xen: event channel arrays are xen_ulong_t and not unsigned long

On ARM we want these to be the same size on 32- and 64-bit.

This is an ABI change on ARM. X86 does not change.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Keir (Xen.org) <keir@xen.org>
Cc: Tim Deegan <tim@xen.org>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: xen-devel@lists.xen.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 67 insertions, 48 deletions

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 0be4df39e953..342edc0495cc 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -120,7 +120,22 @@ static unsigned long *pirq_eoi_map;
 #endif
 static bool (*pirq_needs_eoi)(unsigned irq);
 
-static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG],
+/*
+ * Note sizeof(xen_ulong_t) can be more than sizeof(unsigned long). Be
+ * careful to only use bitops which allow for this (e.g
+ * test_bit/find_first_bit and friends but not __ffs) and to pass
+ * BITS_PER_EVTCHN_WORD as the bitmask length.
+ */
+#define BITS_PER_EVTCHN_WORD (sizeof(xen_ulong_t)*8)
+/*
+ * Make a bitmask (i.e. unsigned long *) of a xen_ulong_t
+ * array. Primarily to avoid long lines (hence the terse name).
+ */
+#define BM(x) (unsigned long *)(x)
+/* Find the first set bit in a evtchn mask */
+#define EVTCHN_FIRST_BIT(w) find_first_bit(BM(&(w)), BITS_PER_EVTCHN_WORD)
+
+static DEFINE_PER_CPU(xen_ulong_t [NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD],
                       cpu_evtchn_mask);
 
 /* Xen will never allocate port zero for any purpose. */
@@ -294,9 +309,9 @@ static bool pirq_needs_eoi_flag(unsigned irq)
         return info->u.pirq.flags & PIRQ_NEEDS_EOI;
 }
 
-static inline unsigned long active_evtchns(unsigned int cpu,
-                                           struct shared_info *sh,
-                                           unsigned int idx)
+static inline xen_ulong_t active_evtchns(unsigned int cpu,
+                                         struct shared_info *sh,
+                                         unsigned int idx)
 {
         return sh->evtchn_pending[idx] &
                 per_cpu(cpu_evtchn_mask, cpu)[idx] &
@@ -312,8 +327,8 @@ static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
         cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
 #endif
 
-        clear_bit(chn, per_cpu(cpu_evtchn_mask, cpu_from_irq(irq)));
-        set_bit(chn, per_cpu(cpu_evtchn_mask, cpu));
+        clear_bit(chn, BM(per_cpu(cpu_evtchn_mask, cpu_from_irq(irq))));
+        set_bit(chn, BM(per_cpu(cpu_evtchn_mask, cpu)));
 
         info_for_irq(irq)->cpu = cpu;
 }
@@ -339,19 +354,19 @@ static void init_evtchn_cpu_bindings(void)
 static inline void clear_evtchn(int port)
 {
         struct shared_info *s = HYPERVISOR_shared_info;
-        sync_clear_bit(port, &s->evtchn_pending[0]);
+        sync_clear_bit(port, BM(&s->evtchn_pending[0]));
 }
 
 static inline void set_evtchn(int port)
 {
         struct shared_info *s = HYPERVISOR_shared_info;
-        sync_set_bit(port, &s->evtchn_pending[0]);
+        sync_set_bit(port, BM(&s->evtchn_pending[0]));
 }
 
 static inline int test_evtchn(int port)
 {
         struct shared_info *s = HYPERVISOR_shared_info;
-        return sync_test_bit(port, &s->evtchn_pending[0]);
+        return sync_test_bit(port, BM(&s->evtchn_pending[0]));
 }
 
 
@@ -375,7 +390,7 @@ EXPORT_SYMBOL_GPL(notify_remote_via_irq);
 static void mask_evtchn(int port)
 {
         struct shared_info *s = HYPERVISOR_shared_info;
-        sync_set_bit(port, &s->evtchn_mask[0]);
+        sync_set_bit(port, BM(&s->evtchn_mask[0]));
 }
 
 static void unmask_evtchn(int port)
@@ -389,7 +404,7 @@ static void unmask_evtchn(int port)
         if (unlikely((cpu != cpu_from_evtchn(port))))
                 do_hypercall = 1;
         else
-                evtchn_pending = sync_test_bit(port, &s->evtchn_pending[0]);
+                evtchn_pending = sync_test_bit(port, BM(&s->evtchn_pending[0]));
 
         if (unlikely(evtchn_pending && xen_hvm_domain()))
                 do_hypercall = 1;
@@ -403,7 +418,7 @@ static void unmask_evtchn(int port)
         } else {
                 struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
 
-                sync_clear_bit(port, &s->evtchn_mask[0]);
+                sync_clear_bit(port, BM(&s->evtchn_mask[0]));
 
