Merge tag 'dma-mapping-5.3' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - move the USB special case that bounced DMA through a device bar into
   the USB code instead of handling it in the common DMA code (Laurentiu
   Tudor and Fredrik Noring)

 - don't dip into the global CMA pool for single page allocations
   (Nicolin Chen)

 - fix a crash when allocating memory for the atomic pool failed during
   boot (Florian Fainelli)

 - move support for MIPS-style uncached segments to the common code and
   use that for MIPS and nios2 (me)

 - make support for DMA_ATTR_NON_CONSISTENT and
   DMA_ATTR_NO_KERNEL_MAPPING generic (me)

 - convert nds32 to the generic remapping allocator (me)

* tag 'dma-mapping-5.3' of git://git.infradead.org/users/hch/dma-mapping: (29 commits)
  dma-mapping: mark dma_alloc_need_uncached as __always_inline
  MIPS: only select ARCH_HAS_UNCACHED_SEGMENT for non-coherent platforms
  usb: host: Fix excessive alignment restriction for local memory allocations
  lib/genalloc.c: Add algorithm, align and zeroed family of DMA allocators
  nios2: use the generic uncached segment support in dma-direct
  nds32: use the generic remapping allocator for coherent DMA allocations
  arc: use the generic remapping allocator for coherent DMA allocations
  dma-direct: handle DMA_ATTR_NO_KERNEL_MAPPING in common code
  dma-direct: handle DMA_ATTR_NON_CONSISTENT in common code
  dma-mapping: add a dma_alloc_need_uncached helper
  openrisc: remove the partial DMA_ATTR_NON_CONSISTENT support
  arc: remove the partial DMA_ATTR_NON_CONSISTENT support
  arm-nommu: remove the partial DMA_ATTR_NON_CONSISTENT support
  ARM: dma-mapping: allow larger DMA mask than supported
  dma-mapping: truncate dma masks to what dma_addr_t can hold
  iommu/dma: Apply dma_{alloc,free}_contiguous functions
  dma-remap: Avoid de-referencing NULL atomic_pool
  MIPS: use the generic uncached segment support in dma-direct
  dma-direct: provide generic support for uncached kernel segments
  au1100fb: fix DMA API abuse
  ...

drivers/usb/core/buffer.c

@@ -16,6 +16,7 @@
 #include <linux/io.h>
 #include <linux/dma-mapping.h>
 #include <linux/dmapool.h>
+#include <linux/genalloc.h>
 #include <linux/usb.h>
 #include <linux/usb/hcd.h>
 
@@ -67,7 +68,7 @@ int hcd_buffer_create(struct usb_hcd *hcd)
 
 	if (!IS_ENABLED(CONFIG_HAS_DMA) ||
 	    (!is_device_dma_capable(hcd->self.sysdev) &&
-	     !(hcd->driver->flags & HCD_LOCAL_MEM)))
+	     !hcd->localmem_pool))
 		return 0;
 
 	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
@@ -124,10 +125,12 @@ void *hcd_buffer_alloc(
 	if (size == 0)
 		return NULL;
 
+	if (hcd->localmem_pool)
+		return gen_pool_dma_alloc(hcd->localmem_pool, size, dma);
+
 	/* some USB hosts just use PIO */
 	if (!IS_ENABLED(CONFIG_HAS_DMA) ||
-	    (!is_device_dma_capable(bus->sysdev) &&
-	     !(hcd->driver->flags & HCD_LOCAL_MEM))) {
+	    !is_device_dma_capable(bus->sysdev)) {
 		*dma = ~(dma_addr_t) 0;
 		return kmalloc(size, mem_flags);
 	}
@@ -152,9 +155,13 @@ void hcd_buffer_free(
 	if (!addr)
 		return;
 
