libata: const-ification bombing run

Enforce access rules where appropriate.

If the compiler is smart enough, this may buy us an optimization or two
as a side effect.
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 9269fd9..d55f12d 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -67,9 +67,9 @@
 static void ata_dev_init_params(struct ata_port *ap, struct ata_device *dev);
 static void ata_set_mode(struct ata_port *ap);
 static void ata_dev_set_xfermode(struct ata_port *ap, struct ata_device *dev);
-static unsigned int ata_get_mode_mask(struct ata_port *ap, int shift);
+static unsigned int ata_get_mode_mask(const struct ata_port *ap, int shift);
 static int fgb(u32 bitmap);
-static int ata_choose_xfer_mode(struct ata_port *ap,
+static int ata_choose_xfer_mode(const struct ata_port *ap,
 				u8 *xfer_mode_out,
 				unsigned int *xfer_shift_out);
 static void __ata_qc_complete(struct ata_queued_cmd *qc);
@@ -97,7 +97,7 @@
  *	Inherited from caller.
  */
 
-static void ata_tf_load_pio(struct ata_port *ap, struct ata_taskfile *tf)
+static void ata_tf_load_pio(struct ata_port *ap, const struct ata_taskfile *tf)
 {
 	struct ata_ioports *ioaddr = &ap->ioaddr;
 	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
@@ -155,7 +155,7 @@
  *	Inherited from caller.
  */
 
-static void ata_tf_load_mmio(struct ata_port *ap, struct ata_taskfile *tf)
+static void ata_tf_load_mmio(struct ata_port *ap, const struct ata_taskfile *tf)
 {
 	struct ata_ioports *ioaddr = &ap->ioaddr;
 	unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
@@ -224,7 +224,7 @@
  *	LOCKING:
  *	Inherited from caller.
  */
-void ata_tf_load(struct ata_port *ap, struct ata_taskfile *tf)
+void ata_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
 {
 	if (ap->flags & ATA_FLAG_MMIO)
 		ata_tf_load_mmio(ap, tf);
@@ -244,7 +244,7 @@
  *	spin_lock_irqsave(host_set lock)
  */
 
-static void ata_exec_command_pio(struct ata_port *ap, struct ata_taskfile *tf)
+static void ata_exec_command_pio(struct ata_port *ap, const struct ata_taskfile *tf)
 {
 	DPRINTK("ata%u: cmd 0x%X\n", ap->id, tf->command);
 
@@ -265,7 +265,7 @@
  *	spin_lock_irqsave(host_set lock)
  */
 
-static void ata_exec_command_mmio(struct ata_port *ap, struct ata_taskfile *tf)
+static void ata_exec_command_mmio(struct ata_port *ap, const struct ata_taskfile *tf)
 {
 	DPRINTK("ata%u: cmd 0x%X\n", ap->id, tf->command);
 
@@ -285,7 +285,7 @@
  *	LOCKING:
  *	spin_lock_irqsave(host_set lock)
  */
-void ata_exec_command(struct ata_port *ap, struct ata_taskfile *tf)
+void ata_exec_command(struct ata_port *ap, const struct ata_taskfile *tf)
 {
 	if (ap->flags & ATA_FLAG_MMIO)
 		ata_exec_command_mmio(ap, tf);
@@ -305,7 +305,7 @@
  *	Obtains host_set lock.
  */
 
-static inline void ata_exec(struct ata_port *ap, struct ata_taskfile *tf)
+static inline void ata_exec(struct ata_port *ap, const struct ata_taskfile *tf)
 {
 	unsigned long flags;
 
@@ -328,7 +328,7 @@
  *	Obtains host_set lock.
  */
 
-static void ata_tf_to_host(struct ata_port *ap, struct ata_taskfile *tf)
+static void ata_tf_to_host(struct ata_port *ap, const struct ata_taskfile *tf)
 {
 	ap->ops->tf_load(ap, tf);
 
@@ -348,7 +348,7 @@
  *	spin_lock_irqsave(host_set lock)
  */
 
-void ata_tf_to_host_nolock(struct ata_port *ap, struct ata_taskfile *tf)
+void ata_tf_to_host_nolock(struct ata_port *ap, const struct ata_taskfile *tf)
 {
 	ap->ops->tf_load(ap, tf);
 	ap->ops->exec_command(ap, tf);
@@ -558,7 +558,7 @@
  *	Inherited from caller.
  */
 
-void ata_tf_to_fis(struct ata_taskfile *tf, u8 *fis, u8 pmp)
+void ata_tf_to_fis(const struct ata_taskfile *tf, u8 *fis, u8 pmp)
 {
 	fis[0] = 0x27;	/* Register - Host to Device FIS */
 	fis[1] = (pmp & 0xf) | (1 << 7); /* Port multiplier number,
@@ -599,7 +599,7 @@
  *	Inherited from caller.
  */
 
-void ata_tf_from_fis(u8 *fis, struct ata_taskfile *tf)
+void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
 {
 	tf->command	= fis[2];	/* status */
 	tf->feature	= fis[3];	/* error */
@@ -845,7 +845,7 @@
  *	the event of failure.
  */
 
-unsigned int ata_dev_classify(struct ata_taskfile *tf)
+unsigned int ata_dev_classify(const struct ata_taskfile *tf)
 {
 	/* Apple's open source Darwin code hints that some devices only
 	 * put a proper signature into the LBA mid/high registers,
@@ -937,7 +937,7 @@
  *	caller.
  */
 
-void ata_dev_id_string(u16 *id, unsigned char *s,
+void ata_dev_id_string(const u16 *id, unsigned char *s,
 		       unsigned int ofs, unsigned int len)
 {
 	unsigned int c;
@@ -1054,7 +1054,7 @@
  *	caller.
  */
 
