commit 08c5fb938e05314b48fc12e697003e91d43c3c9d
author Joerg Roedel <jroedel@suse.de> Mon Dec 21 13:04:49 2015 +0100
committer Joerg Roedel <jroedel@suse.de> Mon Dec 28 17:18:50 2015 +0100
tree 2f00e80cfb6766868bf8015bbc4a96cb0fbcfd8b
parent 007b74bab2739539bbc49bb9e3f022159dc2c279

iommu/amd: Introduce bitmap_lock in struct aperture_range

This lock only protects the address allocation bitmap in one
aperture.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu.c

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 9ce51eb..8ff3331 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -120,6 +120,8 @@
  */
 struct aperture_range {
 
+	spinlock_t bitmap_lock;
+
 	/* address allocation bitmap */
 	unsigned long *bitmap;
 
@@ -1436,6 +1438,8 @@
 
 	dma_dom->aperture[index]->offset = dma_dom->aperture_size;
 
+	spin_lock_init(&dma_dom->aperture[index]->bitmap_lock);
+
 	if (populate) {
 		unsigned long address = dma_dom->aperture_size;
 		int i, num_ptes = APERTURE_RANGE_PAGES / 512;
@@ -1527,6 +1531,7 @@
 	unsigned long boundary_size, mask;
 	unsigned long address = -1;
 	unsigned long limit;
+	unsigned long flags;
 
 	next_bit >>= PAGE_SHIFT;
 
@@ -1544,9 +1549,11 @@
 		limit = iommu_device_max_index(APERTURE_RANGE_PAGES, offset,
 					       dma_mask >> PAGE_SHIFT);
 
+		spin_lock_irqsave(&dom->aperture[i]->bitmap_lock, flags);
 		address = iommu_area_alloc(dom->aperture[i]->bitmap,
 					   limit, next_bit, pages, 0,
 					    boundary_size, align_mask);
+		spin_unlock_irqrestore(&dom->aperture[i]->bitmap_lock, flags);
 		if (address != -1) {
 			address = dom->aperture[i]->offset +
 				  (address << PAGE_SHIFT);
@@ -1602,6 +1609,7 @@
 {
 	unsigned i = address >> APERTURE_RANGE_SHIFT;
 	struct aperture_range *range = dom->aperture[i];
+	unsigned long flags;
 
 	BUG_ON(i >= APERTURE_MAX_RANGES || range == NULL);
 
@@ -1615,7 +1623,9 @@
 
 	address = (address % APERTURE_RANGE_SIZE) >> PAGE_SHIFT;
 
+	spin_lock_irqsave(&range->bitmap_lock, flags);
 	bitmap_clear(range->bitmap, address, pages);
+	spin_unlock_irqrestore(&range->bitmap_lock, flags);
 
 }