msm: kgsl: Create scatter gather lists for memory objects

Create and use scatter-gather lists for memory objects, which
avoids dynamically figuring the physical addresses of pages for
MMU mapping and cache operations.

Change-Id: Ic0dedbad9b973ecce4ae773b6bd682ba01010e5b
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
diff --git a/drivers/gpu/msm/kgsl.c b/drivers/gpu/msm/kgsl.c
index 165bbbf..7e61a32 100644
--- a/drivers/gpu/msm/kgsl.c
+++ b/drivers/gpu/msm/kgsl.c
@@ -1226,7 +1226,11 @@
 	entry->memdesc.size = size;
 	entry->memdesc.physaddr = phys + (offset & PAGE_MASK);
 	entry->memdesc.hostptr = (void *) (virt + (offset & PAGE_MASK));
-	entry->memdesc.ops = &kgsl_contiguous_ops;
+
+	ret = memdesc_sg_phys(&entry->memdesc,
+		phys + (offset & PAGE_MASK), size);
+	if (ret)
+		goto err;
 
 	return 0;
 err:
@@ -1236,6 +1240,60 @@
 	return ret;
 }
 
+static int memdesc_sg_virt(struct kgsl_memdesc *memdesc,
+	void *addr, int size)
+{
+	int i;
+	int sglen = PAGE_ALIGN(size) / PAGE_SIZE;
+	unsigned long paddr = (unsigned long) addr;
+
+	memdesc->sg = kmalloc(sglen * sizeof(struct scatterlist),
+		GFP_KERNEL);
+	if (memdesc->sg == NULL)
+		return -ENOMEM;
+
+	memdesc->sglen = sglen;
+	sg_init_table(memdesc->sg, sglen);
+
+	spin_lock(&current->mm->page_table_lock);
+
+	for (i = 0; i < sglen; i++, paddr += PAGE_SIZE) {
+		struct page *page;
+		pmd_t *ppmd;
+		pte_t *ppte;
+		pgd_t *ppgd = pgd_offset(current->mm, paddr);
+
+		if (pgd_none(*ppgd) || pgd_bad(*ppgd))
+			goto err;
+
+		ppmd = pmd_offset(ppgd, paddr);
+		if (pmd_none(*ppmd) || pmd_bad(*ppmd))
+			goto err;
+
+		ppte = pte_offset_map(ppmd, paddr);
+		if (ppte == NULL)
+			goto err;
+
+		page = pfn_to_page(pte_pfn(*ppte));
+		if (!page)
+			goto err;
+
+		sg_set_page(&memdesc->sg[i], page, PAGE_SIZE, 0);
+		pte_unmap(ppte);
+	}
+
+	spin_unlock(&current->mm->page_table_lock);
+
+	return 0;
+
+err:
+	spin_unlock(&current->mm->page_table_lock);
+	kfree(memdesc->sg);
+	memdesc->sg = NULL;
+
+	return -EINVAL;
+}
+
 static int kgsl_setup_hostptr(struct kgsl_mem_entry *entry,
 			      struct kgsl_pagetable *pagetable,
 			      void *hostptr, unsigned int offset,
@@ -1285,9 +1343,9 @@
 	entry->memdesc.pagetable = pagetable;
 	entry->memdesc.size = size;
 	entry->memdesc.hostptr = hostptr + (offset & PAGE_MASK);
-	entry->memdesc.ops = &kgsl_userptr_ops;
 
-	return 0;
+	return memdesc_sg_virt(&entry->memdesc,
+		hostptr + (offset & PAGE_MASK), size);
 }
 
 #ifdef CONFIG_ASHMEM
@@ -1335,11 +1393,13 @@
 	}
 
 	entry->file_ptr = filep;
-
 	entry->memdesc.pagetable = pagetable;
 	entry->memdesc.size = ALIGN(size, PAGE_SIZE);
 	entry->memdesc.hostptr = hostptr;
-	entry->memdesc.ops = &kgsl_userptr_ops;
+
+	ret = memdesc_sg_virt(&entry->memdesc, hostptr, size);
+	if (ret)
+		goto err;
 
 	return 0;
 
