[PATCH] ioc4: Core driver rewrite

This series of patches reworks the configuration and internal structure
of the SGI IOC4 I/O controller device drivers.

These changes are motivated by several factors:

- The IOC4 chip PCI resources are of mixed use between functions (i.e.
  multiple functions are handled in the same address range, sometimes
  within the same register), muddling resource ownership and initialization
  issues.  Centralizing this ownership in a core driver is desirable.

- The IOC4 chip implements multiple functions (serial, IDE, others not
  yet implemented in the mainline kernel) but is not a multifunction
  PCI device.  In order to properly handle device addition and removal
  as well as module insertion and deletion, an intermediary IOC4-specific
  driver layer is needed to handle these operations cleanly.

- All IOC4 drivers are currently enabled by a single CONFIG value.  As
  not all systems need all IOC4 functions, it is desireable to enable
  these drivers independently.

- The current IOC4 core driver will trigger loading of all function-level
  drivers, as it makes direct calls to them.  This situation should be
  reversed (i.e. function-level drivers cause loading of core driver)
  in order to maintain a clear and least-surprise driver loading model.

- IOC4 hardware design necessitates some driver-level dependency on
  the PCI bus clock speed.  Current code assumes a 66MHz bus, but the
  speed should be autodetected and appropriate compensation taken.

This patch series effects the above changes by a newly and better designed
IOC4 core driver with which the function-level drivers can register and
deregister themselves upon module insertion/removal.  By tracking these
modules, device addition/removal is also handled properly.  PCI resource
management and ownership issues are centralized in this core driver, and
IOC4-wide configuration actions such as bus speed detection are also
handled in this core driver.

This patch:

The SGI IOC4 I/O controller chip implements multiple functions, though it is
not a multi-function PCI device.  Additionally, various PCI resources of the
IOC4 are shared by multiple hardware functions, and thus resource ownership by
driver is not clearly delineated.  Due to the current driver design, all core
and subordinate drivers must be loaded, or none, which is undesirable if not
all IOC4 hardware features are being used.

This patch reorganizes the IOC4 drivers so that the core driver provides a
subdriver registration service.  Through appropriate callbacks the subdrivers
can now handle device addition and removal, as well as module insertion and
deletion (though the IOC4 IDE driver requires further work before module
deletion will work).  The core driver now takes care of allocating PCI
resources and data which must be shared between subdrivers, to clearly
delineate module ownership of these items.

Signed-off-by: Brent Casavant <bcasavan@sgi.com>
Acked-by: Pat Gefre <pfg@sgi.com
Acked-by: Jeremy Higdon <jeremy@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 416 insertions, 215 deletions

diff --git a/drivers/ide/pci/sgiioc4.c b/drivers/ide/pci/sgiioc4.c
index 4651a22bf12..af526b671c4 100644
--- a/drivers/ide/pci/sgiioc4.c
+++ b/drivers/ide/pci/sgiioc4.c
@@ -34,7 +34,7 @@
 #include <linux/mm.h>
 #include <linux/ioport.h>
 #include <linux/blkdev.h>
-#include <linux/ioc4_common.h>
+#include <linux/ioc4.h>
 #include <asm/io.h>
 
 #include <linux/ide.h>
@@ -715,14 +715,34 @@ static ide_pci_device_t sgiioc4_chipsets[] __devinitdata = {
 };
 
 int
-ioc4_ide_attach_one(struct pci_dev *dev, const struct pci_device_id *id)
+ioc4_ide_attach_one(struct ioc4_driver_data *idd)
 {
-	return pci_init_sgiioc4(dev, &sgiioc4_chipsets[id->driver_data]);
+	return pci_init_sgiioc4(idd->idd_pdev,
+				&sgiioc4_chipsets[idd->idd_pci_id->driver_data]);
 }
 
+static struct ioc4_submodule ioc4_ide_submodule = {
+	.is_name = "IOC4_ide",
+	.is_owner = THIS_MODULE,
+	.is_probe = ioc4_ide_attach_one,
+/*	.is_remove = ioc4_ide_remove_one,	*/
+};
+
+static int __devinit
+ioc4_ide_init(void)
+{
+	return ioc4_register_submodule(&ioc4_ide_submodule);
+}
+
+static void __devexit
+ioc4_ide_exit(void)
+{
+	ioc4_unregister_submodule(&ioc4_ide_submodule);
+}
+
+module_init(ioc4_ide_init);
+module_exit(ioc4_ide_exit);
 
 MODULE_AUTHOR("Aniket Malatpure - Silicon Graphics Inc. (SGI)");
 MODULE_DESCRIPTION("IDE PCI driver module for SGI IOC4 Base-IO Card");
 MODULE_LICENSE("GPL");
-
-EXPORT_SYMBOL(ioc4_ide_attach_one);
diff --git a/drivers/serial/ioc4_serial.c b/drivers/serial/ioc4_serial.c
index ba4e13a22a5..da5f10eb484 100644
--- a/drivers/serial/ioc4_serial.c
+++ b/drivers/serial/ioc4_serial.c
@@ -20,7 +20,7 @@
 #include <linux/serial_reg.h>
 #include <linux/module.h>
 #include <linux/pci.h>
-#include <linux/ioc4_common.h>
+#include <linux/ioc4.h>
 #include <linux/serial_core.h>
 
 /*
@@ -130,12 +130,19 @@
 				 IOC4_SIO_IR_S3_TX_EXPLICIT)
 
