_insert_huge(struct i915_address_space *vm,
 			}
 		} while (rem >= page_size && index < I915_PDES);
 
-		clflush_cache_range(vaddr, PAGE_SIZE);
+		drm_clflush_virt_range(vaddr, PAGE_SIZE);
 
 		/*
 		 * Is it safe to mark the 2M block as 64K? -- Either we have
@@ -548,7 +548,7 @@ static void gen8_ppgtt_insert_huge(struct i915_address_space *vm,
 					      I915_GTT_PAGE_SIZE_2M)))) {
 			vaddr = px_vaddr(pd);
 			vaddr[maybe_64K] |= GEN8_PDE_IPS_64K;
-			clflush_cache_range(vaddr, PAGE_SIZE);
+			drm_clflush_virt_range(vaddr, PAGE_SIZE);
 			page_size = I915_GTT_PAGE_SIZE_64K;
 
 			/*
@@ -569,7 +569,7 @@ static void gen8_ppgtt_insert_huge(struct i915_address_space *vm,
 				for (i = 1; i < index; i += 16)
 					memset64(vaddr + i, encode, 15);
 
-				clflush_cache_range(vaddr, PAGE_SIZE);
+				drm_clflush_virt_range(vaddr, PAGE_SIZE);
 			}
 		}
 
@@ -617,7 +617,7 @@ static void gen8_ppgtt_insert_entry(struct i915_address_space *vm,
 
 	vaddr = px_vaddr(i915_pt_entry(pd, gen8_pd_index(idx, 1)));
 	vaddr[gen8_pd_index(idx, 0)] = gen8_pte_encode(addr, level, flags);
-	clflush_cache_range(&vaddr[gen8_pd_index(idx, 0)], sizeof(*vaddr));
+	drm_clflush_virt_range(&vaddr[gen8_pd_index(idx, 0)], sizeof(*vaddr));
 }
 
 static int gen8_init_scratch(struct i915_address_space *vm)
diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
index cc561cfae808..bbe33794b34d 100644
--- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
+++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
@@ -2822,7 +2822,7 @@ static void execlists_sanitize(struct intel_engine_cs *engine)
 	sanitize_hwsp(engine);
 
 	/* And scrub the dirty cachelines for the HWSP */
-	clflush_cache_range(engine->status_page.addr, PAGE_SIZE);
+	drm_clflush_virt_range(engine->status_page.addr, PAGE_SIZE);
 
 	intel_engine_reset_pinned_contexts(engine);
 }
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index 0d6bbc8c57f2..9b594be9102f 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -255,7 +255,7 @@ fill_page_dma(struct drm_i915_gem_object *p, const u64 val, unsigned int count)
 	void *vaddr = __px_vaddr(p);
 
 	memset64(vaddr, val, count);
-	clflush_cache_range(vaddr, PAGE_SIZE);
+	drm_clflush_virt_range(vaddr, PAGE_SIZE);
 }
 
 static void poison_scratch_page(struct drm_i915_gem_object *scratch)
diff --git a/drivers/gpu/drm/i915/gt/intel_ppgtt.c b/drivers/gpu/drm/i915/gt/intel_ppgtt.c
index 48e6e2f87700..bd474a5123cb 100644
--- a/drivers/gpu/drm/i915/gt/intel_ppgtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ppgtt.c
@@ -90,7 +90,7 @@ write_dma_entry(struct drm_i915_gem_object * const pdma,
 	u64 * const vaddr = __px_vaddr(pdma);
 
 	vaddr[idx] = encoded_entry;
-	clflush_cache_range(&vaddr[idx], sizeof(u64));
+	drm_clflush_virt_range(&vaddr[idx], sizeof(u64));
 }
 
 void
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index b3a429a92c0d..89020706adc4 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -3573,7 +3573,7 @@ static void guc_sanitize(struct intel_engine_cs *engine)
 	sanitize_hwsp(engine);
 
 	/* And scrub the dirty cachelines for the HWSP */
-	clflush_cache_range(engine->status_page.addr, PAGE_SIZE);
+	drm_clflush_virt_range(engine->status_page.addr, PAGE_SIZE);
 
 	intel_engine_reset_pinned_contexts(engine);
 }
-- 
2.25.1

[PATCH v6 6/6] drm: Add arch arm64 for drm_clflush_virt_range

[Michael Cheng]