@@ -1725,7 +1785,7 @@
 {
 	struct kgsl_mem_entry *entry = vma->vm_private_data;
 
-	if (!entry->memdesc.ops->vmfault)
+	if (!entry->memdesc.ops || !entry->memdesc.ops->vmfault)
 		return VM_FAULT_SIGBUS;
 
 	return entry->memdesc.ops->vmfault(&entry->memdesc, vma, vmf);
@@ -1772,7 +1832,9 @@
 	if (entry == NULL)
 		return -EINVAL;
 
-	if (!entry->memdesc.ops->vmflags || !entry->memdesc.ops->vmfault)
+	if (!entry->memdesc.ops ||
+		!entry->memdesc.ops->vmflags ||
+		!entry->memdesc.ops->vmfault)
 		return -EINVAL;
 
 	vma->vm_flags |= entry->memdesc.ops->vmflags(&entry->memdesc);
diff --git a/drivers/gpu/msm/kgsl.h b/drivers/gpu/msm/kgsl.h
index 8db2cb4..1480df4 100644
--- a/drivers/gpu/msm/kgsl.h
+++ b/drivers/gpu/msm/kgsl.h
@@ -115,6 +115,8 @@
 	unsigned int physaddr;
 	unsigned int size;
 	unsigned int priv;
+	struct scatterlist *sg;
+	unsigned int sglen;
 	struct kgsl_memdesc_ops *ops;
 };
 
diff --git a/drivers/gpu/msm/kgsl_drm.c b/drivers/gpu/msm/kgsl_drm.c
index 202783b..cdf9dc4 100644
--- a/drivers/gpu/msm/kgsl_drm.c
+++ b/drivers/gpu/msm/kgsl_drm.c
@@ -293,7 +293,6 @@
 		}
 
 		priv->memdesc.size = obj->size * priv->bufcount;
-		priv->memdesc.ops = &kgsl_contiguous_ops;
 
 	} else if (TYPE_IS_MEM(priv->type)) {
 		priv->memdesc.hostptr =
diff --git a/drivers/gpu/msm/kgsl_gpummu.c b/drivers/gpu/msm/kgsl_gpummu.c
index 383b910..fe5677e 100644
--- a/drivers/gpu/msm/kgsl_gpummu.c
+++ b/drivers/gpu/msm/kgsl_gpummu.c
@@ -659,68 +659,45 @@
 	return 0;
 }
 
+#define SUPERPTE_IS_DIRTY(_p) \
+(((_p) & (GSL_PT_SUPER_PTE - 1)) == 0 && \
+GSL_TLBFLUSH_FILTER_ISDIRTY((_p) / GSL_PT_SUPER_PTE))
+
 static int
 kgsl_gpummu_map(void *mmu_specific_pt,
 		struct kgsl_memdesc *memdesc,
 		unsigned int protflags)
 {
-	int numpages;
-	unsigned int pte, ptefirst, ptelast, physaddr;
-	int flushtlb;
-	unsigned int offset = 0;
+	unsigned int pte;
 	struct kgsl_gpummu_pt *gpummu_pt = mmu_specific_pt;
+	struct scatterlist *s;
+	int flushtlb = 0;
+	int i;
 
-	if (!protflags ||
-		protflags & ~(GSL_PT_PAGE_RV | GSL_PT_PAGE_WV)) {
-		KGSL_CORE_ERR("Invalid protflags for "
-			"kgsl_mmu_specific_map: %x", protflags);
-		return -EINVAL;
-	}
+	pte = kgsl_pt_entry_get(KGSL_PAGETABLE_BASE, memdesc->gpuaddr);
 
-	numpages = (memdesc->size >> PAGE_SHIFT);
-
-	ptefirst = kgsl_pt_entry_get(KGSL_PAGETABLE_BASE, memdesc->gpuaddr);
-	ptelast = ptefirst + numpages;
-
-	pte = ptefirst;
-	flushtlb = 0;
-
-	/* tlb needs to be flushed when the first and last pte are not at
-	* superpte boundaries */
-	if ((ptefirst & (GSL_PT_SUPER_PTE - 1)) != 0 ||
-		((ptelast + 1) & (GSL_PT_SUPER_PTE-1)) != 0)
+	/* Flush the TLB if the first PTE isn't at the superpte boundary */
+	if (pte & (GSL_PT_SUPER_PTE - 1))
 		flushtlb = 1;
 
