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Message-ID: <1615267180-9289-2-git-send-email-sparmar@cadence.com>
Date: Tue, 9 Mar 2021 06:19:40 +0100
From: Sanket Parmar <sparmar@...ence.com>
To: <peter.chen@...nel.org>
CC: <pawell@...ence.com>, <a-govindraju@...com>,
<linux-usb@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<kurahul@...ence.com>, <gregkh@...uxfoundation.org>,
<kishon@...com>, Sanket Parmar <sparmar@...ence.com>
Subject: [PATCH 2/2] usb: cdns3: Optimize DMA request buffer allocation
dma_alloc_coherent() might fail on the platform with a small DMA region.
To avoid such failure in cdns3_prepare_aligned_request_buf(),
dma_alloc_coherent() is replaced with kmalloc and dma_map API to
allocate aligned request buffer of dynamic length.
Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Reported-by: Aswath Govindraju <a-govindraju@...com>
Signed-off-by: Sanket Parmar <sparmar@...ence.com>
---
drivers/usb/cdns3/cdns3-gadget.c | 73 +++++++++++++++++++++++++------------
drivers/usb/cdns3/cdns3-gadget.h | 2 +
2 files changed, 51 insertions(+), 24 deletions(-)
diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c
index 5f51215..b4955ce 100644
--- a/drivers/usb/cdns3/cdns3-gadget.c
+++ b/drivers/usb/cdns3/cdns3-gadget.c
@@ -818,10 +818,26 @@ void cdns3_gadget_giveback(struct cdns3_endpoint *priv_ep,
usb_gadget_unmap_request_by_dev(priv_dev->sysdev, request,
priv_ep->dir);
- if ((priv_req->flags & REQUEST_UNALIGNED) &&
- priv_ep->dir == USB_DIR_OUT && !request->status)
- memcpy(request->buf, priv_req->aligned_buf->buf,
- request->length);
+ if ((priv_req->flags & REQUEST_UNALIGNED) && priv_req->aligned_buf) {
+ struct cdns3_aligned_buf *buf;
+
+ buf = priv_req->aligned_buf;
+ dma_unmap_single(priv_dev->sysdev, buf->dma, buf->size,
+ buf->dir);
+ priv_req->flags &= ~REQUEST_UNALIGNED;
+
+ if (priv_ep->dir == USB_DIR_OUT && !request->status) {
+ memcpy(request->buf, priv_req->aligned_buf->buf,
+ request->length);
+ }
+
+ trace_cdns3_free_aligned_request(priv_req);
+ priv_req->aligned_buf->in_use = 0;
+ queue_work(system_freezable_wq,
+ &priv_dev->aligned_buf_wq);
+ priv_req->aligned_buf = NULL;
+
+ }
priv_req->flags &= ~(REQUEST_PENDING | REQUEST_UNALIGNED);
/* All TRBs have finished, clear the counter */
@@ -883,8 +899,7 @@ static void cdns3_free_aligned_request_buf(struct work_struct *work)
* interrupts.
*/
spin_unlock_irqrestore(&priv_dev->lock, flags);
- dma_free_coherent(priv_dev->sysdev, buf->size,
- buf->buf, buf->dma);
+ kfree(buf->buf);
kfree(buf);
spin_lock_irqsave(&priv_dev->lock, flags);
}
@@ -910,27 +925,16 @@ static int cdns3_prepare_aligned_request_buf(struct cdns3_request *priv_req)
if (!buf)
return -ENOMEM;
- buf->size = priv_req->request.length;
+ buf->size = usb_endpoint_dir_out(priv_ep->endpoint.desc) ?
+ usb_ep_align(&(priv_ep->endpoint), priv_req->request.length)
+ : priv_req->request.length;
- buf->buf = dma_alloc_coherent(priv_dev->sysdev,
- buf->size,
- &buf->dma,
- GFP_ATOMIC);
+ buf->buf = kmalloc(buf->size, GFP_ATOMIC);
if (!buf->buf) {
kfree(buf);
return -ENOMEM;
}
- if (priv_req->aligned_buf) {
- trace_cdns3_free_aligned_request(priv_req);
- priv_req->aligned_buf->in_use = 0;
- queue_work(system_freezable_wq,
- &priv_dev->aligned_buf_wq);
- }
-
- buf->in_use = 1;
- priv_req->aligned_buf = buf;
-
list_add_tail(&buf->list,
&priv_dev->aligned_buf_list);
}
@@ -940,6 +944,27 @@ static int cdns3_prepare_aligned_request_buf(struct cdns3_request *priv_req)
priv_req->request.length);
}
+ if (priv_req->aligned_buf) {
+ trace_cdns3_free_aligned_request(priv_req);
+ priv_req->aligned_buf->in_use = 0;
+ queue_work(system_freezable_wq,
+ &priv_dev->aligned_buf_wq);
+ }
+
+ buf->dir = priv_ep->dir ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
+ buf->in_use = 1;
+ priv_req->aligned_buf = buf;
+
+ buf->dma = dma_map_single(priv_dev->sysdev, buf->buf, buf->size,
+ buf->dir);
+
+ if (dma_mapping_error(priv_dev->sysdev, buf->dma)) {
+ dev_err(priv_dev->dev, "Failed to map buffer\n");
+ kfree(buf->buf);
+ kfree(buf);
+ return -EFAULT;
+ }
+
priv_req->flags |= REQUEST_UNALIGNED;
trace_cdns3_prepare_aligned_request(priv_req);
@@ -3088,11 +3113,11 @@ static void cdns3_gadget_exit(struct cdns *cdns)
struct cdns3_aligned_buf *buf;
buf = cdns3_next_align_buf(&priv_dev->aligned_buf_list);
- dma_free_coherent(priv_dev->sysdev, buf->size,
- buf->buf,
- buf->dma);
+ dma_unmap_single(priv_dev->sysdev, buf->dma, buf->size,
+ buf->dir);
list_del(&buf->list);
+ kfree(buf->buf);
kfree(buf);
}
diff --git a/drivers/usb/cdns3/cdns3-gadget.h b/drivers/usb/cdns3/cdns3-gadget.h
index ecf9b91..c5660f2 100644
--- a/drivers/usb/cdns3/cdns3-gadget.h
+++ b/drivers/usb/cdns3/cdns3-gadget.h
@@ -12,6 +12,7 @@
#ifndef __LINUX_CDNS3_GADGET
#define __LINUX_CDNS3_GADGET
#include <linux/usb/gadget.h>
+#include <linux/dma-direction.h>
/*
* USBSS-DEV register interface.
@@ -1205,6 +1206,7 @@ struct cdns3_aligned_buf {
void *buf;
dma_addr_t dma;
u32 size;
+ enum dma_data_direction dir;
unsigned in_use:1;
struct list_head list;
};
--
1.7.1
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