Use flush_tlb_kernel_range when invoking drm_clflush_virt_range on
arm64 platforms. Using flush_tlb_kernel_range will:

1. Make sure prior page-table updates have been completed
2. Invalidate the TLB
3. Check if the TLB invalidation has been completed

Signed-off-by: Michael Cheng <michael.cheng@intel.com>
---
 drivers/gpu/drm/drm_cache.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
index f19d9acbe959..d2506060a7c8 100644
--- a/drivers/gpu/drm/drm_cache.c
+++ b/drivers/gpu/drm/drm_cache.c
@@ -176,6 +176,10 @@ drm_clflush_virt_range(void *addr, unsigned long length)
 
 	if (wbinvd_on_all_cpus())
 		pr_err("Timed out waiting for cache flush\n");
+
+#elif defined(CONFIG_ARM64)
+	void *end = addr + length;
+	flush_tlb_kernel_range(*addr, *end);
 #else
 	pr_err("Architecture has no drm_cache.c support\n");
 	WARN_ON_ONCE(1);
-- 
2.25.1

Re: [Intel-gfx] [PATCH v6 6/6] drm: Add arch arm64 for drm_clflush_virt_range

[kernel test robot]

Hi Michael,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on drm-intel/for-linux-next]
[also build test ERROR on drm-tip/drm-tip drm/drm-next v5.17-rc3 next-20220207]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Michael-Cheng/Use-drm_clflush-instead-of-clflush/20220208-041326
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
config: arm64-randconfig-r005-20220207 (https://download.01.org/0day-ci/archive/20220208/202202081151.wYD1tE4p-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 0d8850ae2cae85d49bea6ae0799fa41c7202c05c)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://github.com/0day-ci/linux/commit/f2fb6ade1531d88b046e245e8b854a7422a05a14
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Michael-Cheng/Use-drm_clflush-instead-of-clflush/20220208-041326
        git checkout f2fb6ade1531d88b046e245e8b854a7422a05a14
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> drivers/gpu/drm/drm_cache.c:182:25: error: passing 'void' to parameter of incompatible type 'unsigned long'
           flush_tlb_kernel_range(*addr, *end);
                                  ^~~~~
   arch/arm64/include/asm/tlbflush.h:374:57: note: passing argument to parameter 'start' here
   static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end)
                                                           ^
   1 error generated.


vim +182 drivers/gpu/drm/drm_cache.c

   151	
   152	/**
   153	 * drm_clflush_virt_range - Flush dcache lines of a region
   154	 * @addr: Initial kernel memory address.
   155	 * @length: Region size.
   156	 *
   157	 * Flush every data cache line entry that points to an address in the
   158	 * region requested.
   159	 */
   160	void
   161	drm_clflush_virt_range(void *addr, unsigned long length)
   162	{
   163	#if defined(CONFIG_X86)
   164		if (static_cpu_has(X86_FEATURE_CLFLUSH)) {
   165			const int size = boot_cpu_data.x86_clflush_size;
   166			void *end = addr + length;
   167	
   168			addr = (void *)(((unsigned long)addr) & -size);
   169			mb(); /*CLFLUSH is only ordered with a full memory barrier*/
   170			for (; addr < end; addr += size)
   171				clflushopt(addr);
   172			clflushopt(end - 1); /* force serialisation */
   173			mb(); /*Ensure that every data cache line entry is flushed*/
   174			return;
   175		}
   176	
   177		if (wbinvd_on_all_cpus())
   178			pr_err("Timed out waiting for cache flush\n");
   179	
   180	#elif defined(CONFIG_ARM64)
   181		void *end = addr + length;
 > 182		flush_tlb_kernel_range(*addr, *end);
   183	#else
   184		pr_err("Architecture has no drm_cache.c support\n");
   185		WARN_ON_ONCE(1);
   186	#endif
   187	}
   188	EXPORT_SYMBOL(drm_clflush_virt_range);
   189	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

Re: [Intel-gfx] [PATCH v6 6/6] drm: Add arch arm64 for drm_clflush_virt_range

[kernel test robot]

