ENGR00293132-1 pxp/v4l2: change memory alloc policy for PxP output buffer

In previous implementation, the memory allocation/free for PxP output buffer is
done each time v4l2 output device is opened/closed. This is not necessary and
may cause memory fragmentation issue after running many many times. Now we
re-allocate the memory for it only if the existing memory size is not sufficent
for new case.

Signed-off-by: Robby Cai <R63905@freescale.com>

2 files changed, 54 insertions, 23 deletions

diff --git a/drivers/media/platform/mxc/output/mxc_pxp_v4l2.c b/drivers/media/platform/mxc/output/mxc_pxp_v4l2.c
index 8fe072ecbf1c..08ea59ab5510 100644
--- a/drivers/media/platform/mxc/output/mxc_pxp_v4l2.c
+++ b/drivers/media/platform/mxc/output/mxc_pxp_v4l2.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2010-2013 Freescale Semiconductor, Inc.
+ * Copyright (C) 2010-2014 Freescale Semiconductor, Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -168,6 +168,30 @@ struct v4l2_queryctrl pxp_controls[] = {
         },
 };
 
+static void free_dma_buf(struct pxps *pxp, struct dma_mem *buf)
+{
+        dma_free_coherent(&pxp->pdev->dev, buf->size, buf->vaddr, buf->paddr);
+        dev_dbg(&pxp->pdev->dev,
+                        "free dma size:0x%x, paddr:0x%x\n",
+                        buf->size, buf->paddr);
+        memset(buf, 0, sizeof(*buf));
+}
+
+static int alloc_dma_buf(struct pxps *pxp, struct dma_mem *buf)
+{
+
+        buf->vaddr = dma_alloc_coherent(&pxp->pdev->dev, buf->size, &buf->paddr,
+                                                GFP_DMA | GFP_KERNEL);
+        if (!buf->vaddr) {
+                dev_err(&pxp->pdev->dev,
+                        "cannot get dma buf size:0x%x\n", buf->size);
+                return -ENOMEM;
+        }
+        dev_dbg(&pxp->pdev->dev,
+                "alloc dma buf size:0x%x, paddr:0x%x\n", buf->size, buf->paddr);
+        return 0;
+}
+
 /* callback function */
 static void video_dma_done(void *arg)
 {
@@ -300,7 +324,7 @@ static int pxp_show_buf(struct pxps *pxp, bool toshow)
 
         console_lock();
         fbi->fix.smem_start = toshow ?
-                        pxp->outb_phys : (unsigned long)pxp->fb.base;
+                        pxp->outbuf.paddr : (unsigned long)pxp->fb.base;
         ret = fb_pan_display(fbi, &fbi->var);
         console_unlock();
 
@@ -381,7 +405,7 @@ static int pxp_enumoutput(struct file *file, void *fh,
         }
         o->type = V4L2_OUTPUT_TYPE_INTERNAL;
         o->std = 0;
-        o->reserved[0] = pxp->outb_phys;
+        o->reserved[0] = pxp->outbuf.paddr;
 
         return 0;
 }
@@ -401,30 +425,27 @@ static int pxp_s_output(struct file *file, void *fh,
 {
         struct pxps *pxp = video_get_drvdata(video_devdata(file));
         struct v4l2_pix_format *fmt = &pxp->fb.fmt;
-        int bpp;
+        u32 size;
+        int ret, bpp;
 
         if ((i < 0) || (i > 1))
                 return -EINVAL;
 
-        if (pxp->outb)
-                return 0;
-
         /* Output buffer is same format as fbdev */
         if (fmt->pixelformat == V4L2_PIX_FMT_RGB24)
                 bpp = 4;
         else
                 bpp = 2;
 
