ENGR00313729 usb: class: acm: use nonbufferable memory for rx dma buffer

use dma_pool_alloc_nonbufferable for rx buf instead of dma_alloc_coherent
for usb host cdc-acm to fix data coherent issue.

Signed-off-by: Li Jun <b47624@freescale.com>

5 files changed, 40 insertions, 2 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 84e69ea2309b..5a97ff143fc3 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1134,8 +1134,8 @@ made_compressed_probe:
 		struct acm_rb *rb = &(acm->read_buffers[i]);
 		struct urb *urb;
 
-		rb->base = usb_alloc_coherent(acm->dev, readsize, GFP_KERNEL,
-								&rb->dma);
+		rb->base = usb_alloc_nonbufferable(acm->dev, readsize,
+							GFP_KERNEL, &rb->dma);
 		if (!rb->base) {
 			dev_err(&intf->dev, "out of memory "
 					"(read bufs usb_alloc_coherent)\n");
diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
index b0585e623ba9..687ddb897ed8 100644
--- a/drivers/usb/core/buffer.c
+++ b/drivers/usb/core/buffer.c
@@ -122,6 +122,31 @@ void *hcd_buffer_alloc(
 	return dma_alloc_coherent(hcd->self.controller, size, dma, mem_flags);
 }
 
+void *hcd_buffer_alloc_nonbufferable(
+	struct usb_bus		*bus,
+	size_t			size,
+	gfp_t			mem_flags,
+	dma_addr_t		*dma
+)
+{
+	struct usb_hcd		*hcd = bus_to_hcd(bus);
+	int			i;
+
+	/* some USB hosts just use PIO */
+	if (!bus->controller->dma_mask &&
+	    !(hcd->driver->flags & HCD_LOCAL_MEM)) {
+		*dma = ~(dma_addr_t) 0;
+		return kmalloc(size, mem_flags);
+	}
+
+	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
+		if (size <= pool_max[i])
+			return dma_pool_alloc_nonbufferable(hcd->pool[i],
+								mem_flags, dma);
+	}
+	return NULL;
+}
+
 void hcd_buffer_free(
 	struct usb_bus		*bus,
 	size_t			size,
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 8706fc97e60f..0463fad320f2 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -682,6 +682,15 @@ void *usb_alloc_coherent(struct usb_device *dev, size_t size, gfp_t mem_flags,
 }
 EXPORT_SYMBOL_GPL(usb_alloc_coherent);
 
+void *usb_alloc_nonbufferable(struct usb_device *dev, size_t size,
+					gfp_t mem_flags, dma_addr_t *dma)
+{
+	if (!dev || !dev->bus)
+		return NULL;
+	return hcd_buffer_alloc_nonbufferable(dev->bus, size, mem_flags, dma);
+}
+EXPORT_SYMBOL_GPL(usb_alloc_nonbufferable);
+
 /**
  * usb_free_coherent - free memory allocated with usb_alloc_coherent()
  * @dev: device the buffer was used with
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 6cd157629772..71997492f34a 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1398,6 +1398,8 @@ static inline int usb_urb_dir_out(struct urb *urb)
 
 void *usb_alloc_coherent(struct usb_device *dev, size_t size,
 	gfp_t mem_flags, dma_addr_t *dma);
+void *usb_alloc_nonbufferable(struct usb_device *dev, size_t size,
+	gfp_t mem_flags, dma_addr_t *dma);
 void usb_free_coherent(struct usb_device *dev, size_t size,
 	void *addr, dma_addr_t dma);
 
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index c0ecc5a2ef9e..fae56f96f0bc 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -405,6 +405,8 @@ void hcd_buffer_destroy(struct usb_hcd *hcd);
 
 void *hcd_buffer_alloc(struct usb_bus *bus, size_t size,
 	gfp_t mem_flags, dma_addr_t *dma);
+void *hcd_buffer_alloc_nonbufferable(struct usb_bus *bus, size_t size,
+	gfp_t mem_flags, dma_addr_t *dma);
 void hcd_buffer_free(struct usb_bus *bus, size_t size,
 	void *addr, dma_addr_t dma);