ARM/vgic: Use for_each_set_bit() in vgic_set_irqs_pending()

... which is better optimised for scalar values, rather than using the
arbitrary-sized bitmap helpers.

For ARM32:

  add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-16 (-16)
  Function                                     old     new   delta
  vgic_set_irqs_pending                        284     268     -16

including removing calls to _find_{first,next}_bit_le(), and two stack-spilled
words too.

For ARM64:

  add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-40 (-40)
  Function                                     old     new   delta
  vgic_set_irqs_pending                        268     228     -40

including removing three calls to find_next_bit().

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>

diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index 3fe1d89c4de219894d53d935eaab4c1fabd7e602..905e5eeb66d4638cbfef20e7dfd7412d919eb0ec 100644 (file)
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -421,15 +421,13 @@ void vgic_enable_irqs(struct vcpu *v, uint32_t r, unsigned int n)
 
 void vgic_set_irqs_pending(struct vcpu *v, uint32_t r, unsigned int rank)
 {
-    const unsigned long mask = r;
-    unsigned int i;
     /* The first rank is always per-vCPU */
     bool private = rank == 0;
 
     /* LPIs will never be set pending via this function */
     ASSERT(!is_lpi(32 * rank + 31));
 
-    bitmap_for_each ( i, &mask, 32 )
+    for_each_set_bit ( i, r )
     {
         unsigned int irq = i + 32 * rank;