-	for (pte = ptefirst; pte < ptelast; pte++, offset += PAGE_SIZE) {
-#ifdef VERBOSE_DEBUG
-		/* check if PTE exists */
-		uint32_t val = kgsl_pt_map_get(gpummu_pt, pte);
-		if (val != 0 && val != GSL_PT_PAGE_DIRTY) {
-			KGSL_CORE_ERR("pt entry %x is already set with "
-			"value %x for pagetable %p\n", pte, val, gpummu_pt);
-			return -EINVAL;
-		}
-#endif
-		if ((pte & (GSL_PT_SUPER_PTE-1)) == 0)
-			if (GSL_TLBFLUSH_FILTER_ISDIRTY(pte / GSL_PT_SUPER_PTE))
-				flushtlb = 1;
-		/* mark pte as in use */
+	for_each_sg(memdesc->sg, s, memdesc->sglen, i) {
+		unsigned int paddr = sg_phys(s);
+		unsigned int j;
 
-		physaddr = memdesc->ops->physaddr(memdesc, offset);
-		if (!physaddr) {
-			KGSL_CORE_ERR("Failed to convert %x address to "
-			"physical", (unsigned int)memdesc->hostptr + offset);
-			kgsl_gpummu_unmap(mmu_specific_pt, memdesc);
-			return -EFAULT;
+		/* Each sg entry might be multiple pages long */
+		for (j = paddr; j < paddr + s->length; pte++, j += PAGE_SIZE) {
+			if (SUPERPTE_IS_DIRTY(pte))
+				flushtlb = 1;
+			kgsl_pt_map_set(gpummu_pt, pte, j | protflags);
 		}
-		kgsl_pt_map_set(gpummu_pt, pte, physaddr | protflags);
 	}
 
-	/* Post all writes to the pagetable */
+	/* Flush the TLB if the last PTE isn't at the superpte boundary */
+	if ((pte + 1) & (GSL_PT_SUPER_PTE - 1))
+		flushtlb = 1;
+
 	wmb();
 
-	/* Invalidate tlb only if current page table used by GPU is the
-	 * pagetable that we used to allocate */
 	if (flushtlb) {
 		/*set all devices as needing flushing*/
 		gpummu_pt->tlb_flags = UINT_MAX;
diff --git a/drivers/gpu/msm/kgsl_iommu.c b/drivers/gpu/msm/kgsl_iommu.c
index f9b9b4a..f43b96e 100644
--- a/drivers/gpu/msm/kgsl_iommu.c
+++ b/drivers/gpu/msm/kgsl_iommu.c
@@ -257,37 +257,33 @@
 			struct kgsl_memdesc *memdesc,
 			unsigned int protflags)
 {
-	int ret = 0;
-	unsigned int physaddr;
+	int ret, i;
+	struct scatterlist *s;
 	unsigned int iommu_virt_addr;
-	unsigned int offset = 0;
 	int map_order;
-	struct iommu_domain *domain = (struct iommu_domain *)
-					mmu_specific_pt;
+	struct iommu_domain *domain = mmu_specific_pt;
 
 	BUG_ON(NULL == domain);
 
 	map_order = get_order(SZ_4K);
 
