[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;
                         }
                 }