[PATCH] x86-64: Try multiple timer variants in check_timer
Andi Kleen [Thu, 7 Dec 2006 01:14:06 +0000 (02:14 +0100)]
Instead of adding all kinds of more quirks try various timer
routing variants in check_timer.

In particular this tries to handle quirks from:
- Nvidia NF2-4 reference BIOS: wrong timer override
- Asus: Wrong timer override but no HPET table
- ATI: require timer disabled in 8259
- Some boards: require timer enabled in 8259

We just try many of the the known variants in the hopefully right order
in check_timer.

Trying pin 0/2 on Nvidia suggested by Tim Hockin.

TBD Experimental. Needs a lot of testing

Signed-off-by: Andi Kleen <ak@suse.de>

Documentation/x86_64/boot-options.txt
arch/x86_64/kernel/early-quirks.c
arch/x86_64/kernel/io_apic.c

index f3c57f4..ab9b1c0 100644 (file)
@@ -52,10 +52,6 @@ APICs
                 apicmaintimer. Useful when your PIT timer is totally
                 broken.
 
-   disable_8254_timer / enable_8254_timer
-                Enable interrupt 0 timer routing over the 8254 in addition to over
-                the IO-APIC. The kernel tries to set a sensible default.
-
 Early Console
 
    syntax: earlyprintk=vga
index 68273bf..fb0c6da 100644 (file)
@@ -69,11 +69,6 @@ static void nvidia_bugs(void)
 
 static void ati_bugs(void)
 {
-       if (timer_over_8254 == 1) {
-               timer_over_8254 = 0;
-               printk(KERN_INFO
-               "ATI board detected. Disabling timer routing over 8254.\n");
-       }
 }
 
 struct chipset {
index f71461b..88fcc4e 100644 (file)
@@ -55,10 +55,6 @@ int sis_apic_bug; /* not actually supported, dummy for compile */
 
 static int no_timer_check;
 
-static int disable_timer_pin_1 __initdata;
-
-int timer_over_8254 __initdata = 1;
-
 /* Where if anywhere is the i8259 connect in external int mode */
 static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
 
@@ -348,29 +344,6 @@ static int __init disable_ioapic_setup(char *str)
 }
 early_param("noapic", disable_ioapic_setup);
 
-/* Actually the next is obsolete, but keep it for paranoid reasons -AK */
-static int __init disable_timer_pin_setup(char *arg)
-{
-       disable_timer_pin_1 = 1;
-       return 1;
-}
-__setup("disable_timer_pin_1", disable_timer_pin_setup);
-
-static int __init setup_disable_8254_timer(char *s)
-{
-       timer_over_8254 = -1;
-       return 1;
-}
-static int __init setup_enable_8254_timer(char *s)
-{
-       timer_over_8254 = 2;
-       return 1;
-}
-
-__setup("disable_8254_timer", setup_disable_8254_timer);
-__setup("enable_8254_timer", setup_enable_8254_timer);
-
-
 /*
  * Find the IRQ entry number of a certain pin.
  */
@@ -1579,10 +1552,33 @@ static inline void unlock_ExtINT_logic(void)
  * a wide range of boards and BIOS bugs.  Fortunately only the timer IRQ
  * is so screwy.  Thanks to Brian Perkins for testing/hacking this beast
  * fanatically on his truly buggy board.
- *
- * FIXME: really need to revamp this for modern platforms only.
  */
-static inline void check_timer(void)
+
+static int try_apic_pin(int apic, int pin, char *msg)
+{
+       apic_printk(APIC_VERBOSE, KERN_INFO
+                   "..TIMER: trying IO-APIC=%d PIN=%d %s",
+                   apic, pin, msg);
+
+       /*
+        * Ok, does IRQ0 through the IOAPIC work?
+        */
+       if (!no_timer_check && timer_irq_works()) {
+               nmi_watchdog_default();
+               if (nmi_watchdog == NMI_IO_APIC) {
+                       disable_8259A_irq(0);
+                       setup_nmi();
+                       enable_8259A_irq(0);
+               }
+               return 1;
+       }
+       clear_IO_APIC_pin(apic, pin);
+       apic_printk(APIC_QUIET, KERN_ERR " .. failed\n");
+       return 0;
+}
+
+/* The function from hell */
+static void check_timer(void)
 {
        int apic1, pin1, apic2, pin2;
        int vector;
@@ -1603,61 +1599,43 @@ static inline void check_timer(void)
         */
        apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
        init_8259A(1);
-       if (timer_over_8254 > 0)
-               enable_8259A_irq(0);
 
