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

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
......@@ -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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