drm/i915: Pull scatterlist utils out of i915_gem.h

Out scatterlist utility routines can be pulled out of i915_gem.h for a
bit more decluttering.

v2: Push I915_GTT_PAGE_SIZE out of i915_scatterlist itself and into the
caller.

Signed-off-by: Chris Wilson <[e-mail]>
Reviewed-by: Matthew Auld <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/i915/Makefile

···
 	  i915_irq.o \
 	  i915_params.o \
 	  i915_pci.o \
+	  i915_scatterlist.o \
 	  i915_suspend.o \
 	  i915_sysfs.o \
 	  intel_csr.o \

drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c

···
 
 #include "i915_drv.h"
 #include "i915_gem_object.h"
+#include "i915_scatterlist.h"
 
 static struct drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf)
 {

drivers/gpu/drm/i915/gem/i915_gem_internal.c

···
 #include "i915_drv.h"
 #include "i915_gem.h"
 #include "i915_gem_object.h"
+#include "i915_scatterlist.h"
 #include "i915_utils.h"
 
 #define QUIET (__GFP_NORETRY | __GFP_NOWARN)

drivers/gpu/drm/i915/gem/i915_gem_pages.c

···
 
 #include "i915_drv.h"
 #include "i915_gem_object.h"
+#include "i915_scatterlist.h"
 
 void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj,
 				 struct sg_table *pages,

drivers/gpu/drm/i915/gem/i915_gem_phys.c

···
 
 #include "i915_drv.h"
 #include "i915_gem_object.h"
+#include "i915_scatterlist.h"
 
 static int i915_gem_object_get_pages_phys(struct drm_i915_gem_object *obj)
 {

drivers/gpu/drm/i915/gem/i915_gem_shmem.c

···
 
 #include "i915_drv.h"
 #include "i915_gem_object.h"
+#include "i915_scatterlist.h"
 
 /*
  * Move pages to appropriate lru and release the pagevec, decrementing the

drivers/gpu/drm/i915/gem/i915_gem_userptr.c

···
 
 #include "i915_gem_ioctls.h"
 #include "i915_gem_object.h"
+#include "i915_scatterlist.h"
 #include "i915_trace.h"
 #include "intel_drv.h"
 

drivers/gpu/drm/i915/gem/selftests/huge_gem_object.c

···
  * Copyright © 2016 Intel Corporation
  */
 
+#include "i915_scatterlist.h"
+
 #include "huge_gem_object.h"
 
 static void huge_free_pages(struct drm_i915_gem_object *obj,

drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c

···
  * Copyright © 2016 Intel Corporation
  */
 
+#include "i915_drv.h"
 #include "i915_selftest.h"
 
 #include "mock_dmabuf.h"

drivers/gpu/drm/i915/i915_drv.h

···
 	GENMASK(INTEL_FRONTBUFFER_BITS_PER_PIPE * ((pipe) + 1) - 1, \
 		INTEL_FRONTBUFFER_BITS_PER_PIPE * (pipe))
 
