usb gadget stack: remove usb_ep_*_buffer(), part 2

This patch removes controller driver infrastructure which supported
the now-removed usb_ep_{alloc,free}_buffer() calls.

As can be seen, many of the implementations of this were broken to
various degrees.  Many didn't properly return dma-coherent mappings;
those which did so were necessarily ugly because of bogosity in the
underlying dma_free_coherent() calls ... which on many platforms
can't be called from the same contexts (notably in_irq) from which
their dma_alloc_coherent() sibling can be called.

The main potential downside of removing this is that gadget drivers
wouldn't have specific knowledge that the controller drivers have:
endpoints that aren't dma-capable don't need any dma mappings at all.

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

10 files changed, 0 insertions, 436 deletions

diff --git a/drivers/usb/gadget/at91_udc.c b/drivers/usb/gadget/at91_udc.c
index ba163f35bf21..63d7d6568699 100644
--- a/drivers/usb/gadget/at91_udc.c
+++ b/drivers/usb/gadget/at91_udc.c
@@ -601,25 +601,6 @@ static void at91_ep_free_request(struct usb_ep *_ep, struct usb_request *_req)
         kfree(req);
 }
 
-static void *at91_ep_alloc_buffer(
-        struct usb_ep *_ep,
-        unsigned bytes,
-        dma_addr_t *dma,
-        gfp_t gfp_flags)
-{
-        *dma = ~0;
-        return kmalloc(bytes, gfp_flags);
-}
-
-static void at91_ep_free_buffer(
-        struct usb_ep *ep,
-        void *buf,
-        dma_addr_t dma,
-        unsigned bytes)
-{
-        kfree(buf);
-}
-
 static int at91_ep_queue(struct usb_ep *_ep,
                         struct usb_request *_req, gfp_t gfp_flags)
 {
@@ -788,8 +769,6 @@ static const struct usb_ep_ops at91_ep_ops = {
         .disable        = at91_ep_disable,
         .alloc_request  = at91_ep_alloc_request,
         .free_request   = at91_ep_free_request,
-        .alloc_buffer   = at91_ep_alloc_buffer,
-        .free_buffer    = at91_ep_free_buffer,
         .queue          = at91_ep_queue,
         .dequeue        = at91_ep_dequeue,
         .set_halt       = at91_ep_set_halt,
diff --git a/drivers/usb/gadget/dummy_hcd.c b/drivers/usb/gadget/dummy_hcd.c
index 9040b50d6425..f2fbdc7fe376 100644
--- a/drivers/usb/gadget/dummy_hcd.c
+++ b/drivers/usb/gadget/dummy_hcd.c
@@ -497,38 +497,6 @@ dummy_free_request (struct usb_ep *_ep, struct usb_request *_req)
         kfree (req);
 }
 
-static void *
-dummy_alloc_buffer (
-        struct usb_ep *_ep,
-        unsigned bytes,
-        dma_addr_t *dma,
-        gfp_t mem_flags
-) {
-        char                    *retval;
-        struct dummy_ep         *ep;
-        struct dummy            *dum;
-
-        ep = usb_ep_to_dummy_ep (_ep);
-        dum = ep_to_dummy (ep);
-
-        if (!dum->driver)
-                return NULL;
-        retval = kmalloc (bytes, mem_flags);
-        *dma = (dma_addr_t) retval;
-        return retval;
-}
-
-static void
-dummy_free_buffer (
-        struct usb_ep *_ep,
-        void *buf,
-        dma_addr_t dma,
-        unsigned bytes
-) {
-        if (bytes)
-                kfree (buf);
-}
-
 static void
 fifo_complete (struct usb_ep *ep, struct usb_request *req)
 {
@@ -659,10 +627,6 @@ static const struct usb_ep_ops dummy_ep_ops = {
         .alloc_request  = dummy_alloc_request,
         .free_request   = dummy_free_request,
 