 /* Bitmasks for IOC4_OTHER_IR, IOC4_OTHER_IEC, and IOC4_OTHER_IES  */
-#define IOC4_OTHER_IR_ATA_INT           0x00000001  /* ATAPI intr pass-thru */
-#define IOC4_OTHER_IR_ATA_MEMERR        0x00000002  /* ATAPI DMA PCI error */
-#define IOC4_OTHER_IR_S0_MEMERR         0x00000004  /* Port 0 PCI error */
-#define IOC4_OTHER_IR_S1_MEMERR         0x00000008  /* Port 1 PCI error */
-#define IOC4_OTHER_IR_S2_MEMERR         0x00000010  /* Port 2 PCI error */
-#define IOC4_OTHER_IR_S3_MEMERR         0x00000020  /* Port 3 PCI error */
+#define IOC4_OTHER_IR_ATA_INT		0x00000001  /* ATAPI intr pass-thru */
+#define IOC4_OTHER_IR_ATA_MEMERR	0x00000002  /* ATAPI DMA PCI error */
+#define IOC4_OTHER_IR_S0_MEMERR		0x00000004  /* Port 0 PCI error */
+#define IOC4_OTHER_IR_S1_MEMERR		0x00000008  /* Port 1 PCI error */
+#define IOC4_OTHER_IR_S2_MEMERR		0x00000010  /* Port 2 PCI error */
+#define IOC4_OTHER_IR_S3_MEMERR		0x00000020  /* Port 3 PCI error */
+#define IOC4_OTHER_IR_KBD_INT		0x00000040  /* Keyboard/mouse */
+#define IOC4_OTHER_IR_RESERVED		0x007fff80  /* Reserved */
+#define IOC4_OTHER_IR_RT_INT		0x00800000  /* INT_OUT section output */
+#define IOC4_OTHER_IR_GEN_INT		0xff000000  /* Generic pins */
+
+#define IOC4_OTHER_IR_SER_MEMERR (IOC4_OTHER_IR_S0_MEMERR | IOC4_OTHER_IR_S1_MEMERR | \
+				  IOC4_OTHER_IR_S2_MEMERR | IOC4_OTHER_IR_S3_MEMERR)
 
 /* Bitmasks for IOC4_SIO_CR */
 #define IOC4_SIO_CR_CMD_PULSE_SHIFT              0  /* byte bus strobe shift */
@@ -274,67 +281,22 @@ struct ioc4_uartregs {
 #define i4u_dlm u2.dlm
 #define i4u_fcr u3.fcr
 
-/* PCI memory space register map addressed using pci_bar0 */
-struct ioc4_memregs {
-	struct ioc4_mem {
-		/* Miscellaneous IOC4  registers */
-		uint32_t pci_err_addr_l;
-		uint32_t pci_err_addr_h;
-		uint32_t sio_ir;
-		uint32_t other_ir;
-
-		/* These registers are read-only for general kernel code.  */
-		uint32_t sio_ies_ro;
-		uint32_t other_ies_ro;
-		uint32_t sio_iec_ro;
-		uint32_t other_iec_ro;
-		uint32_t sio_cr;
-		uint32_t misc_fill1;
-		uint32_t int_out;
-		uint32_t misc_fill2;
-		uint32_t gpcr_s;
-		uint32_t gpcr_c;
-		uint32_t gpdr;
-		uint32_t misc_fill3;
-		uint32_t gppr_0;
-		uint32_t gppr_1;
-		uint32_t gppr_2;
-		uint32_t gppr_3;
-		uint32_t gppr_4;
-		uint32_t gppr_5;
-		uint32_t gppr_6;
-		uint32_t gppr_7;
-	} ioc4_mem;
-
-	char misc_fill4[0x100 - 0x5C - 4];
-
-	/* ATA/ATAP registers */
-	uint32_t ata_notused[9];
-	char ata_fill1[0x140 - 0x120 - 4];
-	uint32_t ata_notused1[8];
-	char ata_fill2[0x200 - 0x15C - 4];
-
-	/* Keyboard and mouse registers */
-	uint32_t km_notused[5];;
-	char km_fill1[0x300 - 0x210 - 4];
-
-	/* Serial port registers used for DMA serial I/O */
-	struct ioc4_serial {
-		uint32_t sbbr01_l;
-		uint32_t sbbr01_h;
-		uint32_t sbbr23_l;
-		uint32_t sbbr23_h;
-
-		struct ioc4_serialregs port_0;
-		struct ioc4_serialregs port_1;
-		struct ioc4_serialregs port_2;
-		struct ioc4_serialregs port_3;
-		struct ioc4_uartregs uart_0;
-		struct ioc4_uartregs uart_1;
-		struct ioc4_uartregs uart_2;
-		struct ioc4_uartregs uart_3;
-	} ioc4_serial;
-};
+/* Serial port registers used for DMA serial I/O */
+struct ioc4_serial {
+	uint32_t sbbr01_l;
+	uint32_t sbbr01_h;
+	uint32_t sbbr23_l;
+	uint32_t sbbr23_h;
+
+	struct ioc4_serialregs port_0;
+	struct ioc4_serialregs port_1;
+	struct ioc4_serialregs port_2;
+	struct ioc4_serialregs port_3;
+	struct ioc4_uartregs uart_0;
+	struct ioc4_uartregs uart_1;
+	struct ioc4_uartregs uart_2;
+	struct ioc4_uartregs uart_3;
+} ioc4_serial;
 
 /* UART clock speed */
 #define IOC4_SER_XIN_CLK        IOC4_SER_XIN_CLK_66
@@ -412,8 +374,8 @@ enum sio_proto {
 					| UART_LCR_WLEN7 | UART_LCR_WLEN8)
 #define LCR_MASK_STOP_BITS	(UART_LCR_STOP)
 
-#define PENDING(_p)	(readl(&(_p)->ip_mem->sio_ir) & _p->ip_ienb)
-#define READ_SIO_IR(_p) readl(&(_p)->ip_mem->sio_ir)
+#define PENDING(_p)	(readl(&(_p)->ip_mem->sio_ir.raw) & _p->ip_ienb)
+#define READ_SIO_IR(_p) readl(&(_p)->ip_mem->sio_ir.raw)
 
 /* Default to 4k buffers */
 #ifdef IOC4_1K_BUFFERS
@@ -447,7 +409,7 @@ struct ioc4_control {
  */
 #define MAX_IOC4_INTR_ENTS	(8 * sizeof(uint32_t))
 struct ioc4_soft {
-	struct ioc4_mem __iomem *is_ioc4_mem_addr;
+	struct ioc4_misc_regs __iomem *is_ioc4_misc_addr;
 	struct ioc4_serial __iomem *is_ioc4_serial_addr;
 
 	/* Each interrupt type has an entry in the array */
@@ -486,7 +448,7 @@ struct ioc4_port {
 	struct ioc4_soft *ip_ioc4_soft;
 
