Call ata_legacy() only once on attach and save it's result. Scanning PCI

configuration registers (which are not going to change) on every interrupt
looks expensive, especially when interrupt is shared. Profiling shows me 3%
of time spent by atapci0 on pure network load due to IRQ sharing with em0.

1 files changed, 19 insertions, 11 deletions

diff --git a/sys/dev/ata/ata-pci.c b/sys/dev/ata/ata-pci.c
index 855a1d0..f2e4805 100644
--- a/sys/dev/ata/ata-pci.c
+++ b/sys/dev/ata/ata-pci.c
@@ -92,7 +92,8 @@ ata_pci_attach(device_t dev)
     int unit;
 
     /* do chipset specific setups only needed once */
-    if (ata_legacy(dev) || pci_read_config(dev, PCIR_BAR(2), 4) & IOMASK)
+    ctlr->legacy = ata_legacy(dev);
+    if (ctlr->legacy || pci_read_config(dev, PCIR_BAR(2), 4) & IOMASK)
 	ctlr->channels = 2;
     else
 	ctlr->channels = 1;
@@ -120,7 +121,7 @@ ata_pci_attach(device_t dev)
 
     /* attach all channels on this controller */
     for (unit = 0; unit < ctlr->channels; unit++) {
-	if ((unit == 0 || unit == 1) && ata_legacy(dev)) {
+	if ((unit == 0 || unit == 1) && ctlr->legacy) {
 	    device_add_child(dev, "ata", unit);
 	    continue;
 	}
@@ -192,7 +193,7 @@ ata_pci_alloc_resource(device_t dev, device_t child, int type, int *rid,
     if (type == SYS_RES_IOPORT) {
 	switch (*rid) {
 	case ATA_IOADDR_RID:
-	    if (ata_legacy(dev)) {
+	    if (controller->legacy) {
 		start = (unit ? ATA_SECONDARY : ATA_PRIMARY);
 		count = ATA_IOSIZE;
 		end = start + count - 1;
@@ -204,7 +205,7 @@ ata_pci_alloc_resource(device_t dev, device_t child, int type, int *rid,
 	    break;
 
 	case ATA_CTLADDR_RID:
-	    if (ata_legacy(dev)) {
+	    if (controller->legacy) {
 		start = (unit ? ATA_SECONDARY : ATA_PRIMARY) + ATA_CTLOFFSET;
 		count = ATA_CTLIOSIZE;
 		end = start + count - 1;
@@ -217,7 +218,7 @@ ata_pci_alloc_resource(device_t dev, device_t child, int type, int *rid,
 	}
     }
     if (type == SYS_RES_IRQ && *rid == ATA_IRQ_RID) {
-	if (ata_legacy(dev)) {
+	if (controller->legacy) {
 	    int irq = (unit == 0 ? 14 : 15);
 	    
 	    res = BUS_ALLOC_RESOURCE(device_get_parent(dev), child,
@@ -233,6 +234,7 @@ int
 ata_pci_release_resource(device_t dev, device_t child, int type, int rid,
 			 struct resource *r)
 {
+    struct ata_pci_controller *controller = device_get_softc(dev);
     int unit = ((struct ata_channel *)device_get_softc(child))->unit;
 
     if (type == SYS_RES_IOPORT) {
@@ -256,7 +258,7 @@ ata_pci_release_resource(device_t dev, device_t child, int type, int rid,
 	if (rid != ATA_IRQ_RID)
 	    return ENOENT;
 
-	if (ata_legacy(dev)) {
+	if (controller->legacy) {
 	    return BUS_RELEASE_RESOURCE(device_get_parent(dev), child,
 					SYS_RES_IRQ, rid, r);
 	}
@@ -271,7 +273,9 @@ ata_pci_setup_intr(device_t dev, device_t child, struct resource *irq,
 		   int flags, driver_filter_t *filter, driver_intr_t *function, 
 		   void *argument, void **cookiep)
 {
-    if (ata_legacy(dev)) {
+    struct ata_pci_controller *controller = device_get_softc(dev);
+
+    if (controller->legacy) {
 	return BUS_SETUP_INTR(device_get_parent(dev), child, irq,
 			      flags, filter, function, argument, cookiep);
     }
@@ -294,7 +298,9 @@ int
 ata_pci_teardown_intr(device_t dev, device_t child, struct resource *irq,
 		      void *cookie)
 {
-    if (ata_legacy(dev)) {
+    struct ata_pci_controller *controller = device_get_softc(dev);
+
+    if (controller->legacy) {
 	return BUS_TEARDOWN_INTR(device_get_parent(dev), child, irq, cookie);
     }
     else {
@@ -352,7 +358,7 @@ ata_pci_allocate(device_t dev)
 	ch->r_io[i].offset = i;
     }
     ch->r_io[ATA_CONTROL].res = ctlio;
-    ch->r_io[ATA_CONTROL].offset = ata_legacy(device_get_parent(dev)) ? 0 : 2;
+    ch->r_io[ATA_CONTROL].offset = ctlr->legacy ? 0 : 2;
     ch->r_io[ATA_IDX_ADDR].res = io;
     ata_default_registers(dev);
     if (ctlr->r_res1) {
@@ -369,9 +375,11 @@ ata_pci_allocate(device_t dev)
 int
 ata_pci_status(device_t dev)
 {
+    struct ata_pci_controller *controller =
+	device_get_softc(device_get_parent(dev));
     struct ata_channel *ch = device_get_softc(dev);
 
-    if ((dumping || !ata_legacy(device_get_parent(dev))) &&
+    if ((dumping || !controller->legacy) &&
 	((ch->flags & ATA_ALWAYS_DMASTAT) ||
 	 (ch->dma.flags & ATA_DMA_ACTIVE))) {
 	int bmstat = ATA_IDX_INB(ch, ATA_BMSTAT_PORT) & ATA_BMSTAT_MASK;
@@ -652,7 +660,7 @@ ata_setup_interrupt(device_t dev, void *intr_func)
     struct ata_pci_controller *ctlr = device_get_softc(dev);
     int rid = ATA_IRQ_RID;
 
-    if (!ata_legacy(dev)) {
+    if (!ctlr->legacy) {
 	if (!(ctlr->r_irq = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
 						   RF_SHAREABLE | RF_ACTIVE))) {
 	    device_printf(dev, "unable to map interrupt\n");