[IA64-SGI] sn pci provider for TIOCE (pci

Altix patch to add an SN pci provider for TIOCE, which is SGI's 
PCI Express implementation.

Signed-off-by: Mark Maule <maule@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

3 files changed, 736 insertions, 1 deletions

diff --git a/arch/ia64/sn/kernel/io_init.c b/arch/ia64/sn/kernel/io_init.c
index 829ea798501..d1fc09b1d51 100644
--- a/arch/ia64/sn/kernel/io_init.c
+++ b/arch/ia64/sn/kernel/io_init.c
@@ -18,6 +18,7 @@
 #include <asm/sn/simulator.h>
 #include <asm/sn/sn_sal.h>
 #include <asm/sn/tioca_provider.h>
+#include <asm/sn/tioce_provider.h>
 #include "xtalk/hubdev.h"
 #include "xtalk/xwidgetdev.h"
 
@@ -481,6 +482,7 @@ static int __init sn_pci_init(void)
 
 	pcibr_init_provider();
 	tioca_init_provider();
+	tioce_init_provider();
 
 	/*
 	 * This is needed to avoid bounce limit checks in the blk layer
diff --git a/arch/ia64/sn/pci/Makefile b/arch/ia64/sn/pci/Makefile
index 2f915bce25f..321576b1b42 100644
--- a/arch/ia64/sn/pci/Makefile
+++ b/arch/ia64/sn/pci/Makefile
@@ -7,4 +7,4 @@
 #
 # Makefile for the sn pci general routines.
 
-obj-y := pci_dma.o tioca_provider.o pcibr/ 
+obj-y := pci_dma.o tioca_provider.o tioce_provider.o pcibr/
diff --git a/arch/ia64/sn/pci/tioce_provider.c b/arch/ia64/sn/pci/tioce_provider.c
new file mode 100644
index 00000000000..d9081369cf9
--- /dev/null
+++ b/arch/ia64/sn/pci/tioce_provider.c
@@ -0,0 +1,733 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2003-2005 Silicon Graphics, Inc.  All Rights Reserved.
+ */
+
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/pci.h>
+#include <asm/sn/sn_sal.h>
+#include <asm/sn/addrs.h>
+#include <asm/sn/pcidev.h>
+#include <asm/sn/pcibus_provider_defs.h>
+#include <asm/sn/tioce_provider.h>
+
+/**
+ * Bus address ranges for the 5 flavors of TIOCE DMA
+ */
+
+#define TIOCE_D64_MIN	0x8000000000000000UL
+#define TIOCE_D64_MAX	0xffffffffffffffffUL
+#define TIOCE_D64_ADDR(a)	((a) >= TIOCE_D64_MIN)
+
+#define TIOCE_D32_MIN	0x0000000080000000UL
+#define TIOCE_D32_MAX	0x00000000ffffffffUL
+#define TIOCE_D32_ADDR(a)	((a) >= TIOCE_D32_MIN && (a) <= TIOCE_D32_MAX)
+
+#define TIOCE_M32_MIN	0x0000000000000000UL
+#define TIOCE_M32_MAX	0x000000007fffffffUL
+#define TIOCE_M32_ADDR(a)	((a) >= TIOCE_M32_MIN && (a) <= TIOCE_M32_MAX)
+
+#define TIOCE_M40_MIN	0x0000004000000000UL
+#define TIOCE_M40_MAX	0x0000007fffffffffUL
+#define TIOCE_M40_ADDR(a)	((a) >= TIOCE_M40_MIN && (a) <= TIOCE_M40_MAX)
+
+#define TIOCE_M40S_MIN	0x0000008000000000UL
+#define TIOCE_M40S_MAX	0x000000ffffffffffUL
+#define TIOCE_M40S_ADDR(a)	((a) >= TIOCE_M40S_MIN && (a) <= TIOCE_M40S_MAX)
+
+/*
+ * ATE manipulation macros.
