[SPARC64]: Only use bypass accesses to INO buckets.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 91 insertions, 31 deletions

diff --git a/arch/sparc64/kernel/irq.c b/arch/sparc64/kernel/irq.c
index 4e9537c96778..dc51bdf853cd 100644
--- a/arch/sparc64/kernel/irq.c
+++ b/arch/sparc64/kernel/irq.c
@@ -42,6 +42,7 @@
 #include <asm/auxio.h>
 #include <asm/head.h>
 #include <asm/hypervisor.h>
+#include <asm/cacheflush.h>
 
 /* UPA nodes send interrupt packet to UltraSparc with first data reg
  * value low 5 (7 on Starfire) bits holding the IRQ identifier being
@@ -56,10 +57,10 @@
  * of the vectored interrupt trap handler(s) in entry.S and sun4v_ivec.S
  */
 struct ino_bucket {
-/*0x00*/unsigned long irq_chain_pa;
+/*0x00*/unsigned long __irq_chain_pa;
 
         /* Virtual interrupt number assigned to this INO.  */
-/*0x08*/unsigned int virt_irq;
+/*0x08*/unsigned int __virt_irq;
 /*0x0c*/unsigned int __pad;
 };
 
@@ -67,6 +68,60 @@ struct ino_bucket {
 struct ino_bucket *ivector_table;
 unsigned long ivector_table_pa;
 
+/* On several sun4u processors, it is illegal to mix bypass and
+ * non-bypass accesses.  Therefore we access all INO buckets
+ * using bypass accesses only.
+ */
+static unsigned long bucket_get_chain_pa(unsigned long bucket_pa)
+{
+        unsigned long ret;
+
+        __asm__ __volatile__("ldxa      [%1] %2, %0"
+                             : "=&r" (ret)
+                             : "r" (bucket_pa +
+                                    offsetof(struct ino_bucket,
+                                             __irq_chain_pa)),
+                               "i" (ASI_PHYS_USE_EC));
+
+        return ret;
+}
+
+static void bucket_clear_chain_pa(unsigned long bucket_pa)
+{
+        __asm__ __volatile__("stxa      %%g0, [%0] %1"
+                             : /* no outputs */
+                             : "r" (bucket_pa +
+                                    offsetof(struct ino_bucket,
+                                             __irq_chain_pa)),
+                               "i" (ASI_PHYS_USE_EC));
+}
+
+static unsigned int bucket_get_virt_irq(unsigned long bucket_pa)
+{
+        unsigned int ret;
+
+        __asm__ __volatile__("lduwa     [%1] %2, %0"
+                             : "=&r" (ret)
+                             : "r" (bucket_pa +
+                                    offsetof(struct ino_bucket,
+                                             __virt_irq)),
+                               "i" (ASI_PHYS_USE_EC));
+
+        return ret;
+}
+
+static void bucket_set_virt_irq(unsigned long bucket_pa,
+                                unsigned int virt_irq)
+{
+        __asm__ __volatile__("stwa      %0, [%1] %2"
+                             : /* no outputs */
+                             : "r" (virt_irq),
+                               "r" (bucket_pa +
+                                    offsetof(struct ino_bucket,
+                                             __virt_irq)),
+                               "i" (ASI_PHYS_USE_EC));
+}
+
 #define __irq_ino(irq) \
         (((struct ino_bucket *)(irq)) - &ivector_table[0])
 #define __bucket(irq) ((struct ino_bucket *)(irq))
@@ -569,18 +624,21 @@ unsigned int build_irq(int inofixup, unsigned long iclr, unsigned long imap)
 {
         struct ino_bucket *bucket;
         struct irq_handler_data *data;
+        unsigned int virt_irq;
         int ino;
 
         BUG_ON(tlb_type == hypervisor);
 
         ino = (upa_readq(imap) & (IMAP_IGN | IMAP_INO)) + inofixup;
         bucket = &ivector_table[ino];
-        if (!bucket->virt_irq) {
-                bucket->virt_irq = virt_irq_alloc(__irq(bucket));
-                set_irq_chip(bucket->virt_irq, &sun4u_irq);
+        virt_irq = bucket_get_virt_irq(__pa(bucket));
+        if (!virt_irq) {
+                virt_irq = virt_irq_alloc(__irq(bucket));
+                bucket_set_virt_irq(__pa(bucket), virt_irq);
+                set_irq_chip(virt_irq, &sun4u_irq);
         }
 
-        data = get_irq_chip_data(bucket->virt_irq);
+        data = get_irq_chip_data(virt_irq);
         if (unlikely(data))
                 goto out;
 
@@ -589,13 +647,13 @@ unsigned int build_irq(int inofixup, unsigned long iclr, unsigned long imap)
                 prom_printf("IRQ: kzalloc(irq_handler_data) failed.\n");
                 prom_halt();
         }
-        set_irq_chip_data(bucket->virt_irq, data);
+        set_irq_chip_data(virt_irq, data);
 
         data->imap  = imap;
         data->iclr  = iclr;
 
 out:
-        return bucket->virt_irq;
+        return virt_irq;
 }
 
 static unsigned int sun4v_build_common(unsigned long sysino,
@@ -603,16 +661,19 @@ static unsigned int sun4v_build_common(unsigned long sysino,
 {
         struct ino_bucket *bucket;
         struct irq_handler_data *data;
+        unsigned int virt_irq;
 
