[3/4] media: ipu6: optimize the IPU6 MMU unmapping flow

Commit Message

Bingbu Cao Oct. 24, 2024, 7:24 a.m. UTC

The MMU mapping flow is optimized for improve the performance, the
unmapping flow could also be optimized to follow same flow.

It also change the ipu6_mmu_unmap() as a void function.

Signed-off-by: Bingbu Cao <[e-mail]>
Signed-off-by: Jianhui Dai <[e-mail]>
---
 drivers/media/pci/intel/ipu6/ipu6-mmu.c | 97 +++++++++++++++------------------
 drivers/media/pci/intel/ipu6/ipu6-mmu.h |  4 +-
 2 files changed, 45 insertions(+), 56 deletions(-)

Patch

diff --git a/drivers/media/pci/intel/ipu6/ipu6-mmu.c b/drivers/media/pci/intel/ipu6/ipu6-mmu.c
index e957ccb4691d..d746e42918ae 100644
--- a/drivers/media/pci/intel/ipu6/ipu6-mmu.c
+++ b/drivers/media/pci/intel/ipu6/ipu6-mmu.c
@@ -252,44 +252,51 @@  static u32 *alloc_l2_pt(struct ipu6_mmu_info *mmu_info)
 	return pt;
 }
 
-static size_t l2_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
-		       phys_addr_t dummy, size_t size)
+static void l2_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
+		     phys_addr_t dummy, size_t size)
 {
-	u32 l1_idx = iova >> ISP_L1PT_SHIFT;
-	u32 iova_start = iova;
+	unsigned int l2_entries;
 	unsigned int l2_idx;
-	size_t unmapped = 0;
 	unsigned long flags;
+	u32 l1_idx;
 	u32 *l2_pt;
 
-	dev_dbg(mmu_info->dev, "unmapping l2 page table for l1 index %u (iova 0x%8.8lx)\n",
-		l1_idx, iova);
-
 	spin_lock_irqsave(&mmu_info->lock, flags);
-	if (mmu_info->l1_pt[l1_idx] == mmu_info->dummy_l2_pteval) {
-		spin_unlock_irqrestore(&mmu_info->lock, flags);
-		dev_err(mmu_info->dev,
-			"unmap iova 0x%8.8lx l1 idx %u which was not mapped\n",
-			iova, l1_idx);
-		return 0;
-	}
-
-	for (l2_idx = (iova_start & ISP_L2PT_MASK) >> ISP_L2PT_SHIFT;
-	     (iova_start & ISP_L1PT_MASK) + (l2_idx << ISP_PAGE_SHIFT)
-		     < iova_start + size && l2_idx < ISP_L2PT_PTES; l2_idx++) {
-		l2_pt = mmu_info->l2_pts[l1_idx];
+	for (l1_idx = iova >> ISP_L1PT_SHIFT;
+	     size > 0 && l1_idx < ISP_L1PT_PTES; l1_idx++) {
 		dev_dbg(mmu_info->dev,
-			"unmap l2 index %u with pteval 0x%10.10llx\n",
-			l2_idx, TBL_PHYS_ADDR(l2_pt[l2_idx]));
-		l2_pt[l2_idx] = mmu_info->dummy_page_pteval;
+			"unmapping l2 pgtable (l1 index %u (iova 0x%8.8lx))\n",
+			l1_idx, iova);
 
-		clflush_cache_range((void *)&l2_pt[l2_idx],
-				    sizeof(l2_pt[l2_idx]));
-		unmapped++;
+		if (mmu_info->l1_pt[l1_idx] == mmu_info->dummy_l2_pteval) {
+			dev_err(mmu_info->dev,
+				"unmap not mapped iova 0x%8.8lx l1 index %u\n",
+				iova, l1_idx);
+			continue;
+		}
+		l2_pt = mmu_info->l2_pts[l1_idx];
+
+		l2_entries = 0;
+		for (l2_idx = (iova & ISP_L2PT_MASK) >> ISP_L2PT_SHIFT;
+		     size > 0 && l2_idx < ISP_L2PT_PTES; l2_idx++) {
+			dev_dbg(mmu_info->dev,
+				"unmap l2 index %u with pteval 0x%10.10llx\n",
+				l2_idx, TBL_PHYS_ADDR(l2_pt[l2_idx]));
+			l2_pt[l2_idx] = mmu_info->dummy_page_pteval;
+
+			iova += ISP_PAGE_SIZE;
+			size -= ISP_PAGE_SIZE;
+
+			l2_entries++;
+		}
+
+		WARN_ON_ONCE(!l2_entries);
+		clflush_cache_range(&l2_pt[l2_idx - l2_entries],
+				    sizeof(l2_pt[0]) * l2_entries);
 	}
+
+	WARN_ON_ONCE(size);
 	spin_unlock_irqrestore(&mmu_info->lock, flags);
-
-	return unmapped << ISP_PAGE_SHIFT;
 }
 