Hi Michael,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on drm-intel/for-linux-next]
[also build test ERROR on drm-tip/drm-tip drm/drm-next v5.17-rc3 next-20220207]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Michael-Cheng/Use-drm_clflush-instead-of-clflush/20220208-041326
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
config: arm64-defconfig (https://download.01.org/0day-ci/archive/20220208/202202081258.VY7Y7JnA-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/f2fb6ade1531d88b046e245e8b854a7422a05a14
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Michael-Cheng/Use-drm_clflush-instead-of-clflush/20220208-041326
        git checkout f2fb6ade1531d88b046e245e8b854a7422a05a14
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=arm64 SHELL=/bin/bash drivers/gpu/drm/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All error/warnings (new ones prefixed by >>):

   drivers/gpu/drm/drm_cache.c: In function 'drm_clflush_virt_range':
>> drivers/gpu/drm/drm_cache.c:182:32: warning: dereferencing 'void *' pointer
     182 |         flush_tlb_kernel_range(*addr, *end);
         |                                ^~~~~
   drivers/gpu/drm/drm_cache.c:182:39: warning: dereferencing 'void *' pointer
     182 |         flush_tlb_kernel_range(*addr, *end);
         |                                       ^~~~
>> drivers/gpu/drm/drm_cache.c:182:32: error: invalid use of void expression
     182 |         flush_tlb_kernel_range(*addr, *end);
         |                                ^~~~~
   drivers/gpu/drm/drm_cache.c:182:39: error: invalid use of void expression
     182 |         flush_tlb_kernel_range(*addr, *end);
         |                                       ^~~~


vim +182 drivers/gpu/drm/drm_cache.c

   151	
   152	/**
   153	 * drm_clflush_virt_range - Flush dcache lines of a region
   154	 * @addr: Initial kernel memory address.
   155	 * @length: Region size.
   156	 *
   157	 * Flush every data cache line entry that points to an address in the
   158	 * region requested.
   159	 */
   160	void
   161	drm_clflush_virt_range(void *addr, unsigned long length)
   162	{
   163	#if defined(CONFIG_X86)
   164		if (static_cpu_has(X86_FEATURE_CLFLUSH)) {
   165			const int size = boot_cpu_data.x86_clflush_size;
   166			void *end = addr + length;
   167	
   168			addr = (void *)(((unsigned long)addr) & -size);
   169			mb(); /*CLFLUSH is only ordered with a full memory barrier*/
   170			for (; addr < end; addr += size)
   171				clflushopt(addr);
   172			clflushopt(end - 1); /* force serialisation */
   173			mb(); /*Ensure that every data cache line entry is flushed*/
   174			return;
   175		}
   176	
   177		if (wbinvd_on_all_cpus())
   178			pr_err("Timed out waiting for cache flush\n");
   179	
   180	#elif defined(CONFIG_ARM64)
   181		void *end = addr + length;
 > 182		flush_tlb_kernel_range(*addr, *end);
   183	#else
   184		pr_err("Architecture has no drm_cache.c support\n");
   185		WARN_ON_ONCE(1);
   186	#endif
   187	}
   188	EXPORT_SYMBOL(drm_clflush_virt_range);
   189	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

Re: [PATCH v6 6/6] drm: Add arch arm64 for drm_clflush_virt_range

[Tvrtko Ursulin]

On 07/02/2022 20:11, Michael Cheng wrote:
> Use flush_tlb_kernel_range when invoking drm_clflush_virt_range on
> arm64 platforms. Using flush_tlb_kernel_range will:
> 
> 1. Make sure prior page-table updates have been completed
> 2. Invalidate the TLB
> 3. Check if the TLB invalidation has been completed

Arm does not have a clflush equivalent but invalidating TLBs there 
includes flushing caches?

Regards,

Tvrtko

> Signed-off-by: Michael Cheng <michael.cheng@intel.com>
> ---
>   drivers/gpu/drm/drm_cache.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
> index f19d9acbe959..d2506060a7c8 100644
> --- a/drivers/gpu/drm/drm_cache.c
> +++ b/drivers/gpu/drm/drm_cache.c
> @@ -176,6 +176,10 @@ drm_clflush_virt_range(void *addr, unsigned long length)
>   
>   	if (wbinvd_on_all_cpus())
>   		pr_err("Timed out waiting for cache flush\n");
> +
> +#elif defined(CONFIG_ARM64)
> +	void *end = addr + length;
> +	flush_tlb_kernel_range(*addr, *end);
>   #else
>   	pr_err("Architecture has no drm_cache.c support\n");
>   	WARN_ON_ONCE(1);

Re: [PATCH v6 6/6] drm: Add arch arm64 for drm_clflush_virt_range

[Michael Cheng]

Ah, thanks for asking this question. It seems like I was not thinking 
correctly. We are trying to flush dcache lines within this function and 
not the tlb.