-	for (iommu_virt_addr = memdesc->gpuaddr;
-		iommu_virt_addr < (memdesc->gpuaddr + memdesc->size);
-		iommu_virt_addr += SZ_4K, offset += PAGE_SIZE) {
-		physaddr = memdesc->ops->physaddr(memdesc, offset);
-		if (!physaddr) {
-			KGSL_CORE_ERR("Failed to convert %x address to "
-			"physical\n", (unsigned int)memdesc->hostptr + offset);
-			kgsl_iommu_unmap(mmu_specific_pt, memdesc);
-			return -EFAULT;
-		}
-		ret = iommu_map(domain, iommu_virt_addr, physaddr,
+	iommu_virt_addr = memdesc->gpuaddr;
+
+	for_each_sg(memdesc->sg, s, memdesc->sglen, i) {
+		unsigned int paddr = sg_phys(s), j;
+		for (j = paddr; j < paddr + s->length; j += PAGE_SIZE) {
+			ret = iommu_map(domain, iommu_virt_addr, j,
 				map_order, MSM_IOMMU_ATTR_NONCACHED);
-		if (ret) {
-			KGSL_CORE_ERR("iommu_map(%p, %x, %x, %d, %d) "
-			"failed with err: %d\n", domain,
-			iommu_virt_addr, physaddr, map_order,
-			MSM_IOMMU_ATTR_NONCACHED, ret);
-			kgsl_iommu_unmap(mmu_specific_pt, memdesc);
-			return ret;
+			if (ret) {
+				KGSL_CORE_ERR("iommu_map(%p, %x, %x, %d, %d) "
+					"failed with err: %d\n", domain,
+					iommu_virt_addr, j, map_order,
+					MSM_IOMMU_ATTR_NONCACHED, ret);
+				kgsl_iommu_unmap(mmu_specific_pt, memdesc);
+				return ret;
+			}
+
+			iommu_virt_addr += SZ_4K;
 		}
 	}
 
diff --git a/drivers/gpu/msm/kgsl_mmu.c b/drivers/gpu/msm/kgsl_mmu.c
index 7eec9e5..1879666 100644
--- a/drivers/gpu/msm/kgsl_mmu.c
+++ b/drivers/gpu/msm/kgsl_mmu.c
@@ -525,37 +525,6 @@
 	 */
 }
 
-unsigned int kgsl_virtaddr_to_physaddr(void *virtaddr)
-{
-	unsigned int physaddr = 0;
-	pgd_t *pgd_ptr = NULL;
-	pmd_t *pmd_ptr = NULL;
-	pte_t *pte_ptr = NULL, pte;
-
-	pgd_ptr = pgd_offset(current->mm, (unsigned long) virtaddr);
-	if (pgd_none(*pgd) || pgd_bad(*pgd)) {
-		KGSL_CORE_ERR("Invalid pgd entry\n");
-		return 0;
-	}
-
-	pmd_ptr = pmd_offset(pgd_ptr, (unsigned long) virtaddr);
-	if (pmd_none(*pmd_ptr) || pmd_bad(*pmd_ptr)) {
-		KGSL_CORE_ERR("Invalid pmd entry\n");
-		return 0;
-	}
-
-	pte_ptr = pte_offset_map(pmd_ptr, (unsigned long) virtaddr);
-	if (!pte_ptr) {
-		KGSL_CORE_ERR("pt_offset_map failed\n");
-		return 0;
-	}
-	pte = *pte_ptr;
-	physaddr = pte_pfn(pte);
-	pte_unmap(pte_ptr);
-	physaddr <<= PAGE_SHIFT;
-	return physaddr;
-}
-
 int
 kgsl_mmu_map(struct kgsl_pagetable *pagetable,
 				struct kgsl_memdesc *memdesc,
diff --git a/drivers/gpu/msm/kgsl_sharedmem.c b/drivers/gpu/msm/kgsl_sharedmem.c
index 09070e4..8f75daa 100644
--- a/drivers/gpu/msm/kgsl_sharedmem.c
+++ b/drivers/gpu/msm/kgsl_sharedmem.c
@@ -207,28 +207,21 @@
 		break;
 	}
 }
-#endif
 
-static unsigned long kgsl_vmalloc_physaddr(struct kgsl_memdesc *memdesc,
-					   unsigned int offset)
+static void outer_cache_range_op_sg(struct scatterlist *sg, int sglen, int op)
 {
-	unsigned int addr;
+	struct scatterlist *s;
+	int i;
 
-	if (offset > memdesc->size)
-		return 0;
-
-	addr = vmalloc_to_pfn(memdesc->hostptr + offset);
-	return addr << PAGE_SHIFT;
+	for_each_sg(sg, s, sglen, i) {
+		unsigned int paddr = sg_phys(s);
+		_outer_cache_range_op(op, paddr, s->length);
+	}
 }
 
