powerpc/macio: Rework hotplug media bay support

The hotplug mediabay has tendrils deep into drivers/ide code
which makes a libata port reather difficult. In addition it's
ugly and could be done better.

This reworks the interface between the mediabay and the rest
of the world so that:

   - Any macio_driver can now have a mediabay_event callback
which will be called when that driver sits on a mediabay and
it's been either plugged or unplugged. The device type is
passed as an argument. We can now move all the IDE cruft
into the IDE driver itself

   - A check_media_bay() function can be used to take a peek
at the type of device currently in the bay if any, a cleaner
variant of the previous function with the same name.

   - A pair of lock/unlock functions are exposed to allow the
IDE driver to block the hotplug callbacks during the initial
setup and probing of the bay in order to avoid nasty race
conditions.

   - The mediabay code no longer needs to spin on the status
register of the IDE interface when it detects an IDE device,
this is done just fine by the IDE code itself

Overall, less code, simpler, and allows for another driver
than our old drivers/ide based one.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/include/asm/macio.h

@@ -134,6 +134,9 @@ struct macio_driver
 	int	(*resume)(struct macio_dev* dev);
 	int	(*shutdown)(struct macio_dev* dev);
 
+#ifdef CONFIG_PMAC_MEDIABAY
+	void	(*mediabay_event)(struct macio_dev* dev, int mb_state);
+#endif
 	struct device_driver	driver;
 };
 #define	to_macio_driver(drv) container_of(drv,struct macio_driver, driver)

arch/powerpc/include/asm/mediabay.h

@@ -17,26 +17,31 @@
 #define MB_POWER	6	/* media bay contains a Power device (???) */
 #define MB_NO		7	/* media bay contains nothing */
 
-/* Number of bays in the machine or 0 */
-extern int media_bay_count;
+struct macio_dev;
 
-#ifdef CONFIG_BLK_DEV_IDE_PMAC
-#include <linux/ide.h>
+#ifdef CONFIG_PMAC_MEDIABAY
 
-int check_media_bay_by_base(unsigned long base, int what);
-/* called by IDE PMAC host driver to register IDE controller for media bay */
-int media_bay_set_ide_infos(struct device_node *which_bay, unsigned long base,
-			    int irq, ide_hwif_t *hwif);
+/* Check the content type of the bay, returns MB_NO if the bay is still
+ * transitionning
+ */
+extern int check_media_bay(struct macio_dev *bay);
 
-int check_media_bay(struct device_node *which_bay, int what);
+/* The ATA driver uses the calls below to temporarily hold on the
+ * media bay callbacks while initializing the interface
+ */
+extern void lock_media_bay(struct macio_dev *bay);
+extern void unlock_media_bay(struct macio_dev *bay);
 
 #else
 
-static inline int check_media_bay(struct device_node *which_bay, int what)
+static inline int check_media_bay(struct macio_dev *bay)
 {
-	return -ENODEV;
+	return MB_NO;
 }
 
+static inline void lock_media_bay(struct macio_dev *bay) { }
+static inline void unlock_media_bay(struct macio_dev *bay) { }
+
 #endif
 
 #endif /* __KERNEL__ */

drivers/block/swim3.c

@@ -200,7 +200,7 @@ struct floppy_state {
 	int	ejected;
 	wait_queue_head_t wait;
 	int	wanted;
-	struct device_node*	media_bay; /* NULL when not in bay */
+	struct macio_dev *mdev;
 	char	dbdma_cmd_space[5 * sizeof(struct dbdma_cmd)];
 };
 
@@ -303,14 +303,13 @@ static int swim3_readbit(struct floppy_state *fs, int bit)
 static void do_fd_request(struct request_queue * q)
 {
 	int i;
-	for(i=0;i<floppy_count;i++)
-	{
-#ifdef CONFIG_PMAC_MEDIABAY
-		if (floppy_states[i].media_bay &&
-			check_media_bay(floppy_states[i].media_bay, MB_FD))
+
+	for(i=0; i<floppy_count; i++) {
+		struct floppy_state *fs = &floppy_states[i];
+		if (fs->mdev->media_bay &&
+		    check_media_bay(fs->mdev->media_bay) != MB_FD)
 			continue;
-#endif /* CONFIG_PMAC_MEDIABAY */
-		start_request(&floppy_states[i]);
+		start_request(fs);
 	}
 }
 