On 2022-02-08 2:20 a.m., Tvrtko Ursulin wrote:
>
> On 07/02/2022 20:11, Michael Cheng wrote:
>> Use flush_tlb_kernel_range when invoking drm_clflush_virt_range on
>> arm64 platforms. Using flush_tlb_kernel_range will:
>>
>> 1. Make sure prior page-table updates have been completed
>> 2. Invalidate the TLB
>> 3. Check if the TLB invalidation has been completed
>
> Arm does not have a clflush equivalent but invalidating TLBs there 
> includes flushing caches?
>
> Regards,
>
> Tvrtko
>
>> Signed-off-by: Michael Cheng <michael.cheng@intel.com>
>> ---
>>   drivers/gpu/drm/drm_cache.c | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
>> index f19d9acbe959..d2506060a7c8 100644
>> --- a/drivers/gpu/drm/drm_cache.c
>> +++ b/drivers/gpu/drm/drm_cache.c
>> @@ -176,6 +176,10 @@ drm_clflush_virt_range(void *addr, unsigned long 
>> length)
>>         if (wbinvd_on_all_cpus())
>>           pr_err("Timed out waiting for cache flush\n");
>> +
>> +#elif defined(CONFIG_ARM64)
>> +    void *end = addr + length;
>> +    flush_tlb_kernel_range(*addr, *end);
>>   #else
>>       pr_err("Architecture has no drm_cache.c support\n");
>>       WARN_ON_ONCE(1);

[PATCH] drm/i915/: fix noderef.cocci warnings

[kernel test robot]

From: kernel test robot <lkp@intel.com>

drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c:1310:32-38: ERROR: application of sizeof to pointer
drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c:1322:32-38: ERROR: application of sizeof to pointer

 sizeof when applied to a pointer typed expression gives the size of
 the pointer

Generated by: scripts/coccinelle/misc/noderef.cocci

CC: Michael Cheng <michael.cheng@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
---

url:    https://github.com/0day-ci/linux/commits/Michael-Cheng/Use-drm_clflush-instead-of-clflush/20220208-041326
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
:::::: branch date: 2 days ago
:::::: commit date: 2 days ago

 i915_gem_execbuffer.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -1307,7 +1307,7 @@ static void clflush_write32(u32 *addr, u
 {
 	if (unlikely(flushes & (CLFLUSH_BEFORE | CLFLUSH_AFTER))) {
 		if (flushes & CLFLUSH_BEFORE)
-			drm_clflush_virt_range(addr, sizeof(addr));
+			drm_clflush_virt_range(addr, sizeof(*addr));
 
 		*addr = value;
 
@@ -1319,7 +1319,7 @@ static void clflush_write32(u32 *addr, u
 		 * to ensure ordering of clflush wrt to the system.
 		 */
 		if (flushes & CLFLUSH_AFTER)
-			drm_clflush_virt_range(addr, sizeof(addr));
+			drm_clflush_virt_range(addr, sizeof(*addr));
 	} else
 		*addr = value;
 }

Re: [Intel-gfx] [PATCH v6 4/6] drm/i915/: Re-work clflush_write32

[kernel test robot]

Hi Michael,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on drm-intel/for-linux-next]
[also build test WARNING on drm-tip/drm-tip drm/drm-next v5.17-rc3]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Michael-Cheng/Use-drm_clflush-instead-of-clflush/20220208-041326
base:   git://anongit.freedesktop.org/drm-intel for-linux-next
config: x86_64-randconfig-c002 (https://download.01.org/0day-ci/archive/20220210/202202100010.fBBNyCpm-lkp@intel.com/config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


cocci warnings: (new ones prefixed by >>)
>> drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c:1310:32-38: ERROR: application of sizeof to pointer
   drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c:1322:32-38: ERROR: application of sizeof to pointer

Please review and possibly fold the followup patch.

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org