+ */
+
+#define ATE_PAGESHIFT(ps)	(__ffs(ps))
+#define ATE_PAGEMASK(ps)	((ps)-1)
+
+#define ATE_PAGE(x, ps) ((x) >> ATE_PAGESHIFT(ps))
+#define ATE_NPAGES(start, len, pagesize) \
+	(ATE_PAGE((start)+(len)-1, pagesize) - ATE_PAGE(start, pagesize) + 1)
+
+#define ATE_VALID(ate)	((ate) & (1UL << 63))
+#define ATE_MAKE(addr, ps) (((addr) & ~ATE_PAGEMASK(ps)) | (1UL << 63))
+
+/*
+ * Flavors of ate-based mapping supported by tioce_alloc_map()
+ */
+
+#define TIOCE_ATE_M32	1
+#define TIOCE_ATE_M40	2
+#define TIOCE_ATE_M40S	3
+
+#define KB(x)	((x) << 10)
+#define MB(x)	((x) << 20)
+#define GB(x)	((x) << 30)
+
+/**
+ * tioce_dma_d64 - create a DMA mapping using 64-bit direct mode
+ * @ct_addr: system coretalk address
+ *
+ * Map @ct_addr into 64-bit CE bus space.  No device context is necessary
+ * and no CE mapping are consumed.
+ *
+ * Bits 53:0 come from the coretalk address.  The remaining bits are set as
+ * follows:
+ *
+ * 63    - must be 1 to indicate d64 mode to CE hardware
+ * 62    - barrier bit ... controlled with tioce_dma_barrier()
+ * 61    - 0 since this is not an MSI transaction
+ * 60:54 - reserved, MBZ
+ */
+static uint64_t
+tioce_dma_d64(unsigned long ct_addr)
+{
+	uint64_t bus_addr;
+
+	bus_addr = ct_addr | (1UL << 63);
+
+	return bus_addr;
+}
+
+/**
+ * pcidev_to_tioce - return misc ce related pointers given a pci_dev
+ * @pci_dev: pci device context
+ * @base: ptr to store struct tioce_mmr * for the CE holding this device
+ * @kernel: ptr to store struct tioce_kernel * for the CE holding this device
+ * @port: ptr to store the CE port number that this device is on
+ *
+ * Return pointers to various CE-related structures for the CE upstream of
+ * @pci_dev.
+ */
+static inline void
+pcidev_to_tioce(struct pci_dev *pdev, struct tioce **base,
+		struct tioce_kernel **kernel, int *port)
+{
+	struct pcidev_info *pcidev_info;
+	struct tioce_common *ce_common;
+	struct tioce_kernel *ce_kernel;
+
+	pcidev_info = SN_PCIDEV_INFO(pdev);
+	ce_common = (struct tioce_common *)pcidev_info->pdi_pcibus_info;
+	ce_kernel = (struct tioce_kernel *)ce_common->ce_kernel_private;
+
+	if (base)
+		*base = (struct tioce *)ce_common->ce_pcibus.bs_base;
+	if (kernel)
+		*kernel = ce_kernel;
+
+	/*
+	 * we use port as a zero-based value internally, even though the
+	 * documentation is 1-based.
+	 */
+	if (port)
+		*port =
+		    (pdev->bus->number < ce_kernel->ce_port1_secondary) ? 0 : 1;
+}
+
+/**
+ * tioce_alloc_map - Given a coretalk address, map it to pcie bus address
+ * space using one of the various ATE-based address modes.
+ * @ce_kern: tioce context
+ * @type: map mode to use
+ * @port: 0-based port that the requesting device is downstream of
+ * @ct_addr: the coretalk address to map
+ * @len: number of bytes to map
+ *
+ * Given the addressing type, set up various paramaters that define the
+ * ATE pool to use.  Search for a contiguous block of entries to cover the
+ * length, and if enough resources exist, fill in the ATE's and construct a
+ * tioce_dmamap struct to track the mapping.
