[IA64-SGI] Fix sn_flush_device_kernel & spinlock initialization

This patch separates the sn_flush_device_list struct into kernel and
common (both kernel and PROM accessible) structures.  As it was, if the
size of a spinlock_t changed (due to additional CONFIG options, etc.) the
sal call which populated the sn_flush_device_list structs would erroneously
write data (and cause memory corruption and/or a panic).

This patch does the following:

1.  Removes sn_flush_device_list and adds sn_flush_device_common and
sn_flush_device_kernel.

2.  Adds a new SAL call to populate a sn_flush_device_common struct per
device, not per widget as previously done.

3.  Correctly initializes each device's sn_flush_device_kernel spinlock_t
struct (before it was only doing each widget's first device).

Signed-off-by: Prarit Bhargava <prarit@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

2 files changed, 28 insertions, 26 deletions

diff --git a/arch/ia64/sn/pci/pcibr/pcibr_dma.c b/arch/ia64/sn/pci/pcibr/pcibr_dma.c
index 34093476e965..e68332d93171 100644
--- a/arch/ia64/sn/pci/pcibr/pcibr_dma.c
+++ b/arch/ia64/sn/pci/pcibr/pcibr_dma.c
@@ -218,7 +218,9 @@ void sn_dma_flush(uint64_t addr)
 	uint64_t flags;
 	uint64_t itte;
 	struct hubdev_info *hubinfo;
-	volatile struct sn_flush_device_list *p;
+	volatile struct sn_flush_device_kernel *p;
+	volatile struct sn_flush_device_common *common;
+
 	struct sn_flush_nasid_entry *flush_nasid_list;
 
 	if (!sn_ioif_inited)
@@ -268,17 +270,17 @@ void sn_dma_flush(uint64_t addr)
 	p = &flush_nasid_list->widget_p[wid_num][0];
 
 	/* find a matching BAR */
-	for (i = 0; i < DEV_PER_WIDGET; i++) {
+	for (i = 0; i < DEV_PER_WIDGET; i++,p++) {
+		common = p->common;
 		for (j = 0; j < PCI_ROM_RESOURCE; j++) {
-			if (p->sfdl_bar_list[j].start == 0)
+			if (common->sfdl_bar_list[j].start == 0)
 				break;
-			if (addr >= p->sfdl_bar_list[j].start
-			    && addr <= p->sfdl_bar_list[j].end)
+			if (addr >= common->sfdl_bar_list[j].start
+			    && addr <= common->sfdl_bar_list[j].end)
 				break;
 		}
-		if (j < PCI_ROM_RESOURCE && p->sfdl_bar_list[j].start != 0)
+		if (j < PCI_ROM_RESOURCE && common->sfdl_bar_list[j].start != 0)
 			break;
-		p++;
 	}
 
 	/* if no matching BAR, return without doing anything. */
@@ -304,24 +306,24 @@ void sn_dma_flush(uint64_t addr)
 		if ((1 << XWIDGET_PART_REV_NUM_REV(revnum)) & PV907516) {
 			return;
 		} else {
-			pcireg_wrb_flush_get(p->sfdl_pcibus_info,
-					     (p->sfdl_slot - 1));
+			pcireg_wrb_flush_get(common->sfdl_pcibus_info,
+					     (common->sfdl_slot - 1));
 		}
 	} else {
-		spin_lock_irqsave(&((struct sn_flush_device_list *)p)->
-				  sfdl_flush_lock, flags);
-
-		*p->sfdl_flush_addr = 0;
+		spin_lock_irqsave((spinlock_t *)&p->sfdl_flush_lock,
+				  flags);
+		*common->sfdl_flush_addr = 0;
 
 		/* force an interrupt. */
-		*(volatile uint32_t *)(p->sfdl_force_int_addr) = 1;
+		*(volatile uint32_t *)(common->sfdl_force_int_addr) = 1;
 
 		/* wait for the interrupt to come back. */
-		while (*(p->sfdl_flush_addr) != 0x10f)
+		while (*(common->sfdl_flush_addr) != 0x10f)
 			cpu_relax();
 
 		/* okay, everything is synched up. */
-		spin_unlock_irqrestore((spinlock_t *)&p->sfdl_flush_lock, flags);
+		spin_unlock_irqrestore((spinlock_t *)&p->sfdl_flush_lock,
+				       flags);
 	}
 	return;
 }
diff --git a/arch/ia64/sn/pci/pcibr/pcibr_provider.c b/arch/ia64/sn/pci/pcibr/pcibr_provider.c
index 1f500c81002c..e328e948175d 100644
--- a/arch/ia64/sn/pci/pcibr/pcibr_provider.c
+++ b/arch/ia64/sn/pci/pcibr/pcibr_provider.c
@@ -92,7 +92,8 @@ pcibr_bus_fixup(struct pcibus_bussoft *prom_bussoft, struct pci_controller *cont
 	cnodeid_t near_cnode;
 	struct hubdev_info *hubdev_info;
 	struct pcibus_info *soft;
-	struct sn_flush_device_list *sn_flush_device_list;
+	struct sn_flush_device_kernel *sn_flush_device_kernel;
+	struct sn_flush_device_common *common;
 
 	if (! IS_PCI_BRIDGE_ASIC(prom_bussoft->bs_asic_type)) {
 		return NULL;
@@ -137,20 +138,19 @@ pcibr_bus_fixup(struct pcibus_bussoft *prom_bussoft, struct pci_controller *cont
 	hubdev_info = (struct hubdev_info *)(NODEPDA(cnode)->pdinfo);
 
 	if (hubdev_info->hdi_flush_nasid_list.widget_p) {
-		sn_flush_device_list = hubdev_info->hdi_flush_nasid_list.
+		sn_flush_device_kernel = hubdev_info->hdi_flush_nasid_list.
 		    widget_p[(int)soft->pbi_buscommon.bs_xid];
-		if (sn_flush_device_list) {
+		if (sn_flush_device_kernel) {
 			for (j = 0; j < DEV_PER_WIDGET;
-			     j++, sn_flush_device_list++) {
-				if (sn_flush_device_list->sfdl_slot == -1)
+			     j++, sn_flush_device_kernel++) {
+				common = sn_flush_device_kernel->common;
+				if (common->sfdl_slot == -1)
 					continue;
-				if ((sn_flush_device_list->
-				     sfdl_persistent_segment ==
+				if ((common->sfdl_persistent_segment ==
 				     soft->pbi_buscommon.bs_persist_segment) &&
-				     (sn_flush_device_list->
-				     sfdl_persistent_busnum ==
+				     (common->sfdl_persistent_busnum ==
 				     soft->pbi_buscommon.bs_persist_busnum))
-					sn_flush_device_list->sfdl_pcibus_info =
+					common->sfdl_pcibus_info =
 					    soft;
 			}
 		}