-#ifdef CONFIG_OUTER_CACHE
-static void kgsl_vmalloc_outer_cache(struct kgsl_memdesc *memdesc, int op)
+#else
+static void outer_cache_range_op_sg(struct scatterlist *sg, int sglen, int op)
 {
-	void *vaddr = memdesc->hostptr;
-	for (; vaddr < (memdesc->hostptr + memdesc->size); vaddr += PAGE_SIZE) {
-		unsigned long paddr = page_to_phys(vmalloc_to_page(vaddr));
-		_outer_cache_range_op(op, paddr, PAGE_SIZE);
-	}
 }
 #endif
 
@@ -306,88 +299,24 @@
 			  memdesc->hostptr, memdesc->physaddr);
 }
 
-static unsigned long kgsl_contiguous_physaddr(struct kgsl_memdesc *memdesc,
-					unsigned int offset)
-{
-	if (offset > memdesc->size)
-		return 0;
-
-	return memdesc->physaddr + offset;
-}
-
-#ifdef CONFIG_OUTER_CACHE
-static void kgsl_contiguous_outer_cache(struct kgsl_memdesc *memdesc, int op)
-{
-	_outer_cache_range_op(op, memdesc->physaddr, memdesc->size);
-}
-#endif
-
-#ifdef CONFIG_OUTER_CACHE
-static void kgsl_userptr_outer_cache(struct kgsl_memdesc *memdesc, int op)
-{
-	void *vaddr = memdesc->hostptr;
-	for (; vaddr < (memdesc->hostptr + memdesc->size); vaddr += PAGE_SIZE) {
-		unsigned long paddr = kgsl_virtaddr_to_physaddr(vaddr);
-		if (paddr)
-			_outer_cache_range_op(op, paddr, PAGE_SIZE);
-	}
-}
-#endif
-
-static unsigned long kgsl_userptr_physaddr(struct kgsl_memdesc *memdesc,
-					   unsigned int offset)
-{
-	return kgsl_virtaddr_to_physaddr(memdesc->hostptr + offset);
-}
-
 /* Global - also used by kgsl_drm.c */
 struct kgsl_memdesc_ops kgsl_vmalloc_ops = {
-	.physaddr = kgsl_vmalloc_physaddr,
 	.free = kgsl_vmalloc_free,
 	.vmflags = kgsl_vmalloc_vmflags,
 	.vmfault = kgsl_vmalloc_vmfault,
-#ifdef CONFIG_OUTER_CACHE
-	.outer_cache = kgsl_vmalloc_outer_cache,
-#endif
 };
 EXPORT_SYMBOL(kgsl_vmalloc_ops);
 
 static struct kgsl_memdesc_ops kgsl_ebimem_ops = {
-	.physaddr = kgsl_contiguous_physaddr,
 	.free = kgsl_ebimem_free,
 	.vmflags = kgsl_contiguous_vmflags,
 	.vmfault = kgsl_contiguous_vmfault,
-#ifdef CONFIG_OUTER_CACHE
-	.outer_cache = kgsl_contiguous_outer_cache,
-#endif
 };
 
 static struct kgsl_memdesc_ops kgsl_coherent_ops = {
-	.physaddr = kgsl_contiguous_physaddr,
 	.free = kgsl_coherent_free,
-#ifdef CONFIG_OUTER_CACHE
-	.outer_cache = kgsl_contiguous_outer_cache,
-#endif
 };
 
-/* Global - also used by kgsl.c and kgsl_drm.c */
-struct kgsl_memdesc_ops kgsl_contiguous_ops = {
-	.physaddr = kgsl_contiguous_physaddr,
-#ifdef CONFIG_OUTER_CACHE
-	.outer_cache = kgsl_contiguous_outer_cache
-#endif
-};
-EXPORT_SYMBOL(kgsl_contiguous_ops);
-
-/* Global - also used by kgsl.c */
-struct kgsl_memdesc_ops kgsl_userptr_ops = {
-	.physaddr = kgsl_userptr_physaddr,
-#ifdef CONFIG_OUTER_CACHE
-	.outer_cache = kgsl_userptr_outer_cache,
-#endif
-};
-EXPORT_SYMBOL(kgsl_userptr_ops);
-
 void kgsl_cache_range_op(struct kgsl_memdesc *memdesc, int op)
 {
 	void *addr = memdesc->hostptr;
@@ -405,8 +334,7 @@
 		break;
 	}
 