                 /*
                  * The following is basically the equivalent of
@@ -411,8 +426,8 @@ static void unmask_evtchn(int port)
                  * the interrupt edge' if the channel is masked.
                  */
                 if (evtchn_pending &&
-                    !sync_test_and_set_bit(port / BITS_PER_LONG,
-                                           &vcpu_info->evtchn_pending_sel))
+                    !sync_test_and_set_bit(port / BITS_PER_EVTCHN_WORD,
+                                           BM(&vcpu_info->evtchn_pending_sel)))
                         vcpu_info->evtchn_upcall_pending = 1;
         }
 
@@ -1189,7 +1204,7 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
 {
         struct shared_info *sh = HYPERVISOR_shared_info;
         int cpu = smp_processor_id();
-        unsigned long *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);
+        xen_ulong_t *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);
         int i;
         unsigned long flags;
         static DEFINE_SPINLOCK(debug_lock);
@@ -1205,7 +1220,7 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
                 pending = (get_irq_regs() && i == cpu)
                         ? xen_irqs_disabled(get_irq_regs())
                         : v->evtchn_upcall_mask;
-                printk("%d: masked=%d pending=%d event_sel %0*lx\n  ", i,
+                printk("%d: masked=%d pending=%d event_sel %0*"PRI_xen_ulong"\n  ", i,
                        pending, v->evtchn_upcall_pending,
                        (int)(sizeof(v->evtchn_pending_sel)*2),
                        v->evtchn_pending_sel);
@@ -1214,49 +1229,52 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
 
         printk("\npending:\n   ");
         for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
-                printk("%0*lx%s", (int)sizeof(sh->evtchn_pending[0])*2,
+                printk("%0*"PRI_xen_ulong"%s",
+                       (int)sizeof(sh->evtchn_pending[0])*2,
                        sh->evtchn_pending[i],
                        i % 8 == 0 ? "\n   " : " ");
         printk("\nglobal mask:\n   ");
         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
-                printk("%0*lx%s",
+                printk("%0*"PRI_xen_ulong"%s",
                        (int)(sizeof(sh->evtchn_mask[0])*2),
                        sh->evtchn_mask[i],
                        i % 8 == 0 ? "\n   " : " ");
 
         printk("\nglobally unmasked:\n   ");
         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
-                printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
+                printk("%0*"PRI_xen_ulong"%s",
+                       (int)(sizeof(sh->evtchn_mask[0])*2),
                        sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
                        i % 8 == 0 ? "\n   " : " ");
 
         printk("\nlocal cpu%d mask:\n   ", cpu);
-        for (i = (NR_EVENT_CHANNELS/BITS_PER_LONG)-1; i >= 0; i--)
-                printk("%0*lx%s", (int)(sizeof(cpu_evtchn[0])*2),
+        for (i = (NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD)-1; i >= 0; i--)
+                printk("%0*"PRI_xen_ulong"%s", (int)(sizeof(cpu_evtchn[0])*2),
                        cpu_evtchn[i],
                        i % 8 == 0 ? "\n   " : " ");
 
         printk("\nlocally unmasked:\n   ");
         for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {
-                unsigned long pending = sh->evtchn_pending[i]
+                xen_ulong_t pending = sh->evtchn_pending[i]
                         & ~sh->evtchn_mask[i]
                         & cpu_evtchn[i];
-                printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
+                printk("%0*"PRI_xen_ulong"%s",
+                       (int)(sizeof(sh->evtchn_mask[0])*2),
                        pending, i % 8 == 0 ? "\n   " : " ");
         }
 
         printk("\npending list:\n");
         for (i = 0; i < NR_EVENT_CHANNELS; i++) {
-                if (sync_test_bit(i, sh->evtchn_pending)) {
-                        int word_idx = i / BITS_PER_LONG;
+                if (sync_test_bit(i, BM(sh->evtchn_pending))) {
+                        int word_idx = i / BITS_PER_EVTCHN_WORD;
                         printk("  %d: event %d -> irq %d%s%s%s\n",
                                cpu_from_evtchn(i), i,
                                evtchn_to_irq[i],
-                               sync_test_bit(word_idx, &v->evtchn_pending_sel)
+                               sync_test_bit(word_idx, BM(&v->evtchn_pending_sel))
                                              ? "" : " l2-clear",
-                               !sync_test_bit(i, sh->evtchn_mask)
+                               !sync_test_bit(i, BM(sh->evtchn_mask))
                                              ? "" : " globally-masked",
-                               sync_test_bit(i, cpu_evtchn)
+                               sync_test_bit(i, BM(cpu_evtchn))
                                              ? "" : " locally-masked");
                 }
         }
@@ -1273,7 +1291,7 @@ static DEFINE_PER_CPU(unsigned int, current_bit_idx);
 /*
  * Mask out the i least significant bits of w
  */
-#define MASK_LSBS(w, i) (w & ((~0UL) << i))
+#define MASK_LSBS(w, i) (w & ((~((xen_ulong_t)0UL)) << i))
 
