[Qemu-devel] [PATCH v2 7/8] xics: Implement xics_ics_free()

[Alexey Kardashevskiy <aik@ozlabs.ru>]

This implements interrupt release function so IRQs can be returned back
to the pool for reuse in cases such as PCI hot plug.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---
 hw/intc/xics.c        | 25 +++++++++++++++++++++++++
 include/hw/ppc/xics.h |  1 +
 trace-events          |  2 ++
 3 files changed, 28 insertions(+)

diff --git a/hw/intc/xics.c b/hw/intc/xics.c
index 1a8cfd7..f6a2066 100644
--- a/hw/intc/xics.c
+++ b/hw/intc/xics.c
@@ -766,6 +766,31 @@ int xics_alloc_block(XICSState *icp, int src, int num, bool lsi, bool align)
     return first;
 }
 
+static void ics_free(ICSState *ics, int srcno, int num)
+{
+    int i;
+
+    for (i = srcno; i < srcno + num; ++i) {
+        if (ICS_IRQ_FREE(ics, i)) {
+            trace_xics_ics_free_warn(ics - ics->icp->ics, i + ics->offset);
+        }
+        memset(&ics->irqs[i], 0, sizeof(ICSIRQState));
+    }
+}
+
+void xics_free(XICSState *icp, int src, int irq, int num)
+{
+    ICSState *ics = &icp->ics[src];
+
+    /* FIXME: implement multiple sources */
+    assert(src == 0);
+
+    trace_xics_ics_free(ics - icp->ics, irq, num);
+    if (src >= 0) {
+        ics_free(ics, irq - ics->offset, num);
+    }
+}
+
 /*
  * Guest interfaces
  */
diff --git a/include/hw/ppc/xics.h b/include/hw/ppc/xics.h
index 0d8af1b..267d045 100644
--- a/include/hw/ppc/xics.h
+++ b/include/hw/ppc/xics.h
@@ -159,6 +159,7 @@ struct ICSIRQState {
 qemu_irq xics_get_qirq(XICSState *icp, int irq);
 int xics_alloc(XICSState *icp, int src, int irq_hint, bool lsi);
 int xics_alloc_block(XICSState *icp, int src, int num, bool lsi, bool align);
+void xics_free(XICSState *icp, int src, int irq, int num);
 
 void xics_cpu_setup(XICSState *icp, PowerPCCPU *cpu);
 
diff --git a/trace-events b/trace-events
index d8e83cc..0a66c71 100644
--- a/trace-events
+++ b/trace-events
@@ -1182,6 +1182,8 @@ xics_alloc(int src, int irq) "source#%d, irq %d"
 xics_alloc_failed_hint(int src, int irq) "source#%d, irq %d is already in use"
 xics_alloc_failed_no_left(int src) "source#%d, no irq left"
 xics_alloc_block(int src, int first, int num, bool lsi, int align) "source#%d, first irq %d, %d irqs, lsi=%d, alignnum %d"
+xics_ics_free(int src, int irq, int num) "Source#%d, first irq %d, %d irqs"
+xics_ics_free_warn(int src, int irq) "Source#%d, irq %d is already free"
 
 # hw/ppc/spapr_iommu.c
 spapr_iommu_put(uint64_t liobn, uint64_t ioba, uint64_t tce, uint64_t ret) "liobn=%"PRIx64" ioba=0x%"PRIx64" tce=0x%"PRIx64" ret=%"PRId64
-- 
1.9.rc0