-	if (memdesc->ops->outer_cache)
-		memdesc->ops->outer_cache(memdesc, op);
+	outer_cache_range_op_sg(memdesc->sg, memdesc->sglen, op);
 }
 EXPORT_SYMBOL(kgsl_cache_range_op);
 
@@ -415,7 +343,9 @@
 			struct kgsl_pagetable *pagetable,
 			void *ptr, size_t size, unsigned int protflags)
 {
-	int result;
+	int order, ret = 0;
+	int sglen = PAGE_ALIGN(size) / PAGE_SIZE;
+	int i;
 
 	memdesc->size = size;
 	memdesc->pagetable = pagetable;
@@ -423,25 +353,44 @@
 	memdesc->ops = &kgsl_vmalloc_ops;
 	memdesc->hostptr = (void *) ptr;
 
-	kgsl_cache_range_op(memdesc, KGSL_CACHE_OP_INV);
-
-	result = kgsl_mmu_map(pagetable, memdesc, protflags);
-
-	if (result) {
-		kgsl_sharedmem_free(memdesc);
-	} else {
-		int order;
-
-		KGSL_STATS_ADD(size, kgsl_driver.stats.vmalloc,
-			kgsl_driver.stats.vmalloc_max);
-
-		order = get_order(size);
-
-		if (order < 16)
-			kgsl_driver.stats.histogram[order]++;
+	memdesc->sg = kmalloc(sglen * sizeof(struct scatterlist), GFP_KERNEL);
+	if (memdesc->sg == NULL) {
+		ret = -ENOMEM;
+		goto done;
 	}
 
-	return result;
+	memdesc->sglen = sglen;
+	sg_init_table(memdesc->sg, sglen);
+
+	for (i = 0; i < memdesc->sglen; i++, ptr += PAGE_SIZE) {
+		struct page *page = vmalloc_to_page(ptr);
+		if (!page) {
+			ret = -EINVAL;
+			goto done;
+		}
+		sg_set_page(&memdesc->sg[i], page, PAGE_SIZE, 0);
+	}
+
+	kgsl_cache_range_op(memdesc, KGSL_CACHE_OP_INV);
+
+	ret = kgsl_mmu_map(pagetable, memdesc, protflags);
+
+	if (ret)
+		goto done;
+
+	KGSL_STATS_ADD(size, kgsl_driver.stats.vmalloc,
+		kgsl_driver.stats.vmalloc_max);
+
+	order = get_order(size);
+
+	if (order < 16)
+		kgsl_driver.stats.histogram[order]++;
+
+done:
+	if (ret)
+		kgsl_sharedmem_free(memdesc);
+
+	return ret;
 }
 
 int
@@ -494,24 +443,35 @@
 int
 kgsl_sharedmem_alloc_coherent(struct kgsl_memdesc *memdesc, size_t size)
 {
+	int result = 0;
+
 	size = ALIGN(size, PAGE_SIZE);
 
+	memdesc->size = size;
+	memdesc->ops = &kgsl_coherent_ops;
+
 	memdesc->hostptr = dma_alloc_coherent(NULL, size, &memdesc->physaddr,
 					      GFP_KERNEL);
 	if (memdesc->hostptr == NULL) {
 		KGSL_CORE_ERR("dma_alloc_coherent(%d) failed\n", size);
-		return -ENOMEM;
+		result = -ENOMEM;
+		goto err;
 	}
 
-	memdesc->size = size;
-	memdesc->ops = &kgsl_coherent_ops;
+	result = memdesc_sg_phys(memdesc, memdesc->physaddr, size);
+	if (result)
+		goto err;
 
 	/* Record statistics */
 
 	KGSL_STATS_ADD(size, kgsl_driver.stats.coherent,
 		       kgsl_driver.stats.coherent_max);
 
-	return 0;
+err:
+	if (result)
+		kgsl_sharedmem_free(memdesc);
+
+	return result;
 }
 EXPORT_SYMBOL(kgsl_sharedmem_alloc_coherent);
 
@@ -523,9 +483,11 @@
 	if (memdesc->gpuaddr)
 		kgsl_mmu_unmap(memdesc->pagetable, memdesc);
 
