usb gadget stack: remove usb_ep_*_buffer(), part 1

Remove usb_ep_{alloc,free}_buffer() calls, for small dma-coherent buffers.
This patch just removes the interface and its users; later patches will
remove controller driver support.

  - This interface is invariably not implemented correctly in the
    controller drivers (e.g. using dma pools, a mechanism which
    post-dates the interface by several years).

  - At this point no gadget driver really *needs* to use it.  In
    current kernels, any driver that needs such a mechanism could
    allocate a dma pool themselves.

Removing this interface is thus a simplification and improvement.

Note that the gmidi.c driver had a bug in this area; fixed.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

5 files changed, 11 insertions, 70 deletions

diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index 7e650d015585..8712ef987179 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -3733,19 +3733,12 @@ static void /* __init_or_exit */ fsg_unbind(struct usb_gadget *gadget)
         }
 
         /* Free the data buffers */
-        for (i = 0; i < NUM_BUFFERS; ++i) {
-                struct fsg_buffhd       *bh = &fsg->buffhds[i];
-
-                if (bh->buf)
-                        usb_ep_free_buffer(fsg->bulk_in, bh->buf, bh->dma,
-                                        mod_data.buflen);
-        }
+        for (i = 0; i < NUM_BUFFERS; ++i)
+                kfree(fsg->buffhds[i].buf);
 
         /* Free the request and buffer for endpoint 0 */
         if (req) {
-                if (req->buf)
-                        usb_ep_free_buffer(fsg->ep0, req->buf,
-                                        req->dma, EP0_BUFSIZE);
+                kfree(req->buf);
                 usb_ep_free_request(fsg->ep0, req);
         }
 
@@ -3972,8 +3965,7 @@ static int __init fsg_bind(struct usb_gadget *gadget)
         fsg->ep0req = req = usb_ep_alloc_request(fsg->ep0, GFP_KERNEL);
         if (!req)
                 goto out;
-        req->buf = usb_ep_alloc_buffer(fsg->ep0, EP0_BUFSIZE,
-                        &req->dma, GFP_KERNEL);
+        req->buf = kmalloc(EP0_BUFSIZE, GFP_KERNEL);
         if (!req->buf)
                 goto out;
         req->complete = ep0_complete;
@@ -3985,8 +3977,7 @@ static int __init fsg_bind(struct usb_gadget *gadget)
                 /* Allocate for the bulk-in endpoint.  We assume that
                  * the buffer will also work with the bulk-out (and
                  * interrupt-in) endpoint. */
-                bh->buf = usb_ep_alloc_buffer(fsg->bulk_in, mod_data.buflen,
-                                &bh->dma, GFP_KERNEL);
+                bh->buf = kmalloc(mod_data.buflen, GFP_KERNEL);
                 if (!bh->buf)
                         goto out;
                 bh->next = bh + 1;
diff --git a/drivers/usb/gadget/gmidi.c b/drivers/usb/gadget/gmidi.c
index d08a8d0e6427..1c5aa49d7432 100644
--- a/drivers/usb/gadget/gmidi.c
+++ b/drivers/usb/gadget/gmidi.c
@@ -1248,17 +1248,11 @@ autoconf_fail:
         tasklet_init(&dev->tasklet, gmidi_in_tasklet, (unsigned long)dev);
 
         /* preallocate control response and buffer */
-        dev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
+        dev->req = alloc_ep_req(gadget->ep0, USB_BUFSIZ);
         if (!dev->req) {
                 err = -ENOMEM;
                 goto fail;
         }
-        dev->req->buf = usb_ep_alloc_buffer(gadget->ep0, USB_BUFSIZ,
-                                &dev->req->dma, GFP_KERNEL);
-        if (!dev->req->buf) {
-                err = -ENOMEM;
-                goto fail;
-        }
 
         dev->req->complete = gmidi_setup_complete;
 
diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
index f723e083c9d0..e60745ffaf8e 100644
--- a/drivers/usb/gadget/inode.c
+++ b/drivers/usb/gadget/inode.c
@@ -923,7 +923,7 @@ static void clean_req (struct usb_ep *ep, struct usb_request *req)
         struct dev_data         *dev = ep->driver_data;
 
