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| author | Tejun Heo <htejun@gmail.com> | 2007-11-22 12:46:57 +0300 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2007-11-24 03:23:55 +0300 |
| commit | 93e2618e0cee1f5b5a4cfc1b7521939318dbf5bb (patch) | |
| tree | e535579b3e39c603f81e0144dbf744d0204c6975 /drivers/ata/sata_sil24.c | |
| parent | 0706efd61edfcf958c2c19669aa65c2180ec3ba0 (diff) | |
| download | linux-93e2618e0cee1f5b5a4cfc1b7521939318dbf5bb.tar.xz | |
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: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers/ata/sata_sil24.c')
| -rw-r--r-- | drivers/ata/sata_sil24.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c index 187dcb02c681..96fd5260446d 100644 --- a/drivers/ata/sata_sil24.c +++ b/drivers/ata/sata_sil24.c @@ -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"); |