KVM: arm/arm64: Optimize away redundant LR tracking

Currently we use vgic_irq_lr_map in order to track which LRs hold which
IRQs, and lr_used bitmap in order to track which LRs are used or free.

vgic_irq_lr_map is actually used only for piggy-back optimization, and
can be easily replaced by iteration over lr_used. This is good because in
future, when LPI support is introduced, number of IRQs will grow up to at
least 16384, while numbers from 1024 to 8192 are never going to be used.
This would be a huge memory waste.

In its turn, lr_used is also completely redundant since
ae705930fca6322600690df9dc1c7d0516145a93 ("arm/arm64: KVM: Keep elrsr/aisr
in sync with software model"), because together with lr_used we also update
elrsr. This allows to easily replace lr_used with elrsr, inverting all
conditions (because in elrsr '1' means 'free').

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

1 files changed, 0 insertions, 6 deletions

diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 8065801a1847..3936bf802e1d 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -295,9 +295,6 @@ struct vgic_v3_cpu_if {
 };
 
 struct vgic_cpu {
-        /* per IRQ to LR mapping */
-        u8              *vgic_irq_lr_map;
-
         /* Pending/active/both interrupts on this VCPU */
         DECLARE_BITMAP(pending_percpu, VGIC_NR_PRIVATE_IRQS);
         DECLARE_BITMAP(active_percpu, VGIC_NR_PRIVATE_IRQS);
@@ -308,9 +305,6 @@ struct vgic_cpu {
         unsigned long   *active_shared;
         unsigned long   *pend_act_shared;
 
-        /* Bitmap of used/free list registers */
-        DECLARE_BITMAP(lr_used, VGIC_V2_MAX_LRS);
-
         /* Number of list registers on this CPU */
         int             nr_lr;