@@ -37,8 +37,27 @@
typedef PCIHostState I440FXState;
+#define PIIX_NUM_PIC_IRQS 16 /* i8259 * 2 */
+#define PIIX_NUM_PIRQS 4ULL /* PIRQ[A-D] */
+#define PIIX_PIRQC 0x60
+
typedef struct PIIX3State {
PCIDevice dev;
+
+ /*
+ * bitmap to track pic levels.
+ * The pic level is the logical OR of all the PCI irqs mapped to it
+ * So one PIC level is tracked by PIIX_NUM_PIRQS bits.
+ *
+ * PIRQ is mapped to PIC pins, we track it by
+ * PIIX_NUM_PIRQS * PIIX_NUM_PIC_IRQS = 64 bits with
+ * pic_irq * PIIX_NUM_PIRQS + pirq
+ */
+#if PIIX_NUM_PIC_IRQS * PIIX_NUM_PIRQS > 64
+#error "unable to encode pic state in 64bit in pic_levels."
+#endif
+ uint64_t pic_levels;
+
int32_t dummy_for_save_load_compat[4];
qemu_irq *pic;
} PIIX3State;
@@ -252,25 +271,63 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix3_devfn, qemu_irq *
}
/* PIIX3 PCI to ISA bridge */
+static void piix3_set_irq_pic(PIIX3State *piix3, int pic_irq)
+{
+ qemu_set_irq(piix3->pic[pic_irq],
+ !!(piix3->pic_levels &
+ ((PIIX_NUM_PIRQS - 1) << (pic_irq * PIIX_NUM_PIRQS))));
+}
+
+static void piix3_set_irq_level(PIIX3State *piix3, int irq_num, int level,
+ bool propagate)
+{
+ int pic_irq;
+ uint64_t mask;
+
+ pic_irq = piix3->dev.config[PIIX_PIRQC + irq_num];
+ if (pic_irq >= PIIX_NUM_PIC_IRQS) {
+ return;
+ }
+
+ mask = 1ULL << ((pic_irq * PIIX_NUM_PIRQS) + irq_num);
+ piix3->pic_levels &= ~mask;
+ piix3->pic_levels |= mask * !!level;
+
+ if (propagate) {
+ piix3_set_irq_pic(piix3, pic_irq);
+ }
+}
static void piix3_set_irq(void *opaque, int irq_num, int level)
{
- int i, pic_irq, pic_level;
PIIX3State *piix3 = opaque;
+ piix3_set_irq_level(piix3, irq_num, level, true);
+}
- /* now we change the pic irq level according to the piix irq mappings */
- /* XXX: optimize */
- pic_irq = piix3->dev.config[0x60 + irq_num];
- if (pic_irq < 16) {
- /* The pic level is the logical OR of all the PCI irqs mapped
- to it */
- pic_level = 0;
- for (i = 0; i < 4; i++) {
- if (pic_irq == piix3->dev.config[0x60 + i]) {
- pic_level |= pci_bus_get_irq_level(piix3->dev.bus, i);
- }
+/* irq routing is changed. so rebuild bitmap */
+static void piix3_update_irq_levels(PIIX3State *piix3)
+{
+ int pirq;
+
+ piix3->pic_levels = 0;
+ for (pirq = 0; pirq < PIIX_NUM_PIRQS; pirq++) {
+ piix3_set_irq_level(piix3, pirq,
+ pci_bus_get_irq_level(piix3->dev.bus, pirq),
+ false);
+ }
+}
+
+static void piix3_write_config(PCIDevice *dev,
+ uint32_t address, uint32_t val, int len)
+{
+ pci_default_write_config(dev, address, val, len);
+ if (ranges_overlap(address, len, PIIX_PIRQC, 4)) {
+ PIIX3State *piix3 = DO_UPCAST(PIIX3State, dev, dev);
+ int pic_irq;
+ piix3_update_irq_levels(piix3);
+ for (pic_irq = 0; pic_irq < PIIX_NUM_PIC_IRQS; pic_irq++) {
+ piix3_set_irq_pic(piix3, pic_irq);
}
- qemu_set_irq(piix3->pic[pic_irq], pic_level);
}
}
@@ -310,6 +367,15 @@ static void piix3_reset(void *opaque)
pci_conf[0xab] = 0x00;
pci_conf[0xac] = 0x00;
pci_conf[0xae] = 0x00;
+
+ d->pic_levels = 0;
+}
+
+static int piix3_post_load(void *opaque, int version_id)
+{
+ PIIX3State *piix3 = opaque;
+ piix3_update_irq_levels(piix3);
+ return 0;
}
static void piix3_pre_save(void *opaque)
@@ -328,6 +394,7 @@ static const VMStateDescription vmstate_piix3 = {
.version_id = 3,
.minimum_version_id = 2,
.minimum_version_id_old = 2,
+ .post_load = piix3_post_load,
.pre_save = piix3_pre_save,
.fields = (VMStateField []) {
VMSTATE_PCI_DEVICE(dev, PIIX3State),
@@ -370,6 +437,7 @@ static PCIDeviceInfo i440fx_info[] = {
.qdev.no_user = 1,
.no_hotplug = 1,
.init = piix3_initfn,
+ .config_write = piix3_write_config,
},{
/* end of list */
}
optimize irq routing in piix_pic.c which has been a TODO. So far piix3 tracks each pirq level and checks whether a given pic pins is asserted by seeing if each pirq is mapped into the pic pin. This is independent on irq routing, but data path is on slow path. Given that irq routing is rarely changed and asserting pic pins is on data path, the path that asserts pic pins should be optimized and chainging irq routing should be on slow path. The new behavior with this patch series is to use bitmap which is addressed by pirq and pic pins with a given irq routing. When pirq is asserted, the bitmap is set and see if the pic pins is asserted by checking the bitmaps. When irq routing is changed, rebuild the bitmap and re-assert pic pins. Cc: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp> --- hw/piix_pci.c | 94 +++++++++++++++++++++++++++++++++++++++++++++++++-------- 1 files changed, 81 insertions(+), 13 deletions(-)