+	if (hcd->localmem_pool) {
+		gen_pool_free(hcd->localmem_pool, (unsigned long)addr, size);
+		return;
+	}
+
 	if (!IS_ENABLED(CONFIG_HAS_DMA) ||
-	    (!is_device_dma_capable(bus->sysdev) &&
-	     !(hcd->driver->flags & HCD_LOCAL_MEM))) {
+	    !is_device_dma_capable(bus->sysdev)) {
 		kfree(addr);
 		return;
 	}

drivers/usb/core/hcd.c

@@ -29,6 +29,8 @@
 #include <linux/workqueue.h>
 #include <linux/pm_runtime.h>
 #include <linux/types.h>
+#include <linux/genalloc.h>
+#include <linux/io.h>
 
 #include <linux/phy/phy.h>
 #include <linux/usb.h>
@@ -1345,14 +1347,14 @@ EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
  * using regular system memory - like pci devices doing bus mastering.
  *
  * To support host controllers with limited dma capabilities we provide dma
- * bounce buffers. This feature can be enabled using the HCD_LOCAL_MEM flag.
+ * bounce buffers. This feature can be enabled by initializing
+ * hcd->localmem_pool using usb_hcd_setup_local_mem().
  * For this to work properly the host controller code must first use the
  * function dma_declare_coherent_memory() to point out which memory area
  * that should be used for dma allocations.
  *
- * The HCD_LOCAL_MEM flag then tells the usb code to allocate all data for
- * dma using dma_alloc_coherent() which in turn allocates from the memory
- * area pointed out with dma_declare_coherent_memory().
+ * The initialized hcd->localmem_pool then tells the usb code to allocate all
+ * data for dma using the genalloc API.
  *
  * So, to summarize...
  *
@@ -1362,9 +1364,6 @@ EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
  *   (a) "normal" kernel memory is no good, and
  *   (b) there's not enough to share
  *
- * - The only *portable* hook for such stuff in the
- *   DMA framework is dma_declare_coherent_memory()
- *
  * - So we use that, even though the primary requirement
  *   is that the memory be "local" (hence addressable
  *   by that device), not "coherent".
@@ -1531,7 +1530,7 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 						urb->setup_dma))
 				return -EAGAIN;
 			urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
-		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
+		} else if (hcd->localmem_pool) {
 			ret = hcd_alloc_coherent(
 					urb->dev->bus, mem_flags,
 					&urb->setup_dma,
@@ -1601,7 +1600,7 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 				else
 					urb->transfer_flags |= URB_DMA_MAP_SINGLE;
 			}
-		} else if (hcd->driver->flags & HCD_LOCAL_MEM) {
+		} else if (hcd->localmem_pool) {
 			ret = hcd_alloc_coherent(
 					urb->dev->bus, mem_flags,
 					&urb->transfer_dma,
@@ -3039,6 +3038,40 @@ usb_hcd_platform_shutdown(struct platform_device *dev)
 }
 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
 
+int usb_hcd_setup_local_mem(struct usb_hcd *hcd, phys_addr_t phys_addr,
+			    dma_addr_t dma, size_t size)
+{
+	int err;
+	void *local_mem;
+
+	hcd->localmem_pool = devm_gen_pool_create(hcd->self.sysdev, 4,
+						  dev_to_node(hcd->self.sysdev),
+						  dev_name(hcd->self.sysdev));
+	if (IS_ERR(hcd->localmem_pool))
+		return PTR_ERR(hcd->localmem_pool);
+
+	local_mem = devm_memremap(hcd->self.sysdev, phys_addr,
+				  size, MEMREMAP_WC);
+	if (!local_mem)
+		return -ENOMEM;
+
+	/*
+	 * Here we pass a dma_addr_t but the arg type is a phys_addr_t.
+	 * It's not backed by system memory and thus there's no kernel mapping
+	 * for it.
+	 */
+	err = gen_pool_add_virt(hcd->localmem_pool, (unsigned long)local_mem,
+				dma, size, dev_to_node(hcd->self.sysdev));
+	if (err < 0) {
+		dev_err(hcd->self.sysdev, "gen_pool_add_virt failed with %d\n",
+			err);
+		return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usb_hcd_setup_local_mem);
+
 /*-------------------------------------------------------------------------*/
 
 #if IS_ENABLED(CONFIG_USB_MON)