 static int l2_map(struct ipu6_mmu_info *mmu_info, unsigned long iova,
@@ -394,8 +401,8 @@  static int __ipu6_mmu_map(struct ipu6_mmu_info *mmu_info, unsigned long iova,
 	return l2_map(mmu_info, iova_start, paddr, size);
 }
 
-static size_t __ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info,
-			       unsigned long iova, size_t size)
+static void __ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info,
+			     unsigned long iova, size_t size)
 {
 	return l2_unmap(mmu_info, iova, 0, size);
 }
@@ -665,12 +672,13 @@  static size_t ipu6_mmu_pgsize(unsigned long pgsize_bitmap,
 	return pgsize;
 }
 
-size_t ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
-		      size_t size)
+void ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
+		    size_t size)
 {
-	size_t unmapped_page, unmapped = 0;
 	unsigned int min_pagesz;
 
+	dev_dbg(mmu_info->dev, "unmapping iova 0x%lx size 0x%zx\n", iova, size);
+
 	/* find out the minimum page size supported */
 	min_pagesz = 1 << __ffs(mmu_info->pgsize_bitmap);
 
@@ -682,29 +690,10 @@  size_t ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
 	if (!IS_ALIGNED(iova | size, min_pagesz)) {
 		dev_err(NULL, "unaligned: iova 0x%lx size 0x%zx min_pagesz 0x%x\n",
 			iova, size, min_pagesz);
-		return -EINVAL;
+		return;
 	}
 
-	/*
-	 * Keep iterating until we either unmap 'size' bytes (or more)
-	 * or we hit an area that isn't mapped.
-	 */
-	while (unmapped < size) {
-		size_t pgsize = ipu6_mmu_pgsize(mmu_info->pgsize_bitmap,
-						iova, size - unmapped);
-
-		unmapped_page = __ipu6_mmu_unmap(mmu_info, iova, pgsize);
-		if (!unmapped_page)
-			break;
-
-		dev_dbg(mmu_info->dev, "unmapped: iova 0x%lx size 0x%zx\n",
-			iova, unmapped_page);
-
-		iova += unmapped_page;
-		unmapped += unmapped_page;
-	}
-
-	return unmapped;
+	return __ipu6_mmu_unmap(mmu_info, iova, size);
 }
 
 int ipu6_mmu_map(struct ipu6_mmu_info *mmu_info, unsigned long iova,
diff --git a/drivers/media/pci/intel/ipu6/ipu6-mmu.h b/drivers/media/pci/intel/ipu6/ipu6-mmu.h
index 21cdb0f146eb..8e40b4a66d7d 100644
--- a/drivers/media/pci/intel/ipu6/ipu6-mmu.h
+++ b/drivers/media/pci/intel/ipu6/ipu6-mmu.h
@@ -66,8 +66,8 @@  int ipu6_mmu_hw_init(struct ipu6_mmu *mmu);
 void ipu6_mmu_hw_cleanup(struct ipu6_mmu *mmu);
 int ipu6_mmu_map(struct ipu6_mmu_info *mmu_info, unsigned long iova,
 		 phys_addr_t paddr, size_t size);
-size_t ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
-		      size_t size);
+void ipu6_mmu_unmap(struct ipu6_mmu_info *mmu_info, unsigned long iova,
+		    size_t size);
 phys_addr_t ipu6_mmu_iova_to_phys(struct ipu6_mmu_info *mmu_info,
 				  dma_addr_t iova);
 #endif