ipw2200: firmware DMA loading rework

Bartlomiej Zolnierkiewicz reported an atomic order-6 allocation failure
for ipw2200 firmware loading in kernel 2.6.30. High order allocation is
likely to fail and should always be avoided.

The patch fixes this problem by replacing the original order-6
pci_alloc_consistent() with an array of order-1 pages from a pci pool.
This utilized the ipw2200 DMA command blocks (up to 64 slots). The
maximum firmware size support remains the same (64*8K).

This patch fixes bug http://bugzilla.kernel.org/show_bug.cgi?id=14016

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ipw2x00/ipw2200.c

@@ -2874,45 +2874,27 @@ static int ipw_fw_dma_add_command_block(struct ipw_priv *priv,
 	return 0;
 }
 
-static int ipw_fw_dma_add_buffer(struct ipw_priv *priv,
-				 u32 src_phys, u32 dest_address, u32 length)
+static int ipw_fw_dma_add_buffer(struct ipw_priv *priv, dma_addr_t *src_address,
+				 int nr, u32 dest_address, u32 len)
 {
-	u32 bytes_left = length;
-	u32 src_offset = 0;
-	u32 dest_offset = 0;
-	int status = 0;
+	int ret, i;
+	u32 size;
+
 	IPW_DEBUG_FW(">> \n");
-	IPW_DEBUG_FW_INFO("src_phys=0x%x dest_address=0x%x length=0x%x\n",
-			  src_phys, dest_address, length);
-	while (bytes_left > CB_MAX_LENGTH) {
-		status = ipw_fw_dma_add_command_block(priv,
-						      src_phys + src_offset,
+	IPW_DEBUG_FW_INFO("nr=%d dest_address=0x%x len=0x%x\n",
+			  nr, dest_address, len);
+
+	for (i = 0; i < nr; i++) {
+		size = min_t(u32, len - i * CB_MAX_LENGTH, CB_MAX_LENGTH);
+		ret = ipw_fw_dma_add_command_block(priv, src_address[i],
 						   dest_address +
-						      dest_offset,
-						      CB_MAX_LENGTH, 0, 0);
-		if (status) {
+						   i * CB_MAX_LENGTH, size,
+						   0, 0);
+		if (ret) {
 			IPW_DEBUG_FW_INFO(": Failed\n");
 			return -1;
 		} else
 			IPW_DEBUG_FW_INFO(": Added new cb\n");
-
-		src_offset += CB_MAX_LENGTH;
-		dest_offset += CB_MAX_LENGTH;
-		bytes_left -= CB_MAX_LENGTH;
-	}
-
-	/* add the buffer tail */
-	if (bytes_left > 0) {
-		status =
-		    ipw_fw_dma_add_command_block(priv, src_phys + src_offset,
-						 dest_address + dest_offset,
-						 bytes_left, 0, 0);
-		if (status) {
-			IPW_DEBUG_FW_INFO(": Failed on the buffer tail\n");
-			return -1;
-		} else
-			IPW_DEBUG_FW_INFO
-			    (": Adding new cb - the buffer tail\n");
 	}
 
 	IPW_DEBUG_FW("<< \n");
@@ -3160,59 +3142,91 @@ static int ipw_load_ucode(struct ipw_priv *priv, u8 * data, size_t len)
 
 static int ipw_load_firmware(struct ipw_priv *priv, u8 * data, size_t len)
 {
-	int rc = -1;
+	int ret = -1;
 	int offset = 0;
 	struct fw_chunk *chunk;
-	dma_addr_t shared_phys;
-	u8 *shared_virt;
+	int total_nr = 0;
+	int i;
+	struct pci_pool *pool;
+	u32 *virts[CB_NUMBER_OF_ELEMENTS_SMALL];
+	dma_addr_t phys[CB_NUMBER_OF_ELEMENTS_SMALL];
 
 	IPW_DEBUG_TRACE("<< : \n");
-	shared_virt = pci_alloc_consistent(priv->pci_dev, len, &shared_phys);
 
-	if (!shared_virt)
+	pool = pci_pool_create("ipw2200", priv->pci_dev, CB_MAX_LENGTH, 0, 0);
+	if (!pool) {
+		IPW_ERROR("pci_pool_create failed\n");
 		return -ENOMEM;
-
-	memmove(shared_virt, data, len);
+	}
 
 	/* Start the Dma */
-	rc = ipw_fw_dma_enable(priv);
+	ret = ipw_fw_dma_enable(priv);
 
 	/* the DMA is already ready this would be a bug. */
 	BUG_ON(priv->sram_desc.last_cb_index > 0);
 
 	do {
+		u32 chunk_len;
+		u8 *start;
+		int size;
+		int nr = 0;
+
 		chunk = (struct fw_chunk *)(data + offset);
 		offset += sizeof(struct fw_chunk);
+		chunk_len = le32_to_cpu(chunk->length);
+		start = data + offset;
+
+		nr = (chunk_len + CB_MAX_LENGTH - 1) / CB_MAX_LENGTH;
+		for (i = 0; i < nr; i++) {
+			virts[total_nr] = pci_pool_alloc(pool, GFP_KERNEL,
+							 &phys[total_nr]);
+			if (!virts[total_nr]) {
+				ret = -ENOMEM;
+				goto out;
+			}
+			size = min_t(u32, chunk_len - i * CB_MAX_LENGTH,
+				     CB_MAX_LENGTH);
+			memcpy(virts[total_nr], start, size);
+			start += size;
+			total_nr++;
+			/* We don't support fw chunk larger than 64*8K */
+			BUG_ON(total_nr > CB_NUMBER_OF_ELEMENTS_SMALL);
+		}
+
 		/* build DMA packet and queue up for sending */
 		/* dma to chunk->address, the chunk->length bytes from data +
 		 * offeset*/
 		/* Dma loading */
-		rc = ipw_fw_dma_add_buffer(priv, shared_phys + offset,
-					   le32_to_cpu(chunk->address),
-					   le32_to_cpu(chunk->length));
-		if (rc) {
+		ret = ipw_fw_dma_add_buffer(priv, &phys[total_nr - nr],
+					    nr, le32_to_cpu(chunk->address),
+					    chunk_len);
+		if (ret) {
 			IPW_DEBUG_INFO("dmaAddBuffer Failed\n");
 			goto out;
 		}
 
-		offset += le32_to_cpu(chunk->length);
+		offset += chunk_len;
 	} while (offset < len);
 
 	/* Run the DMA and wait for the answer */
-	rc = ipw_fw_dma_kick(priv);
-	if (rc) {
+	ret = ipw_fw_dma_kick(priv);
+	if (ret) {
 		IPW_ERROR("dmaKick Failed\n");
 		goto out;
 	}
 
-	rc = ipw_fw_dma_wait(priv);
-	if (rc) {
+	ret = ipw_fw_dma_wait(priv);
+	if (ret) {
 		IPW_ERROR("dmaWaitSync Failed\n");
 		goto out;
 	}
  out:
-	pci_free_consistent(priv->pci_dev, len, shared_virt, shared_phys);
-	return rc;
+	for (i = 0; i < total_nr; i++)
+		pci_pool_free(pool, virts[i], phys[i]);
+
+	pci_pool_destroy(pool);
+
+	return ret;
 }
 
 /* stop nic */