 	/* pci mem addresses */
-	struct ioc4_mem __iomem *ip_mem;
+	struct ioc4_misc_regs __iomem *ip_mem;
 	struct ioc4_serial __iomem *ip_serial;
 	struct ioc4_serialregs __iomem *ip_serial_regs;
 	struct ioc4_uartregs __iomem *ip_uart_regs;
@@ -553,7 +515,7 @@ struct hooks {
 	uint32_t intr_dma_error;
 	uint32_t intr_clear;
 	uint32_t intr_all;
-	char rs422_select_pin;
+	int rs422_select_pin;
 };
 
 static struct hooks hooks_array[IOC4_NUM_SERIAL_PORTS] = {
@@ -669,7 +631,7 @@ static void handle_intr(void *arg, uint32_t sio_ir);
 static inline void
 write_ireg(struct ioc4_soft *ioc4_soft, uint32_t val, int which, int type)
 {
-	struct ioc4_mem __iomem *mem = ioc4_soft->is_ioc4_mem_addr;
+	struct ioc4_misc_regs __iomem *mem = ioc4_soft->is_ioc4_misc_addr;
 	unsigned long flags;
 
 	spin_lock_irqsave(&ioc4_soft->is_ir_lock, flags);
@@ -678,11 +640,11 @@ write_ireg(struct ioc4_soft *ioc4_soft, uint32_t val, int which, int type)
 	case IOC4_SIO_INTR_TYPE:
 		switch (which) {
 		case IOC4_W_IES:
-			writel(val, &mem->sio_ies_ro);
+			writel(val, &mem->sio_ies.raw);
 			break;
 
 		case IOC4_W_IEC:
-			writel(val, &mem->sio_iec_ro);
+			writel(val, &mem->sio_iec.raw);
 			break;
 		}
 		break;
@@ -690,11 +652,11 @@ write_ireg(struct ioc4_soft *ioc4_soft, uint32_t val, int which, int type)
 	case IOC4_OTHER_INTR_TYPE:
 		switch (which) {
 		case IOC4_W_IES:
-			writel(val, &mem->other_ies_ro);
+			writel(val, &mem->other_ies.raw);
 			break;
 
 		case IOC4_W_IEC:
-			writel(val, &mem->other_iec_ro);
+			writel(val, &mem->other_iec.raw);
 			break;
 		}
 		break;
@@ -747,7 +709,8 @@ static int set_baud(struct ioc4_port *port, int baud)
  */
 static struct ioc4_port *get_ioc4_port(struct uart_port *the_port)
 {
-	struct ioc4_control *control = dev_get_drvdata(the_port->dev);
+	struct ioc4_driver_data *idd = dev_get_drvdata(the_port->dev);
+	struct ioc4_control *control = idd->idd_serial_data;
 	int ii;
 
 	if (control) {
@@ -782,7 +745,7 @@ static struct ioc4_port *get_ioc4_port(struct uart_port *the_port)
 static inline uint32_t
 pending_intrs(struct ioc4_soft *soft, int type)
 {
-	struct ioc4_mem __iomem *mem = soft->is_ioc4_mem_addr;
+	struct ioc4_misc_regs __iomem *mem = soft->is_ioc4_misc_addr;
 	unsigned long flag;
 	uint32_t intrs = 0;
 
@@ -793,11 +756,11 @@ pending_intrs(struct ioc4_soft *soft, int type)
 
 	switch (type) {
 	case IOC4_SIO_INTR_TYPE:
-		intrs = readl(&mem->sio_ir) & readl(&mem->sio_ies_ro);
+		intrs = readl(&mem->sio_ir.raw) & readl(&mem->sio_ies.raw);
 		break;
 
 	case IOC4_OTHER_INTR_TYPE:
-		intrs = readl(&mem->other_ir) & readl(&mem->other_ies_ro);
+		intrs = readl(&mem->other_ir.raw) & readl(&mem->other_ies.raw);
 
 		/* Don't process any ATA interrupte */
 		intrs &= ~(IOC4_OTHER_IR_ATA_INT | IOC4_OTHER_IR_ATA_MEMERR);
@@ -826,7 +789,7 @@ static int inline port_init(struct ioc4_port *port)
 
 	/* Wait until any pending bus activity for this port has ceased */
 	do
-		sio_cr = readl(&port->ip_mem->sio_cr);
+		sio_cr = readl(&port->ip_mem->sio_cr.raw);
 	while (!(sio_cr & IOC4_SIO_CR_SIO_DIAG_IDLE));
 
 	/* Finish reset sequence */
@@ -899,7 +862,7 @@ static int inline port_init(struct ioc4_port *port)
 	write_ireg(port->ip_ioc4_soft, hooks->intr_clear,
 		       IOC4_W_IEC, IOC4_SIO_INTR_TYPE);
 	port->ip_ienb &= ~hooks->intr_clear;
-	writel(hooks->intr_clear, &port->ip_mem->sio_ir);
+	writel(hooks->intr_clear, &port->ip_mem->sio_ir.raw);
 	return 0;
 }
 
@@ -918,23 +881,23 @@ static void handle_dma_error_intr(void *arg, uint32_t other_ir)
 	spin_lock_irqsave(&port->ip_lock, flags);
 
 	/* ACK the interrupt */
-	writel(hooks->intr_dma_error, &port->ip_mem->other_ir);
+	writel(hooks->intr_dma_error, &port->ip_mem->other_ir.raw);
 
-	if (readl(&port->ip_mem->pci_err_addr_l) & IOC4_PCI_ERR_ADDR_VLD) {
+	if (readl(&port->ip_mem->pci_err_addr_l.raw) & IOC4_PCI_ERR_ADDR_VLD) {
 		printk(KERN_ERR
 			"PCI error address is 0x%lx, "
 				"master is serial port %c %s\n",
 		     (((uint64_t)readl(&port->ip_mem->pci_err_addr_h)
 							 << 32)
-				| readl(&port->ip_mem->pci_err_addr_l))
+				| readl(&port->ip_mem->pci_err_addr_l.raw))
 					& IOC4_PCI_ERR_ADDR_ADDR_MSK, '1' +
-		     ((char)(readl(&port->ip_mem-> pci_err_addr_l) &
+		     ((char)(readl(&port->ip_mem->pci_err_addr_l.raw) &
 			     IOC4_PCI_ERR_ADDR_MST_NUM_MSK) >> 1),
-		     (readl(&port->ip_mem->pci_err_addr_l)
+		     (readl(&port->ip_mem->pci_err_addr_l.raw)
 				& IOC4_PCI_ERR_ADDR_MST_TYP_MSK)
 				? "RX" : "TX");
 