-/*
- * Optimised SGL iterator for GEM objects
- */
-static __always_inline struct sgt_iter {
-	struct scatterlist *sgp;
-	union {
-		unsigned long pfn;
-		dma_addr_t dma;
-	};
-	unsigned int curr;
-	unsigned int max;
-} __sgt_iter(struct scatterlist *sgl, bool dma) {
-	struct sgt_iter s = { .sgp = sgl };
-
-	if (s.sgp) {
-		s.max = s.curr = s.sgp->offset;
-		s.max += s.sgp->length;
-		if (dma)
-			s.dma = sg_dma_address(s.sgp);
-		else
-			s.pfn = page_to_pfn(sg_page(s.sgp));
-	}
-
-	return s;
-}
-
-static inline struct scatterlist *____sg_next(struct scatterlist *sg)
-{
-	++sg;
-	if (unlikely(sg_is_chain(sg)))
-		sg = sg_chain_ptr(sg);
-	return sg;
-}
-
-/**
- * __sg_next - return the next scatterlist entry in a list
- * @sg:		The current sg entry
- *
- * Description:
- *   If the entry is the last, return NULL; otherwise, step to the next
- *   element in the array (@sg@+1). If that's a chain pointer, follow it;
- *   otherwise just return the pointer to the current element.
- **/
-static inline struct scatterlist *__sg_next(struct scatterlist *sg)
-{
-	return sg_is_last(sg) ? NULL : ____sg_next(sg);
-}
-
-/**
- * for_each_sgt_dma - iterate over the DMA addresses of the given sg_table
- * @__dmap:	DMA address (output)
- * @__iter:	'struct sgt_iter' (iterator state, internal)
- * @__sgt:	sg_table to iterate over (input)
- */
-#define for_each_sgt_dma(__dmap, __iter, __sgt)				\
-	for ((__iter) = __sgt_iter((__sgt)->sgl, true);			\
-	     ((__dmap) = (__iter).dma + (__iter).curr);			\
-	     (((__iter).curr += I915_GTT_PAGE_SIZE) >= (__iter).max) ?	\
-	     (__iter) = __sgt_iter(__sg_next((__iter).sgp), true), 0 : 0)
-
-/**
- * for_each_sgt_page - iterate over the pages of the given sg_table
- * @__pp:	page pointer (output)
- * @__iter:	'struct sgt_iter' (iterator state, internal)
- * @__sgt:	sg_table to iterate over (input)
- */
-#define for_each_sgt_page(__pp, __iter, __sgt)				\
-	for ((__iter) = __sgt_iter((__sgt)->sgl, false);		\
-	     ((__pp) = (__iter).pfn == 0 ? NULL :			\
-	      pfn_to_page((__iter).pfn + ((__iter).curr >> PAGE_SHIFT))); \
-	     (((__iter).curr += PAGE_SIZE) >= (__iter).max) ?		\
-	     (__iter) = __sgt_iter(__sg_next((__iter).sgp), false), 0 : 0)
-
-bool i915_sg_trim(struct sg_table *orig_st);
-
-static inline unsigned int i915_sg_page_sizes(struct scatterlist *sg)
-{
-	unsigned int page_sizes;
-
-	page_sizes = 0;
-	while (sg) {
-		GEM_BUG_ON(sg->offset);
-		GEM_BUG_ON(!IS_ALIGNED(sg->length, PAGE_SIZE));
-		page_sizes |= sg->length;
-		sg = __sg_next(sg);
-	}
-
-	return page_sizes;
-}
-
-static inline unsigned int i915_sg_segment_size(void)
-{
-	unsigned int size = swiotlb_max_segment();
-
-	if (size == 0)
-		return SCATTERLIST_MAX_SEGMENT;
-
-	size = rounddown(size, PAGE_SIZE);
-	/* swiotlb_max_segment_size can return 1 byte when it means one page. */
-	if (size < PAGE_SIZE)
-		size = PAGE_SIZE;
-
-	return size;
-}
-
 #define INTEL_INFO(dev_priv)	(&(dev_priv)->__info)
 #define RUNTIME_INFO(dev_priv)	(&(dev_priv)->__runtime)
 #define DRIVER_CAPS(dev_priv)	(&(dev_priv)->caps)
···
 int i915_gem_object_unbind(struct drm_i915_gem_object *obj);
 
 void i915_gem_runtime_suspend(struct drm_i915_private *dev_priv);
-
-static inline int __sg_page_count(const struct scatterlist *sg)
-{
-	return sg->length >> PAGE_SHIFT;
-}
 
 static inline int __must_check
 i915_mutex_lock_interruptible(struct drm_device *dev)

drivers/gpu/drm/i915/i915_gem.c

···
 #include "gt/intel_workarounds.h"
 
 #include "i915_drv.h"
+#include "i915_scatterlist.h"
 #include "i915_trace.h"
 #include "i915_vgpu.h"
 
···
 		GEM_BUG_ON(i915_vma_has_userfault(reg->vma));
 		reg->dirty = true;
 	}
-}
-
-bool i915_sg_trim(struct sg_table *orig_st)
-{
-	struct sg_table new_st;
-	struct scatterlist *sg, *new_sg;
-	unsigned int i;
-
-	if (orig_st->nents == orig_st->orig_nents)
-		return false;
-
-	if (sg_alloc_table(&new_st, orig_st->nents, GFP_KERNEL | __GFP_NOWARN))
-		return false;
-
-	new_sg = new_st.sgl;
-	for_each_sg(orig_st->sgl, sg, orig_st->nents, i) {
-		sg_set_page(new_sg, sg_page(sg), sg->length, 0);
-		sg_dma_address(new_sg) = sg_dma_address(sg);
-		sg_dma_len(new_sg) = sg_dma_len(sg);
-
-		new_sg = sg_next(new_sg);
-	}
-	GEM_BUG_ON(new_sg); /* Should walk exactly nents and hit the end */
-
-	sg_free_table(orig_st);
-
-	*orig_st = new_st;
-	return true;
 }
 
