commit d17e9aa8d509d152726ab9d3027edbeb50847c99
author Jordan Crouse <jcrouse@codeaurora.org> Wed Oct 12 16:57:48 2011 -0600
committer Jordan Crouse <jcrouse@codeaurora.org> Fri Oct 21 10:32:26 2011 -0600
tree 5e3493bf1ed993be91b67ddfbbfd437bdf29d071
parent dac6e12bae17439e9b344d03ca05e9ed0fe1a4a4

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>

drivers/gpu/msm/kgsl.c

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);