diff mbox

kvm/irqchip: use bitmap utility for gsi tracking

Message ID 1457229445-25954-1-git-send-email-richard.weiyang@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Wei Yang March 6, 2016, 1:57 a.m. UTC 
By using utilities in bitops and bitmap, this patch tries to make it more
friendly to audience. No functional change.

Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
---
 kvm-all.c | 34 ++++++++++------------------------
 1 file changed, 10 insertions(+), 24 deletions(-)

Comments

Paolo Bonzini March 7, 2016, 9:47 a.m. UTC | #1 
On 06/03/2016 02:57, Wei Yang wrote:
> By using utilities in bitops and bitmap, this patch tries to make it more
> friendly to audience. No functional change.
> 
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> ---
>  kvm-all.c | 34 ++++++++++------------------------
>  1 file changed, 10 insertions(+), 24 deletions(-)
> 
> diff --git a/kvm-all.c b/kvm-all.c
> index bd9e764..ed3f4a2 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -90,7 +90,7 @@ struct KVMState
>  #ifdef KVM_CAP_IRQ_ROUTING
>      struct kvm_irq_routing *irq_routes;
>      int nr_allocated_irq_routes;
> -    uint32_t *used_gsi_bitmap;
> +    unsigned long *used_gsi_bitmap;
>      unsigned int gsi_count;
>      QTAILQ_HEAD(msi_hashtab, KVMMSIRoute) msi_hashtab[KVM_MSI_HASHTAB_SIZE];
>  #endif
> @@ -951,12 +951,12 @@ typedef struct KVMMSIRoute {
>  
>  static void set_gsi(KVMState *s, unsigned int gsi)
>  {
> -    s->used_gsi_bitmap[gsi / 32] |= 1U << (gsi % 32);
> +    set_bit(gsi, s->used_gsi_bitmap);
>  }
>  
>  static void clear_gsi(KVMState *s, unsigned int gsi)
>  {
> -    s->used_gsi_bitmap[gsi / 32] &= ~(1U << (gsi % 32));
> +    clear_bit(gsi, s->used_gsi_bitmap);
>  }
>  
>  void kvm_init_irq_routing(KVMState *s)
> @@ -965,17 +965,9 @@ void kvm_init_irq_routing(KVMState *s)
>  
>      gsi_count = kvm_check_extension(s, KVM_CAP_IRQ_ROUTING) - 1;
>      if (gsi_count > 0) {
> -        unsigned int gsi_bits, i;
> -
>          /* Round up so we can search ints using ffs */
> -        gsi_bits = ALIGN(gsi_count, 32);
> -        s->used_gsi_bitmap = g_malloc0(gsi_bits / 8);
> +        s->used_gsi_bitmap = bitmap_new(gsi_count);
>          s->gsi_count = gsi_count;
> -
> -        /* Mark any over-allocated bits as already in use */
> -        for (i = gsi_count; i < gsi_bits; i++) {
> -            set_gsi(s, i);
> -        }
>      }
>  
>      s->irq_routes = g_malloc0(sizeof(*s->irq_routes));
> @@ -1105,9 +1097,7 @@ static void kvm_flush_dynamic_msi_routes(KVMState *s)
>  
>  static int kvm_irqchip_get_virq(KVMState *s)
>  {
> -    uint32_t *word = s->used_gsi_bitmap;
> -    int max_words = ALIGN(s->gsi_count, 32) / 32;
> -    int i, zeroes;
> +    int next_virq;
>  
>      /*
>       * PIC and IOAPIC share the first 16 GSI numbers, thus the available
> @@ -1120,16 +1110,12 @@ static int kvm_irqchip_get_virq(KVMState *s)
>      }
>  
>      /* Return the lowest unused GSI in the bitmap */
> -    for (i = 0; i < max_words; i++) {
> -        zeroes = ctz32(~word[i]);
> -        if (zeroes == 32) {
> -            continue;
> -        }
> -
> -        return zeroes + i * 32;
> +    next_virq = find_first_zero_bit(s->used_gsi_bitmap, s->gsi_count);
> +    if (next_virq >= s->gsi_count) {
> +            return -ENOSPC;
> +    } else {
> +            return next_virq;
>      }
> -    return -ENOSPC;
> -
>  }
>  
>  static KVMMSIRoute *kvm_lookup_msi_route(KVMState *s, MSIMessage msg)
> 

Queued, thanks.  I will send a pull request today.

