Merge branch 'for-linus-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb

Pull swiotlb updates from Konrad Rzeszutek Wilk:
 "One compiler fix, and a bug-fix in swiotlb_nr_tbl() and
  swiotlb_max_segment() to check also for no_iotlb_memory"

* 'for-linus-5.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb: fix phys_addr_t overflow warning
  swiotlb: Return consistent SWIOTLB segments/nr_tbl
  swiotlb: Group identical cleanup in swiotlb_cleanup()

drivers/xen/swiotlb-xen.c

@@ -402,7 +402,7 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
 
 	map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir,
 				     attrs);
-	if (map == DMA_MAPPING_ERROR)
+	if (map == (phys_addr_t)DMA_MAPPING_ERROR)
 		return DMA_MAPPING_ERROR;
 
 	dev_addr = xen_phys_to_bus(map);

kernel/dma/swiotlb.c

@@ -129,15 +129,17 @@ setup_io_tlb_npages(char *str)
 }
 early_param("swiotlb", setup_io_tlb_npages);
 
+static bool no_iotlb_memory;
+
 unsigned long swiotlb_nr_tbl(void)
 {
-	return io_tlb_nslabs;
+	return unlikely(no_iotlb_memory) ? 0 : io_tlb_nslabs;
 }
 EXPORT_SYMBOL_GPL(swiotlb_nr_tbl);
 
 unsigned int swiotlb_max_segment(void)
 {
-	return max_segment;
+	return unlikely(no_iotlb_memory) ? 0 : max_segment;
 }
 EXPORT_SYMBOL_GPL(swiotlb_max_segment);
 
@@ -160,8 +162,6 @@ unsigned long swiotlb_size_or_default(void)
 	return size ? size : (IO_TLB_DEFAULT_SIZE);
 }
 
-static bool no_iotlb_memory;
-
 void swiotlb_print_info(void)
 {
 	unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT;
@@ -317,6 +317,14 @@ swiotlb_late_init_with_default_size(size_t default_size)
 	return rc;
 }
 
+static void swiotlb_cleanup(void)
+{
+	io_tlb_end = 0;
+	io_tlb_start = 0;
+	io_tlb_nslabs = 0;
+	max_segment = 0;
+}
+
 int
 swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
 {
@@ -367,10 +375,7 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
 	                                                 sizeof(int)));
 	io_tlb_list = NULL;
 cleanup3:
-	io_tlb_end = 0;
-	io_tlb_start = 0;
-	io_tlb_nslabs = 0;
-	max_segment = 0;
+	swiotlb_cleanup();
 	return -ENOMEM;
 }
 
@@ -394,10 +399,7 @@ void __init swiotlb_exit(void)
 		memblock_free_late(io_tlb_start,
 				   PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
 	}
-	io_tlb_start = 0;
-	io_tlb_end = 0;
-	io_tlb_nslabs = 0;
-	max_segment = 0;
+	swiotlb_cleanup();
 }
 
 /*
@@ -546,7 +548,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
 	if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit())
 		dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n",
 			 size, io_tlb_nslabs, tmp_io_tlb_used);
-	return DMA_MAPPING_ERROR;
+	return (phys_addr_t)DMA_MAPPING_ERROR;
 found:
 	io_tlb_used += nslots;
 	spin_unlock_irqrestore(&io_tlb_lock, flags);
@@ -664,7 +666,7 @@ bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr,
 	/* Oh well, have to allocate and map a bounce buffer. */
 	*phys = swiotlb_tbl_map_single(dev, __phys_to_dma(dev, io_tlb_start),
 			*phys, size, dir, attrs);
-	if (*phys == DMA_MAPPING_ERROR)
+	if (*phys == (phys_addr_t)DMA_MAPPING_ERROR)
 		return false;
 
 	/* Ensure that the address returned is DMA'ble */