-static inline void ata_dump_id(struct ata_device *dev)
+static inline void ata_dump_id(const struct ata_device *dev)
 {
 	DPRINTK("49==0x%04x  "
 		"53==0x%04x  "
@@ -1089,7 +1089,7 @@
  *	FIXME: pre IDE drive timing (do we care ?). 
  */
 
-static unsigned int ata_pio_modes(struct ata_device *adev)
+static unsigned int ata_pio_modes(const struct ata_device *adev)
 {
 	u16 modes;
 
@@ -1352,7 +1352,7 @@
 }
 
 
-static inline u8 ata_dev_knobble(struct ata_port *ap)
+static inline u8 ata_dev_knobble(const struct ata_port *ap)
 {
 	return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(ap->device->id)));
 }
@@ -1684,7 +1684,7 @@
 	return 0;
 }
 
-static struct {
+static const struct {
 	unsigned int shift;
 	u8 base;
 } xfer_mode_classes[] = {
@@ -2093,7 +2093,8 @@
 	DPRINTK("EXIT\n");
 }
 
-static void ata_pr_blacklisted(struct ata_port *ap, struct ata_device *dev)
+static void ata_pr_blacklisted(const struct ata_port *ap,
+			       const struct ata_device *dev)
 {
 	printk(KERN_WARNING "ata%u: dev %u is on DMA blacklist, disabling DMA\n",
 		ap->id, dev->devno);
@@ -2131,7 +2132,7 @@
 	"_NEC DV5800A",
 };
 
-static int ata_dma_blacklisted(struct ata_port *ap, struct ata_device *dev)
+static int ata_dma_blacklisted(const struct ata_device *dev)
 {
 	unsigned char model_num[40];
 	char *s;
@@ -2156,9 +2157,9 @@
 	return 0;
 }
 
-static unsigned int ata_get_mode_mask(struct ata_port *ap, int shift)
+static unsigned int ata_get_mode_mask(const struct ata_port *ap, int shift)
 {
-	struct ata_device *master, *slave;
+	const struct ata_device *master, *slave;
 	unsigned int mask;
 
 	master = &ap->device[0];
@@ -2170,14 +2171,14 @@
 		mask = ap->udma_mask;
 		if (ata_dev_present(master)) {
 			mask &= (master->id[ATA_ID_UDMA_MODES] & 0xff);
-			if (ata_dma_blacklisted(ap, master)) {
+			if (ata_dma_blacklisted(master)) {
 				mask = 0;
 				ata_pr_blacklisted(ap, master);
 			}
 		}
 		if (ata_dev_present(slave)) {
 			mask &= (slave->id[ATA_ID_UDMA_MODES] & 0xff);
-			if (ata_dma_blacklisted(ap, slave)) {
+			if (ata_dma_blacklisted(slave)) {
 				mask = 0;
 				ata_pr_blacklisted(ap, slave);
 			}
@@ -2187,14 +2188,14 @@
 		mask = ap->mwdma_mask;
 		if (ata_dev_present(master)) {
 			mask &= (master->id[ATA_ID_MWDMA_MODES] & 0x07);
-			if (ata_dma_blacklisted(ap, master)) {
+			if (ata_dma_blacklisted(master)) {
 				mask = 0;
 				ata_pr_blacklisted(ap, master);
 			}
 		}
 		if (ata_dev_present(slave)) {
 			mask &= (slave->id[ATA_ID_MWDMA_MODES] & 0x07);
-			if (ata_dma_blacklisted(ap, slave)) {
+			if (ata_dma_blacklisted(slave)) {
 				mask = 0;
 				ata_pr_blacklisted(ap, slave);
 			}
@@ -2258,7 +2259,7 @@
  *	Zero on success, negative on error.
  */
 
-static int ata_choose_xfer_mode(struct ata_port *ap,
+static int ata_choose_xfer_mode(const struct ata_port *ap,
 				u8 *xfer_mode_out,
 				unsigned int *xfer_shift_out)
 {
@@ -4144,7 +4145,7 @@
 
 static void ata_host_init(struct ata_port *ap, struct Scsi_Host *host,
 			  struct ata_host_set *host_set,
-			  struct ata_probe_ent *ent, unsigned int port_no)
+			  const struct ata_probe_ent *ent, unsigned int port_no)
 {
 	unsigned int i;
 
@@ -4203,7 +4204,7 @@
  *
  */
 
-static struct ata_port * ata_host_add(struct ata_probe_ent *ent,
+static struct ata_port * ata_host_add(const struct ata_probe_ent *ent,
 				      struct ata_host_set *host_set,
 				      unsigned int port_no)
 {
@@ -4251,7 +4252,7 @@
  *
  */
 
-int ata_device_add(struct ata_probe_ent *ent)
+int ata_device_add(const struct ata_probe_ent *ent)
 {
 	unsigned int count = 0, i;
 	struct device *dev = ent->dev;
@@ -4470,7 +4471,7 @@
 }
 
 static struct ata_probe_ent *
-ata_probe_ent_alloc(struct device *dev, struct ata_port_info *port)
+ata_probe_ent_alloc(struct device *dev, const struct ata_port_info *port)
 {
 	struct ata_probe_ent *probe_ent;
 
@@ -4570,7 +4571,6 @@
 	if (!probe_ent)
 		return NULL;
 
-	
 	probe_ent->legacy_mode = 1;
 	probe_ent->n_ports = 1;
 	probe_ent->hard_port_no = port_num;
@@ -4783,7 +4783,7 @@
 }
 
 /* move to PCI subsystem */
-int pci_test_config_bits(struct pci_dev *pdev, struct pci_bits *bits)
+int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits)
 {
 	unsigned long tmp = 0;