 static unsigned long to_wait_timeout(s64 timeout_ns)
···
 }
 
 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
-#include "selftests/scatterlist.c"
 #include "selftests/mock_gem_device.c"
 #include "selftests/i915_gem.c"
 #endif

drivers/gpu/drm/i915/i915_gem_fence_reg.c

···
  */
 
 #include <drm/i915_drm.h>
+
 #include "i915_drv.h"
+#include "i915_scatterlist.h"
 
 /**
  * DOC: fence register handling

drivers/gpu/drm/i915/i915_gem_gtt.c

···
 #include <drm/i915_drm.h>
 
 #include "i915_drv.h"
-#include "i915_vgpu.h"
+#include "i915_scatterlist.h"
 #include "i915_trace.h"
+#include "i915_vgpu.h"
 #include "intel_drv.h"
 #include "intel_frontbuffer.h"
 

drivers/gpu/drm/i915/i915_gem_gtt.h

···
 
 #include "gt/intel_reset.h"
 #include "i915_request.h"
+#include "i915_scatterlist.h"
 #include "i915_selftest.h"
 #include "i915_timeline.h"
 
···
 #define GEN8_PDE_IPS_64K BIT(11)
 #define GEN8_PDE_PS_2M   BIT(7)
 
-struct sg_table;
+#define for_each_sgt_dma(__dmap, __iter, __sgt) \
+	__for_each_sgt_dma(__dmap, __iter, __sgt, I915_GTT_PAGE_SIZE)
 
 struct intel_remapped_plane_info {
 	/* in gtt pages */

drivers/gpu/drm/i915/i915_gpu_error.c

···
 
 #include "i915_drv.h"
 #include "i915_gpu_error.h"
+#include "i915_scatterlist.h"
 #include "intel_atomic.h"
 #include "intel_csr.h"
 #include "intel_overlay.h"

drivers/gpu/drm/i915/i915_scatterlist.c

···
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2016 Intel Corporation
+ */
+
+#include "i915_scatterlist.h"
+
+bool i915_sg_trim(struct sg_table *orig_st)
+{
+	struct sg_table new_st;
+	struct scatterlist *sg, *new_sg;
+	unsigned int i;
+
+	if (orig_st->nents == orig_st->orig_nents)
+		return false;
+
+	if (sg_alloc_table(&new_st, orig_st->nents, GFP_KERNEL | __GFP_NOWARN))
+		return false;
+
+	new_sg = new_st.sgl;
+	for_each_sg(orig_st->sgl, sg, orig_st->nents, i) {
+		sg_set_page(new_sg, sg_page(sg), sg->length, 0);
+		sg_dma_address(new_sg) = sg_dma_address(sg);
+		sg_dma_len(new_sg) = sg_dma_len(sg);
+
+		new_sg = sg_next(new_sg);
+	}
+	GEM_BUG_ON(new_sg); /* Should walk exactly nents and hit the end */
+
+	sg_free_table(orig_st);
+
+	*orig_st = new_st;
+	return true;
+}
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftests/scatterlist.c"
+#endif

