platform/x86: dell_rbu: stop abusing the DMA API

For some odd reason dell_rbu actually seems to want the physical and
not a bus address for the allocated buffer.  Lets assume that actually
is correct given that it is BIOS-related and that is a good source
of insanity.  In that case we should not use dma_alloc_coherent with
a NULL device to allocate memory, but use GFP_DMA32 to stay under
the 32-bit BIOS limit.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Stuart Hayes <stuart.w.hayes@gmail.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

diff --git a/drivers/platform/x86/dell_rbu.c b/drivers/platform/x86/dell_rbu.c
index ccefa84f730576874cfa5f78751088612cafc632..8104ca0c44caa888fb85c4598c68545f0bdbb91d 100644 (file)
--- a/drivers/platform/x86/dell_rbu.c
+++ b/drivers/platform/x86/dell_rbu.c
@@ -59,7 +59,6 @@ static struct _rbu_data {
        unsigned long image_update_buffer_size;
        unsigned long bios_image_size;
        int image_update_ordernum;
-       int dma_alloc;
        spinlock_t lock;
        unsigned long packet_read_count;
        unsigned long num_packets;
@@ -89,7 +88,6 @@ static struct packet_data packet_data_head;
 
 static struct platform_device *rbu_device;
 static int context;
-static dma_addr_t dell_rbu_dmaaddr;
 
 static void init_packet_head(void)
 {
@@ -380,12 +378,8 @@ static void img_update_free(void)
         */
        memset(rbu_data.image_update_buffer, 0,
                rbu_data.image_update_buffer_size);
-       if (rbu_data.dma_alloc == 1)
-               dma_free_coherent(NULL, rbu_data.bios_image_size,
-                       rbu_data.image_update_buffer, dell_rbu_dmaaddr);
-       else
-               free_pages((unsigned long) rbu_data.image_update_buffer,
-                       rbu_data.image_update_ordernum);
+       free_pages((unsigned long) rbu_data.image_update_buffer,
+               rbu_data.image_update_ordernum);
 
        /*
         * Re-initialize the rbu_data variables after a free
@@ -394,7 +388,6 @@ static void img_update_free(void)
        rbu_data.image_update_buffer = NULL;
        rbu_data.image_update_buffer_size = 0;
        rbu_data.bios_image_size = 0;
-       rbu_data.dma_alloc = 0;
 }
 
 /*
@@ -410,10 +403,8 @@ static void img_update_free(void)
 static int img_update_realloc(unsigned long size)
 {
        unsigned char *image_update_buffer = NULL;
-       unsigned long rc;
        unsigned long img_buf_phys_addr;
        int ordernum;
-       int dma_alloc = 0;
 
        /*
         * check if the buffer of sufficient size has been
@@ -444,36 +435,23 @@ static int img_update_realloc(unsigned long size)
 
        ordernum = get_order(size);
        image_update_buffer =
-               (unsigned char *) __get_free_pages(GFP_KERNEL, ordernum);
-
-       img_buf_phys_addr =
-               (unsigned long) virt_to_phys(image_update_buffer);
-
-       if (img_buf_phys_addr > BIOS_SCAN_LIMIT) {
-               free_pages((unsigned long) image_update_buffer, ordernum);
-               ordernum = -1;
-               image_update_buffer = dma_alloc_coherent(NULL, size,
-                       &dell_rbu_dmaaddr, GFP_KERNEL);
-               dma_alloc = 1;
-       }
-
-       spin_lock(&rbu_data.lock);
-
-       if (image_update_buffer != NULL) {
-               rbu_data.image_update_buffer = image_update_buffer;
-               rbu_data.image_update_buffer_size = size;
-               rbu_data.bios_image_size =
-                       rbu_data.image_update_buffer_size;
-               rbu_data.image_update_ordernum = ordernum;
-               rbu_data.dma_alloc = dma_alloc;
-               rc = 0;
-       } else {
+               (unsigned char *)__get_free_pages(GFP_DMA32, ordernum);
+       if (!image_update_buffer) {
                pr_debug("Not enough memory for image update:"
                        "size = %ld\n", size);
-               rc = -ENOMEM;
+               return -ENOMEM;
        }
 
-       return rc;
+       img_buf_phys_addr = (unsigned long)virt_to_phys(image_update_buffer);
+       if (WARN_ON_ONCE(img_buf_phys_addr > BIOS_SCAN_LIMIT))
+               return -EINVAL; /* can't happen per definition */
+
+       spin_lock(&rbu_data.lock);
+       rbu_data.image_update_buffer = image_update_buffer;
+       rbu_data.image_update_buffer_size = size;
+       rbu_data.bios_image_size = rbu_data.image_update_buffer_size;
+       rbu_data.image_update_ordernum = ordernum;
+       return 0;
 }
 
 static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count)