-		if (readl(&port->ip_mem->pci_err_addr_l)
+		if (readl(&port->ip_mem->pci_err_addr_l.raw)
 						& IOC4_PCI_ERR_ADDR_MUL_ERR) {
 			printk(KERN_ERR
 				"Multiple errors occurred\n");
@@ -1018,26 +981,26 @@ static irqreturn_t ioc4_intr(int irq, void *arg, struct pt_regs *regs)
 				"other_ies = 0x%x\n",
 			       (intr_type == IOC4_SIO_INTR_TYPE) ? "sio" :
 			       "other", this_ir,
-			       readl(&soft->is_ioc4_mem_addr->sio_ir),
-			       readl(&soft->is_ioc4_mem_addr->sio_ies_ro),
-			       readl(&soft->is_ioc4_mem_addr->other_ir),
-			       readl(&soft->is_ioc4_mem_addr->other_ies_ro));
+			       readl(&soft->is_ioc4_misc_addr->sio_ir.raw),
+			       readl(&soft->is_ioc4_misc_addr->sio_ies.raw),
+			       readl(&soft->is_ioc4_misc_addr->other_ir.raw),
+			       readl(&soft->is_ioc4_misc_addr->other_ies.raw));
 		}
 	}
 #ifdef DEBUG_INTERRUPTS
 	{
-		struct ioc4_mem __iomem *mem = soft->is_ioc4_mem_addr;
+		struct ioc4_misc_regs __iomem *mem = soft->is_ioc4_misc_addr;
 		spinlock_t *lp = &soft->is_ir_lock;
 		unsigned long flag;
 
 		spin_lock_irqsave(&soft->is_ir_lock, flag);
-		printk ("%s : %d : mem 0x%p sio_ir 0x%x sio_ies_ro 0x%x "
-				"other_ir 0x%x other_ies_ro 0x%x mask 0x%x\n",
+		printk ("%s : %d : mem 0x%p sio_ir 0x%x sio_ies 0x%x "
+				"other_ir 0x%x other_ies 0x%x mask 0x%x\n",
 		     __FUNCTION__, __LINE__,
-		     (void *)mem, readl(&mem->sio_ir),
-		     readl(&mem->sio_ies_ro),
-		     readl(&mem->other_ir),
-		     readl(&mem->other_ies_ro),
+		     (void *)mem, readl(&mem->sio_ir.raw),
+		     readl(&mem->sio_ies.raw),
+		     readl(&mem->other_ir.raw),
+		     readl(&mem->other_ies.raw),
 		     IOC4_OTHER_IR_ATA_INT | IOC4_OTHER_IR_ATA_MEMERR);
 		spin_unlock_irqrestore(&soft->is_ir_lock, flag);
 	}
@@ -1056,7 +1019,7 @@ static irqreturn_t ioc4_intr(int irq, void *arg, struct pt_regs *regs)
  */
 static int inline ioc4_attach_local(struct pci_dev *pdev,
 			struct ioc4_control *control,
-			struct ioc4_soft *soft, void __iomem *ioc4_mem,
+			struct ioc4_soft *soft, void __iomem *ioc4_misc,
 			void __iomem *ioc4_serial)
 {
 	struct ioc4_port *port;
@@ -1076,7 +1039,7 @@ static int inline ioc4_attach_local(struct pci_dev *pdev,
 				ioc4_revid, ioc4_revid_min);
 		return -EPERM;
 	}
-	BUG_ON(ioc4_mem == NULL);
+	BUG_ON(ioc4_misc == NULL);
 	BUG_ON(ioc4_serial == NULL);
 
 	/* Create port structures for each port */
@@ -1103,7 +1066,7 @@ static int inline ioc4_attach_local(struct pci_dev *pdev,
 		port->ip_pci_bus_speed = IOC4_SER_XIN_CLK;
 		port->ip_baud = 9600;
 		port->ip_control = control;
-		port->ip_mem = ioc4_mem;
+		port->ip_mem = ioc4_misc;
 		port->ip_serial = ioc4_serial;
 
 		/* point to the right hook */
@@ -1604,14 +1567,12 @@ static int ioc4_set_proto(struct ioc4_port *port, enum sio_proto proto)
 	switch (proto) {
 	case PROTO_RS232:
 		/* Clear the appropriate GIO pin */
-		writel(0, (&port->ip_mem->gppr_0 +
-				  hooks->rs422_select_pin));
+		writel(0, (&port->ip_mem->gppr[hooks->rs422_select_pin].raw));
 		break;
 
 	case PROTO_RS422:
 		/* Set the appropriate GIO pin */
-		writel(1, (&port->ip_mem->gppr_0 +
-				  hooks->rs422_select_pin));
+		writel(1, (&port->ip_mem->gppr[hooks->rs422_select_pin].raw));
 		break;
 
 	default:
@@ -1885,7 +1846,7 @@ static void handle_intr(void *arg, uint32_t sio_ir)
 		if (sio_ir & hooks->intr_delta_dcd) {
 			/* ACK the interrupt */
 			writel(hooks->intr_delta_dcd,
-				&port->ip_mem->sio_ir);
+				&port->ip_mem->sio_ir.raw);
 
 			shadow = readl(&port->ip_serial_regs->shadow);
 
@@ -1907,7 +1868,7 @@ static void handle_intr(void *arg, uint32_t sio_ir)
 		if (sio_ir & hooks->intr_delta_cts) {
 			/* ACK the interrupt */
 			writel(hooks->intr_delta_cts,
-					&port->ip_mem->sio_ir);
+					&port->ip_mem->sio_ir.raw);
 
 			shadow = readl(&port->ip_serial_regs->shadow);
 
