staging: apf: Made allocated buffers properly configure TLB.

dma_alloc_coherent inherently assumes certain TLB settings, that we were
then manually violating.  Instead, user-space accessed DMA buffers
are allocated using kmalloc, which we can make use of more flexibly.

Signed-off-by: Michael Gill <gill@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/drivers/staging/apf/xlnk.c b/drivers/staging/apf/xlnk.c
index 1d18a1fd4d990da322983b6189ce158449e6171d..24b6417fe2251f2bd5e50ff16c205d87ca92533c 100644 (file)
--- a/drivers/staging/apf/xlnk.c
+++ b/drivers/staging/apf/xlnk.c
@@ -84,13 +84,14 @@ static ssize_t xlnk_dev_size;
 static int xlnk_dev_vmas;
 
 #define XLNK_BUF_POOL_SIZE     256
-static void **xlnk_bufpool;
 static unsigned int xlnk_bufpool_size = XLNK_BUF_POOL_SIZE;
+static void *xlnk_bufpool[XLNK_BUF_POOL_SIZE];
+static void *xlnk_bufpool_alloc_point[XLNK_BUF_POOL_SIZE];
+static unsigned int xlnk_userbuf[XLNK_BUF_POOL_SIZE];
 static dma_addr_t xlnk_phyaddr[XLNK_BUF_POOL_SIZE];
 static size_t xlnk_buflen[XLNK_BUF_POOL_SIZE];
 static unsigned int  xlnk_bufcacheable[XLNK_BUF_POOL_SIZE];
 
-
 static int xlnk_open(struct inode *ip, struct file *filp);  /* Open */
 static int xlnk_release(struct inode *ip, struct file *filp);   /* Release */
 static long xlnk_ioctl(struct file *filp, unsigned int code,
@@ -254,7 +255,6 @@ static int xlnk_probe(struct platform_device *pdev)
        xlnk_dev_buf = NULL;
        xlnk_dev_size = 0;
        xlnk_dev_vmas = 0;
-       xlnk_bufpool = NULL;
 
        /* use 2.6 device model */
        err = alloc_chrdev_region(&dev, 0, 1, driver_name);
@@ -377,23 +377,27 @@ static int xlnk_buf_find_by_phys_addr(unsigned long addr)
 static int xlnk_allocbuf(unsigned int len, unsigned int cacheable)
 {
        int id;
+       void *kaddr;
+       dma_addr_t phys_addr_anchor;
+       unsigned int page_dst;
 
        id = xlnk_buf_findnull();
 
-       if (id <= 0)
+       if (id <= 0 || id >= XLNK_BUF_POOL_SIZE) {
+               pr_err("No id could be found in range\n");
                return -ENOMEM;
-
-       xlnk_bufpool[id] = dma_alloc_coherent(xlnk_dev, len,
-                                             &xlnk_phyaddr[id],
-                                             GFP_KERNEL | GFP_DMA);
+       }
+       kaddr = kmalloc(len + PAGE_SIZE, GFP_KERNEL | GFP_DMA);
+       if (!kaddr)
+               return -ENOMEM;
+       phys_addr_anchor = virt_to_phys(kaddr);
+       xlnk_bufpool_alloc_point[id] = kaddr;
+       page_dst = (((phys_addr_anchor + (PAGE_SIZE - 1))
+               / PAGE_SIZE) * PAGE_SIZE) - phys_addr_anchor;
+       xlnk_bufpool[id] = (void *)((uint8_t *)kaddr + page_dst);
        xlnk_buflen[id] = len;
        xlnk_bufcacheable[id] = cacheable;
-
-       if (!xlnk_bufpool[id]) {
-               dev_err(xlnk_dev, "%s: dma_alloc_coherent of %d byte buffer failed\n",
-                        __func__, len);
-               return -ENOMEM;
-       }
+       xlnk_phyaddr[id] = phys_addr_anchor + page_dst;
 
        return id;
 }
@@ -410,9 +414,6 @@ static int xlnk_init_bufpool(void)
                return -ENOMEM;
        }
 
-       xlnk_bufpool = kmalloc(sizeof(void *) * xlnk_bufpool_size,
-                                  GFP_KERNEL);
-
        xlnk_bufpool[0] = xlnk_dev_buf;
        for (i = 1; i < xlnk_bufpool_size; i++)
                xlnk_bufpool[i] = NULL;
@@ -430,9 +431,6 @@ static int xlnk_remove(struct platform_device *pdev)
        kfree(xlnk_dev_buf);
        xlnk_dev_buf = NULL;
 
-       kfree(xlnk_bufpool);
-       xlnk_bufpool = NULL;
-
        devno = MKDEV(driver_major, 0);
        cdev_del(&xlnk_cdev);
        unregister_chrdev_region(devno, 1);
@@ -795,9 +793,7 @@ static int xlnk_freebuf(int id)
        if (!xlnk_bufpool[id])
                return -ENOMEM;
 
-       dma_free_coherent(xlnk_dev, xlnk_buflen[id], xlnk_bufpool[id],
-                         xlnk_phyaddr[id]);
-
+       kfree(xlnk_bufpool_alloc_point[id]);
        xlnk_bufpool[id] = NULL;
        xlnk_phyaddr[id] = (dma_addr_t)NULL;
        xlnk_buflen[id] = 0;