-        .alloc_buffer   = dummy_alloc_buffer,
-        .free_buffer    = dummy_free_buffer,
-        /* map, unmap, ... eventually hook the "generic" dma calls */
-
         .queue          = dummy_queue,
         .dequeue        = dummy_dequeue,
 
diff --git a/drivers/usb/gadget/fsl_usb2_udc.c b/drivers/usb/gadget/fsl_usb2_udc.c
index 4e14bcd7c3b1..10b2b33b8698 100644
--- a/drivers/usb/gadget/fsl_usb2_udc.c
+++ b/drivers/usb/gadget/fsl_usb2_udc.c
@@ -601,39 +601,6 @@ static void fsl_free_request(struct usb_ep *_ep, struct usb_request *_req)
                 kfree(req);
 }
 
-/*------------------------------------------------------------------
- * Allocate an I/O buffer
-*---------------------------------------------------------------------*/
-static void *fsl_alloc_buffer(struct usb_ep *_ep, unsigned bytes,
-                dma_addr_t *dma, gfp_t gfp_flags)
-{
-        struct fsl_ep *ep;
-
-        if (!_ep)
-                return NULL;
-
-        ep = container_of(_ep, struct fsl_ep, ep);
-
-        return dma_alloc_coherent(ep->udc->gadget.dev.parent,
-                        bytes, dma, gfp_flags);
-}
-
-/*------------------------------------------------------------------
- * frees an i/o buffer
-*---------------------------------------------------------------------*/
-static void fsl_free_buffer(struct usb_ep *_ep, void *buf,
-                dma_addr_t dma, unsigned bytes)
-{
-        struct fsl_ep *ep;
-
-        if (!_ep)
-                return;
-
-        ep = container_of(_ep, struct fsl_ep, ep);
-
-        dma_free_coherent(ep->udc->gadget.dev.parent, bytes, buf, dma);
-}
-
 /*-------------------------------------------------------------------------*/
 static int fsl_queue_td(struct fsl_ep *ep, struct fsl_req *req)
 {
@@ -1047,9 +1014,6 @@ static struct usb_ep_ops fsl_ep_ops = {
         .alloc_request = fsl_alloc_request,
         .free_request = fsl_free_request,
 
-        .alloc_buffer = fsl_alloc_buffer,
-        .free_buffer = fsl_free_buffer,
-
         .queue = fsl_ep_queue,
         .dequeue = fsl_ep_dequeue,
 
diff --git a/drivers/usb/gadget/goku_udc.c b/drivers/usb/gadget/goku_udc.c
index ae931af05cef..dfadb643597b 100644
--- a/drivers/usb/gadget/goku_udc.c
+++ b/drivers/usb/gadget/goku_udc.c
@@ -296,51 +296,6 @@ goku_free_request(struct usb_ep *_ep, struct usb_request *_req)
 
 /*-------------------------------------------------------------------------*/
 
-/* allocating buffers this way eliminates dma mapping overhead, which
- * on some platforms will mean eliminating a per-io buffer copy.  with
- * some kinds of system caches, further tweaks may still be needed.
- */
-static void *
-goku_alloc_buffer(struct usb_ep *_ep, unsigned bytes,
-                        dma_addr_t *dma, gfp_t gfp_flags)
-{
-        void            *retval;
-        struct goku_ep  *ep;
-
-        ep = container_of(_ep, struct goku_ep, ep);
-        if (!_ep)
-                return NULL;
-        *dma = DMA_ADDR_INVALID;
-
-        if (ep->dma) {
-                /* the main problem with this call is that it wastes memory
-                 * on typical 1/N page allocations: it allocates 1-N pages.
-                 */
-#warning Using dma_alloc_coherent even with buffers smaller than a page.
-                retval = dma_alloc_coherent(&ep->dev->pdev->dev,
-                                bytes, dma, gfp_flags);
-        } else
-                retval = kmalloc(bytes, gfp_flags);
-        return retval;
-}
-
-static void
-goku_free_buffer(struct usb_ep *_ep, void *buf, dma_addr_t dma, unsigned bytes)
-{
-        /* free memory into the right allocator */
-        if (dma != DMA_ADDR_INVALID) {
-                struct goku_ep  *ep;
-
-                ep = container_of(_ep, struct goku_ep, ep);
-                if (!_ep)
-                        return;
-                dma_free_coherent(&ep->dev->pdev->dev, bytes, buf, dma);
-        } else
-                kfree (buf);
-}
-
-/*-------------------------------------------------------------------------*/
-
 static void
 done(struct goku_ep *ep, struct goku_request *req, int status)
 {
@@ -1026,9 +981,6 @@ static struct usb_ep_ops goku_ep_ops = {
         .alloc_request  = goku_alloc_request,
         .free_request   = goku_free_request,
 