+ */
+static uint64_t
+tioce_alloc_map(struct tioce_kernel *ce_kern, int type, int port,
+		uint64_t ct_addr, int len)
+{
+	int i;
+	int j;
+	int first;
+	int last;
+	int entries;
+	int nates;
+	int pagesize;
+	uint64_t *ate_shadow;
+	uint64_t *ate_reg;
+	uint64_t addr;
+	struct tioce *ce_mmr;
+	uint64_t bus_base;
+	struct tioce_dmamap *map;
+
+	ce_mmr = (struct tioce *)ce_kern->ce_common->ce_pcibus.bs_base;
+
+	switch (type) {
+	case TIOCE_ATE_M32:
+		/*
+		 * The first 64 entries of the ate3240 pool are dedicated to
+		 * super-page (TIOCE_ATE_M40S) mode.
+		 */
+		first = 64;
+		entries = TIOCE_NUM_M3240_ATES - 64;
+		ate_shadow = ce_kern->ce_ate3240_shadow;
+		ate_reg = ce_mmr->ce_ure_ate3240;
+		pagesize = ce_kern->ce_ate3240_pagesize;
+		bus_base = TIOCE_M32_MIN;
+		break;
+	case TIOCE_ATE_M40:
+		first = 0;
+		entries = TIOCE_NUM_M40_ATES;
+		ate_shadow = ce_kern->ce_ate40_shadow;
+		ate_reg = ce_mmr->ce_ure_ate40;
+		pagesize = MB(64);
+		bus_base = TIOCE_M40_MIN;
+		break;
+	case TIOCE_ATE_M40S:
+		/*
+		 * ate3240 entries 0-31 are dedicated to port1 super-page
+		 * mappings.  ate3240 entries 32-63 are dedicated to port2.
+		 */
+		first = port * 32;
+		entries = 32;
+		ate_shadow = ce_kern->ce_ate3240_shadow;
+		ate_reg = ce_mmr->ce_ure_ate3240;
+		pagesize = GB(16);
+		bus_base = TIOCE_M40S_MIN;
+		break;
+	default:
+		return 0;
+	}
+
+	nates = ATE_NPAGES(ct_addr, len, pagesize);
+	if (nates > entries)
+		return 0;
+
+	last = first + entries - nates;
+	for (i = first; i <= last; i++) {
+		if (ATE_VALID(ate_shadow[i]))
+			continue;
+
+		for (j = i; j < i + nates; j++)
+			if (ATE_VALID(ate_shadow[j]))
+				break;
+
+		if (j >= i + nates)
+			break;
+	}
+
+	if (i > last)
+		return 0;
+
+	map = kcalloc(1, sizeof(struct tioce_dmamap), GFP_ATOMIC);
+	if (!map)
+		return 0;
+
+	addr = ct_addr;
+	for (j = 0; j < nates; j++) {
+		uint64_t ate;
+
+		ate = ATE_MAKE(addr, pagesize);
+		ate_shadow[i + j] = ate;
+		ate_reg[i + j] = ate;
+		addr += pagesize;
+	}
+
+	map->refcnt = 1;
+	map->nbytes = nates * pagesize;
+	map->ct_start = ct_addr & ~ATE_PAGEMASK(pagesize);
+	map->pci_start = bus_base + (i * pagesize);
+	map->ate_hw = &ate_reg[i];
+	map->ate_shadow = &ate_shadow[i];
+	map->ate_count = nates;
+
+	list_add(&map->ce_dmamap_list, &ce_kern->ce_dmamap_list);
+
+	return (map->pci_start + (ct_addr - map->ct_start));
+}
+
+/**
+ * tioce_dma_d32 - create a DMA mapping using 32-bit direct mode
+ * @pdev: linux pci_dev representing the function
+ * @paddr: system physical address
+ *
+ * Map @paddr into 32-bit bus space of the CE associated with @pcidev_info.
