1 files changed, 329 insertions, 0 deletions
diff --git a/arch/powerpc/oprofile/op_model_power4.c b/arch/powerpc/oprofile/op_model_power4.c
new file mode 100644
index 000000000000..a3401b46f3ba
--- /dev/null
+++ b/arch/powerpc/oprofile/op_model_power4.c
@@ -0,0 +1,329 @@
+/*
+ * Copyright (C) 2004 Anton Blanchard <anton@au.ibm.com>, IBM
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/oprofile.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <asm/ptrace.h>
+#include <asm/system.h>
+#include <asm/processor.h>
+#include <asm/cputable.h>
+#include <asm/rtas.h>
+#include <asm/oprofile_impl.h>
+#include <asm/reg.h>
+
+#define dbg(args...)
+
+static unsigned long reset_value[OP_MAX_COUNTER];
+
+static int oprofile_running;
+static int mmcra_has_sihv;
+
+/* mmcr values are set in power4_reg_setup, used in power4_cpu_setup */
+static u32 mmcr0_val;
+static u64 mmcr1_val;
+static u32 mmcra_val;
+
+/*
+ * Since we do not have an NMI, backtracing through spinlocks is
+ * only a best guess. In light of this, allow it to be disabled at
+ * runtime.
+ */
+static int backtrace_spinlocks;
+
+static void power4_reg_setup(struct op_counter_config *ctr,
+			     struct op_system_config *sys,
+			     int num_ctrs)
+{
+	int i;
+
+	/*
+	 * SIHV / SIPR bits are only implemented on POWER4+ (GQ) and above.
+	 * However we disable it on all POWER4 until we verify it works
+	 * (I was seeing some strange behaviour last time I tried).
+	 *
+	 * It has been verified to work on POWER5 so we enable it there.
+	 */
+	if (cpu_has_feature(CPU_FTR_MMCRA_SIHV))
+		mmcra_has_sihv = 1;
+
+	/*
+	 * The performance counter event settings are given in the mmcr0,
+	 * mmcr1 and mmcra values passed from the user in the
+	 * op_system_config structure (sys variable).
+	 */
+	mmcr0_val = sys->mmcr0;
+	mmcr1_val = sys->mmcr1;
+	mmcra_val = sys->mmcra;
+
+	backtrace_spinlocks = sys->backtrace_spinlocks;
+
+	for (i = 0; i < cur_cpu_spec->num_pmcs; ++i)
+		reset_value[i] = 0x80000000UL - ctr[i].count;
+
+	/* setup user and kernel profiling */
+	if (sys->enable_kernel)
+		mmcr0_val &= ~MMCR0_KERNEL_DISABLE;
+	else
+		mmcr0_val |= MMCR0_KERNEL_DISABLE;
+
+	if (sys->enable_user)
+		mmcr0_val &= ~MMCR0_PROBLEM_DISABLE;
+	else
+		mmcr0_val |= MMCR0_PROBLEM_DISABLE;
+}
+
+extern void ppc64_enable_pmcs(void);
+
+/*
+ * Older CPUs require the MMCRA sample bit to be always set, but newer 
+ * CPUs only want it set for some groups. Eventually we will remove all
+ * knowledge of this bit in the kernel, oprofile userspace should be
+ * setting it when required.
+ *
+ * In order to keep current installations working we force the bit for
+ * those older CPUs. Once everyone has updated their oprofile userspace we
+ * can remove this hack.
+ */
+static inline int mmcra_must_set_sample(void)
+{
+	if (__is_processor(PV_POWER4) || __is_processor(PV_POWER4p) ||
+	    __is_processor(PV_970) || __is_processor(PV_970FX) ||
+	    __is_processor(PV_970MP))
+		return 1;
+
+	return 0;
+}
+
+static void power4_cpu_setup(void *unused)
+{
+	unsigned int mmcr0 = mmcr0_val;
+	unsigned long mmcra = mmcra_val;
+
+	ppc64_enable_pmcs();
+
+	/* set the freeze bit */
+	mmcr0 |= MMCR0_FC;
+	mtspr(SPRN_MMCR0, mmcr0);
+
+	mmcr0 |= MMCR0_FCM1|MMCR0_PMXE|MMCR0_FCECE;
+	mmcr0 |= MMCR0_PMC1CE|MMCR0_PMCjCE;
+	mtspr(SPRN_MMCR0, mmcr0);
+
+	mtspr(SPRN_MMCR1, mmcr1_val);
+
+	if (mmcra_must_set_sample())
+		mmcra |= MMCRA_SAMPLE_ENABLE;
+	mtspr(SPRN_MMCRA, mmcra);
+
+	dbg("setup on cpu %d, mmcr0 %lx\n", smp_processor_id(),
+	    mfspr(SPRN_MMCR0));
+	dbg("setup on cpu %d, mmcr1 %lx\n", smp_processor_id(),
+	    mfspr(SPRN_MMCR1));
+	dbg("setup on cpu %d, mmcra %lx\n", smp_processor_id(),
+	    mfspr(SPRN_MMCRA));
+}
+
+static void power4_start(struct op_counter_config *ctr)
+{
+	int i;
+	unsigned int mmcr0;
+
+	/* set the PMM bit (see comment below) */
+	mtmsrd(mfmsr() | MSR_PMM);
+
+	for (i = 0; i < cur_cpu_spec->num_pmcs; ++i) {
+		if (ctr[i].enabled) {
+			ctr_write(i, reset_value[i]);
+		} else {
+			ctr_write(i, 0);
+		}
+	}
+
+	mmcr0 = mfspr(SPRN_MMCR0);
+
+	/*
+	 * We must clear the PMAO bit on some (GQ) chips. Just do it
+	 * all the time
+	 */