drivers/gpu/drm/i915/i915_scatterlist.h

···
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2016 Intel Corporation
+ */
+
+#ifndef I915_SCATTERLIST_H
+#define I915_SCATTERLIST_H
+
+#include <linux/pfn.h>
+#include <linux/scatterlist.h>
+#include <linux/swiotlb.h>
+
+#include "i915_gem.h"
+
+/*
+ * Optimised SGL iterator for GEM objects
+ */
+static __always_inline struct sgt_iter {
+	struct scatterlist *sgp;
+	union {
+		unsigned long pfn;
+		dma_addr_t dma;
+	};
+	unsigned int curr;
+	unsigned int max;
+} __sgt_iter(struct scatterlist *sgl, bool dma) {
+	struct sgt_iter s = { .sgp = sgl };
+
+	if (s.sgp) {
+		s.max = s.curr = s.sgp->offset;
+		s.max += s.sgp->length;
+		if (dma)
+			s.dma = sg_dma_address(s.sgp);
+		else
+			s.pfn = page_to_pfn(sg_page(s.sgp));
+	}
+
+	return s;
+}
+
+static inline int __sg_page_count(const struct scatterlist *sg)
+{
+	return sg->length >> PAGE_SHIFT;
+}
+
+static inline struct scatterlist *____sg_next(struct scatterlist *sg)
+{
+	++sg;
+	if (unlikely(sg_is_chain(sg)))
+		sg = sg_chain_ptr(sg);
+	return sg;
+}
+
+/**
+ * __sg_next - return the next scatterlist entry in a list
+ * @sg:		The current sg entry
+ *
+ * Description:
+ *   If the entry is the last, return NULL; otherwise, step to the next
+ *   element in the array (@sg@+1). If that's a chain pointer, follow it;
+ *   otherwise just return the pointer to the current element.
+ **/
+static inline struct scatterlist *__sg_next(struct scatterlist *sg)
+{
+	return sg_is_last(sg) ? NULL : ____sg_next(sg);
+}
+
+/**
+ * __for_each_sgt_dma - iterate over the DMA addresses of the given sg_table
+ * @__dmap:	DMA address (output)
+ * @__iter:	'struct sgt_iter' (iterator state, internal)
+ * @__sgt:	sg_table to iterate over (input)
+ * @__step:	step size
+ */
+#define __for_each_sgt_dma(__dmap, __iter, __sgt, __step)		\
+	for ((__iter) = __sgt_iter((__sgt)->sgl, true);			\
+	     ((__dmap) = (__iter).dma + (__iter).curr);			\
+	     (((__iter).curr += (__step)) >= (__iter).max) ?		\
+	     (__iter) = __sgt_iter(__sg_next((__iter).sgp), true), 0 : 0)
+
+/**
+ * for_each_sgt_page - iterate over the pages of the given sg_table
+ * @__pp:	page pointer (output)
+ * @__iter:	'struct sgt_iter' (iterator state, internal)
+ * @__sgt:	sg_table to iterate over (input)
+ */
+#define for_each_sgt_page(__pp, __iter, __sgt)				\
+	for ((__iter) = __sgt_iter((__sgt)->sgl, false);		\
+	     ((__pp) = (__iter).pfn == 0 ? NULL :			\
+	      pfn_to_page((__iter).pfn + ((__iter).curr >> PAGE_SHIFT))); \
+	     (((__iter).curr += PAGE_SIZE) >= (__iter).max) ?		\
+	     (__iter) = __sgt_iter(__sg_next((__iter).sgp), false), 0 : 0)
+
+static inline unsigned int i915_sg_page_sizes(struct scatterlist *sg)
+{
+	unsigned int page_sizes;
+
+	page_sizes = 0;
+	while (sg) {
+		GEM_BUG_ON(sg->offset);
+		GEM_BUG_ON(!IS_ALIGNED(sg->length, PAGE_SIZE));
+		page_sizes |= sg->length;
+		sg = __sg_next(sg);
+	}
+
+	return page_sizes;
+}
+
+static inline unsigned int i915_sg_segment_size(void)
+{
+	unsigned int size = swiotlb_max_segment();
+
+	if (size == 0)
+		return SCATTERLIST_MAX_SEGMENT;
+
+	size = rounddown(size, PAGE_SIZE);
+	/* swiotlb_max_segment_size can return 1 byte when it means one page. */
+	if (size < PAGE_SIZE)
+		size = PAGE_SIZE;
+
+	return size;
+}
+
+bool i915_sg_trim(struct sg_table *orig_st);
+
+#endif

drivers/gpu/drm/i915/selftests/i915_vma.c

···
 
 #include "gem/selftests/mock_context.h"
 
+#include "i915_scatterlist.h"
 #include "i915_selftest.h"
 
 #include "mock_gem_device.h"

drivers/gpu/drm/i915/selftests/scatterlist.c

···
 #include <linux/prime_numbers.h>
 #include <linux/random.h>
 
-#include "../i915_selftest.h"
+#include "i915_selftest.h"
+#include "i915_utils.h"
 
 #define PFN_BIAS (1 << 10)