+ */
+static uint64_t
+tioce_dma_d32(struct pci_dev *pdev, uint64_t ct_addr)
+{
+	int dma_ok;
+	int port;
+	struct tioce *ce_mmr;
+	struct tioce_kernel *ce_kern;
+	uint64_t ct_upper;
+	uint64_t ct_lower;
+	dma_addr_t bus_addr;
+
+	ct_upper = ct_addr & ~0x3fffffffUL;
+	ct_lower = ct_addr & 0x3fffffffUL;
+
+	pcidev_to_tioce(pdev, &ce_mmr, &ce_kern, &port);
+
+	if (ce_kern->ce_port[port].dirmap_refcnt == 0) {
+		volatile uint64_t tmp;
+
+		ce_kern->ce_port[port].dirmap_shadow = ct_upper;
+		ce_mmr->ce_ure_dir_map[port] = ct_upper;
+		tmp = ce_mmr->ce_ure_dir_map[port];
+		dma_ok = 1;
+	} else
+		dma_ok = (ce_kern->ce_port[port].dirmap_shadow == ct_upper);
+
+	if (dma_ok) {
+		ce_kern->ce_port[port].dirmap_refcnt++;
+		bus_addr = TIOCE_D32_MIN + ct_lower;
+	} else
+		bus_addr = 0;
+
+	return bus_addr;
+}
+
+/**
+ * tioce_dma_barrier - swizzle a TIOCE bus address to include or exclude
+ * the barrier bit.
+ * @bus_addr:  bus address to swizzle
+ *
+ * Given a TIOCE bus address, set the appropriate bit to indicate barrier
+ * attributes.
+ */
+static uint64_t
+tioce_dma_barrier(uint64_t bus_addr, int on)
+{
+	uint64_t barrier_bit;
+
+	/* barrier not supported in M40/M40S mode */
+	if (TIOCE_M40_ADDR(bus_addr) || TIOCE_M40S_ADDR(bus_addr))
+		return bus_addr;
+
+	if (TIOCE_D64_ADDR(bus_addr))
+		barrier_bit = (1UL << 62);
+	else			/* must be m32 or d32 */
+		barrier_bit = (1UL << 30);
+
+	return (on) ? (bus_addr | barrier_bit) : (bus_addr & ~barrier_bit);
+}
+
+/**
+ * tioce_dma_unmap - release CE mapping resources
+ * @pdev: linux pci_dev representing the function
+ * @bus_addr: bus address returned by an earlier tioce_dma_map
+ * @dir: mapping direction (unused)
+ *
+ * Locate mapping resources associated with @bus_addr and release them.
+ * For mappings created using the direct modes there are no resources
+ * to release.
+ */
+void
+tioce_dma_unmap(struct pci_dev *pdev, dma_addr_t bus_addr, int dir)
+{
+	int i;
+	int port;
+	struct tioce_kernel *ce_kern;
+	struct tioce *ce_mmr;
+	unsigned long flags;
+
+	bus_addr = tioce_dma_barrier(bus_addr, 0);
+	pcidev_to_tioce(pdev, &ce_mmr, &ce_kern, &port);
+
+	/* nothing to do for D64 */
+
+	if (TIOCE_D64_ADDR(bus_addr))
+		return;
+
+	spin_lock_irqsave(&ce_kern->ce_lock, flags);
+
+	if (TIOCE_D32_ADDR(bus_addr)) {
+		if (--ce_kern->ce_port[port].dirmap_refcnt == 0) {
+			ce_kern->ce_port[port].dirmap_shadow = 0;
+			ce_mmr->ce_ure_dir_map[port] = 0;
+		}
+	} else {
+		struct tioce_dmamap *map;
+
+		list_for_each_entry(map, &ce_kern->ce_dmamap_list,
+				    ce_dmamap_list) {
+			uint64_t last;
+
+			last = map->pci_start + map->nbytes - 1;
+			if (bus_addr >= map->pci_start && bus_addr <= last)
+				break;
+		}
+
+		if (&map->ce_dmamap_list == &ce_kern->ce_dmamap_list) {
+			printk(KERN_WARNING
+			       "%s:  %s - no map found for bus_addr 0x%lx\n",
+			       __FUNCTION__, pci_name(pdev), bus_addr);
+		} else if (--map->refcnt == 0) {
+			for (i = 0; i < map->ate_count; i++) {
+				map->ate_shadow[i] = 0;
+				map->ate_hw[i] = 0;
+			}
+
+			list_del(&map->ce_dmamap_list);
+			kfree(map);
+		}
+	}
+
+	spin_unlock_irqrestore(&ce_kern->ce_lock, flags);
+}
+
+/**
+ * tioce_do_dma_map - map pages for PCI DMA
+ * @pdev: linux pci_dev representing the function
+ * @paddr: host physical address to map
+ * @byte_count: bytes to map
+ *
+ * This is the main wrapper for mapping host physical pages to CE PCI space.