@@ -849,10 +848,9 @@ static int floppy_ioctl(struct block_device *bdev, fmode_t mode,
 	if ((cmd & 0x80) && !capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-#ifdef CONFIG_PMAC_MEDIABAY
-	if (fs->media_bay && check_media_bay(fs->media_bay, MB_FD))
+	if (fs->mdev->media_bay &&
+	    check_media_bay(fs->mdev->media_bay) != MB_FD)
 		return -ENXIO;
-#endif
 
 	switch (cmd) {
 	case FDEJECT:
@@ -876,10 +874,9 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
 	int n, err = 0;
 
 	if (fs->ref_count == 0) {
-#ifdef CONFIG_PMAC_MEDIABAY
-		if (fs->media_bay && check_media_bay(fs->media_bay, MB_FD))
+		if (fs->mdev->media_bay &&
+		    check_media_bay(fs->mdev->media_bay) != MB_FD)
 			return -ENXIO;
-#endif
 		out_8(&sw->setup, S_IBM_DRIVE | S_FCLK_DIV2);
 		out_8(&sw->control_bic, 0xff);
 		out_8(&sw->mode, 0x95);
@@ -963,10 +960,9 @@ static int floppy_revalidate(struct gendisk *disk)
 	struct swim3 __iomem *sw;
 	int ret, n;
 
-#ifdef CONFIG_PMAC_MEDIABAY
-	if (fs->media_bay && check_media_bay(fs->media_bay, MB_FD))
+	if (fs->mdev->media_bay &&
+	    check_media_bay(fs->mdev->media_bay) != MB_FD)
 		return -ENXIO;
-#endif
 
 	sw = fs->swim3;
 	grab_drive(fs, revalidating, 0);
@@ -1009,7 +1005,6 @@ static const struct block_device_operations floppy_fops = {
 static int swim3_add_device(struct macio_dev *mdev, int index)
 {
 	struct device_node *swim = mdev->ofdev.node;
-	struct device_node *mediabay;
 	struct floppy_state *fs = &floppy_states[index];
 	int rc = -EBUSY;
 
@@ -1036,9 +1031,7 @@ static int swim3_add_device(struct macio_dev *mdev, int index)
 	}
 	dev_set_drvdata(&mdev->ofdev.dev, fs);
 
-	mediabay = (strcasecmp(swim->parent->type, "media-bay") == 0) ?
-		swim->parent : NULL;
-	if (mediabay == NULL)
+	if (mdev->media_bay == NULL)
 		pmac_call_feature(PMAC_FTR_SWIM3_ENABLE, swim, 0, 1);
 	
 	memset(fs, 0, sizeof(*fs));
@@ -1068,7 +1061,7 @@ static int swim3_add_device(struct macio_dev *mdev, int index)
 	fs->secpercyl = 36;
 	fs->secpertrack = 18;
 	fs->total_secs = 2880;
-	fs->media_bay = mediabay;
+	fs->mdev = mdev;
 	init_waitqueue_head(&fs->wait);
 
 	fs->dma_cmd = (struct dbdma_cmd *) DBDMA_ALIGN(fs->dbdma_cmd_space);
@@ -1093,7 +1086,7 @@ static int swim3_add_device(struct macio_dev *mdev, int index)
 	init_timer(&fs->timeout);
 
 	printk(KERN_INFO "fd%d: SWIM3 floppy controller %s\n", floppy_count,
-		mediabay ? "in media bay" : "");
+		mdev->media_bay ? "in media bay" : "");
 
 	return 0;
 

drivers/ide/pmac.c

@@ -43,10 +43,7 @@
 #include <asm/pmac_feature.h>
 #include <asm/sections.h>
 #include <asm/irq.h>
-
-#ifndef CONFIG_PPC64
 #include <asm/mediabay.h>
-#endif
 
