usb: cdns3: Use dma_pool_* api to alloc trb pool

Allocation of DMA coherent memory in atomic context using
dma_alloc_coherent() might fail on platforms with smaller
DMA region.

To fix it, dma_alloc_coherent() is replaced with dma_pool
API to allocate a smaller chunk of DMA coherent memory for
TRB rings.

Reported-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Sanket Parmar <sparmar@cadence.com>
Signed-off-by: Peter Chen <peter.chen@kernel.org>

diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index 44b7301..0b892a2 100644 (file)
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -59,6 +59,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/usb/gadget.h>
 #include <linux/module.h>
+#include <linux/dmapool.h>
 #include <linux/iopoll.h>
 
 #include "core.h"
@@ -190,29 +191,13 @@ dma_addr_t cdns3_trb_virt_to_dma(struct cdns3_endpoint *priv_ep,
        return priv_ep->trb_pool_dma + offset;
 }
 
-static int cdns3_ring_size(struct cdns3_endpoint *priv_ep)
-{
-       switch (priv_ep->type) {
-       case USB_ENDPOINT_XFER_ISOC:
-               return TRB_ISO_RING_SIZE;
-       case USB_ENDPOINT_XFER_CONTROL:
-               return TRB_CTRL_RING_SIZE;
-       default:
-               if (priv_ep->use_streams)
-                       return TRB_STREAM_RING_SIZE;
-               else
-                       return TRB_RING_SIZE;
-       }
-}
-
 static void cdns3_free_trb_pool(struct cdns3_endpoint *priv_ep)
 {
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
 
        if (priv_ep->trb_pool) {
-               dma_free_coherent(priv_dev->sysdev,
-                                 cdns3_ring_size(priv_ep),
-                                 priv_ep->trb_pool, priv_ep->trb_pool_dma);
+               dma_pool_free(priv_dev->eps_dma_pool,
+                             priv_ep->trb_pool, priv_ep->trb_pool_dma);
                priv_ep->trb_pool = NULL;
        }
 }
@@ -226,7 +211,7 @@ static void cdns3_free_trb_pool(struct cdns3_endpoint *priv_ep)
 int cdns3_allocate_trb_pool(struct cdns3_endpoint *priv_ep)
 {
        struct cdns3_device *priv_dev = priv_ep->cdns3_dev;
-       int ring_size = cdns3_ring_size(priv_ep);
+       int ring_size = TRB_RING_SIZE;
        int num_trbs = ring_size / TRB_SIZE;
        struct cdns3_trb *link_trb;
 
@@ -234,10 +219,10 @@ int cdns3_allocate_trb_pool(struct cdns3_endpoint *priv_ep)
                cdns3_free_trb_pool(priv_ep);
 
        if (!priv_ep->trb_pool) {
-               priv_ep->trb_pool = dma_alloc_coherent(priv_dev->sysdev,
-                                                      ring_size,
-                                                      &priv_ep->trb_pool_dma,
-                                                      GFP_DMA32 | GFP_ATOMIC);
+               priv_ep->trb_pool = dma_pool_alloc(priv_dev->eps_dma_pool,
+                                                  GFP_DMA32 | GFP_ATOMIC,
+                                                  &priv_ep->trb_pool_dma);
+
                if (!priv_ep->trb_pool)
                        return -ENOMEM;
 
@@ -3113,6 +3098,7 @@ static void cdns3_gadget_exit(struct cdns *cdns)
 
        dma_free_coherent(priv_dev->sysdev, 8, priv_dev->setup_buf,
                          priv_dev->setup_dma);
+       dma_pool_destroy(priv_dev->eps_dma_pool);
 
        kfree(priv_dev->zlp_buf);
        usb_put_gadget(&priv_dev->gadget);
@@ -3185,6 +3171,14 @@ static int cdns3_gadget_start(struct cdns *cdns)
        /* initialize endpoint container */
        INIT_LIST_HEAD(&priv_dev->gadget.ep_list);
        INIT_LIST_HEAD(&priv_dev->aligned_buf_list);
+       priv_dev->eps_dma_pool = dma_pool_create("cdns3_eps_dma_pool",
+                                                priv_dev->sysdev,
+                                                TRB_RING_SIZE, 8, 0);
+       if (!priv_dev->eps_dma_pool) {
+               dev_err(priv_dev->dev, "Failed to create TRB dma pool\n");
+               ret = -ENOMEM;
+               goto err1;
+       }
 
        ret = cdns3_init_eps(priv_dev);
        if (ret) {
@@ -3235,6 +3229,8 @@ err3:
 err2:
        cdns3_free_all_eps(priv_dev);
 err1:
+       dma_pool_destroy(priv_dev->eps_dma_pool);
+
        usb_put_gadget(&priv_dev->gadget);
        cdns->gadget_dev = NULL;
        return ret;

diff --git a/drivers/usb/cdns3/cdns3-gadget.h b/drivers/usb/cdns3/cdns3-gadget.h
index 21fa461..ecf9b91 100644 (file)
--- a/drivers/usb/cdns3/cdns3-gadget.h
+++ b/drivers/usb/cdns3/cdns3-gadget.h
@@ -1298,6 +1298,7 @@ struct cdns3_device {
 
        struct cdns3_usb_regs           __iomem *regs;
 
+       struct dma_pool                 *eps_dma_pool;
        struct usb_ctrlrequest          *setup_buf;
        dma_addr_t                      setup_dma;
        void                            *zlp_buf;