+ * The mapping mode used is based on the device's dma_mask.
+ */
+static uint64_t
+tioce_do_dma_map(struct pci_dev *pdev, uint64_t paddr, size_t byte_count,
+		 int barrier)
+{
+	unsigned long flags;
+	uint64_t ct_addr;
+	uint64_t mapaddr = 0;
+	struct tioce_kernel *ce_kern;
+	struct tioce_dmamap *map;
+	int port;
+	uint64_t dma_mask;
+
+	dma_mask = (barrier) ? pdev->dev.coherent_dma_mask : pdev->dma_mask;
+
+	/* cards must be able to address at least 31 bits */
+	if (dma_mask < 0x7fffffffUL)
+		return 0;
+
+	ct_addr = PHYS_TO_TIODMA(paddr);
+
+	/*
+	 * If the device can generate 64 bit addresses, create a D64 map.
+	 * Since this should never fail, bypass the rest of the checks.
+	 */
+	if (dma_mask == ~0UL) {
+		mapaddr = tioce_dma_d64(ct_addr);
+		goto dma_map_done;
+	}
+
+	pcidev_to_tioce(pdev, NULL, &ce_kern, &port);
+
+	spin_lock_irqsave(&ce_kern->ce_lock, flags);
+
+	/*
+	 * D64 didn't work ... See if we have an existing map that covers
+	 * this address range.  Must account for devices dma_mask here since
+	 * an existing map might have been done in a mode using more pci
+	 * address bits than this device can support.
+	 */
+	list_for_each_entry(map, &ce_kern->ce_dmamap_list, ce_dmamap_list) {
+		uint64_t last;
+
+		last = map->ct_start + map->nbytes - 1;
+		if (ct_addr >= map->ct_start &&
+		    ct_addr + byte_count - 1 <= last &&
+		    map->pci_start <= dma_mask) {
+			map->refcnt++;
+			mapaddr = map->pci_start + (ct_addr - map->ct_start);
+			break;
+		}
+	}
+
+	/*
+	 * If we don't have a map yet, and the card can generate 40
+	 * bit addresses, try the M40/M40S modes.  Note these modes do not
+	 * support a barrier bit, so if we need a consistent map these
+	 * won't work.
+	 */
+	if (!mapaddr && !barrier && dma_mask >= 0xffffffffffUL) {
+		/*
+		 * We have two options for 40-bit mappings:  16GB "super" ATE's
+		 * and 64MB "regular" ATE's.  We'll try both if needed for a
+		 * given mapping but which one we try first depends on the
+		 * size.  For requests >64MB, prefer to use a super page with
+		 * regular as the fallback. Otherwise, try in the reverse order.
