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From: Matthew Auld <matthew.auld@intel.com>
Date: Fri, 6 Oct 2017 23:18:18 +0100
Subject: drm/i915: introduce page_size members
Git-commit: a5c08166265adc172a4cbde8ed26a1a96ce77fb7
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

In preparation for supporting huge gtt pages for the ppgtt, we introduce
page size members for gem objects.  We fill in the page sizes by
scanning the sg table.

v2: pass the sg_mask to set_pages

v3: calculate the sg_mask inline with populating the sg_table where
possible, and pass to set_pages along with the pages.

v4: bunch of improvements from Joonas

v5: fix num_pages blunder
    introduce i915_sg_page_sizes helper

v6: prefer GEM_BUG_ON(sizes == 0)

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel@ffwll.ch>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20171006145041.21673-7-matthew.auld@intel.com
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20171006221833.32439-6-chris@chris-wilson.co.uk

Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/i915/i915_drv.h                  |   22 +++++++++++-
 drivers/gpu/drm/i915/i915_gem.c                  |   42 ++++++++++++++++++++---
 drivers/gpu/drm/i915/i915_gem_dmabuf.c           |    5 ++
 drivers/gpu/drm/i915/i915_gem_internal.c         |    5 ++
 drivers/gpu/drm/i915/i915_gem_object.h           |   17 +++++++++
 drivers/gpu/drm/i915/i915_gem_stolen.c           |    2 -
 drivers/gpu/drm/i915/i915_gem_userptr.c          |    5 ++
 drivers/gpu/drm/i915/selftests/huge_gem_object.c |    2 -
 drivers/gpu/drm/i915/selftests/i915_gem_gtt.c    |    5 ++
 9 files changed, 93 insertions(+), 12 deletions(-)

--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2872,6 +2872,21 @@ static inline struct scatterlist *__sg_n
 	     (((__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();
@@ -3101,6 +3116,10 @@ intel_info(const struct drm_i915_private
 #define USES_PPGTT(dev_priv)		(i915_modparams.enable_ppgtt)
 #define USES_FULL_PPGTT(dev_priv)	(i915_modparams.enable_ppgtt >= 2)
 #define USES_FULL_48BIT_PPGTT(dev_priv)	(i915_modparams.enable_ppgtt == 3)
+#define HAS_PAGE_SIZES(dev_priv, sizes) ({ \
+	GEM_BUG_ON((sizes) == 0); \
+	((sizes) & ~(dev_priv)->info.page_sizes) == 0; \
+})
 
 #define HAS_OVERLAY(dev_priv)		 ((dev_priv)->info.has_overlay)
 #define OVERLAY_NEEDS_PHYSICAL(dev_priv) \
@@ -3517,7 +3536,8 @@ i915_gem_object_get_dma_address(struct d
 				unsigned long n);
 
 void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj,
-				 struct sg_table *pages);
+				 struct sg_table *pages,
+				 unsigned int sg_mask);
 int __i915_gem_object_get_pages(struct drm_i915_gem_object *obj);
 
 static inline int __must_check
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -228,7 +228,7 @@ static int i915_gem_object_get_pages_phy
 
 	obj->phys_handle = phys;
 
-	__i915_gem_object_set_pages(obj, st);
+	__i915_gem_object_set_pages(obj, st, sg->length);
 
 	return 0;
 
@@ -2268,6 +2268,8 @@ void __i915_gem_object_put_pages(struct
 	if (!IS_ERR(pages))
 		obj->ops->put_pages(obj, pages);
 
+	obj->mm.page_sizes.phys = obj->mm.page_sizes.sg = 0;
+
 unlock:
 	mutex_unlock(&obj->mm.lock);
 }
@@ -2310,6 +2312,7 @@ static int i915_gem_object_get_pages_gtt
 	struct page *page;
 	unsigned long last_pfn = 0;	/* suppress gcc warning */
 	unsigned int max_segment = i915_sg_segment_size();
+	unsigned int sg_mask;
 	gfp_t noreclaim;
 	int ret;
 
