> > I'm unsure about the K7_NMI_EVENT macro -- I think it should go into
> > include/asm-i386/msr.h, but the comment should remain here. It should get
> > reworded a bit in this case, I suppose, though.
>
> I'd prefer to keep it in nmi.c -- it doesn't really have any relevance
> elsewhere. I made a macro of it so that I wouldn't need any #ifdef:s
> or long explanations in the code proper.
I'm worrying of numeric constants scattered throughout the source. As
0x76 is a generic K7 performance monitoring event it should exist in
include/asm-i386/msr.h only and be assigned to a macro with a readable
name. That's not a problem now, when it's only used in a single place,
but it will become a problem once somebody uses the constant elsewhere --
I bet he won't bother to search through the whole Linux tree to check if
it's already assigned a macro.
The name is certainly inappropriate for include/asm-i386/msr.h. Another
one should be used there and K7_NMI_EVENT defined to substitute it.
> ... however, nmi_perfctr_msr could serve this purpose since it will be
> non-zero if and only if (cpu_has_apic && nmi_watchdog == NMI_LOCAL_APIC).
> So I would actually suggest something like:
>
> if (nmi_perfctr_msr)
> wrmsr(nmi_perfctr_msr, -(cpu_khz/HZ*1000), -1);
Of course. Here is an updated patch.
Maciej
-- + Maciej W. Rozycki, Technical University of Gdansk, Poland + +--------------------------------------------------------------+ + e-mail: macro@ds2.pg.gda.pl, PGP key available +patch-2.4.1-ac1-upapic-21 diff -up --recursive --new-file linux-2.4.1-ac1.macro/arch/i386/kernel/apic.c linux-2.4.1-ac1/arch/i386/kernel/apic.c --- linux-2.4.1-ac1.macro/arch/i386/kernel/apic.c Fri Feb 2 12:32:24 2001 +++ linux-2.4.1-ac1/arch/i386/kernel/apic.c Fri Feb 2 13:25:21 2001 @@ -885,10 +885,10 @@ asmlinkage void smp_error_interrupt(void * This initializes the IO-APIC and APIC hardware if this is * a UP kernel. */ -void __init APIC_init_uniprocessor (void) +int __init APIC_init_uniprocessor (void) { if (!smp_found_config && !cpu_has_apic) - return; + return -1; /* * Complain if the BIOS pretends there is one. @@ -896,7 +896,7 @@ void __init APIC_init_uniprocessor (void if (!cpu_has_apic && APIC_INTEGRATED(apic_version[boot_cpu_id])) { printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n", boot_cpu_id); - return; + return -1; } verify_local_APIC(); @@ -915,4 +915,6 @@ void __init APIC_init_uniprocessor (void setup_IO_APIC(); #endif setup_APIC_clocks(); + + return 0; } diff -up --recursive --new-file linux-2.4.1-ac1.macro/arch/i386/kernel/io_apic.c linux-2.4.1-ac1/arch/i386/kernel/io_apic.c --- linux-2.4.1-ac1.macro/arch/i386/kernel/io_apic.c Fri Feb 2 12:32:24 2001 +++ linux-2.4.1-ac1/arch/i386/kernel/io_apic.c Fri Feb 2 13:05:37 2001 @@ -38,7 +38,6 @@ static spinlock_t ioapic_lock = SPIN_LOC /* * # of IRQ routing registers */ -int nr_ioapics; int nr_ioapic_registers[MAX_IO_APICS]; #if CONFIG_SMP diff -up --recursive --new-file linux-2.4.1-ac1.macro/arch/i386/kernel/mpparse.c linux-2.4.1-ac1/arch/i386/kernel/mpparse.c --- linux-2.4.1-ac1.macro/arch/i386/kernel/mpparse.c