@@ -1928,7 +1889,7 @@ static void handle_intr(void *arg, uint32_t sio_ir)
 		if (sio_ir & hooks->intr_rx_timer) {
 			/* ACK the interrupt */
 			writel(hooks->intr_rx_timer,
-				&port->ip_mem->sio_ir);
+				&port->ip_mem->sio_ir.raw);
 
 			if ((port->ip_notify & N_DATA_READY)
 					&& (port->ip_port)) {
@@ -1974,7 +1935,7 @@ static void handle_intr(void *arg, uint32_t sio_ir)
 
 			/* ACK the interrupt */
 			writel(hooks->intr_tx_explicit,
-					&port->ip_mem->sio_ir);
+					&port->ip_mem->sio_ir.raw);
 
 			if (port->ip_notify & N_OUTPUT_LOWAT)
 				ioc4_cb_output_lowat(port);
@@ -2634,7 +2595,8 @@ ioc4_serial_core_attach(struct pci_dev *pdev)
 {
 	struct ioc4_port *port;
 	struct uart_port *the_port;
-	struct ioc4_control *control = pci_get_drvdata(pdev);
+	struct ioc4_driver_data *idd = pci_get_drvdata(pdev);
+	struct ioc4_control *control = idd->idd_serial_data;
 	int ii;
 
 	DPRINT_CONFIG(("%s: attach pdev 0x%p - control 0x%p\n",
@@ -2680,55 +2642,29 @@ ioc4_serial_core_attach(struct pci_dev *pdev)
 
 /**
  * ioc4_serial_attach_one - register attach function
- *		called per card found from ioc4_serial_detect as part
- *		of module_init().
- * @pdev: handle for this card
- * @pci_id: pci id for this card
+ *		called per card found from IOC4 master module.
+ * @idd: Master module data for this IOC4
  */
 int
-ioc4_serial_attach_one(struct pci_dev *pdev, const struct pci_device_id *pci_id)
+ioc4_serial_attach_one(struct ioc4_driver_data *idd)
 {
-	struct ioc4_mem __iomem *mem;
-	unsigned long tmp_addr, tmp_addr1;
+	unsigned long tmp_addr1;
 	struct ioc4_serial __iomem *serial;
 	struct ioc4_soft *soft;
 	struct ioc4_control *control;
-	int tmp, ret = 0;
+	int ret = 0;
 
 
-	DPRINT_CONFIG(("%s (0x%p, 0x%p)\n", __FUNCTION__, pdev, pci_id));
-
-	/* Map in the ioc4 memory */
-	tmp_addr = pci_resource_start(pdev, 0);
-	if (!tmp_addr) {
-		printk(KERN_WARNING
-			 "ioc4 (%p) : unable to get PIO mapping for "
-				"MEM space\n", (void *)pdev);
-		return -ENODEV;
-	}
-	if (!request_region(tmp_addr, sizeof(struct ioc4_mem), "sioc4_mem")) {
-		printk(KERN_ALERT
-			"ioc4 (%p): unable to get request region for "
-			"MEM space\n", (void *)pdev);
-		return -ENODEV;
-	}
-	mem = ioremap(tmp_addr, sizeof(struct ioc4_mem));
-	if (!mem) {
-		printk(KERN_WARNING
-			 "ioc4 (%p) : unable to remap ioc4 memory\n",
-				(void *)pdev);
-		ret = -ENODEV;
-		goto out1;
-	}
+	DPRINT_CONFIG(("%s (0x%p, 0x%p)\n", __FUNCTION__, idd->idd_pdev, idd->idd_pci_id));
 
 	/* request serial registers */
-	tmp_addr1 = pci_resource_start(pdev, 0) + IOC4_SERIAL_OFFSET;
+	tmp_addr1 = idd->idd_bar0 + IOC4_SERIAL_OFFSET;
 
 	if (!request_region(tmp_addr1, sizeof(struct ioc4_serial),
 					"sioc4_uart")) {
 		printk(KERN_WARNING
 			"ioc4 (%p): unable to get request region for "
-				"uart space\n", (void *)pdev);
+				"uart space\n", (void *)idd->idd_pdev);
 		ret = -ENODEV;
 		goto out1;
 	}
@@ -2736,12 +2672,12 @@ ioc4_serial_attach_one(struct pci_dev *pdev, const struct pci_device_id *pci_id)
 	if (!serial) {
 		printk(KERN_WARNING
 			 "ioc4 (%p) : unable to remap ioc4 serial register\n",
-				(void *)pdev);
+				(void *)idd->idd_pdev);
 		ret = -ENODEV;
 		goto out2;
 	}
 	DPRINT_CONFIG(("%s : mem 0x%p, serial 0x%p\n",
-				__FUNCTION__, (void *)mem, (void *)serial));
+				__FUNCTION__, (void *)idd->idd_misc_regs, (void *)serial));
 
 	/* Get memory for the new card */
 	control = kmalloc(sizeof(struct ioc4_control) * IOC4_NUM_SERIAL_PORTS,
@@ -2754,59 +2690,57 @@ ioc4_serial_attach_one(struct pci_dev *pdev, const struct pci_device_id *pci_id)
 		goto out2;
 	}
 	memset(control, 0, sizeof(struct ioc4_control));
-	pci_set_drvdata(pdev, control);
+	idd->idd_serial_data = control;
 
 	/* Allocate the soft structure */
 	soft = kmalloc(sizeof(struct ioc4_soft), GFP_KERNEL);
 	if (!soft) {
 		printk(KERN_WARNING
 		       "ioc4 (%p): unable to get memory for the soft struct\n",
-		       (void *)pdev);
+		       (void *)idd->idd_pdev);
 		ret = -ENOMEM;
 		goto out3;
 	}
 	memset(soft, 0, sizeof(struct ioc4_soft));
 
 	spin_lock_init(&soft->is_ir_lock);
-	soft->is_ioc4_mem_addr = mem;
+	soft->is_ioc4_misc_addr = idd->idd_misc_regs;
 	soft->is_ioc4_serial_addr = serial;
 
