patch-2.4.19 linux-2.4.19/arch/i386/kernel/apic.c

• Lines: 96
• Date: Fri Aug 2 17:39:42 2002
• Orig file: linux-2.4.18/arch/i386/kernel/apic.c
• Orig date: Mon Feb 25 11:37:52 2002

diff -urN linux-2.4.18/arch/i386/kernel/apic.c linux-2.4.19/arch/i386/kernel/apic.c
@@ -582,12 +582,17 @@
  * Detect and enable local APICs on non-SMP boards.
  * Original code written by Keir Fraser.
  */
+int dont_enable_local_apic __initdata = 0;
 
 static int __init detect_init_APIC (void)
 {
 	u32 h, l, features;
 	extern void get_cpu_vendor(struct cpuinfo_x86*);
 
+	/* Disabled by DMI scan or kernel option? */
+	if (dont_enable_local_apic)
+		return -1;
+
 	/* Workaround for us being called before identify_cpu(). */
 	get_cpu_vendor(&boot_cpu_data);
 
@@ -679,7 +684,15 @@
 		for (i = 0; i < nr_ioapics; i++) {
 			if (smp_found_config) {
 				ioapic_phys = mp_ioapics[i].mpc_apicaddr;
+				if (!ioapic_phys) {
+					printk(KERN_ERR "WARNING: bogus zero IO-APIC address found in MPTABLE, disabling IO/APIC support!\n");
+
+					smp_found_config = 0;
+					skip_ioapic_setup = 1;
+					goto fake_ioapic_page;
+				}
 			} else {
+fake_ioapic_page:
 				ioapic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
 				ioapic_phys = __pa(ioapic_phys);
 			}
@@ -796,8 +809,7 @@
 	 */
 
 	slice = clocks / (smp_num_cpus+1);
-	printk("cpu: %d, clocks: %d, slice: %d\n",
-		smp_processor_id(), clocks, slice);
+	printk("cpu: %d, clocks: %d, slice: %d\n", smp_processor_id(), clocks, slice);
 
 	/*
 	 * Wait for IRQ0's slice:
@@ -820,8 +832,7 @@
 
 	__setup_APIC_LVTT(clocks);
 
-	printk("CPU%d<T0:%d,T1:%d,D:%d,S:%d,C:%d>\n",
-			smp_processor_id(), t0, t1, delta, slice, clocks);
+	printk("CPU%d<T0:%d,T1:%d,D:%d,S:%d,C:%d>\n", smp_processor_id(), t0, t1, delta, slice, clocks);
 
 	__restore_flags(flags);
 }
@@ -905,8 +916,14 @@
 
 static unsigned int calibration_result;
 
+int dont_use_local_apic_timer __initdata = 0;
+
 void __init setup_APIC_clocks (void)
 {
+	/* Disabled by DMI scan or kernel option? */
+	if (dont_use_local_apic_timer)
+		return;
+
 	printk("Using local APIC timer interrupts.\n");
 	using_apic_timer = 1;
 
@@ -924,6 +941,26 @@
 	smp_call_function(setup_APIC_timer, (void *)calibration_result, 1, 1);
 }
 
+void __init disable_APIC_timer(void)
+{
+	if (using_apic_timer) {
+		unsigned long v;
+
+		v = apic_read(APIC_LVTT);
+		apic_write_around(APIC_LVTT, v | APIC_LVT_MASKED);
+	}
+}
+
+void enable_APIC_timer(void)
+{
+	if (using_apic_timer) {
+		unsigned long v;
+
+		v = apic_read(APIC_LVTT);
+		apic_write_around(APIC_LVTT, v & ~APIC_LVT_MASKED);
+	}
+}
+
 /*
  * the frequency of the profiling timer can be changed
  * by writing a multiplier value into /proc/profile.