+		 */
+
+		if (byte_count > MB(64)) {
+			mapaddr = tioce_alloc_map(ce_kern, TIOCE_ATE_M40S,
+						  port, ct_addr, byte_count);
+			if (!mapaddr)
+				mapaddr =
+				    tioce_alloc_map(ce_kern, TIOCE_ATE_M40, -1,
+						    ct_addr, byte_count);
+		} else {
+			mapaddr = tioce_alloc_map(ce_kern, TIOCE_ATE_M40, -1,
+						  ct_addr, byte_count);
+			if (!mapaddr)
+				mapaddr =
+				    tioce_alloc_map(ce_kern, TIOCE_ATE_M40S,
+						    port, ct_addr, byte_count);
+		}
+	}
+
+	/*
+	 * 32-bit direct is the next mode to try
+	 */
+	if (!mapaddr && dma_mask >= 0xffffffffUL)
+		mapaddr = tioce_dma_d32(pdev, ct_addr);
+
+	/*
+	 * Last resort, try 32-bit ATE-based map.
+	 */
+	if (!mapaddr)
+		mapaddr =
+		    tioce_alloc_map(ce_kern, TIOCE_ATE_M32, -1, ct_addr,
+				    byte_count);
+
+	spin_unlock_irqrestore(&ce_kern->ce_lock, flags);
+
+dma_map_done:
+	if (mapaddr & barrier)
+		mapaddr = tioce_dma_barrier(mapaddr, 1);
+
+	return mapaddr;
+}
+
+/**
+ * tioce_dma - standard pci dma map interface
+ * @pdev: pci device requesting the map
+ * @paddr: system physical address to map into pci space
+ * @byte_count: # bytes to map
+ *
+ * Simply call tioce_do_dma_map() to create a map with the barrier bit clear
+ * in the address.
+ */
+static uint64_t
+tioce_dma(struct pci_dev *pdev, uint64_t paddr, size_t byte_count)
+{
+	return tioce_do_dma_map(pdev, paddr, byte_count, 0);
+}
+
+/**
+ * tioce_dma_consistent - consistent pci dma map interface
+ * @pdev: pci device requesting the map
+ * @paddr: system physical address to map into pci space
+ * @byte_count: # bytes to map
+ *
+ * Simply call tioce_do_dma_map() to create a map with the barrier bit set
+ * in the address.
+ */ static uint64_t
+tioce_dma_consistent(struct pci_dev *pdev, uint64_t paddr, size_t byte_count)
+{
+	return tioce_do_dma_map(pdev, paddr, byte_count, 1);
+}
+
+/**
+ * tioce_error_intr_handler - SGI TIO CE error interrupt handler
+ * @irq: unused
+ * @arg: pointer to tioce_common struct for the given CE
+ * @pt: unused
+ *
+ * Handle a CE error interrupt.  Simply a wrapper around a SAL call which
+ * defers processing to the SGI prom.
+ */ static irqreturn_t
+tioce_error_intr_handler(int irq, void *arg, struct pt_regs *pt)
+{
+	struct tioce_common *soft = arg;
+	struct ia64_sal_retval ret_stuff;
+	ret_stuff.status = 0;
+	ret_stuff.v0 = 0;
+
+	SAL_CALL_NOLOCK(ret_stuff, (u64) SN_SAL_IOIF_ERROR_INTERRUPT,
+			soft->ce_pcibus.bs_persist_segment,
+			soft->ce_pcibus.bs_persist_busnum, 0, 0, 0, 0, 0);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * tioce_kern_init - init kernel structures related to a given TIOCE
+ * @tioce_common: ptr to a cached tioce_common struct that originated in prom
+ */ static struct tioce_kernel *
+tioce_kern_init(struct tioce_common *tioce_common)
+{
+	int i;
+	uint32_t tmp;
+	struct tioce *tioce_mmr;
+	struct tioce_kernel *tioce_kern;
+
+	tioce_kern = kcalloc(1, sizeof(struct tioce_kernel), GFP_KERNEL);
+	if (!tioce_kern) {
+		return NULL;
+	}
+
+	tioce_kern->ce_common = tioce_common;
+	spin_lock_init(&tioce_kern->ce_lock);
+	INIT_LIST_HEAD(&tioce_kern->ce_dmamap_list);
+	tioce_common->ce_kernel_private = (uint64_t) tioce_kern;
+
+	/*
+	 * Determine the secondary bus number of the port2 logical PPB.