Paolo
Wei Yang March 7, 2016, 1:53 p.m. UTC | #2 
On Mon, Mar 07, 2016 at 10:47:53AM +0100, Paolo Bonzini wrote:
>On 06/03/2016 02:57, Wei Yang wrote:
>> By using utilities in bitops and bitmap, this patch tries to make it more
>> friendly to audience. No functional change.
>> 
>> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>> ---
>>  kvm-all.c | 34 ++++++++++------------------------
>>  1 file changed, 10 insertions(+), 24 deletions(-)
>> 
>> diff --git a/kvm-all.c b/kvm-all.c
>> index bd9e764..ed3f4a2 100644
>> --- a/kvm-all.c
>> +++ b/kvm-all.c
>> @@ -90,7 +90,7 @@ struct KVMState
>>  #ifdef KVM_CAP_IRQ_ROUTING
>>      struct kvm_irq_routing *irq_routes;
>>      int nr_allocated_irq_routes;
>> -    uint32_t *used_gsi_bitmap;
>> +    unsigned long *used_gsi_bitmap;
>>      unsigned int gsi_count;
>>      QTAILQ_HEAD(msi_hashtab, KVMMSIRoute) msi_hashtab[KVM_MSI_HASHTAB_SIZE];
>>  #endif
>> @@ -951,12 +951,12 @@ typedef struct KVMMSIRoute {
>>  
>>  static void set_gsi(KVMState *s, unsigned int gsi)
>>  {
>> -    s->used_gsi_bitmap[gsi / 32] |= 1U << (gsi % 32);
>> +    set_bit(gsi, s->used_gsi_bitmap);
>>  }
>>  
>>  static void clear_gsi(KVMState *s, unsigned int gsi)
>>  {
>> -    s->used_gsi_bitmap[gsi / 32] &= ~(1U << (gsi % 32));
>> +    clear_bit(gsi, s->used_gsi_bitmap);
>>  }
>>  
>>  void kvm_init_irq_routing(KVMState *s)
>> @@ -965,17 +965,9 @@ void kvm_init_irq_routing(KVMState *s)
>>  
>>      gsi_count = kvm_check_extension(s, KVM_CAP_IRQ_ROUTING) - 1;
>>      if (gsi_count > 0) {
>> -        unsigned int gsi_bits, i;
>> -
>>          /* Round up so we can search ints using ffs */
>> -        gsi_bits = ALIGN(gsi_count, 32);
>> -        s->used_gsi_bitmap = g_malloc0(gsi_bits / 8);
>> +        s->used_gsi_bitmap = bitmap_new(gsi_count);
>>          s->gsi_count = gsi_count;
>> -
>> -        /* Mark any over-allocated bits as already in use */
>> -        for (i = gsi_count; i < gsi_bits; i++) {
>> -            set_gsi(s, i);
>> -        }
>>      }
>>  
>>      s->irq_routes = g_malloc0(sizeof(*s->irq_routes));
>> @@ -1105,9 +1097,7 @@ static void kvm_flush_dynamic_msi_routes(KVMState *s)
>>  
>>  static int kvm_irqchip_get_virq(KVMState *s)
>>  {
>> -    uint32_t *word = s->used_gsi_bitmap;
>> -    int max_words = ALIGN(s->gsi_count, 32) / 32;
>> -    int i, zeroes;
>> +    int next_virq;
>>  
>>      /*
>>       * PIC and IOAPIC share the first 16 GSI numbers, thus the available
>> @@ -1120,16 +1110,12 @@ static int kvm_irqchip_get_virq(KVMState *s)
>>      }
>>  
>>      /* Return the lowest unused GSI in the bitmap */
>> -    for (i = 0; i < max_words; i++) {
>> -        zeroes = ctz32(~word[i]);
>> -        if (zeroes == 32) {
>> -            continue;
>> -        }
>> -
>> -        return zeroes + i * 32;
>> +    next_virq = find_first_zero_bit(s->used_gsi_bitmap, s->gsi_count);
>> +    if (next_virq >= s->gsi_count) {
>> +            return -ENOSPC;
>> +    } else {
>> +            return next_virq;
>>      }
>> -    return -ENOSPC;
>> -
>>  }
>>  
>>  static KVMMSIRoute *kvm_lookup_msi_route(KVMState *s, MSIMessage msg)
>> 
>
>Queued, thanks.  I will send a pull request today.
>