-        pxp->outb_size = fmt->width * fmt->height * bpp;
-        pxp->outb = kmalloc(fmt->width * fmt->height * bpp,
-                                GFP_KERNEL | GFP_DMA);
-        if (pxp->outb == NULL) {
-                dev_err(&pxp->pdev->dev, "No enough memory!\n");
-                return -ENOMEM;
+        size = fmt->width * fmt->height * bpp;
+        if (size > pxp->outbuf.size) {
+                if (pxp->outbuf.vaddr)
+                        free_dma_buf(pxp, &pxp->outbuf);
+                pxp->outbuf.size = size;
+                ret = alloc_dma_buf(pxp, &pxp->outbuf);
+                if (ret < 0)
+                        return ret;
         }
-        pxp->outb_phys = virt_to_phys(pxp->outb);
-        dma_map_single(NULL, pxp->outb,
-                        fmt->width * fmt->height * bpp, DMA_TO_DEVICE);
 
         pxp->pxp_conf.out_param.width = fmt->width;
         pxp->pxp_conf.out_param.height = fmt->height;
@@ -726,6 +747,12 @@ static int pxp_buf_prepare(struct videobuf_queue *q,
         int ret = 0;
         int i, length;
 
+        if (!pxp->outbuf.paddr)  {
+                dev_err(&pxp->pdev->dev, "Not allocate memory for "
+                        "PxP Out buffer?\n");
+                return -ENOMEM;
+        }
+
         vb->width = pxp->pxp_conf.s0_param.width;
         vb->height = pxp->pxp_conf.s0_param.height;
         vb->size = vb->width * vb->height * pxp->s0_fmt->bpp;
@@ -785,7 +812,7 @@ static int pxp_buf_prepare(struct videobuf_queue *q,
                                                 pxp->fb.fmt.height;
                                 }
 
-                                pxp_conf->out_param.paddr = pxp->outb_phys;
+                                pxp_conf->out_param.paddr = pxp->outbuf.paddr;
                                 memcpy(&desc->layer_param.out_param,
                                         &pxp_conf->out_param,
                                         sizeof(struct pxp_layer_param));
@@ -1100,8 +1127,6 @@ static int pxp_close(struct file *file)
         videobuf_stop(&pxp->s0_vbq);
         videobuf_mmap_free(&pxp->s0_vbq);
         pxp->active = NULL;
-        kfree(pxp->outb);
-        pxp->outb = NULL;
 
         mutex_lock(&pxp->mutex);
         pxp->users--;
@@ -1238,6 +1263,8 @@ static int pxp_remove(struct platform_device *pdev)
         video_unregister_device(pxp->vdev);
         video_device_release(pxp->vdev);
 
+        free_dma_buf(pxp, &pxp->outbuf);
+
         kfree(pxp);
 
         return 0;
diff --git a/drivers/media/platform/mxc/output/mxc_pxp_v4l2.h b/drivers/media/platform/mxc/output/mxc_pxp_v4l2.h
index f1d3da78c345..8abb4c17f3fd 100644
--- a/drivers/media/platform/mxc/output/mxc_pxp_v4l2.h
+++ b/drivers/media/platform/mxc/output/mxc_pxp_v4l2.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2010-2013 Freescale Semiconductor, Inc.
+ * Copyright (C) 2010-2014 Freescale Semiconductor, Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -37,6 +37,12 @@ struct pxp_buffer {
         struct scatterlist                      sg[3];
 };
 
+struct dma_mem {
+        void *vaddr;
+        dma_addr_t paddr;
+        size_t size;
+};
+
 struct pxps {
         struct platform_device *pdev;
 
@@ -51,11 +57,9 @@ struct pxps {
         struct list_head outq;
         struct pxp_channel      *pxp_channel[1];        /* We need 1 channel */
         struct pxp_config_data pxp_conf;
+        struct dma_mem outbuf;
 
         int output;
-        u32 *outb;
-        dma_addr_t outb_phys;
-        u32 outb_size;
 
         /* Current S0 configuration */
         struct pxp_data_format *s0_fmt;