-        .alloc_buffer   = goku_alloc_buffer,
-        .free_buffer    = goku_free_buffer,
-
         .queue          = goku_queue,
         .dequeue        = goku_dequeue,
 
diff --git a/drivers/usb/gadget/lh7a40x_udc.c b/drivers/usb/gadget/lh7a40x_udc.c
index a0a73c08a344..e78c2ddc1f88 100644
--- a/drivers/usb/gadget/lh7a40x_udc.c
+++ b/drivers/usb/gadget/lh7a40x_udc.c
@@ -75,10 +75,6 @@ static int lh7a40x_ep_enable(struct usb_ep *ep,
 static int lh7a40x_ep_disable(struct usb_ep *ep);
 static struct usb_request *lh7a40x_alloc_request(struct usb_ep *ep, gfp_t);
 static void lh7a40x_free_request(struct usb_ep *ep, struct usb_request *);
-static void *lh7a40x_alloc_buffer(struct usb_ep *ep, unsigned, dma_addr_t *,
-                                  gfp_t);
-static void lh7a40x_free_buffer(struct usb_ep *ep, void *, dma_addr_t,
-                                unsigned);
 static int lh7a40x_queue(struct usb_ep *ep, struct usb_request *, gfp_t);
 static int lh7a40x_dequeue(struct usb_ep *ep, struct usb_request *);
 static int lh7a40x_set_halt(struct usb_ep *ep, int);
@@ -104,9 +100,6 @@ static struct usb_ep_ops lh7a40x_ep_ops = {
         .alloc_request = lh7a40x_alloc_request,
         .free_request = lh7a40x_free_request,
 
-        .alloc_buffer = lh7a40x_alloc_buffer,
-        .free_buffer = lh7a40x_free_buffer,
-
         .queue = lh7a40x_queue,
         .dequeue = lh7a40x_dequeue,
 
@@ -1134,26 +1127,6 @@ static void lh7a40x_free_request(struct usb_ep *ep, struct usb_request *_req)
         kfree(req);
 }
 
-static void *lh7a40x_alloc_buffer(struct usb_ep *ep, unsigned bytes,
-                                  dma_addr_t * dma, gfp_t gfp_flags)
-{
-        char *retval;
-
-        DEBUG("%s (%p, %d, %d)\n", __FUNCTION__, ep, bytes, gfp_flags);
-
-        retval = kmalloc(bytes, gfp_flags & ~(__GFP_DMA | __GFP_HIGHMEM));
-        if (retval)
-                *dma = virt_to_bus(retval);
-        return retval;
-}
-
-static void lh7a40x_free_buffer(struct usb_ep *ep, void *buf, dma_addr_t dma,
-                                unsigned bytes)
-{
-        DEBUG("%s, %p\n", __FUNCTION__, ep);
-        kfree(buf);
-}
-
 /** Queue one request
  *  Kickstart transfer if needed
  *  NOTE: Sets INDEX register
diff --git a/drivers/usb/gadget/net2280.c b/drivers/usb/gadget/net2280.c
index 00fda334dc72..c3d364ecd4f8 100644
--- a/drivers/usb/gadget/net2280.c
+++ b/drivers/usb/gadget/net2280.c
@@ -450,100 +450,6 @@ net2280_free_request (struct usb_ep *_ep, struct usb_request *_req)
 
