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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/ppc64/kernel/pmc.c | |
download | op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip op-kernel-dev-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/ppc64/kernel/pmc.c')
-rw-r--r-- | arch/ppc64/kernel/pmc.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/pmc.c b/arch/ppc64/kernel/pmc.c new file mode 100644 index 0000000..67be773 --- /dev/null +++ b/arch/ppc64/kernel/pmc.c @@ -0,0 +1,67 @@ +/* + * linux/arch/ppc64/kernel/pmc.c + * + * Copyright (C) 2004 David Gibson, IBM Corporation. + * + * 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/config.h> +#include <linux/errno.h> +#include <linux/spinlock.h> +#include <linux/module.h> + +#include <asm/processor.h> +#include <asm/pmc.h> + +/* Ensure exceptions are disabled */ +static void dummy_perf(struct pt_regs *regs) +{ + unsigned int mmcr0 = mfspr(SPRN_MMCR0); + + mmcr0 &= ~(MMCR0_PMXE|MMCR0_PMAO); + mtspr(SPRN_MMCR0, mmcr0); +} + +static spinlock_t pmc_owner_lock = SPIN_LOCK_UNLOCKED; +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; + + 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 ? : dummy_perf; + + out: + spin_unlock(&pmc_owner_lock); + return err; +} +EXPORT_SYMBOL_GPL(reserve_pmc_hardware); + +void release_pmc_hardware(void) +{ + spin_lock(&pmc_owner_lock); + + WARN_ON(! pmc_owner_caller); + + pmc_owner_caller = NULL; + perf_irq = dummy_perf; + + spin_unlock(&pmc_owner_lock); +} +EXPORT_SYMBOL_GPL(release_pmc_hardware); |