x86, ioapic: Simplify probe_nr_irqs_gsi.

Use the global gsi_end value now that all ioapics have
valid gsi numbers instead of a combination of acpi_probe_gsi
and walking all of the ioapics and couting their number of
entries by hand if acpi_probe_gsi gave us an answer we did
not like.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
LKML-Reference: <1269936436-7039-13-git-send-email-ebiederm@xmission.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/include/asm/mpspec.h

@@ -105,12 +105,6 @@ extern void mp_config_acpi_legacy_irqs(void);
 struct device;
 extern int mp_register_gsi(struct device *dev, u32 gsi, int edge_level,
 				 int active_high_low);
-extern int acpi_probe_gsi(void);
-#else /* !CONFIG_ACPI: */
-static inline int acpi_probe_gsi(void)
-{
-	return 0;
-}
 #endif /* CONFIG_ACPI */
 
 #define PHYSID_ARRAY_SIZE	BITS_TO_LONGS(MAX_APICS)

arch/x86/kernel/acpi/boot.c

@@ -876,29 +876,6 @@ static int __init acpi_parse_madt_lapic_entries(void)
 extern int es7000_plat;
 #endif
 
-int __init acpi_probe_gsi(void)
-{
-	int idx;
-	int gsi;
-	int max_gsi = 0;
-
-	if (acpi_disabled)
-		return 0;
-
-	if (!acpi_ioapic)
-		return 0;
-
-	max_gsi = 0;
-	for (idx = 0; idx < nr_ioapics; idx++) {
-		gsi = mp_gsi_routing[idx].gsi_end;
-
-		if (gsi > max_gsi)
-			max_gsi = gsi;
-	}
-
-	return max_gsi + 1;
-}
-
 static void assign_to_mp_irq(struct mpc_intsrc *m,
 				    struct mpc_intsrc *mp_irq)
 {

arch/x86/kernel/apic/io_apic.c

@@ -3850,22 +3850,11 @@ int __init io_apic_get_redir_entries (int ioapic)
 
 void __init probe_nr_irqs_gsi(void)
 {
-	int nr = 0;
+	int nr;
 
-	nr = acpi_probe_gsi();
-	if (nr > nr_irqs_gsi) {
+	nr = gsi_end + 1;
+	if (nr > nr_irqs_gsi)
 		nr_irqs_gsi = nr;
-	} else {
-		/* for acpi=off or acpi is not compiled in */
-		int idx;
-
-		nr = 0;
-		for (idx = 0; idx < nr_ioapics; idx++)
-			nr += io_apic_get_redir_entries(idx);
-
-		if (nr > nr_irqs_gsi)
-			nr_irqs_gsi = nr;
-	}
 
 	printk(KERN_DEBUG "nr_irqs_gsi: %d\n", nr_irqs_gsi);
 }