[PATCH] mark several libata datastructures const

Hi,

the patch below marks several libata (and libata-driver) structures
const so that they end up in the .rodata segment and don't false-share
cachelines with things that get dirtied often.
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>

drivers/scsi/ahci.c

@@ -243,7 +243,7 @@ static const struct ata_port_operations ahci_ops = {
 	.port_stop		= ahci_port_stop,
 };
 
-static struct ata_port_info ahci_port_info[] = {
+static const struct ata_port_info ahci_port_info[] = {
 	/* board_ahci */
 	{
 		.sht		= &ahci_sht,

drivers/scsi/libata-core.c

@@ -605,7 +605,7 @@ void ata_rwcmd_protocol(struct ata_queued_cmd *qc)
 	tf->command = ata_rw_cmds[index + lba48 + write];
 }
 
-static const char * xfer_mode_str[] = {
+static const char * const xfer_mode_str[] = {
 	"UDMA/16",
 	"UDMA/25",
 	"UDMA/33",
@@ -2083,7 +2083,7 @@ static void ata_pr_blacklisted(const struct ata_port *ap,
 		ap->id, dev->devno);
 }
 
-static const char * ata_dma_blacklist [] = {
+static const char * const ata_dma_blacklist [] = {
 	"WDC AC11000H",
 	"WDC AC22100H",
 	"WDC AC32500H",

drivers/scsi/libata-scsi.c

@@ -418,7 +418,7 @@ void ata_to_sense_error(unsigned id, u8 drv_stat, u8 drv_err, u8 *sk, u8 *asc,
 	int i;
 
 	/* Based on the 3ware driver translation table */
-	static unsigned char sense_table[][4] = {
+	static const unsigned char sense_table[][4] = {
 		/* BBD|ECC|ID|MAR */
 		{0xd1, 		ABORTED_COMMAND, 0x00, 0x00}, 	// Device busy                  Aborted command
 		/* BBD|ECC|ID */
@@ -449,7 +449,7 @@ void ata_to_sense_error(unsigned id, u8 drv_stat, u8 drv_err, u8 *sk, u8 *asc,
 		{0x80, 		MEDIUM_ERROR, 0x11, 0x04}, 	// Block marked bad		  Medium error, unrecovered read error
 		{0xFF, 0xFF, 0xFF, 0xFF}, // END mark
 	};
-	static unsigned char stat_table[][4] = {
+	static const unsigned char stat_table[][4] = {
 		/* Must be first because BUSY means no other bits valid */
 		{0x80, 		ABORTED_COMMAND, 0x47, 0x00},	// Busy, fake parity for now
 		{0x20, 		HARDWARE_ERROR,  0x00, 0x00}, 	// Device fault
@@ -1532,7 +1532,7 @@ unsigned int ata_scsiop_inq_80(struct ata_scsi_args *args, u8 *rbuf,
 	return 0;
 }
 
-static const char *inq_83_str = "Linux ATA-SCSI simulator";
+static const char * const inq_83_str = "Linux ATA-SCSI simulator";
 
 /**
  *	ata_scsiop_inq_83 - Simulate INQUIRY EVPD page 83, device identity

drivers/scsi/sata_mv.c

@@ -430,7 +430,7 @@ static const struct ata_port_operations mv6_ops = {
 	.host_stop		= mv_host_stop,
 };
 
-static struct ata_port_info mv_port_info[] = {
+static const struct ata_port_info mv_port_info[] = {
 	{  /* chip_504x */
 		.sht		= &mv_sht,
 		.host_flags	= MV_COMMON_FLAGS,

drivers/scsi/sata_promise.c

@@ -158,7 +158,7 @@ static const struct ata_port_operations pdc_pata_ops = {
 	.host_stop		= ata_pci_host_stop,
 };
 
-static struct ata_port_info pdc_port_info[] = {
+static const struct ata_port_info pdc_port_info[] = {
 	/* board_2037x */
 	{
 		.sht		= &pdc_ata_sht,

drivers/scsi/sata_qstor.c

@@ -170,7 +170,7 @@ static const struct ata_port_operations qs_ata_ops = {
 	.bmdma_status		= qs_bmdma_status,
 };
 
-static struct ata_port_info qs_port_info[] = {
+static const struct ata_port_info qs_port_info[] = {
 	/* board_2068_idx */
 	{
 		.sht		= &qs_ata_sht,

drivers/scsi/sata_sil.c

@@ -176,7 +176,7 @@ static const struct ata_port_operations sil_ops = {
 	.host_stop		= ata_pci_host_stop,
 };
 
-static struct ata_port_info sil_port_info[] = {
+static const struct ata_port_info sil_port_info[] = {
 	/* sil_3112 */
 	{
 		.sht		= &sil_sht,

drivers/scsi/sata_sx4.c

@@ -215,7 +215,7 @@ static const struct ata_port_operations pdc_20621_ops = {
 	.host_stop		= pdc20621_host_stop,
 };
 
-static struct ata_port_info pdc_port_info[] = {
+static const struct ata_port_info pdc_port_info[] = {
 	/* board_20621 */
 	{
 		.sht		= &pdc_sata_sht,