@@ -2341,6 +2344,7 @@ rebuild_st:
 
 	sg = st->sgl;
 	st->nents = 0;
+	sg_mask = 0;
 	for (i = 0; i < page_count; i++) {
 		const unsigned int shrink[] = {
 			I915_SHRINK_BOUND | I915_SHRINK_UNBOUND | I915_SHRINK_PURGEABLE,
@@ -2393,8 +2397,10 @@ rebuild_st:
 		if (!i ||
 		    sg->length >= max_segment ||
 		    page_to_pfn(page) != last_pfn + 1) {
-			if (i)
+			if (i) {
+				sg_mask |= sg->length;
 				sg = sg_next(sg);
+			}
 			st->nents++;
 			sg_set_page(sg, page, PAGE_SIZE, 0);
 		} else {
@@ -2405,8 +2411,10 @@ rebuild_st:
 		/* Check that the i965g/gm workaround works. */
 		WARN_ON((gfp & __GFP_DMA32) && (last_pfn >= 0x00100000UL));
 	}
-	if (sg) /* loop terminated early; short sg table */
+	if (sg) { /* loop terminated early; short sg table */
+		sg_mask |= sg->length;
 		sg_mark_end(sg);
+	}
 
 	/* Trim unused sg entries to avoid wasting memory. */
 	i915_sg_trim(st);
@@ -2435,7 +2443,7 @@ rebuild_st:
 	if (i915_gem_object_needs_bit17_swizzle(obj))
 		i915_gem_object_do_bit_17_swizzle(obj, st);
 
-	__i915_gem_object_set_pages(obj, st);
+	__i915_gem_object_set_pages(obj, st, sg_mask);
 
 	return 0;
 
@@ -2462,8 +2470,13 @@ err_pages:
 }
 
 void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj,
-				 struct sg_table *pages)
+				 struct sg_table *pages,
+				 unsigned int sg_mask)
 {
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	unsigned long supported = INTEL_INFO(i915)->page_sizes;
+	int i;
+
 	lockdep_assert_held(&obj->mm.lock);
 
 	obj->mm.get_page.sg_pos = pages->sgl;
@@ -2477,6 +2490,25 @@ void __i915_gem_object_set_pages(struct
 		__i915_gem_object_pin_pages(obj);
 		obj->mm.quirked = true;
 	}
+
+	GEM_BUG_ON(!sg_mask);
+	obj->mm.page_sizes.phys = sg_mask;
+
+	/*
+	 * Calculate the supported page-sizes which fit into the given sg_mask.
+	 * This will give us the page-sizes which we may be able to use
+	 * opportunistically when later inserting into the GTT. For example if
+	 * phys=2G, then in theory we should be able to use 1G, 2M, 64K or 4K
+	 * pages, although in practice this will depend on a number of other
+	 * factors.
+	 */
+	obj->mm.page_sizes.sg = 0;
+	for_each_set_bit(i, &supported, ilog2(I915_GTT_MAX_PAGE_SIZE) + 1) {
+		if (obj->mm.page_sizes.phys & ~0u << i)
+			obj->mm.page_sizes.sg |= BIT(i);
+	}
+
+	GEM_BUG_ON(!HAS_PAGE_SIZES(i915, obj->mm.page_sizes.sg));
 }
 
 static int ____i915_gem_object_get_pages(struct drm_i915_gem_object *obj)
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -259,13 +259,16 @@ struct dma_buf *i915_gem_prime_export(st
 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
 {
 	struct sg_table *pages;
+	unsigned int sg_mask;
 
 	pages = dma_buf_map_attachment(obj->base.import_attach,
 				       DMA_BIDIRECTIONAL);
 	if (IS_ERR(pages))
 		return PTR_ERR(pages);
 
-	__i915_gem_object_set_pages(obj, pages);
+	sg_mask = i915_sg_page_sizes(pages->sgl);
+
+	__i915_gem_object_set_pages(obj, pages, sg_mask);
 
 	return 0;
 }
--- a/drivers/gpu/drm/i915/i915_gem_internal.c
+++ b/drivers/gpu/drm/i915/i915_gem_internal.c
@@ -49,6 +49,7 @@ static int i915_gem_object_get_pages_int
 	struct drm_i915_private *i915 = to_i915(obj->base.dev);
 	struct sg_table *st;
 	struct scatterlist *sg;
+	unsigned int sg_mask;
 	unsigned int npages;
 	int max_order;
 	gfp_t gfp;
@@ -87,6 +88,7 @@ create_st:
 
 	sg = st->sgl;
 	st->nents = 0;
+	sg_mask = 0;
 
 	do {
 		int order = min(fls(npages) - 1, max_order);
@@ -104,6 +106,7 @@ create_st:
 		} while (1);
 
 		sg_set_page(sg, page, PAGE_SIZE << order, 0);
+		sg_mask |= PAGE_SIZE << order;
 		st->nents++;
 
 		npages -= 1 << order;
@@ -132,7 +135,7 @@ create_st:
 	 */
 	obj->mm.madv = I915_MADV_DONTNEED;
 