-	if (memdesc->ops->free)
+	if (memdesc->ops && memdesc->ops->free)
 		memdesc->ops->free(memdesc);
 
+	kfree(memdesc->sg);
+
 	memset(memdesc, 0, sizeof(*memdesc));
 }
 EXPORT_SYMBOL(kgsl_sharedmem_free);
@@ -534,8 +496,11 @@
 _kgsl_sharedmem_ebimem(struct kgsl_memdesc *memdesc,
 			struct kgsl_pagetable *pagetable, size_t size)
 {
-	int result;
+	int result = 0;
 
+	memdesc->size = size;
+	memdesc->pagetable = pagetable;
+	memdesc->ops = &kgsl_ebimem_ops;
 	memdesc->physaddr = allocate_contiguous_ebi_nomap(size, SZ_8K);
 
 	if (memdesc->physaddr == 0) {
@@ -544,19 +509,24 @@
 		return -ENOMEM;
 	}
 
-	memdesc->size = size;
-	memdesc->pagetable = pagetable;
-	memdesc->ops = &kgsl_ebimem_ops;
+	result = memdesc_sg_phys(memdesc, memdesc->physaddr, size);
+
+	if (result)
+		goto err;
 
 	result = kgsl_mmu_map(pagetable, memdesc,
 		GSL_PT_PAGE_RV | GSL_PT_PAGE_WV);
 
 	if (result)
-		kgsl_sharedmem_free(memdesc);
+		goto err;
 
 	KGSL_STATS_ADD(size, kgsl_driver.stats.coherent,
 		kgsl_driver.stats.coherent_max);
 
+err:
+	if (result)
+		kgsl_sharedmem_free(memdesc);
+
 	return result;
 }
 
diff --git a/drivers/gpu/msm/kgsl_sharedmem.h b/drivers/gpu/msm/kgsl_sharedmem.h
index 9e57e78..a9abcf9 100644
--- a/drivers/gpu/msm/kgsl_sharedmem.h
+++ b/drivers/gpu/msm/kgsl_sharedmem.h
@@ -13,6 +13,7 @@
 #ifndef __KGSL_SHAREDMEM_H
 #define __KGSL_SHAREDMEM_H
 
+#include <linux/slab.h>
 #include <linux/dma-mapping.h>
 
 struct kgsl_device;
@@ -26,8 +27,6 @@
 #define KGSL_MEMFLAGS_CACHED    0x00000001
 
 struct kgsl_memdesc_ops {
-	unsigned long (*physaddr)(struct kgsl_memdesc *, unsigned int);
-	void (*outer_cache)(struct kgsl_memdesc *, int);
 	int (*vmflags)(struct kgsl_memdesc *);
 	int (*vmfault)(struct kgsl_memdesc *, struct vm_area_struct *,
 		       struct vm_fault *);
@@ -35,8 +34,6 @@
 };
 
 extern struct kgsl_memdesc_ops kgsl_vmalloc_ops;
-extern struct kgsl_memdesc_ops kgsl_contiguous_ops;
-extern struct kgsl_memdesc_ops kgsl_userptr_ops;
 
 int kgsl_sharedmem_vmalloc(struct kgsl_memdesc *memdesc,
 			   struct kgsl_pagetable *pagetable, size_t size);
@@ -78,6 +75,22 @@
 void kgsl_sharedmem_uninit_sysfs(void);
 
 static inline int
+memdesc_sg_phys(struct kgsl_memdesc *memdesc,
+		unsigned int physaddr, unsigned int size)
+{
+	struct page *page = phys_to_page(physaddr);
+
+	memdesc->sg = kmalloc(sizeof(struct scatterlist) * 1, GFP_KERNEL);
+	if (memdesc->sg == NULL)
+		return -ENOMEM;
+
+	memdesc->sglen = 1;
+	sg_init_table(memdesc->sg, 1);
+	sg_set_page(&memdesc->sg[0], page, size, 0);
+	return 0;
+}
+
+static inline int
 kgsl_allocate(struct kgsl_memdesc *memdesc,
 		struct kgsl_pagetable *pagetable, size_t size)
 {