 /*-------------------------------------------------------------------------*/
 
-/*
- * dma-coherent memory allocation (for dma-capable endpoints)
- *
- * NOTE: the dma_*_coherent() API calls suck.  Most implementations are
- * (a) page-oriented, so small buffers lose big; and (b) asymmetric with
- * respect to calls with irqs disabled:  alloc is safe, free is not.
- * We currently work around (b), but not (a).
- */
-
-static void *
-net2280_alloc_buffer (
-        struct usb_ep           *_ep,
-        unsigned                bytes,
-        dma_addr_t              *dma,
-        gfp_t                   gfp_flags
-)
-{
-        void                    *retval;
-        struct net2280_ep       *ep;
-
-        ep = container_of (_ep, struct net2280_ep, ep);
-        if (!_ep)
-                return NULL;
-        *dma = DMA_ADDR_INVALID;
-
-        if (ep->dma)
-                retval = dma_alloc_coherent(&ep->dev->pdev->dev,
-                                bytes, dma, gfp_flags);
-        else
-                retval = kmalloc(bytes, gfp_flags);
-        return retval;
-}
-
-static DEFINE_SPINLOCK(buflock);
-static LIST_HEAD(buffers);
-
-struct free_record {
-        struct list_head        list;
-        struct device           *dev;
-        unsigned                bytes;
-        dma_addr_t              dma;
-};
-
-static void do_free(unsigned long ignored)
-{
-        spin_lock_irq(&buflock);
-        while (!list_empty(&buffers)) {
-                struct free_record      *buf;
-
-                buf = list_entry(buffers.next, struct free_record, list);
-                list_del(&buf->list);
-                spin_unlock_irq(&buflock);
-
-                dma_free_coherent(buf->dev, buf->bytes, buf, buf->dma);
-
-                spin_lock_irq(&buflock);
-        }
-        spin_unlock_irq(&buflock);
-}
-
-static DECLARE_TASKLET(deferred_free, do_free, 0);
-
-static void
-net2280_free_buffer (
-        struct usb_ep *_ep,
-        void *address,
-        dma_addr_t dma,
-        unsigned bytes
-) {
-        /* free memory into the right allocator */
-        if (dma != DMA_ADDR_INVALID) {
-                struct net2280_ep       *ep;
-                struct free_record      *buf = address;
-                unsigned long           flags;
-
-                ep = container_of(_ep, struct net2280_ep, ep);
-                if (!_ep)
-                        return;
-
-                ep = container_of (_ep, struct net2280_ep, ep);
-                buf->dev = &ep->dev->pdev->dev;
-                buf->bytes = bytes;
-                buf->dma = dma;
-
-                spin_lock_irqsave(&buflock, flags);
-                list_add_tail(&buf->list, &buffers);
-                tasklet_schedule(&deferred_free);
-                spin_unlock_irqrestore(&buflock, flags);
-        } else
-                kfree (address);
-}
-
-/*-------------------------------------------------------------------------*/
-
 /* load a packet into the fifo we use for usb IN transfers.
  * works for all endpoints.
  *
@@ -1392,9 +1298,6 @@ static const struct usb_ep_ops net2280_ep_ops = {
         .alloc_request  = net2280_alloc_request,
         .free_request   = net2280_free_request,
 
-        .alloc_buffer   = net2280_alloc_buffer,
-        .free_buffer    = net2280_free_buffer,
-
         .queue          = net2280_queue,
         .dequeue        = net2280_dequeue,
 
diff --git a/drivers/usb/gadget/omap_udc.c b/drivers/usb/gadget/omap_udc.c
index c4975a6cf777..9b0f0925dddf 100644
--- a/drivers/usb/gadget/omap_udc.c
+++ b/drivers/usb/gadget/omap_udc.c
@@ -296,111 +296,6 @@ omap_free_request(struct usb_ep *ep, struct usb_request *_req)
 