Thanks, glad to contribute :-)

>Paolo
diff mbox

Patch

diff --git a/kvm-all.c b/kvm-all.c
index bd9e764..ed3f4a2 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -90,7 +90,7 @@  struct KVMState
 #ifdef KVM_CAP_IRQ_ROUTING
     struct kvm_irq_routing *irq_routes;
     int nr_allocated_irq_routes;
-    uint32_t *used_gsi_bitmap;
+    unsigned long *used_gsi_bitmap;
     unsigned int gsi_count;
     QTAILQ_HEAD(msi_hashtab, KVMMSIRoute) msi_hashtab[KVM_MSI_HASHTAB_SIZE];
 #endif
@@ -951,12 +951,12 @@  typedef struct KVMMSIRoute {
 
 static void set_gsi(KVMState *s, unsigned int gsi)
 {
-    s->used_gsi_bitmap[gsi / 32] |= 1U << (gsi % 32);
+    set_bit(gsi, s->used_gsi_bitmap);
 }
 
 static void clear_gsi(KVMState *s, unsigned int gsi)
 {
-    s->used_gsi_bitmap[gsi / 32] &= ~(1U << (gsi % 32));
+    clear_bit(gsi, s->used_gsi_bitmap);
 }
 
 void kvm_init_irq_routing(KVMState *s)
@@ -965,17 +965,9 @@  void kvm_init_irq_routing(KVMState *s)
 
     gsi_count = kvm_check_extension(s, KVM_CAP_IRQ_ROUTING) - 1;
     if (gsi_count > 0) {
-        unsigned int gsi_bits, i;
-
         /* Round up so we can search ints using ffs */
-        gsi_bits = ALIGN(gsi_count, 32);
-        s->used_gsi_bitmap = g_malloc0(gsi_bits / 8);
+        s->used_gsi_bitmap = bitmap_new(gsi_count);
         s->gsi_count = gsi_count;
-
-        /* Mark any over-allocated bits as already in use */
-        for (i = gsi_count; i < gsi_bits; i++) {
-            set_gsi(s, i);
-        }
     }
 
     s->irq_routes = g_malloc0(sizeof(*s->irq_routes));
@@ -1105,9 +1097,7 @@  static void kvm_flush_dynamic_msi_routes(KVMState *s)
 
 static int kvm_irqchip_get_virq(KVMState *s)
 {
-    uint32_t *word = s->used_gsi_bitmap;
-    int max_words = ALIGN(s->gsi_count, 32) / 32;
-    int i, zeroes;
+    int next_virq;
 
     /*
      * PIC and IOAPIC share the first 16 GSI numbers, thus the available
@@ -1120,16 +1110,12 @@  static int kvm_irqchip_get_virq(KVMState *s)
     }
 
     /* Return the lowest unused GSI in the bitmap */
-    for (i = 0; i < max_words; i++) {
-        zeroes = ctz32(~word[i]);
-        if (zeroes == 32) {
-            continue;
-        }
-
-        return zeroes + i * 32;
+    next_virq = find_first_zero_bit(s->used_gsi_bitmap, s->gsi_count);
+    if (next_virq >= s->gsi_count) {
+            return -ENOSPC;
+    } else {
+            return next_virq;
     }
-    return -ENOSPC;
-
 }
 
 static KVMMSIRoute *kvm_lookup_msi_route(KVMState *s, MSIMessage msg)