[Xen-devel] [RFC 08/16] gic: separate ppi processing

[Andrii Anisov <andrii.anisov@xxxxxxxxx>]

From: Andrii Anisov <andrii_anisov@xxxxxxxx>

PPI are pcpu private, so their processing is not concurrent and do not
need pcpu shared flags and correspondent lockings. So avoid odd bits
sets, checks and locks.

Signed-off-by: Andrii Anisov <andrii_anisov@xxxxxxxx>
---
 xen/arch/arm/gic.c        |  8 ++++++--
 xen/arch/arm/irq.c        | 32 ++++++++++++++++++++++++++++++++
 xen/include/asm-arm/irq.h |  1 +
 3 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index b10783b..52e4270 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -387,8 +387,7 @@ void gic_interrupt(struct cpu_user_regs *regs, int is_fiq)
     do  {
         /* Reading IRQ will ACK it */
         irq = gic_hw_ops->read_irq();
-
-        if ( likely(irq >= 16 && irq < 1020) )
+        if ( likely(irq >= 32 && irq < 1020) )
         {
             isb();
             do_IRQ(regs, irq, is_fiq);
@@ -406,6 +405,11 @@ void gic_interrupt(struct cpu_user_regs *regs, int is_fiq)
         {
             do_sgi(regs, irq);
         }
+        else if ( irq < 32 )
+        {
+            isb();
+            do_ppi(regs, irq);
+        }
         else
         {
             local_irq_disable();
diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c
index 098281f..596a8b8 100644
--- a/xen/arch/arm/irq.c
+++ b/xen/arch/arm/irq.c
@@ -268,6 +268,38 @@ out_no_end:
     irq_exit();
 }
 
+void do_ppi(struct cpu_user_regs *regs, unsigned int irq)
+{
+    struct irq_desc *desc = irq_to_desc(irq);
+    struct irqaction *action;
+
+    irq_enter();
+
+    desc->handler->ack(desc);
+
+    if ( unlikely(!desc->action) )
+    {
+        printk("Unknown %s %#3.3x\n",
+               "IRQ", irq);
+        goto out;
+    }
+
+    if ( test_bit(_IRQ_DISABLED, &desc->status) )
+        goto out;
+
+    action = desc->action;
+
+    do
+    {
+        action->handler(irq, action->dev_id, regs);
+        action = action->next;
+    } while ( action );
+
+out:
+    desc->handler->end(desc);
+    irq_exit();
+}
+
 void release_irq(unsigned int irq, const void *dev_id)
 {
     struct irq_desc *desc;
diff --git a/xen/include/asm-arm/irq.h b/xen/include/asm-arm/irq.h
index 4f1ef3c..3143468 100644
--- a/xen/include/asm-arm/irq.h
+++ b/xen/include/asm-arm/irq.h
@@ -62,6 +62,7 @@ struct irq_desc *__irq_to_desc(int irq);
 #define irq_to_desc(irq)    __irq_to_desc(irq)
 
 void do_IRQ(struct cpu_user_regs *regs, unsigned int irq, int is_fiq);
+void do_ppi(struct cpu_user_regs *regs, unsigned int irq);
 
 #ifdef CONFIG_GICV3
 static inline bool is_lpi(unsigned int irq)
-- 
2.7.4


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