 /*
  * Search the CPUs pending events bitmasks.  For each one found, map
@@ -1295,18 +1313,19 @@ static void __xen_evtchn_do_upcall(void)
         unsigned count;
 
         do {
-                unsigned long pending_words;
+                xen_ulong_t pending_words;
 
                 vcpu_info->evtchn_upcall_pending = 0;
 
                 if (__this_cpu_inc_return(xed_nesting_count) - 1)
                         goto out;
 
-#ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
-                /* Clear master flag /before/ clearing selector flag. */
-                wmb();
-#endif
-                pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
+                /*
+                 * Master flag must be cleared /before/ clearing
+                 * selector flag. xchg_xen_ulong must contain an
+                 * appropriate barrier.
+                 */
+                pending_words = xchg_xen_ulong(&vcpu_info->evtchn_pending_sel, 0);
 
                 start_word_idx = __this_cpu_read(current_word_idx);
                 start_bit_idx = __this_cpu_read(current_bit_idx);
@@ -1314,8 +1333,8 @@ static void __xen_evtchn_do_upcall(void)
                 word_idx = start_word_idx;
 
                 for (i = 0; pending_words != 0; i++) {
-                        unsigned long pending_bits;
-                        unsigned long words;
+                        xen_ulong_t pending_bits;
+                        xen_ulong_t words;
 
                         words = MASK_LSBS(pending_words, word_idx);
 
@@ -1327,7 +1346,7 @@ static void __xen_evtchn_do_upcall(void)
                                 bit_idx = 0;
                                 continue;
                         }
-                        word_idx = __ffs(words);
+                        word_idx = EVTCHN_FIRST_BIT(words);
 
                         pending_bits = active_evtchns(cpu, s, word_idx);
                         bit_idx = 0; /* usually scan entire word from start */
@@ -1342,7 +1361,7 @@ static void __xen_evtchn_do_upcall(void)
                         }
 
                         do {
-                                unsigned long bits;
+                                xen_ulong_t bits;
                                 int port, irq;
                                 struct irq_desc *desc;
 
@@ -1352,10 +1371,10 @@ static void __xen_evtchn_do_upcall(void)
                                 if (bits == 0)
                                         break;
 
-                                bit_idx = __ffs(bits);
+                                bit_idx = EVTCHN_FIRST_BIT(bits);
 
                                 /* Process port. */
-                                port = (word_idx * BITS_PER_LONG) + bit_idx;
+                                port = (word_idx * BITS_PER_EVTCHN_WORD) + bit_idx;
                                 irq = evtchn_to_irq[port];
 
                                 if (irq != -1) {
@@ -1364,12 +1383,12 @@ static void __xen_evtchn_do_upcall(void)
                                                 generic_handle_irq_desc(irq, desc);
                                 }
 
-                                bit_idx = (bit_idx + 1) % BITS_PER_LONG;
+                                bit_idx = (bit_idx + 1) % BITS_PER_EVTCHN_WORD;
 
                                 /* Next caller starts at last processed + 1 */
                                 __this_cpu_write(current_word_idx,
                                                  bit_idx ? word_idx :
-                                                 (word_idx+1) % BITS_PER_LONG);
+                                                 (word_idx+1) % BITS_PER_EVTCHN_WORD);
                                 __this_cpu_write(current_bit_idx, bit_idx);
                         } while (bit_idx != 0);
 
@@ -1377,7 +1396,7 @@ static void __xen_evtchn_do_upcall(void)
                         if ((word_idx != start_word_idx) || (i != 0))
                                 pending_words &= ~(1UL << word_idx);
 
-                        word_idx = (word_idx + 1) % BITS_PER_LONG;
+                        word_idx = (word_idx + 1) % BITS_PER_EVTCHN_WORD;
                 }
 
                 BUG_ON(!irqs_disabled());
@@ -1487,8 +1506,8 @@ int resend_irq_on_evtchn(unsigned int irq)
         if (!VALID_EVTCHN(evtchn))
                 return 1;
 
-        masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
-        sync_set_bit(evtchn, s->evtchn_pending);
+        masked = sync_test_and_set_bit(evtchn, BM(s->evtchn_mask));
+        sync_set_bit(evtchn, BM(s->evtchn_pending));
         if (!masked)
                 unmask_evtchn(evtchn);
 
@@ -1536,8 +1555,8 @@ static int retrigger_dynirq(struct irq_data *data)
         if (VALID_EVTCHN(evtchn)) {
                 int masked;
 
-                masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
-                sync_set_bit(evtchn, sh->evtchn_pending);
+                masked = sync_test_and_set_bit(evtchn, BM(sh->evtchn_mask));
+                sync_set_bit(evtchn, BM(sh->evtchn_pending));
                 if (!masked)
                         unmask_evtchn(evtchn);
                 ret = 1;