        pin1  = find_isa_irq_pin(0, mp_INT);
        apic1 = find_isa_irq_apic(0, mp_INT);
        pin2  = ioapic_i8259.pin;
        apic2 = ioapic_i8259.apic;
 
-       apic_printk(APIC_VERBOSE,KERN_INFO "..TIMER: vector=0x%02X apic1=%d pin1=%d apic2=%d pin2=%d\n",
-               vector, apic1, pin1, apic2, pin2);
+       /* Do this first, otherwise we get double interrupts on ATI boards */
+       if ((pin1 != -1) && try_apic_pin(apic1, pin1,"with 8259 IRQ0 disabled"))
+               return;
 
-       if (pin1 != -1) {
-               /*
-                * Ok, does IRQ0 through the IOAPIC work?
-                */
-               unmask_IO_APIC_irq(0);
-               if (!no_timer_check && timer_irq_works()) {
-                       nmi_watchdog_default();
-                       if (nmi_watchdog == NMI_IO_APIC) {
-                               disable_8259A_irq(0);
-                               setup_nmi();
-                               enable_8259A_irq(0);
-                       }
-                       if (disable_timer_pin_1 > 0)
-                               clear_IO_APIC_pin(0, pin1);
-                       return;
-               }
-               clear_IO_APIC_pin(apic1, pin1);
-               apic_printk(APIC_QUIET,KERN_ERR "..MP-BIOS bug: 8254 timer not "
-                               "connected to IO-APIC\n");
-       }
+       /* Now try again with IRQ0 8259A enabled.
+          Assumes timer is on IO-APIC 0 ?!? */
+       enable_8259A_irq(0);
+       unmask_IO_APIC_irq(0);
+       if (try_apic_pin(apic1, pin1, "with 8259 IRQ0 enabled"))
+               return;
+       disable_8259A_irq(0);
 
-       apic_printk(APIC_VERBOSE,KERN_INFO "...trying to set up timer (IRQ0) "
-                               "through the 8259A ... ");
+       /* Always try pin0 and pin2 on APIC 0 to handle buggy timer overrides
+          on Nvidia boards */
+       if (!(apic1 == 0 && pin1 == 0) &&
+           try_apic_pin(0, 0, "fallback with 8259 IRQ0 disabled"))
+               return;
+       if (!(apic1 == 0 && pin1 == 2) &&
+           try_apic_pin(0, 2, "fallback with 8259 IRQ0 disabled"))
+               return;
+
+       /* Then try pure 8259A routing on the 8259 as reported by BIOS*/
+       enable_8259A_irq(0);
        if (pin2 != -1) {
-               apic_printk(APIC_VERBOSE,"\n..... (found apic %d pin %d) ...",
-                       apic2, pin2);
-               /*
-                * legacy devices should be connected to IO APIC #0
-                */
                setup_ExtINT_IRQ0_pin(apic2, pin2, vector);
-               if (timer_irq_works()) {
-                       apic_printk(APIC_VERBOSE," works.\n");
-                       nmi_watchdog_default();
-                       if (nmi_watchdog == NMI_IO_APIC) {
-                               setup_nmi();
-                       }
+               if (try_apic_pin(apic2,pin2,"8259A broadcast ExtINT from BIOS"))
                        return;
-               }
-               /*
-                * Cleanup, just in case ...
-                */
-               clear_IO_APIC_pin(apic2, pin2);
        }
-       apic_printk(APIC_VERBOSE," failed.\n");
+
+       /* Tried all possibilities to go through the IO-APIC. Now come the
+          really cheesy fallbacks. */
 
        if (nmi_watchdog == NMI_IO_APIC) {
                printk(KERN_WARNING "timer doesn't work through the IO-APIC - disabling NMI Watchdog!\n");