+	 * This is used to decide whether a given pci device resides on
+	 * port1 or port2.  Note:  We don't have enough plumbing set up
+	 * here to use pci_read_config_xxx() so use the raw_pci_ops vector.
+	 */
+
+	raw_pci_ops->read(tioce_common->ce_pcibus.bs_persist_segment,
+			  tioce_common->ce_pcibus.bs_persist_busnum,
+			  PCI_DEVFN(2, 0), PCI_SECONDARY_BUS, 1, &tmp);
+	tioce_kern->ce_port1_secondary = (uint8_t) tmp;
+
+	/*
+	 * Set PMU pagesize to the largest size available, and zero out
+	 * the ate's.
+	 */
+
+	tioce_mmr = (struct tioce *)tioce_common->ce_pcibus.bs_base;
+	tioce_mmr->ce_ure_page_map &= ~CE_URE_PAGESIZE_MASK;
+	tioce_mmr->ce_ure_page_map |= CE_URE_256K_PAGESIZE;
+	tioce_kern->ce_ate3240_pagesize = KB(256);
+
+	for (i = 0; i < TIOCE_NUM_M40_ATES; i++) {
+		tioce_kern->ce_ate40_shadow[i] = 0;
+		tioce_mmr->ce_ure_ate40[i] = 0;
+	}
+
+	for (i = 0; i < TIOCE_NUM_M3240_ATES; i++) {
+		tioce_kern->ce_ate3240_shadow[i] = 0;
+		tioce_mmr->ce_ure_ate3240[i] = 0;
+	}
+
+	return tioce_kern;
+}
+
+/**
+ * tioce_force_interrupt - implement altix force_interrupt() backend for CE
+ * @sn_irq_info: sn asic irq that we need an interrupt generated for
+ *
+ * Given an sn_irq_info struct, set the proper bit in ce_adm_force_int to
+ * force a secondary interrupt to be generated.  This is to work around an
+ * asic issue where there is a small window of opportunity for a legacy device
+ * interrupt to be lost.
+ */
+static void
+tioce_force_interrupt(struct sn_irq_info *sn_irq_info)
+{
+	struct pcidev_info *pcidev_info;
+	struct tioce_common *ce_common;
+	struct tioce *ce_mmr;
+	uint64_t force_int_val;
+
+	if (!sn_irq_info->irq_bridge)
+		return;
+
+	if (sn_irq_info->irq_bridge_type != PCIIO_ASIC_TYPE_TIOCE)
+		return;
+
+	pcidev_info = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
+	if (!pcidev_info)
+		return;
+
+	ce_common = (struct tioce_common *)pcidev_info->pdi_pcibus_info;
+	ce_mmr = (struct tioce *)ce_common->ce_pcibus.bs_base;
+
+	/*
+	 * irq_int_bit is originally set up by prom, and holds the interrupt
+	 * bit shift (not mask) as defined by the bit definitions in the
+	 * ce_adm_int mmr.  These shifts are not the same for the
+	 * ce_adm_force_int register, so do an explicit mapping here to make
+	 * things clearer.