 /*-------------------------------------------------------------------------*/
 
-/*
- * dma-coherent memory allocation (for dma-capable endpoints)
- *
- * NOTE: the dma_*_coherent() API calls suck.  Most implementations are
- * (a) page-oriented, so small buffers lose big; and (b) asymmetric with
- * respect to calls with irqs disabled:  alloc is safe, free is not.
- * We currently work around (b), but not (a).
- */
-
-static void *
-omap_alloc_buffer(
-        struct usb_ep   *_ep,
-        unsigned        bytes,
-        dma_addr_t      *dma,
-        gfp_t           gfp_flags
-)
-{
-        void            *retval;
-        struct omap_ep  *ep;
-
-        if (!_ep)
-                return NULL;
-
-        ep = container_of(_ep, struct omap_ep, ep);
-        if (use_dma && ep->has_dma) {
-                static int      warned;
-                if (!warned && bytes < PAGE_SIZE) {
-                        dev_warn(ep->udc->gadget.dev.parent,
-                                "using dma_alloc_coherent for "
-                                "small allocations wastes memory\n");
-                        warned++;
-                }
-                return dma_alloc_coherent(ep->udc->gadget.dev.parent,
-                                bytes, dma, gfp_flags);
-        }
-
-        retval = kmalloc(bytes, gfp_flags);
-        if (retval)
-                *dma = virt_to_phys(retval);
-        return retval;
-}
-
-static DEFINE_SPINLOCK(buflock);
-static LIST_HEAD(buffers);
-
-struct free_record {
-        struct list_head        list;
-        struct device           *dev;
-        unsigned                bytes;
-        dma_addr_t              dma;
-};
-
-static void do_free(unsigned long ignored)
-{
-        spin_lock_irq(&buflock);
-        while (!list_empty(&buffers)) {
-                struct free_record      *buf;
-
-                buf = list_entry(buffers.next, struct free_record, list);
-                list_del(&buf->list);
-                spin_unlock_irq(&buflock);
-
-                dma_free_coherent(buf->dev, buf->bytes, buf, buf->dma);
-
-                spin_lock_irq(&buflock);
-        }
-        spin_unlock_irq(&buflock);
-}
-
-static DECLARE_TASKLET(deferred_free, do_free, 0);
-
-static void omap_free_buffer(
-        struct usb_ep   *_ep,
-        void            *buf,
-        dma_addr_t      dma,
-        unsigned        bytes
-)
-{
-        if (!_ep) {
-                WARN_ON(1);
-                return;
-        }
-
-        /* free memory into the right allocator */
-        if (dma != DMA_ADDR_INVALID) {
-                struct omap_ep          *ep;
-                struct free_record      *rec = buf;
-                unsigned long           flags;
-
-                ep = container_of(_ep, struct omap_ep, ep);
-
-                rec->dev = ep->udc->gadget.dev.parent;
-                rec->bytes = bytes;
-                rec->dma = dma;
-
-                spin_lock_irqsave(&buflock, flags);
-                list_add_tail(&rec->list, &buffers);
-                tasklet_schedule(&deferred_free);
-                spin_unlock_irqrestore(&buflock, flags);
-        } else
-                kfree(buf);
-}
-
-/*-------------------------------------------------------------------------*/
-
 static void
 done(struct omap_ep *ep, struct omap_req *req, int status)
 {
@@ -1271,9 +1166,6 @@ static struct usb_ep_ops omap_ep_ops = {
         .alloc_request  = omap_alloc_request,
         .free_request   = omap_free_request,
 
-        .alloc_buffer   = omap_alloc_buffer,
-        .free_buffer    = omap_free_buffer,
-
         .queue          = omap_ep_queue,
         .dequeue        = omap_ep_dequeue,
 
diff --git a/drivers/usb/gadget/pxa2xx_udc.c b/drivers/usb/gadget/pxa2xx_udc.c
index 484de6e97662..63b9521c1322 100644
--- a/drivers/usb/gadget/pxa2xx_udc.c
+++ b/drivers/usb/gadget/pxa2xx_udc.c
@@ -341,26 +341,6 @@ pxa2xx_ep_free_request (struct usb_ep *_ep, struct usb_request *_req)
         kfree(req);
 }
 
