From 343b4f3a4f6822a97c1e4b8fa2604a17240322af Mon Sep 17 00:00:00 2001
From: Sepherosa Ziehau <sephe@dragonflybsd.org>
Date: Tue, 30 Oct 2012 10:53:59 +0800
Subject: [PATCH] ioapic/x86_64: Allow GSI > 191

Some BIOSes seem to assume that all 256 IDT vectors could be used,
while we limit the available IDT vectors percpu to 192.   Find an
unused IRQ for these GSIs, if this ever happens.

Reported-by: thowe on EFnet #dragonflybsd
---
 sys/platform/pc64/apic/ioapic_abi.c | 44 +++++++++++++++++++++++++----
 1 file changed, 38 insertions(+), 6 deletions(-)

diff --git a/sys/platform/pc64/apic/ioapic_abi.c b/sys/platform/pc64/apic/ioapic_abi.c
index 367e70f28b..9d8b79b282 100644
--- a/sys/platform/pc64/apic/ioapic_abi.c
+++ b/sys/platform/pc64/apic/ioapic_abi.c
@@ -518,6 +518,7 @@ static void	ioapic_abi_initmap(void);
 static void	ioapic_abi_rman_setup(struct rman *);
 
 static int	ioapic_abi_gsi_cpuid(int, int);
+static int	ioapic_find_unused_irqmap(int);
 
 struct machintr_abi MachIntrABI_IOAPIC = {
 	MACHINTR_IOAPIC,
@@ -764,6 +765,22 @@ ioapic_abi_initmap(void)
 	}
 }
 
+static int
+ioapic_find_unused_irqmap(int gsi)
+{
+	int cpuid, i;
+
+	cpuid = ioapic_abi_gsi_cpuid(-1, gsi);
+
+	for (i = ISA_IRQ_CNT; i < IOAPIC_HWI_VECTORS; ++i) {
+		if (i == acpi_sci_irqno())
+			continue;
+		if (ioapic_irqmaps[cpuid][i].im_type == IOAPIC_IMT_UNUSED)
+			return i;
+	}
+	return -1;
+}
+
 void
 ioapic_set_legacy_irqmap(int irq, int gsi, enum intr_trigger trig,
     enum intr_polarity pola)
@@ -776,7 +793,21 @@ ioapic_set_legacy_irqmap(int irq, int gsi, enum intr_trigger trig,
 	KKASSERT(trig == INTR_TRIGGER_EDGE || trig == INTR_TRIGGER_LEVEL);
 	KKASSERT(pola == INTR_POLARITY_HIGH || pola == INTR_POLARITY_LOW);
 
-	KKASSERT(irq >= 0 && irq < IOAPIC_HWI_VECTORS);
+	KKASSERT(irq >= 0);
+	if (irq >= IOAPIC_HWI_VECTORS) {
+		/*
+		 * Some BIOSes seem to assume that all 256 IDT vectors
+		 * could be used, while we limit the available IDT
+		 * vectors to 192; find an unused IRQ for this GSI.
+		 */
+		irq = ioapic_find_unused_irqmap(gsi);
+		if (irq < 0) {
+			kprintf("failed to find unused irq for gsi %d\n", gsi);
+			return;
+		}
+	}
+	KKASSERT(irq < IOAPIC_HWI_VECTORS);
+
 	if (irq > ioapic_abi_legacy_irq_max)
 		ioapic_abi_legacy_irq_max = irq;
 
@@ -1088,6 +1119,7 @@ ioapic_abi_gsi_cpuid(int irq, int gsi)
 	KKASSERT(gsi >= 0);
 
 	if (irq == 0 || gsi == 0) {
+		KKASSERT(irq >= 0);
 		if (bootverbose) {
 			kprintf("IOAPIC: irq %d, gsi %d -> cpu0 (0)\n",
 			    irq, gsi);
@@ -1095,7 +1127,7 @@ ioapic_abi_gsi_cpuid(int irq, int gsi)
 		return 0;
 	}
 
-	if (irq == acpi_sci_irqno()) {
+	if (irq >= 0 && irq == acpi_sci_irqno()) {
 		if (bootverbose) {
 			kprintf("IOAPIC: irq %d, gsi %d -> cpu0 (sci)\n",
 			    irq, gsi);
@@ -1108,7 +1140,7 @@ ioapic_abi_gsi_cpuid(int irq, int gsi)
 
 	if (cpuid < 0) {
 		if (!ioapic_abi_gsi_balance) {
-			if (bootverbose) {
+			if (irq >= 0 && bootverbose) {
 				kprintf("IOAPIC: irq %d, gsi %d -> cpu0 "
 				    "(fixed)\n", irq, gsi);
 			}
@@ -1116,18 +1148,18 @@ ioapic_abi_gsi_cpuid(int irq, int gsi)
 		}
 
 		cpuid = gsi % ncpus;
-		if (bootverbose) {
+		if (irq >= 0 && bootverbose) {
 			kprintf("IOAPIC: irq %d, gsi %d -> cpu%d (auto)\n",
 			    irq, gsi, cpuid);
 		}
 	} else if (cpuid >= ncpus) {
 		cpuid = ncpus - 1;
-		if (bootverbose) {
+		if (irq >= 0 && bootverbose) {
 			kprintf("IOAPIC: irq %d, gsi %d -> cpu%d (fixup)\n",
 			    irq, gsi, cpuid);
 		}
 	} else {
-		if (bootverbose) {
+		if (irq >= 0 && bootverbose) {
 			kprintf("IOAPIC: irq %d, gsi %d -> cpu%d (user)\n",
 			    irq, gsi, cpuid);
 		}
-- 
2.41.0