+	mmcr0 &= ~MMCR0_PMAO;
+
+	/*
+	 * now clear the freeze bit, counting will not start until we
+	 * rfid from this excetion, because only at that point will
+	 * the PMM bit be cleared
+	 */
+	mmcr0 &= ~MMCR0_FC;
+	mtspr(SPRN_MMCR0, mmcr0);
+
+	oprofile_running = 1;
+
+	dbg("start on cpu %d, mmcr0 %x\n", smp_processor_id(), mmcr0);
+}
+
+static void power4_stop(void)
+{
+	unsigned int mmcr0;
+
+	/* freeze counters */
+	mmcr0 = mfspr(SPRN_MMCR0);
+	mmcr0 |= MMCR0_FC;
+	mtspr(SPRN_MMCR0, mmcr0);
+
+	oprofile_running = 0;
+
+	dbg("stop on cpu %d, mmcr0 %x\n", smp_processor_id(), mmcr0);
+
+	mb();
+}
+
+/* Fake functions used by canonicalize_pc */
+static void __attribute_used__ hypervisor_bucket(void)
+{
+}
+
+static void __attribute_used__ rtas_bucket(void)
+{
+}
+
+static void __attribute_used__ kernel_unknown_bucket(void)
+{
+}
+
+static unsigned long check_spinlock_pc(struct pt_regs *regs,
+				       unsigned long profile_pc)
+{
+	unsigned long pc = instruction_pointer(regs);
+
+	/*
+	 * If both the SIAR (sampled instruction) and the perfmon exception
+	 * occurred in a spinlock region then we account the sample to the
+	 * calling function. This isnt 100% correct, we really need soft
+	 * IRQ disable so we always get the perfmon exception at the
+	 * point at which the SIAR is set.
+	 */
+	if (backtrace_spinlocks && in_lock_functions(pc) &&
+			in_lock_functions(profile_pc))
+		return regs->link;
+	else
+		return profile_pc;
+}
+
+/*
+ * On GQ and newer the MMCRA stores the HV and PR bits at the time
+ * the SIAR was sampled. We use that to work out if the SIAR was sampled in
+ * the hypervisor, our exception vectors or RTAS.
+ */
+static unsigned long get_pc(struct pt_regs *regs)
+{
+	unsigned long pc = mfspr(SPRN_SIAR);
+	unsigned long mmcra;
+
+	/* Cant do much about it */
+	if (!mmcra_has_sihv)
+		return check_spinlock_pc(regs, pc);
+
+	mmcra = mfspr(SPRN_MMCRA);
+
+	/* Were we in the hypervisor? */
+	if (platform_is_lpar() && (mmcra & MMCRA_SIHV))
+		/* function descriptor madness */
+		return *((unsigned long *)hypervisor_bucket);
+
+	/* We were in userspace, nothing to do */
+	if (mmcra & MMCRA_SIPR)
+		return pc;
+
+#ifdef CONFIG_PPC_RTAS
+	/* Were we in RTAS? */
+	if (pc >= rtas.base && pc < (rtas.base + rtas.size))
+		/* function descriptor madness */
+		return *((unsigned long *)rtas_bucket);
+#endif
+
+	/* Were we in our exception vectors or SLB real mode miss handler? */
+	if (pc < 0x1000000UL)
+		return (unsigned long)__va(pc);
+
+	/* Not sure where we were */
+	if (pc < KERNELBASE)
+		/* function descriptor madness */
+		return *((unsigned long *)kernel_unknown_bucket);
+
+	return check_spinlock_pc(regs, pc);
+}
+
+static int get_kernel(unsigned long pc)
+{
+	int is_kernel;
+
+	if (!mmcra_has_sihv) {
+		is_kernel = (pc >= KERNELBASE);
+	} else {
+		unsigned long mmcra = mfspr(SPRN_MMCRA);
+		is_kernel = ((mmcra & MMCRA_SIPR) == 0);
+	}
+
+	return is_kernel;
+}
+
+static void power4_handle_interrupt(struct pt_regs *regs,
+				    struct op_counter_config *ctr)
+{
+	unsigned long pc;
+	int is_kernel;
+	int val;
+	int i;
+	unsigned int mmcr0;
+
+	pc = get_pc(regs);
+	is_kernel = get_kernel(pc);
+
+	/* set the PMM bit (see comment below) */
+	mtmsrd(mfmsr() | MSR_PMM);
+
+	for (i = 0; i < cur_cpu_spec->num_pmcs; ++i) {
+		val = ctr_read(i);
+		if (val < 0) {
+			if (oprofile_running && ctr[i].enabled) {
+				oprofile_add_pc(pc, is_kernel, i);
+				ctr_write(i, reset_value[i]);
+			} else {
+				ctr_write(i, 0);
+			}
+		}
+	}
+
+	mmcr0 = mfspr(SPRN_MMCR0);
+
+	/* reset the perfmon trigger */
+	mmcr0 |= MMCR0_PMXE;
+
+	/*
+	 * We must clear the PMAO bit on some (GQ) chips. Just do it
+	 * all the time
+	 */
+	mmcr0 &= ~MMCR0_PMAO;
+
+	/*
+	 * now clear the freeze bit, counting will not start until we
+	 * rfid from this exception, because only at that point will
+	 * the PMM bit be cleared
+	 */
+	mmcr0 &= ~MMCR0_FC;
+	mtspr(SPRN_MMCR0, mmcr0);
+}
+
+struct op_powerpc_model op_model_power4 = {
+	.reg_setup		= power4_reg_setup,
+	.cpu_setup		= power4_cpu_setup,
+	.start			= power4_start,
+	.stop			= power4_stop,
+	.handle_interrupt	= power4_handle_interrupt,
+};