 	/* Init the IOC4 */
-	pci_read_config_dword(pdev, PCI_COMMAND, &tmp);
-	pci_write_config_dword(pdev, PCI_COMMAND,
-			       tmp | PCI_COMMAND_PARITY | PCI_COMMAND_SERR);
-
-	writel(0xf << IOC4_SIO_CR_CMD_PULSE_SHIFT, &mem->sio_cr);
+	writel(0xf << IOC4_SIO_CR_CMD_PULSE_SHIFT,
+	       &idd->idd_misc_regs->sio_cr.raw);
 
 	/* Enable serial port mode select generic PIO pins as outputs */
 	writel(IOC4_GPCR_UART0_MODESEL | IOC4_GPCR_UART1_MODESEL
 		| IOC4_GPCR_UART2_MODESEL | IOC4_GPCR_UART3_MODESEL,
-		&mem->gpcr_s);
+		&idd->idd_misc_regs->gpcr_s.raw);
 
-	/* Clear and disable all interrupts */
+	/* Clear and disable all serial interrupts */
 	write_ireg(soft, ~0, IOC4_W_IEC, IOC4_SIO_INTR_TYPE);
-	writel(~0, &mem->sio_ir);
-	write_ireg(soft, ~(IOC4_OTHER_IR_ATA_INT | IOC4_OTHER_IR_ATA_MEMERR),
-			IOC4_W_IEC, IOC4_OTHER_INTR_TYPE);
-	writel(~(IOC4_OTHER_IR_ATA_MEMERR | IOC4_OTHER_IR_ATA_MEMERR),
-					&mem->other_ir);
+	writel(~0, &idd->idd_misc_regs->sio_ir.raw);
+	write_ireg(soft, IOC4_OTHER_IR_SER_MEMERR, IOC4_W_IEC,
+		   IOC4_OTHER_INTR_TYPE);
+	writel(IOC4_OTHER_IR_SER_MEMERR, &idd->idd_misc_regs->other_ir.raw);
 	control->ic_soft = soft;
-	if (!request_irq(pdev->irq, ioc4_intr, SA_SHIRQ,
+
+	/* Hook up interrupt handler */
+	if (!request_irq(idd->idd_pdev->irq, ioc4_intr, SA_SHIRQ,
 				"sgi-ioc4serial", (void *)soft)) {
-		control->ic_irq = pdev->irq;
+		control->ic_irq = idd->idd_pdev->irq;
 	} else {
 		printk(KERN_WARNING
 		    "%s : request_irq fails for IRQ 0x%x\n ",
-			__FUNCTION__, pdev->irq);
+			__FUNCTION__, idd->idd_pdev->irq);
 	}
-	if ((ret = ioc4_attach_local(pdev, control, soft,
-				soft->is_ioc4_mem_addr,
+	if ((ret = ioc4_attach_local(idd->idd_pdev, control, soft,
+				soft->is_ioc4_misc_addr,
 				soft->is_ioc4_serial_addr)))
 		goto out4;
 
 	/* register port with the serial core */
 
-	if ((ret = ioc4_serial_core_attach(pdev)))
+	if ((ret = ioc4_serial_core_attach(idd->idd_pdev)))
 		goto out4;
 
 	return ret;
@@ -2819,7 +2753,6 @@ out3:
 out2:
 	release_region(tmp_addr1, sizeof(struct ioc4_serial));
 out1:
-	release_region(tmp_addr, sizeof(struct ioc4_mem));
 
 	return ret;
 }
@@ -2828,11 +2761,10 @@ out1:
 /**
  * ioc4_serial_remove_one - detach function
  *
- * @pdev: handle for this card
+ * @idd: IOC4 master module data for this IOC4
  */
 
-#if 0
-void ioc4_serial_remove_one(struct pci_dev *pdev)
+int ioc4_serial_remove_one(struct ioc4_driver_data *idd)
 {
 	int ii;
 	struct ioc4_control *control;
@@ -2840,7 +2772,7 @@ void ioc4_serial_remove_one(struct pci_dev *pdev)
 	struct ioc4_port *port;
 	struct ioc4_soft *soft;
 
-	control = pci_get_drvdata(pdev);
+	control = idd->idd_serial_data;
 
 	for (ii = 0; ii < IOC4_NUM_SERIAL_PORTS; ii++) {
 		the_port = &control->ic_port[ii].icp_uart_port;
@@ -2867,10 +2799,17 @@ void ioc4_serial_remove_one(struct pci_dev *pdev)
 		kfree(soft);
 	}
 	kfree(control);
-	pci_set_drvdata(pdev, NULL);
-	uart_unregister_driver(&ioc4_uart);
+	idd->idd_serial_data = NULL;
+
+	return 0;
 }
-#endif
+
+static struct ioc4_submodule ioc4_serial_submodule = {
+	.is_name = "IOC4_serial",
+	.is_owner = THIS_MODULE,
+	.is_probe = ioc4_serial_attach_one,
+	.is_remove = ioc4_serial_remove_one,
+};
 
 /**
  * ioc4_serial_init - module init
@@ -2886,12 +2825,20 @@ int ioc4_serial_init(void)
 			__FUNCTION__);
 		return ret;
 	}
-	return 0;
+
+	/* register with IOC4 main module */
+	return ioc4_register_submodule(&ioc4_serial_submodule);
 }
 
+static void __devexit ioc4_serial_exit(void)
+{
+	ioc4_unregister_submodule(&ioc4_serial_submodule);
+	uart_unregister_driver(&ioc4_uart);
+}
+
+module_init(ioc4_serial_init);
+module_exit(ioc4_serial_exit);
+
 MODULE_AUTHOR("Pat Gefre - Silicon Graphics Inc. (SGI) <pfg@sgi.com>");
 MODULE_DESCRIPTION("Serial PCI driver module for SGI IOC4 Base-IO Card");
 MODULE_LICENSE("GPL");
-
-EXPORT_SYMBOL(ioc4_serial_init);
-EXPORT_SYMBOL(ioc4_serial_attach_one);
diff --git a/drivers/sn/ioc4.c b/drivers/sn/ioc4.c
index d9e4ee280e5..70862d72ea9 100644
--- a/drivers/sn/ioc4.c
+++ b/drivers/sn/ioc4.c
@@ -6,60 +6,294 @@
  * Copyright (C) 2005 Silicon Graphics, Inc.  All Rights Reserved.
  */
 
