1 files changed, 18 insertions, 58 deletions

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 03e3251cd9d2..0fb16bdbbcae 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -73,8 +73,6 @@ static bool swiotlb_force_disable;
 
 struct io_tlb_mem io_tlb_default_mem;
 
-phys_addr_t swiotlb_unencrypted_base;
-
 static unsigned long default_nslabs = IO_TLB_DEFAULT_SIZE >> IO_TLB_SHIFT;
 static unsigned long default_nareas;
 
@@ -202,34 +200,6 @@ static inline unsigned long nr_slots(u64 val)
 }
 
 /*
- * Remap swioltb memory in the unencrypted physical address space
- * when swiotlb_unencrypted_base is set. (e.g. for Hyper-V AMD SEV-SNP
- * Isolation VMs).
- */
-#ifdef CONFIG_HAS_IOMEM
-static void *swiotlb_mem_remap(struct io_tlb_mem *mem, unsigned long bytes)
-{
-	void *vaddr = NULL;
-
-	if (swiotlb_unencrypted_base) {
-		phys_addr_t paddr = mem->start + swiotlb_unencrypted_base;
-
-		vaddr = memremap(paddr, bytes, MEMREMAP_WB);
-		if (!vaddr)
-			pr_err("Failed to map the unencrypted memory %pa size %lx.\n",
-			       &paddr, bytes);
-	}
-
-	return vaddr;
-}
-#else
-static void *swiotlb_mem_remap(struct io_tlb_mem *mem, unsigned long bytes)
-{
-	return NULL;
-}
-#endif
-
-/*
  * Early SWIOTLB allocation may be too early to allow an architecture to
  * perform the desired operations.  This function allows the architecture to
  * call SWIOTLB when the operations are possible.  It needs to be called
@@ -238,18 +208,12 @@ static void *swiotlb_mem_remap(struct io_tlb_mem *mem, unsigned long bytes)
 void __init swiotlb_update_mem_attributes(void)
 {
 	struct io_tlb_mem *mem = &io_tlb_default_mem;
-	void *vaddr;
 	unsigned long bytes;
 
 	if (!mem->nslabs || mem->late_alloc)
 		return;
-	vaddr = phys_to_virt(mem->start);
 	bytes = PAGE_ALIGN(mem->nslabs << IO_TLB_SHIFT);
-	set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
-
-	mem->vaddr = swiotlb_mem_remap(mem, bytes);
-	if (!mem->vaddr)
-		mem->vaddr = vaddr;
+	set_memory_decrypted((unsigned long)mem->vaddr, bytes >> PAGE_SHIFT);
 }
 
 static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
@@ -280,13 +244,6 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
 		mem->slots[i].alloc_size = 0;
 	}
 
-	/*
-	 * If swiotlb_unencrypted_base is set, the bounce buffer memory will
-	 * be remapped and cleared in swiotlb_update_mem_attributes.
-	 */
-	if (swiotlb_unencrypted_base)
-		return;
-
 	memset(vaddr, 0, bytes);
 	mem->vaddr = vaddr;
 	return;
@@ -623,10 +580,10 @@ static int swiotlb_do_find_slots(struct device *dev, int area_index,
 		phys_to_dma_unencrypted(dev, mem->start) & boundary_mask;
 	unsigned long max_slots = get_max_slots(boundary_mask);
 	unsigned int iotlb_align_mask =
-		dma_get_min_align_mask(dev) & ~(IO_TLB_SIZE - 1);
+		dma_get_min_align_mask(dev) | alloc_align_mask;
 	unsigned int nslots = nr_slots(alloc_size), stride;
-	unsigned int index, wrap, count = 0, i;
 	unsigned int offset = swiotlb_align_offset(dev, orig_addr);
+	unsigned int index, slots_checked, count = 0, i;
 	unsigned long flags;
 	unsigned int slot_base;
 	unsigned int slot_index;
@@ -635,29 +592,34 @@ static int swiotlb_do_find_slots(struct device *dev, int area_index,
 	BUG_ON(area_index >= mem->nareas);
 
 	/*
+	 * For allocations of PAGE_SIZE or larger only look for page aligned
+	 * allocations.
+	 */
+	if (alloc_size >= PAGE_SIZE)
+		iotlb_align_mask |= ~PAGE_MASK;
+	iotlb_align_mask &= ~(IO_TLB_SIZE - 1);
+
+	/*
 	 * For mappings with an alignment requirement don't bother looping to
-	 * unaligned slots once we found an aligned one.  For allocations of
-	 * PAGE_SIZE or larger only look for page aligned allocations.
+	 * unaligned slots once we found an aligned one.
 	 */
 	stride = (iotlb_align_mask >> IO_TLB_SHIFT) + 1;
-	if (alloc_size >= PAGE_SIZE)
-		stride = max(stride, stride << (PAGE_SHIFT - IO_TLB_SHIFT));
-	stride = max(stride, (alloc_align_mask >> IO_TLB_SHIFT) + 1);
 
 	spin_lock_irqsave(&area->lock, flags);
 	if (unlikely(nslots > mem->area_nslabs - area->used))
 		goto not_found;
 
 	slot_base = area_index * mem->area_nslabs;
-	index = wrap = wrap_area_index(mem, ALIGN(area->index, stride));
+	index = area->index;
 
-	do {
+	for (slots_checked = 0; slots_checked < mem->area_nslabs; ) {
 		slot_index = slot_base + index;
 
 		if (orig_addr &&
 		    (slot_addr(tbl_dma_addr, slot_index) &
 		     iotlb_align_mask) != (orig_addr & iotlb_align_mask)) {
 			index = wrap_area_index(mem, index + 1);
+			slots_checked++;
 			continue;
 		}
 
@@ -673,7 +635,8 @@ static int swiotlb_do_find_slots(struct device *dev, int area_index,
 				goto found;
 		}
 		index = wrap_area_index(mem, index + stride);
-	} while (index != wrap);
+		slots_checked += stride;
+	}
 
 not_found:
 	spin_unlock_irqrestore(&area->lock, flags);
@@ -693,10 +656,7 @@ found:
 	/*
 	 * Update the indices to avoid searching in the next round.
 	 */
-	if (index + nslots < mem->area_nslabs)
-		area->index = index + nslots;
-	else
-		area->index = 0;
+	area->index = wrap_area_index(mem, index + nslots);
 	area->used += nslots;
 	spin_unlock_irqrestore(&area->lock, flags);
 	return slot_index;