 #define DRV_NAME "ide-pmac"
 
@@ -59,13 +56,14 @@ typedef struct pmac_ide_hwif {
 	int				irq;
 	int				kind;
 	int				aapl_bus_id;
-	unsigned			mediabay : 1;
 	unsigned			broken_dma : 1;
 	unsigned			broken_dma_warn : 1;
 	struct device_node*		node;
 	struct macio_dev		*mdev;
 	u32				timings[4];
 	volatile u32 __iomem *		*kauai_fcr;
+	ide_hwif_t			*hwif;
+
 	/* Those fields are duplicating what is in hwif. We currently
 	 * can't use the hwif ones because of some assumptions that are
 	 * beeing done by the generic code about the kind of dma controller
@@ -854,6 +852,11 @@ sanitize_timings(pmac_ide_hwif_t *pmif)
 	pmif->timings[2] = pmif->timings[3] = value2;
 }
 
+static int on_media_bay(pmac_ide_hwif_t *pmif)
+{
+	return pmif->mdev && pmif->mdev->media_bay != NULL;
+}
+
 /* Suspend call back, should be called after the child devices
  * have actually been suspended
  */
@@ -866,7 +869,7 @@ static int pmac_ide_do_suspend(pmac_ide_hwif_t *pmif)
 	disable_irq(pmif->irq);
 
 	/* The media bay will handle itself just fine */
-	if (pmif->mediabay)
+	if (on_media_bay(pmif))
 		return 0;
 	
 	/* Kauai has bus control FCRs directly here */
@@ -889,7 +892,7 @@ static int pmac_ide_do_suspend(pmac_ide_hwif_t *pmif)
 static int pmac_ide_do_resume(pmac_ide_hwif_t *pmif)
 {
 	/* Hard reset & re-enable controller (do we really need to reset ? -BenH) */
-	if (!pmif->mediabay) {
+	if (!on_media_bay(pmif)) {
 		ppc_md.feature_call(PMAC_FTR_IDE_RESET, pmif->node, pmif->aapl_bus_id, 1);
 		ppc_md.feature_call(PMAC_FTR_IDE_ENABLE, pmif->node, pmif->aapl_bus_id, 1);
 		msleep(10);
@@ -950,13 +953,11 @@ static void pmac_ide_init_dev(ide_drive_t *drive)
 	pmac_ide_hwif_t *pmif =
 		(pmac_ide_hwif_t *)dev_get_drvdata(hwif->gendev.parent);
 
-	if (pmif->mediabay) {
-#ifdef CONFIG_PMAC_MEDIABAY
-		if (check_media_bay_by_base(pmif->regbase, MB_CD) == 0) {
+	if (on_media_bay(pmif)) {
+		if (check_media_bay(pmif->mdev->media_bay) == MB_CD) {
 			drive->dev_flags &= ~IDE_DFLAG_NOPROBE;
 			return;
 		}
-#endif
 		drive->dev_flags |= IDE_DFLAG_NOPROBE;
 	}
 }
@@ -1073,25 +1074,22 @@ static int __devinit pmac_ide_setup_device(pmac_ide_hwif_t *pmif,
 		       KAUAI_FCR_UATA_RESET_N |
 		       KAUAI_FCR_UATA_ENABLE, pmif->kauai_fcr);
 	
-	pmif->mediabay = 0;
-	
 	/* Make sure we have sane timings */
 	sanitize_timings(pmif);
 
+	/* If we are on a media bay, wait for it to settle and lock it */
+	if (pmif->mdev)
+		lock_media_bay(pmif->mdev->media_bay);
+
 	host = ide_host_alloc(&d, hws, 1);
-	if (host == NULL)
-		return -ENOMEM;
-	hwif = host->ports[0];
+	if (host == NULL) {
+		rc = -ENOMEM;
+		goto bail;
+	}
+	hwif = pmif->hwif = host->ports[0];
 