-/*
- * This file contains a shim driver for the IOC4 IDE and serial drivers.
+/* This file contains the master driver module for use by SGI IOC4 subdrivers.
+ *
+ * It allocates any resources shared between multiple subdevices, and
+ * provides accessor functions (where needed) and the like for those
+ * resources.  It also provides a mechanism for the subdevice modules
+ * to support loading and unloading.
+ *
+ * Non-shared resources (e.g. external interrupt A_INT_OUT register page
+ * alias, serial port and UART registers) are handled by the subdevice
+ * modules themselves.
+ *
+ * This is all necessary because IOC4 is not implemented as a multi-function
+ * PCI device, but an amalgamation of disparate registers for several
+ * types of device (ATA, serial, external interrupts).  The normal
+ * resource management in the kernel doesn't have quite the right interfaces
+ * to handle this situation (e.g. multiple modules can't claim the same
+ * PCI ID), thus this IOC4 master module.
  */
 
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/pci.h>
-#include <linux/ioc4_common.h>
-#include <linux/ide.h>
+#include <linux/ioc4.h>
+#include <linux/rwsem.h>
 
+/************************
+ * Submodule management *
+ ************************/
 
-static int __devinit
-ioc4_probe_one(struct pci_dev *pdev, const struct pci_device_id *pci_id)
+static LIST_HEAD(ioc4_devices);
+static DECLARE_RWSEM(ioc4_devices_rwsem);
+
+static LIST_HEAD(ioc4_submodules);
+static DECLARE_RWSEM(ioc4_submodules_rwsem);
+
+/* Register an IOC4 submodule */
+int
+ioc4_register_submodule(struct ioc4_submodule *is)
+{
+	struct ioc4_driver_data *idd;
+
+	down_write(&ioc4_submodules_rwsem);
+	list_add(&is->is_list, &ioc4_submodules);
+	up_write(&ioc4_submodules_rwsem);
+
+	/* Initialize submodule for each IOC4 */
+	if (!is->is_probe)
+		return 0;
+
+	down_read(&ioc4_devices_rwsem);
+	list_for_each_entry(idd, &ioc4_devices, idd_list) {
+		if (is->is_probe(idd)) {
+			printk(KERN_WARNING
+			       "%s: IOC4 submodule %s probe failed "
+			       "for pci_dev %s",
+			       __FUNCTION__, module_name(is->is_owner),
+			       pci_name(idd->idd_pdev));
+		}
+	}
+	up_read(&ioc4_devices_rwsem);
+
+	return 0;
+}
+
+/* Unregister an IOC4 submodule */
+void
+ioc4_unregister_submodule(struct ioc4_submodule *is)
 {
+	struct ioc4_driver_data *idd;
+
+	down_write(&ioc4_submodules_rwsem);
+	list_del(&is->is_list);
+	up_write(&ioc4_submodules_rwsem);
+
+	/* Remove submodule for each IOC4 */
+	if (!is->is_remove)
+		return;
+
+	down_read(&ioc4_devices_rwsem);
+	list_for_each_entry(idd, &ioc4_devices, idd_list) {
+		if (is->is_remove(idd)) {
+			printk(KERN_WARNING
+			       "%s: IOC4 submodule %s remove failed "
+			       "for pci_dev %s.\n",
+			       __FUNCTION__, module_name(is->is_owner),
+			       pci_name(idd->idd_pdev));
+		}
+	}
+	up_read(&ioc4_devices_rwsem);
+}
+
+/*********************
+ * Device management *
+ *********************/
+
+/* Adds a new instance of an IOC4 card */
+static int
+ioc4_probe(struct pci_dev *pdev, const struct pci_device_id *pci_id)
+{
+	struct ioc4_driver_data *idd;
+	struct ioc4_submodule *is;
+	uint32_t pcmd;
 	int ret;
 
+	/* Enable IOC4 and take ownership of it */
 	if ((ret = pci_enable_device(pdev))) {
 		printk(KERN_WARNING
-			 "%s: Failed to enable device with "
-				"pci_dev 0x%p... returning\n",
-				__FUNCTION__, (void *)pdev);
-		return ret;
+		       "%s: Failed to enable IOC4 device for pci_dev %s.\n",
+		       __FUNCTION__, pci_name(pdev));
+		goto out;
 	}
 	pci_set_master(pdev);
 