+	 */
+
+	switch (sn_irq_info->irq_int_bit) {
+	case CE_ADM_INT_PCIE_PORT1_DEV_A_SHFT:
+		force_int_val = 1UL << CE_ADM_FORCE_INT_PCIE_PORT1_DEV_A_SHFT;
+		break;
+	case CE_ADM_INT_PCIE_PORT1_DEV_B_SHFT:
+		force_int_val = 1UL << CE_ADM_FORCE_INT_PCIE_PORT1_DEV_B_SHFT;
+		break;
+	case CE_ADM_INT_PCIE_PORT1_DEV_C_SHFT:
+		force_int_val = 1UL << CE_ADM_FORCE_INT_PCIE_PORT1_DEV_C_SHFT;
+		break;
+	case CE_ADM_INT_PCIE_PORT1_DEV_D_SHFT:
+		force_int_val = 1UL << CE_ADM_FORCE_INT_PCIE_PORT1_DEV_D_SHFT;
+		break;
+	case CE_ADM_INT_PCIE_PORT2_DEV_A_SHFT:
+		force_int_val = 1UL << CE_ADM_FORCE_INT_PCIE_PORT2_DEV_A_SHFT;
+		break;
+	case CE_ADM_INT_PCIE_PORT2_DEV_B_SHFT:
+		force_int_val = 1UL << CE_ADM_FORCE_INT_PCIE_PORT2_DEV_B_SHFT;
+		break;
+	case CE_ADM_INT_PCIE_PORT2_DEV_C_SHFT:
+		force_int_val = 1UL << CE_ADM_FORCE_INT_PCIE_PORT2_DEV_C_SHFT;
+		break;
+	case CE_ADM_INT_PCIE_PORT2_DEV_D_SHFT:
+		force_int_val = 1UL << CE_ADM_FORCE_INT_PCIE_PORT2_DEV_D_SHFT;
+		break;
+	default:
+		return;
+	}
+	ce_mmr->ce_adm_force_int = force_int_val;
+}
+
+/**
+ * tioce_bus_fixup - perform final PCI fixup for a TIO CE bus
+ * @prom_bussoft: Common prom/kernel struct representing the bus
+ *
+ * Replicates the tioce_common pointed to by @prom_bussoft in kernel
+ * space.  Allocates and initializes a kernel-only area for a given CE,
+ * and sets up an irq for handling CE error interrupts.
+ *
+ * On successful setup, returns the kernel version of tioce_common back to
+ * the caller.
+ */
+static void *
+tioce_bus_fixup(struct pcibus_bussoft *prom_bussoft, struct pci_controller *controller)
+{
+	struct tioce_common *tioce_common;
+
+	/*
+	 * Allocate kernel bus soft and copy from prom.
+	 */
+
+	tioce_common = kcalloc(1, sizeof(struct tioce_common), GFP_KERNEL);
+	if (!tioce_common)
+		return NULL;
+
+	memcpy(tioce_common, prom_bussoft, sizeof(struct tioce_common));
+	tioce_common->ce_pcibus.bs_base |= __IA64_UNCACHED_OFFSET;
+
+	if (tioce_kern_init(tioce_common) == NULL) {
+		kfree(tioce_common);
+		return NULL;
+	}
+
+	if (request_irq(SGI_PCIASIC_ERROR,
+			tioce_error_intr_handler,
+			SA_SHIRQ, "TIOCE error", (void *)tioce_common))
+		printk(KERN_WARNING
+		       "%s:  Unable to get irq %d.  "
+		       "Error interrupts won't be routed for "
+		       "TIOCE bus %04x:%02x\n",
+		       __FUNCTION__, SGI_PCIASIC_ERROR,
+		       tioce_common->ce_pcibus.bs_persist_segment,
+		       tioce_common->ce_pcibus.bs_persist_busnum);
+
+	return tioce_common;
+}
+
+static struct sn_pcibus_provider tioce_pci_interfaces = {
+	.dma_map = tioce_dma,
+	.dma_map_consistent = tioce_dma_consistent,
+	.dma_unmap = tioce_dma_unmap,
+	.bus_fixup = tioce_bus_fixup,
+	.force_interrupt = tioce_force_interrupt
+};
+
+/**
+ * tioce_init_provider - init SN PCI provider ops for TIO CE
+ */
+int
+tioce_init_provider(void)
+{
+	sn_pci_provider[PCIIO_ASIC_TYPE_TIOCE] = &tioce_pci_interfaces;
+	return 0;
+}