Fri Feb 2 12:32:24 2001 +++ linux-2.4.1-ac1/arch/i386/kernel/mpparse.c Fri Feb 2 13:05:37 2001 @@ -48,6 +48,8 @@ struct mpc_config_intsrc mp_irqs[MAX_IRQ /* MP IRQ source entries */ int mp_irq_entries; +int nr_ioapics; + int pic_mode; unsigned long mp_lapic_addr; diff -up --recursive --new-file linux-2.4.1-ac1.macro/arch/i386/kernel/nmi.c linux-2.4.1-ac1/arch/i386/kernel/nmi.c --- linux-2.4.1-ac1.macro/arch/i386/kernel/nmi.c Wed Jan 31 22:01:50 2001 +++ linux-2.4.1-ac1/arch/i386/kernel/nmi.c Fri Feb 2 13:25:21 2001 @@ -82,25 +82,34 @@ __setup("nmi_watchdog=", setup_nmi_watch /* * Activate the NMI watchdog via the local APIC. * Original code written by Keith Owens. + * AMD K7 code by Mikael Pettersson. */ -#define MSR_K7_EVNTSEL0 0xC0010000 -#define MSR_K7_PERFCTR0 0xC0010004 +static unsigned int nmi_perfctr_msr; /* the MSR to reset in NMI handler */ -void setup_apic_nmi_watchdog (void) +/* Event 0x76 isn't listed in recent revisions of AMD #22007, and it + slows down (but doesn't halt) when the CPU is idle. Unfortunately + the K7 doesn't appear to have any other clock-like perfctr event. */ +#define K7_NMI_EVENT 0x76 /* CYCLES_PROCESSOR_IS_RUNNING */ +#define K7_NMI_EVNTSEL ((1<<20)|(3<<16)|K7_NMI_EVENT) /* INT,OS,USR,<event> */ + +void __init setup_apic_nmi_watchdog (void) { int value; if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD && boot_cpu_data.x86 == 6) { - unsigned evntsel = (1<<20)|(3<<16); /* INT, OS, USR */ -#if 1 /* listed in old docs */ - evntsel |= 0x76; /* CYCLES_PROCESSOR_IS_RUNNING */ -#else /* try this if the above doesn't work */ - evntsel |= 0xC0; /* RETIRED_INSTRUCTIONS */ -#endif - wrmsr(MSR_K7_EVNTSEL0, 0, 0); - wrmsr(MSR_K7_PERFCTR0, 0, 0); + int i; + unsigned int evntsel; + + nmi_perfctr_msr = MSR_K7_PERFCTR0; + + for (i = 0; i < 4; ++i) { + wrmsr(MSR_K7_EVNTSEL0 + i, 0, 0); + wrmsr(MSR_K7_PERFCTR0 + i, 0, 0); + } + + evntsel = K7_NMI_EVNTSEL; wrmsr(MSR_K7_EVNTSEL0, evntsel, 0); printk("setting K7_PERFCTR0 to %08lx\n", -(cpu_khz/HZ*1000)); wrmsr(MSR_K7_PERFCTR0, -(cpu_khz/HZ*1000), -1); @@ -112,28 +121,35 @@ void setup_apic_nmi_watchdog (void) return; } - /* clear performance counters 0, 1 */ + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && + boot_cpu_data.x86 == 6) { + + nmi_perfctr_msr = MSR_IA32_PERFCTR1; - wrmsr(MSR_IA32_EVNTSEL0, 0, 0); - wrmsr(MSR_IA32_EVNTSEL1, 0, 0); - wrmsr(MSR_IA32_PERFCTR0, 0, 0); - wrmsr(MSR_IA32_PERFCTR1, 0, 0); - - /* send local-APIC timer counter overflow event as an NMI */ - - value = 1 << 20 /* Interrupt on overflow */ - | 1 << 17 /* OS mode */ - | 1 << 16 /* User mode */ - | 0x79; /* Event, cpu clocks not halted */ - wrmsr(MSR_IA32_EVNTSEL1, value, 0); - printk("PERFCTR1: %08lx\n", -(cpu_khz/HZ*1000)); - wrmsr(MSR_IA32_PERFCTR1, -(cpu_khz/HZ*1000), 0); - - /* Enable performance counters, only using ctr1 */ - - apic_write_around(APIC_LVTPC, APIC_DM_NMI); - value = 1 << 22; - wrmsr(MSR_IA32_EVNTSEL0, value, 0); + /* clear performance counters 0, 1 */ + + wrmsr(MSR_IA32_EVNTSEL0, 0, 0); + wrmsr(MSR_IA32_EVNTSEL1, 0, 0); + wrmsr(MSR_IA32_PERFCTR0, 