         if (req->buf != dev->rbuf) {
-                usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
+                kfree(req->buf);
                 req->buf = dev->rbuf;
                 req->dma = DMA_ADDR_INVALID;
         }
@@ -963,7 +963,7 @@ static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
                 return -EBUSY;
         }
         if (len > sizeof (dev->rbuf))
-                req->buf = usb_ep_alloc_buffer (ep, len, &req->dma, GFP_ATOMIC);
+                req->buf = kmalloc(len, GFP_ATOMIC);
         if (req->buf == 0) {
                 req->buf = dev->rbuf;
                 return -ENOMEM;
diff --git a/drivers/usb/gadget/zero.c b/drivers/usb/gadget/zero.c
index 7078374d0b79..a2e6e3fc8c8d 100644
--- a/drivers/usb/gadget/zero.c
+++ b/drivers/usb/gadget/zero.c
@@ -481,8 +481,7 @@ alloc_ep_req (struct usb_ep *ep, unsigned length)
         req = usb_ep_alloc_request (ep, GFP_ATOMIC);
         if (req) {
                 req->length = length;
-                req->buf = usb_ep_alloc_buffer (ep, length,
-                                &req->dma, GFP_ATOMIC);
+                req->buf = kmalloc(length, GFP_ATOMIC);
                 if (!req->buf) {
                         usb_ep_free_request (ep, req);
                         req = NULL;
@@ -493,8 +492,7 @@ alloc_ep_req (struct usb_ep *ep, unsigned length)
 
 static void free_ep_req (struct usb_ep *ep, struct usb_request *req)
 {
-        if (req->buf)
-                usb_ep_free_buffer (ep, req->buf, req->dma, req->length);
+        kfree(req->buf);
         usb_ep_free_request (ep, req);
 }
 
@@ -1199,8 +1197,7 @@ autoconf_fail:
         dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
         if (!dev->req)
                 goto enomem;
-        dev->req->buf = usb_ep_alloc_buffer (gadget->ep0, USB_BUFSIZ,
-                                &dev->req->dma, GFP_KERNEL);
+        dev->req->buf = kmalloc(USB_BUFSIZ, GFP_KERNEL);
         if (!dev->req->buf)
                 goto enomem;
 
diff --git a/include/linux/usb_gadget.h b/include/linux/usb_gadget.h
index e17186dbcdca..703fd84c46fc 100644
--- a/include/linux/usb_gadget.h
+++ b/include/linux/usb_gadget.h
@@ -235,47 +235,6 @@ usb_ep_free_request (struct usb_ep *ep, struct usb_request *req)
 }
 
 /**
- * usb_ep_alloc_buffer - allocate an I/O buffer
- * @ep:the endpoint associated with the buffer
- * @len:length of the desired buffer
- * @dma:pointer to the buffer's DMA address; must be valid
- * @gfp_flags:GFP_* flags to use
- *
- * Returns a new buffer, or null if one could not be allocated.
- * The buffer is suitably aligned for dma, if that endpoint uses DMA,
- * and the caller won't have to care about dma-inconsistency
- * or any hidden "bounce buffer" mechanism.  No additional per-request
- * DMA mapping will be required for such buffers.
- * Free it later with usb_ep_free_buffer().
- *
- * You don't need to use this call to allocate I/O buffers unless you
- * want to make sure drivers don't incur costs for such "bounce buffer"
- * copies or per-request DMA mappings.
- */
-static inline void *
-usb_ep_alloc_buffer (struct usb_ep *ep, unsigned len, dma_addr_t *dma,
-        gfp_t gfp_flags)
-{
-        return ep->ops->alloc_buffer (ep, len, dma, gfp_flags);
-}
-
-/**
- * usb_ep_free_buffer - frees an i/o buffer
- * @ep:the endpoint associated with the buffer
- * @buf:CPU view address of the buffer
- * @dma:the buffer's DMA address
- * @len:length of the buffer
- *
- * reverses the effect of usb_ep_alloc_buffer().
- * caller guarantees the buffer will no longer be accessed
- */
-static inline void
-usb_ep_free_buffer (struct usb_ep *ep, void *buf, dma_addr_t dma, unsigned len)
-{
-        ep->ops->free_buffer (ep, buf, dma, len);
-}
-
-/**
  * usb_ep_queue - queues (submits) an I/O request to an endpoint.
  * @ep:the endpoint associated with the request
  * @req:the request being submitted