         BUG_ON(tlb_type != hypervisor);
 
         bucket = &ivector_table[sysino];
-        if (!bucket->virt_irq) {
-                bucket->virt_irq = virt_irq_alloc(__irq(bucket));
-                set_irq_chip(bucket->virt_irq, chip);
+        virt_irq = bucket_get_virt_irq(__pa(bucket));
+        if (!virt_irq) {
+                virt_irq = virt_irq_alloc(__irq(bucket));
+                bucket_set_virt_irq(__pa(bucket), virt_irq);
+                set_irq_chip(virt_irq, chip);
         }
 
-        data = get_irq_chip_data(bucket->virt_irq);
+        data = get_irq_chip_data(virt_irq);
         if (unlikely(data))
                 goto out;
 
@@ -621,7 +682,7 @@ static unsigned int sun4v_build_common(unsigned long sysino,
                 prom_printf("IRQ: kzalloc(irq_handler_data) failed.\n");
                 prom_halt();
         }
-        set_irq_chip_data(bucket->virt_irq, data);
+        set_irq_chip_data(virt_irq, data);
 
         /* Catch accidental accesses to these things.  IMAP/ICLR handling
          * is done by hypervisor calls on sun4v platforms, not by direct
@@ -631,7 +692,7 @@ static unsigned int sun4v_build_common(unsigned long sysino,
         data->iclr = ~0UL;
 
 out:
-        return bucket->virt_irq;
+        return virt_irq;
 }
 
 unsigned int sun4v_build_irq(u32 devhandle, unsigned int devino)
@@ -646,19 +707,24 @@ unsigned int sun4v_build_virq(u32 devhandle, unsigned int devino)
         struct irq_handler_data *data;
         struct ino_bucket *bucket;
         unsigned long hv_err, cookie;
+        unsigned int virt_irq;
 
         bucket = kzalloc(sizeof(struct ino_bucket), GFP_ATOMIC);
         if (unlikely(!bucket))
                 return 0;
+        __flush_dcache_range((unsigned long) bucket,
+                             ((unsigned long) bucket +
+                              sizeof(struct ino_bucket)));
 
-        bucket->virt_irq = virt_irq_alloc(__irq(bucket));
-        set_irq_chip(bucket->virt_irq, &sun4v_virq);
+        virt_irq = virt_irq_alloc(__irq(bucket));
+        bucket_set_virt_irq(__pa(bucket), virt_irq);
+        set_irq_chip(virt_irq, &sun4v_virq);
 
         data = kzalloc(sizeof(struct irq_handler_data), GFP_ATOMIC);
         if (unlikely(!data))
                 return 0;
 
-        set_irq_chip_data(bucket->virt_irq, data);
+        set_irq_chip_data(virt_irq, data);
 
         /* Catch accidental accesses to these things.  IMAP/ICLR handling
          * is done by hypervisor calls on sun4v platforms, not by direct
@@ -675,10 +741,10 @@ unsigned int sun4v_build_virq(u32 devhandle, unsigned int devino)
                 prom_halt();
         }
 
-        virt_to_real_irq_table[bucket->virt_irq].dev_handle = devhandle;
-        virt_to_real_irq_table[bucket->virt_irq].dev_ino = devino;
+        virt_to_real_irq_table[virt_irq].dev_handle = devhandle;
+        virt_to_real_irq_table[virt_irq].dev_ino = devino;
 
-        return bucket->virt_irq;
+        return virt_irq;
 }
 
 void ack_bad_irq(unsigned int virt_irq)
@@ -718,17 +784,9 @@ void handler_irq(int irq, struct pt_regs *regs)
                 unsigned long next_pa;
                 unsigned int virt_irq;
 
-                __asm__ __volatile__("ldxa      [%2] %4, %0\n\t"
-                                     "lduwa     [%3] %4, %1\n\t"
-                                     "stxa      %%g0, [%2] %4"
-                                     : "=&r" (next_pa), "=&r" (virt_irq)
-                                     : "r" (bucket_pa +
-                                            offsetof(struct ino_bucket,
-                                                     irq_chain_pa)),
-                                       "r" (bucket_pa +
-                                            offsetof(struct ino_bucket,
-                                                     virt_irq)),
-                                       "i" (ASI_PHYS_USE_EC));
+                next_pa = bucket_get_chain_pa(bucket_pa);
+                virt_irq = bucket_get_virt_irq(bucket_pa);
+                bucket_clear_chain_pa(bucket_pa);
 
                 __do_IRQ(virt_irq);
 
@@ -957,6 +1015,8 @@ void __init init_IRQ(void)
                 prom_printf("Fatal error, cannot allocate ivector_table\n");
                 prom_halt();
         }
+        __flush_dcache_range((unsigned long) ivector_table,
+                             ((unsigned long) ivector_table) + size);
 
         ivector_table_pa = __pa(ivector_table);