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>

diff --git a/arch/arm/include/asm/xen/events.h b/arch/arm/include/asm/xen/events.h
index 94b4e9020b0227465953e3332624424cbc520653..5c27696de14fda11bf6866138387f1149128e485 100644 (file)
--- a/arch/arm/include/asm/xen/events.h
+++ b/arch/arm/include/asm/xen/events.h
@@ -15,4 +15,26 @@ static inline int xen_irqs_disabled(struct pt_regs *regs)
        return raw_irqs_disabled_flags(regs->ARM_cpsr);
 }
 
+/*
+ * We cannot use xchg because it does not support 8-byte
+ * values. However it is safe to use {ldr,dtd}exd directly because all
+ * platforms which Xen can run on support those instructions.
+ */
+static inline xen_ulong_t xchg_xen_ulong(xen_ulong_t *ptr, xen_ulong_t val)
+{
+       xen_ulong_t oldval;
+       unsigned int tmp;
+
+       wmb();
+       asm volatile("@ xchg_xen_ulong\n"
+               "1:     ldrexd  %0, %H0, [%3]\n"
+               "       strexd  %1, %2, %H2, [%3]\n"
+               "       teq     %1, #0\n"
+               "       bne     1b"
+               : "=&r" (oldval), "=&r" (tmp)
+               : "r" (val), "r" (ptr)
+               : "memory", "cc");
+       return oldval;
+}
+
 #endif /* _ASM_ARM_XEN_EVENTS_H */

diff --git a/arch/x86/include/asm/xen/events.h b/arch/x86/include/asm/xen/events.h
index cc146d51449e372549cfafded1b99815ffa92aec..ca842f2769efa1545951f52647b34a7e6c051c7f 100644 (file)
--- a/arch/x86/include/asm/xen/events.h
+++ b/arch/x86/include/asm/xen/events.h
@@ -16,4 +16,7 @@ static inline int xen_irqs_disabled(struct pt_regs *regs)
        return raw_irqs_disabled_flags(regs->flags);
 }
 
+/* No need for a barrier -- XCHG is a barrier on x86. */
+#define xchg_xen_ulong(ptr, val) xchg((ptr), (val))
+
 #endif /* _ASM_X86_XEN_EVENTS_H */

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 0be4df39e953a5b870948e6ed8a1553a15cc2c2a..342edc0495cc893bd037e27303bfdc9dc4144707 100644 (file)
--- 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;

diff --git a/include/xen/interface/xen.h b/include/xen/interface/xen.h
index 886a5d80a18fdcbaa572c8350a400d59ab4455ba..53ec4167bd0b15c29710fcebf8e023e2b583e520 100644 (file)
--- a/include/xen/interface/xen.h
+++ b/include/xen/interface/xen.h
@@ -285,7 +285,7 @@ DEFINE_GUEST_HANDLE_STRUCT(multicall_entry);
  * Event channel endpoints per domain:
  *  1024 if a long is 32 bits; 4096 if a long is 64 bits.
  */
-#define NR_EVENT_CHANNELS (sizeof(unsigned long) * sizeof(unsigned long) * 64)
+#define NR_EVENT_CHANNELS (sizeof(xen_ulong_t) * sizeof(xen_ulong_t) * 64)
 
 struct vcpu_time_info {
        /*
@@ -341,7 +341,7 @@ struct vcpu_info {
         */
        uint8_t evtchn_upcall_pending;
        uint8_t evtchn_upcall_mask;
-       unsigned long evtchn_pending_sel;
+       xen_ulong_t evtchn_pending_sel;
        struct arch_vcpu_info arch;
        struct pvclock_vcpu_time_info time;
 }; /* 64 bytes (x86) */
@@ -384,8 +384,8 @@ struct shared_info {
         * per-vcpu selector word to be set. Each bit in the selector covers a
         * 'C long' in the PENDING bitfield array.
         */
-       unsigned long evtchn_pending[sizeof(unsigned long) * 8];
-       unsigned long evtchn_mask[sizeof(unsigned long) * 8];
+       xen_ulong_t evtchn_pending[sizeof(xen_ulong_t) * 8];
+       xen_ulong_t evtchn_mask[sizeof(xen_ulong_t) * 8];
 
        /*
         * Wallclock time: updated only by control software. Guests should base