0, 0); + wrmsr(MSR_IA32_PERFCTR1, 0, 0); + + /* send local-APIC timer counter overflow event as an NMI */ + + value = 1 << 20 /* Interrupt on overflow */ + | 1 << 17 /* OS mode */ + | 1 << 16 /* User mode */ + | 0x79; /* Event, cpu clocks not halted */ + wrmsr(MSR_IA32_EVNTSEL1, value, 0); + printk("PERFCTR1: %08lx\n", -(cpu_khz/HZ*1000)); + wrmsr(MSR_IA32_PERFCTR1, -(cpu_khz/HZ*1000), 0); + + /* Enable performance counters, only using ctr1 */ + + apic_write_around(APIC_LVTPC, APIC_DM_NMI); + value = 1 << 22; + wrmsr(MSR_IA32_EVNTSEL0, value, 0); + return; + } } static spinlock_t nmi_print_lock = SPIN_LOCK_UNLOCKED; @@ -190,14 +206,6 @@ void nmi_watchdog_tick (struct pt_regs * last_irq_sums[cpu] = sum; alert_counter[cpu] = 0; } - if (cpu_has_apic && (nmi_watchdog == NMI_LOCAL_APIC)) { - /* XXX: nmi_watchdog should carry this info */ - unsigned msr; - if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) { - wrmsr(MSR_K7_PERFCTR0, -(cpu_khz/HZ*1000), -1); - } else { - wrmsr(MSR_IA32_PERFCTR1, -(cpu_khz/HZ*1000), 0); - } - } + if (nmi_perfctr_msr) + wrmsr(nmi_perfctr_msr, -(cpu_khz/HZ*1000), -1); } - diff -up --recursive --new-file linux-2.4.1-ac1.macro/arch/i386/kernel/smpboot.c linux-2.4.1-ac1/arch/i386/kernel/smpboot.c --- linux-2.4.1-ac1.macro/arch/i386/kernel/smpboot.c Fri Feb 2 12:32:24 2001 +++ linux-2.4.1-ac1/arch/i386/kernel/smpboot.c Fri Feb 2 13:25:21 2001 @@ -868,12 +868,15 @@ void __init smp_boot_cpus(void) * get out of here now! */ if (!smp_found_config) { - printk(KERN_NOTICE "SMP motherboard not detected. Using dummy APIC emulation.\n"); + printk(KERN_NOTICE "SMP motherboard not detected.\n"); #ifndef CONFIG_VISWS io_apic_irqs = 0; #endif cpu_online_map = phys_cpu_present_map = 1; smp_num_cpus = 1; + if (APIC_init_uniprocessor()) + printk(KERN_NOTICE "Local APIC not detected." + " Using dummy APIC emulation.\n"); goto smp_done; } @@ -1019,4 +1022,3 @@ void __init smp_boot_cpus(void) smp_done: zap_low_mappings(); } - diff -up --recursive --new-file linux-2.4.1-ac1.macro/include/asm-i386/apic.h linux-2.4.1-ac1/include/asm-i386/apic.h --- linux-2.4.1-ac1.macro/include/asm-i386/apic.h Fri Feb 2 12:56:56 2001 +++ linux-2.4.1-ac1/include/asm-i386/apic.h Fri Feb 2 13:25:21 2001 @@ -77,7 +77,7 @@ extern void smp_local_timer_interrupt (s extern void setup_APIC_clocks (void); extern void setup_apic_nmi_watchdog (void); extern inline void nmi_watchdog_tick (struct pt_regs * regs); -extern void APIC_init_uniprocessor (void); +extern int APIC_init_uniprocessor (void); extern unsigned int apic_timer_irqs [NR_CPUS]; extern int check_nmi_watchdog (void); diff -up --recursive --new-file linux-2.4.1-ac1.macro/include/asm-i386/msr.h linux-2.4.1-ac1/include/asm-i386/msr.h --- linux-2.4.1-ac1.macro/include/asm-i386/msr.h Fri Feb 2 12:33:07 2001 +++ linux-2.4.1-ac1/include/asm-i386/msr.h Fri Feb 2 13:25:21 2001 @@ -67,4 +67,8 @@ #define MSR_IA32_MC0_MISC_OFFSET 0x3 #define MSR_IA32_MC0_BANK_COUNT 0x4 + +#define MSR_K7_EVNTSEL0 0xC0010000 +#define MSR_K7_PERFCTR0 0xC0010004 + #endif
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/