-#ifndef CONFIG_PPC64
-	/* XXX FIXME: Media bay stuff need re-organizing */
-	if (np->parent && np->parent->name
-	    && strcasecmp(np->parent->name, "media-bay") == 0) {
-#ifdef CONFIG_PMAC_MEDIABAY
-		media_bay_set_ide_infos(np->parent, pmif->regbase, pmif->irq,
-					hwif);
-#endif /* CONFIG_PMAC_MEDIABAY */
-		pmif->mediabay = 1;
+	if (on_media_bay(pmif)) {
+		/* Fixup bus ID for media bay */
 		if (!bidp)
 			pmif->aapl_bus_id = 1;
 	} else if (pmif->kind == controller_ohare) {
@@ -1100,9 +1098,7 @@ static int __devinit pmac_ide_setup_device(pmac_ide_hwif_t *pmif,
 		 * units, I keep the old way
 		 */
 		ppc_md.feature_call(PMAC_FTR_IDE_ENABLE, np, 0, 1);
-	} else
-#endif
-	{
+	} else {
  		/* This is necessary to enable IDE when net-booting */
 		ppc_md.feature_call(PMAC_FTR_IDE_RESET, np, pmif->aapl_bus_id, 1);
 		ppc_md.feature_call(PMAC_FTR_IDE_ENABLE, np, pmif->aapl_bus_id, 1);
@@ -1114,15 +1110,19 @@ static int __devinit pmac_ide_setup_device(pmac_ide_hwif_t *pmif,
 	printk(KERN_INFO DRV_NAME ": Found Apple %s controller (%s), "
 	       "bus ID %d%s, irq %d\n", model_name[pmif->kind],
 	       pmif->mdev ? "macio" : "PCI", pmif->aapl_bus_id,
-			 pmif->mediabay ? " (mediabay)" : "", hw->irq);
+	       on_media_bay(pmif) ? " (mediabay)" : "", hw->irq);
 
 	rc = ide_host_register(host, &d, hws);
-	if (rc) {
+	if (rc)
+		pmif->hwif = NULL;
+
+	if (pmif->mdev)
+		unlock_media_bay(pmif->mdev->media_bay);
+
+ bail:
+	if (rc && host)
 		ide_host_free(host);
 	return rc;
-	}
-
-	return 0;
 }
 
 static void __devinit pmac_ide_init_ports(struct ide_hw *hw, unsigned long base)
@@ -1362,6 +1362,25 @@ pmac_ide_pci_resume(struct pci_dev *pdev)
 	return rc;
 }
 
+#ifdef CONFIG_PMAC_MEDIABAY
+static void pmac_ide_macio_mb_event(struct macio_dev* mdev, int mb_state)
+{
+	pmac_ide_hwif_t *pmif =
+		(pmac_ide_hwif_t *)dev_get_drvdata(&mdev->ofdev.dev);
+
+	switch(mb_state) {
+	case MB_CD:
+		if (!pmif->hwif->present)
+			ide_port_scan(pmif->hwif);
+		break;
+	default:
+		if (pmif->hwif->present)
+			ide_port_unregister_devices(pmif->hwif);
+	}
+}
+#endif /* CONFIG_PMAC_MEDIABAY */
+
+
 static struct of_device_id pmac_ide_macio_match[] = 
 {
 	{
@@ -1386,6 +1405,9 @@ static struct macio_driver pmac_ide_macio_driver =
 	.probe		= pmac_ide_macio_attach,
 	.suspend	= pmac_ide_macio_suspend,
 	.resume		= pmac_ide_macio_resume,
+#ifdef CONFIG_PMAC_MEDIABAY
+	.mediabay_event	= pmac_ide_macio_mb_event,
+#endif
 };
 
 static const struct pci_device_id pmac_ide_pci_match[] = {