hw/intc/arm_gicv3_redist: Factor out "update bit in pending table" code

Factor out the code which sets a single bit in an LPI pending table.
We're going to need this for handling vLPI tables, not just the
physical LPI table.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 24 insertions, 19 deletions

diff --git a/hw/intc/arm_gicv3_redist.c b/hw/intc/arm_gicv3_redist.c
index 600b080d79..9f8854b372 100644
--- a/hw/intc/arm_gicv3_redist.c
+++ b/hw/intc/arm_gicv3_redist.c
@@ -725,36 +725,41 @@ void gicv3_redist_update_lpi(GICv3CPUState *cs)
     gicv3_redist_update(cs);
 }
 
-void gicv3_redist_lpi_pending(GICv3CPUState *cs, int irq, int level)
+static bool set_pending_table_bit(GICv3CPUState *cs, uint64_t addr,
+                                  int irq, int level)
 {
     /*
-     * This function updates the pending bit in lpi pending table for
-     * the irq being activated or deactivated.
+     * Set the pending bit for LPI @irq to @level in the LPI pending table
+     * at guest address @addr. Returns true if we needed to do something,
+     * false if the bit was already at @level.
      */
     AddressSpace *as = &cs->gic->dma_as;
-    uint64_t lpipt_baddr;
-    bool ispend = false;
     uint8_t pend;
 
+    addr += irq / 8;
+    address_space_read(as, addr, MEMTXATTRS_UNSPECIFIED, &pend, sizeof(pend));
+    if (extract32(pend, irq % 8, 1) == level) {
+        /* Bit already at requested state, no action required */
+        return false;
+    }
+    pend = deposit32(pend, irq % 8, 1, level ? 1 : 0);
+    address_space_write(as, addr, MEMTXATTRS_UNSPECIFIED, &pend, sizeof(pend));
+    return true;
+}
+
+void gicv3_redist_lpi_pending(GICv3CPUState *cs, int irq, int level)
+{
     /*
-     * get the bit value corresponding to this irq in the
-     * lpi pending table
+     * This function updates the pending bit in lpi pending table for
+     * the irq being activated or deactivated.
      */
-    lpipt_baddr = cs->gicr_pendbaser & R_GICR_PENDBASER_PHYADDR_MASK;
-
-    address_space_read(as, lpipt_baddr + ((irq / 8) * sizeof(pend)),
-                       MEMTXATTRS_UNSPECIFIED, &pend, sizeof(pend));
-
-    ispend = extract32(pend, irq % 8, 1);
+    uint64_t lpipt_baddr;
 
-    /* no change in the value of pending bit, return */
-    if (ispend == level) {
+    lpipt_baddr = cs->gicr_pendbaser & R_GICR_PENDBASER_PHYADDR_MASK;
+    if (!set_pending_table_bit(cs, lpipt_baddr, irq, level)) {
+        /* no change in the value of pending bit, return */
         return;
     }
-    pend = deposit32(pend, irq % 8, 1, level ? 1 : 0);
-
-    address_space_write(as, lpipt_baddr + ((irq / 8) * sizeof(pend)),
-                        MEMTXATTRS_UNSPECIFIED, &pend, sizeof(pend));
 
     /*
      * check if this LPI is better than the current hpplpi, if yes