1 files changed, 98 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/pmc.c b/arch/powerpc/kernel/pmc.c
new file mode 100644
index 000000000..15414c8a2
--- /dev/null
+++ b/arch/powerpc/kernel/pmc.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  arch/powerpc/kernel/pmc.c
+ *
+ *  Copyright (C) 2004 David Gibson, IBM Corporation.
+ *  Includes code formerly from arch/ppc/kernel/perfmon.c:
+ *    Author: Andy Fleming
+ *    Copyright (c) 2004 Freescale Semiconductor, Inc
+ */
+
+#include <linux/errno.h>
+#include <linux/bug.h>
+#include <linux/spinlock.h>
+#include <linux/export.h>
+
+#include <asm/processor.h>
+#include <asm/cputable.h>
+#include <asm/pmc.h>
+
+#ifndef MMCR0_PMAO
+#define MMCR0_PMAO	0
+#endif
+
+static void dummy_perf(struct pt_regs *regs)
+{
+#if defined(CONFIG_FSL_EMB_PERFMON)
+	mtpmr(PMRN_PMGC0, mfpmr(PMRN_PMGC0) & ~PMGC0_PMIE);
+#elif defined(CONFIG_PPC64) || defined(CONFIG_PPC_BOOK3S_32)
+	if (cur_cpu_spec->pmc_type == PPC_PMC_IBM)
+		mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~(MMCR0_PMXE|MMCR0_PMAO));
+#else
+	mtspr(SPRN_MMCR0, mfspr(SPRN_MMCR0) & ~MMCR0_PMXE);
+#endif
+}
+
+
+static DEFINE_RAW_SPINLOCK(pmc_owner_lock);
+static void *pmc_owner_caller; /* mostly for debugging */
+perf_irq_t perf_irq = dummy_perf;
+
+int reserve_pmc_hardware(perf_irq_t new_perf_irq)
+{
+	int err = 0;
+
+	raw_spin_lock(&pmc_owner_lock);
+
+	if (pmc_owner_caller) {
+		printk(KERN_WARNING "reserve_pmc_hardware: "
+		       "PMC hardware busy (reserved by caller %p)\n",
+		       pmc_owner_caller);
+		err = -EBUSY;
+		goto out;
+	}
+
+	pmc_owner_caller = __builtin_return_address(0);
+	perf_irq = new_perf_irq ? new_perf_irq : dummy_perf;
+
+ out:
+	raw_spin_unlock(&pmc_owner_lock);
+	return err;
+}
+EXPORT_SYMBOL_GPL(reserve_pmc_hardware);
+
+void release_pmc_hardware(void)
+{
+	raw_spin_lock(&pmc_owner_lock);
+
+	WARN_ON(! pmc_owner_caller);
+
+	pmc_owner_caller = NULL;
+	perf_irq = dummy_perf;
+
+	raw_spin_unlock(&pmc_owner_lock);
+}
+EXPORT_SYMBOL_GPL(release_pmc_hardware);
+
+#ifdef CONFIG_PPC64
+void power4_enable_pmcs(void)
+{
+	unsigned long hid0;
+
+	hid0 = mfspr(SPRN_HID0);
+	hid0 |= 1UL << (63 - 20);
+
+	/* POWER4 requires the following sequence */
+	asm volatile(
+		"sync\n"
+		"mtspr     %1, %0\n"
+		"mfspr     %0, %1\n"
+		"mfspr     %0, %1\n"
+		"mfspr     %0, %1\n"
+		"mfspr     %0, %1\n"
+		"mfspr     %0, %1\n"
+		"mfspr     %0, %1\n"
+		"isync" : "=&r" (hid0) : "i" (SPRN_HID0), "0" (hid0):
+		"memory");
+}
+#endif /* CONFIG_PPC64 */