-	/* attach each sub-device */
-	ret = ioc4_ide_attach_one(pdev, pci_id);
-	if (ret)
-		return ret;
-	return ioc4_serial_attach_one(pdev, pci_id);
+	/* Set up per-IOC4 data */
+	idd = kmalloc(sizeof(struct ioc4_driver_data), GFP_KERNEL);
+	if (!idd) {
+		printk(KERN_WARNING
+		       "%s: Failed to allocate IOC4 data for pci_dev %s.\n",
+		       __FUNCTION__, pci_name(pdev));
+		ret = -ENODEV;
+		goto out_idd;
+	}
+	idd->idd_pdev = pdev;
+	idd->idd_pci_id = pci_id;
+
+	/* Map IOC4 misc registers.  These are shared between subdevices
+	 * so the main IOC4 module manages them.
+	 */
+	idd->idd_bar0 = pci_resource_start(idd->idd_pdev, 0);
+	if (!idd->idd_bar0) {
+		printk(KERN_WARNING
+		       "%s: Unable to find IOC4 misc resource "
+		       "for pci_dev %s.\n",
+		       __FUNCTION__, pci_name(idd->idd_pdev));
+		ret = -ENODEV;
+		goto out_pci;
+	}
+	if (!request_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs),
+			    "ioc4_misc")) {
+		printk(KERN_WARNING
+		       "%s: Unable to request IOC4 misc region "
+		       "for pci_dev %s.\n",
+		       __FUNCTION__, pci_name(idd->idd_pdev));
+		ret = -ENODEV;
+		goto out_pci;
+	}
+	idd->idd_misc_regs = ioremap(idd->idd_bar0,
+				     sizeof(struct ioc4_misc_regs));
+	if (!idd->idd_misc_regs) {
+		printk(KERN_WARNING
+		       "%s: Unable to remap IOC4 misc region "
+		       "for pci_dev %s.\n",
+		       __FUNCTION__, pci_name(idd->idd_pdev));
+		ret = -ENODEV;
+		goto out_misc_region;
+	}
+
+	/* Failsafe portion of per-IOC4 initialization */
+
+	/* Initialize IOC4 */
+	pci_read_config_dword(idd->idd_pdev, PCI_COMMAND, &pcmd);
+	pci_write_config_dword(idd->idd_pdev, PCI_COMMAND,
+			       pcmd | PCI_COMMAND_PARITY | PCI_COMMAND_SERR);
+
+	/* Disable/clear all interrupts.  Need to do this here lest
+	 * one submodule request the shared IOC4 IRQ, but interrupt
+	 * is generated by a different subdevice.
+	 */
+	/* Disable */
+	writel(~0, &idd->idd_misc_regs->other_iec.raw);
+	writel(~0, &idd->idd_misc_regs->sio_iec);
+	/* Clear (i.e. acknowledge) */
+	writel(~0, &idd->idd_misc_regs->other_ir.raw);
+	writel(~0, &idd->idd_misc_regs->sio_ir);
+
+	/* Track PCI-device specific data */
+	idd->idd_serial_data = NULL;
+	pci_set_drvdata(idd->idd_pdev, idd);
+	down_write(&ioc4_devices_rwsem);
+	list_add(&idd->idd_list, &ioc4_devices);
+	up_write(&ioc4_devices_rwsem);
+
+	/* Add this IOC4 to all submodules */
+	down_read(&ioc4_submodules_rwsem);
+	list_for_each_entry(is, &ioc4_submodules, is_list) {
+		if (is->is_probe && is->is_probe(idd)) {
+			printk(KERN_WARNING
+			       "%s: IOC4 submodule 0x%s probe failed "
+			       "for pci_dev %s.\n",
+			       __FUNCTION__, module_name(is->is_owner),
+			       pci_name(idd->idd_pdev));
+		}
+	}
+	up_read(&ioc4_submodules_rwsem);
+
+	return 0;
+
+out_misc_region:
+	release_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs));
+out_pci:
+	kfree(idd);
+out_idd:
+	pci_disable_device(pdev);
+out:
+	return ret;
 }
 
-/* pci device struct */
-static struct pci_device_id ioc4_s_id_table[] = {
+/* Removes a particular instance of an IOC4 card. */
+static void
+ioc4_remove(struct pci_dev *pdev)
+{
+	struct ioc4_submodule *is;
+	struct ioc4_driver_data *idd;
+
+	idd = pci_get_drvdata(pdev);
+
+	/* Remove this IOC4 from all submodules */
+	down_read(&ioc4_submodules_rwsem);
+	list_for_each_entry(is, &ioc4_submodules, is_list) {
+		if (is->is_remove && is->is_remove(idd)) {
+			printk(KERN_WARNING
+			       "%s: IOC4 submodule 0x%s remove failed "
+			       "for pci_dev %s.\n",
+			       __FUNCTION__, module_name(is->is_owner),
+			       pci_name(idd->idd_pdev));
+		}
+	}
+	up_read(&ioc4_submodules_rwsem);
+
+	/* Release resources */
+	iounmap(idd->idd_misc_regs);
+	if (!idd->idd_bar0) {
+		printk(KERN_WARNING
+		       "%s: Unable to get IOC4 misc mapping for pci_dev %s. "
+		       "Device removal may be incomplete.\n",
+		       __FUNCTION__, pci_name(idd->idd_pdev));
+	}
+	release_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs));
+
+	/* Disable IOC4 and relinquish */
+	pci_disable_device(pdev);
+
+	/* Remove and free driver data */
+	down_write(&ioc4_devices_rwsem);
+	list_del(&idd->idd_list);
+	up_write(&ioc4_devices_rwsem);
+	kfree(idd);
+}
+
+static struct pci_device_id ioc4_id_table[] = {
 	{PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC4, PCI_ANY_ID,
 	 PCI_ANY_ID, 0x0b4000, 0xFFFFFF},
 	{0}
 };
-MODULE_DEVICE_TABLE(pci, ioc4_s_id_table);
 
-static struct pci_driver __devinitdata ioc4_s_driver = {
-	.name	= "IOC4",
-	.id_table = ioc4_s_id_table,
-	.probe	= ioc4_probe_one,
+static struct pci_driver __devinitdata ioc4_driver = {
+	.name = "IOC4",
+	.id_table = ioc4_id_table,
+	.probe = ioc4_probe,
+	.remove = ioc4_remove,
 };
 
-static int __devinit ioc4_detect(void)
+MODULE_DEVICE_TABLE(pci, ioc4_id_table);
+
+/*********************
+ * Module management *
+ *********************/
+
+/* Module load */
+static int __devinit
+ioc4_init(void)
 {
-	ioc4_serial_init();
+	return pci_register_driver(&ioc4_driver);
+}
 
-	return pci_register_driver(&ioc4_s_driver);
+/* Module unload */
+static void __devexit
+ioc4_exit(void)
+{
+	pci_unregister_driver(&ioc4_driver);
 }
-module_init(ioc4_detect);
 
-MODULE_AUTHOR("Pat Gefre - Silicon Graphics Inc. (SGI) <pfg@sgi.com>");
-MODULE_DESCRIPTION("PCI driver module for SGI IOC4 Base-IO Card");
+module_init(ioc4_init);
+module_exit(ioc4_exit);
+
+MODULE_AUTHOR("Brent Casavant - Silicon Graphics, Inc. <bcasavan@sgi.com>");
+MODULE_DESCRIPTION("PCI driver master module for SGI IOC4 Base-IO Card");
 MODULE_LICENSE("GPL");
+
+EXPORT_SYMBOL(ioc4_register_submodule);
+EXPORT_SYMBOL(ioc4_unregister_submodule);