Commit 93e2618e authored by Tejun Heo's avatar Tejun Heo Committed by Jeff Garzik
Browse files

sata_sil24: fix sg table sizing 



sil24 unnecessarily used LIBATA_MAX_PRD and ATAPI sg table was short
by one entry which might cause very obscure problems.  This patch
updates sg table sizing such that

* One full page is used for PRB + sg table.  On 4k page,
  this results in 253 sg's.

* Make ATAPI sg block properly sized.

* Make build fail if command block size doesn't equal PAGE_SIZE.

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 0706efd6

drivers/ata/sata_sil24.c

+23 −3
Original line number Diff line number Diff line
@@ -63,6 +63,21 @@ enum { 
	SIL24_HOST_BAR		= 0,

	SIL24_PORT_BAR		= 2,



	/* sil24 fetches in chunks of 64bytes.  The first block

	 * contains the PRB and two SGEs.  From the second block, it's

	 * consisted of four SGEs and called SGT.  Calculate the

	 * number of SGTs that fit into one page.

	 */

	SIL24_PRB_SZ		= sizeof(struct sil24_prb)

				  + 2 * sizeof(struct sil24_sge),

	SIL24_MAX_SGT		= (PAGE_SIZE - SIL24_PRB_SZ)

				  / (4 * sizeof(struct sil24_sge)),



	/* This will give us one unused SGEs for ATA.  This extra SGE

	 * will be used to store CDB for ATAPI devices.

	 */

	SIL24_MAX_SGE		= 4 * SIL24_MAX_SGT + 1,



	/*

	 * Global controller registers (128 bytes @ BAR0)

	 */
@@ -247,13 +262,13 @@ enum { 


struct sil24_ata_block {

	struct sil24_prb prb;

	struct sil24_sge sge[LIBATA_MAX_PRD];

	struct sil24_sge sge[SIL24_MAX_SGE];

};



struct sil24_atapi_block {

	struct sil24_prb prb;

	u8 cdb[16];

	struct sil24_sge sge[LIBATA_MAX_PRD - 1];

	struct sil24_sge sge[SIL24_MAX_SGE];

};



union sil24_cmd_block {
@@ -378,7 +393,7 @@ static struct scsi_host_template sil24_sht = { 
	.change_queue_depth	= ata_scsi_change_queue_depth,

	.can_queue		= SIL24_MAX_CMDS,

	.this_id		= ATA_SHT_THIS_ID,

	.sg_tablesize		= LIBATA_MAX_PRD,

	.sg_tablesize		= SIL24_MAX_SGE,

	.cmd_per_lun		= ATA_SHT_CMD_PER_LUN,

	.emulated		= ATA_SHT_EMULATED,

	.use_clustering		= ATA_SHT_USE_CLUSTERING,
@@ -1284,6 +1299,7 @@ static void sil24_init_controller(struct ata_host *host) 


static int sil24_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)

{

	extern int __MARKER__sil24_cmd_block_is_sized_wrongly;

	static int printed_version;

	struct ata_port_info pi = sil24_port_info[ent->driver_data];

	const struct ata_port_info *ppi[] = { &pi, NULL };
@@ -1292,6 +1308,10 @@ static int sil24_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) 
	int i, rc;

	u32 tmp;



	/* cause link error if sil24_cmd_block is sized wrongly */

	if (sizeof(union sil24_cmd_block) != PAGE_SIZE)

		__MARKER__sil24_cmd_block_is_sized_wrongly = 1;



	if (!printed_version++)

		dev_printk(KERN_DEBUG, &pdev->dev, "version " DRV_VERSION "\n");

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