-	__i915_gem_object_set_pages(obj, st);
+	__i915_gem_object_set_pages(obj, st, sg_mask);
 
 	return 0;
 
--- a/drivers/gpu/drm/i915/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/i915_gem_object.h
@@ -169,6 +169,23 @@ struct drm_i915_gem_object {
 		struct sg_table *pages;
 		void *mapping;
 
+		struct i915_page_sizes {
+			/**
+			 * The sg mask of the pages sg_table. i.e the mask of
+			 * of the lengths for each sg entry.
+			 */
+			unsigned int phys;
+
+			/**
+			 * The gtt page sizes we are allowed to use given the
+			 * sg mask and the supported page sizes. This will
+			 * express the smallest unit we can use for the whole
+			 * object, as well as the larger sizes we may be able
+			 * to use opportunistically.
+			 */
+			unsigned int sg;
+		} page_sizes;
+
 		struct i915_gem_object_page_iter {
 			struct scatterlist *sg_pos;
 			unsigned int sg_idx; /* in pages, but 32bit eek! */
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -548,7 +548,7 @@ static int i915_gem_object_get_pages_sto
 	if (IS_ERR(pages))
 		return PTR_ERR(pages);
 
-	__i915_gem_object_set_pages(obj, pages);
+	__i915_gem_object_set_pages(obj, pages, obj->stolen->size);
 
 	return 0;
 }
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -405,6 +405,7 @@ __i915_gem_userptr_alloc_pages(struct dr
 {
 	unsigned int max_segment = i915_sg_segment_size();
 	struct sg_table *st;
+	unsigned int sg_mask;
 	int ret;
 
 	st = kmalloc(sizeof(*st), GFP_KERNEL);
@@ -434,7 +435,9 @@ alloc_table:
 		return ERR_PTR(ret);
 	}
 
-	__i915_gem_object_set_pages(obj, st);
+	sg_mask = i915_sg_page_sizes(st->sgl);
+
+	__i915_gem_object_set_pages(obj, st, sg_mask);
 
 	return st;
 }
--- a/drivers/gpu/drm/i915/selftests/huge_gem_object.c
+++ b/drivers/gpu/drm/i915/selftests/huge_gem_object.c
@@ -80,7 +80,7 @@ static int huge_get_pages(struct drm_i91
 	if (i915_gem_gtt_prepare_pages(obj, pages))
 		goto err;
 
-	__i915_gem_object_set_pages(obj, pages);
+	__i915_gem_object_set_pages(obj, pages, PAGE_SIZE);
 
 	return 0;
 
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -45,6 +45,7 @@ static int fake_get_pages(struct drm_i91
 #define PFN_BIAS 0x1000
 	struct sg_table *pages;
 	struct scatterlist *sg;
+	unsigned int sg_mask;
 	typeof(obj->base.size) rem;
 
 	pages = kmalloc(sizeof(*pages), GFP);
@@ -57,6 +58,7 @@ static int fake_get_pages(struct drm_i91
 		return -ENOMEM;
 	}
 
+	sg_mask = 0;
 	rem = obj->base.size;
 	for (sg = pages->sgl; sg; sg = sg_next(sg)) {
 		unsigned long len = min_t(typeof(rem), rem, BIT(31));
@@ -65,6 +67,7 @@ static int fake_get_pages(struct drm_i91
 		sg_set_page(sg, pfn_to_page(PFN_BIAS), len, 0);
 		sg_dma_address(sg) = page_to_phys(sg_page(sg));
 		sg_dma_len(sg) = len;
+		sg_mask |= len;
 
 		rem -= len;
 	}
@@ -72,7 +75,7 @@ static int fake_get_pages(struct drm_i91
 
 	obj->mm.madv = I915_MADV_DONTNEED;
 
-	__i915_gem_object_set_pages(obj, pages);
+	__i915_gem_object_set_pages(obj, pages, sg_mask);
 
 	return 0;
 #undef GFP