-
-static void *
-pxa2xx_ep_alloc_buffer(struct usb_ep *_ep, unsigned bytes,
-        dma_addr_t *dma, gfp_t gfp_flags)
-{
-        char                    *retval;
-
-        retval = kmalloc (bytes, gfp_flags & ~(__GFP_DMA|__GFP_HIGHMEM));
-        if (retval)
-                *dma = (dma_addr_t)~0;
-        return retval;
-}
-
-static void
-pxa2xx_ep_free_buffer(struct usb_ep *_ep, void *buf, dma_addr_t dma,
-                unsigned bytes)
-{
-        kfree (buf);
-}
-
 /*-------------------------------------------------------------------------*/
 
 /*
@@ -927,9 +907,6 @@ static struct usb_ep_ops pxa2xx_ep_ops = {
         .alloc_request  = pxa2xx_ep_alloc_request,
         .free_request   = pxa2xx_ep_free_request,
 
-        .alloc_buffer   = pxa2xx_ep_alloc_buffer,
-        .free_buffer    = pxa2xx_ep_free_buffer,
-
         .queue          = pxa2xx_ep_queue,
         .dequeue        = pxa2xx_ep_dequeue,
 
diff --git a/drivers/usb/gadget/s3c2410_udc.c b/drivers/usb/gadget/s3c2410_udc.c
index d60748add325..0be80c635c48 100644
--- a/drivers/usb/gadget/s3c2410_udc.c
+++ b/drivers/usb/gadget/s3c2410_udc.c
@@ -1197,36 +1197,6 @@ s3c2410_udc_free_request(struct usb_ep *_ep, struct usb_request *_req)
 }
 
 /*
- *      s3c2410_udc_alloc_buffer
- */
-static void *s3c2410_udc_alloc_buffer(struct usb_ep *_ep,
-                unsigned bytes, dma_addr_t *dma, gfp_t mem_flags)
-{
-        char *retval;
-
-        dprintk(DEBUG_VERBOSE, "%s()\n", __func__);
-
-        if (!the_controller->driver)
-                return NULL;
-
-        retval = kmalloc (bytes, mem_flags);
-        *dma = (dma_addr_t) retval;
-        return retval;
-}
-
-/*
- * s3c2410_udc_free_buffer
- */
-static void s3c2410_udc_free_buffer (struct usb_ep *_ep, void *buf,
-                dma_addr_t dma, unsigned bytes)
-{
-        dprintk(DEBUG_VERBOSE, "%s()\n", __func__);
-
-        if (bytes)
-                kfree (buf);
-}
-
-/*
  *      s3c2410_udc_queue
  */
 static int s3c2410_udc_queue(struct usb_ep *_ep, struct usb_request *_req,
@@ -1441,9 +1411,6 @@ static const struct usb_ep_ops s3c2410_ep_ops = {
         .alloc_request  = s3c2410_udc_alloc_request,
         .free_request   = s3c2410_udc_free_request,
 
-        .alloc_buffer   = s3c2410_udc_alloc_buffer,
-        .free_buffer    = s3c2410_udc_free_buffer,
-
         .queue          = s3c2410_udc_queue,
         .dequeue        = s3c2410_udc_dequeue,
 
diff --git a/include/linux/usb_gadget.h b/include/linux/usb_gadget.h
index 703fd84c46fc..4f59b2aa8a9e 100644
--- a/include/linux/usb_gadget.h
+++ b/include/linux/usb_gadget.h
@@ -110,13 +110,6 @@ struct usb_ep_ops {
                 gfp_t gfp_flags);
         void (*free_request) (struct usb_ep *ep, struct usb_request *req);
 
-        void *(*alloc_buffer) (struct usb_ep *ep, unsigned bytes,
-                dma_addr_t *dma, gfp_t gfp_flags);
-        void (*free_buffer) (struct usb_ep *ep, void *buf, dma_addr_t dma,
-                unsigned bytes);
-        // NOTE:  on 2.6, drivers may also use dma_map() and
-        // dma_sync_single_*() to directly manage dma overhead. 
-
         int (*queue) (struct usb_ep *ep, struct usb_request *req,
                 gfp_t gfp_flags);
         int (*dequeue) (struct usb_ep *ep, struct usb_request *req);