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tile: Add support for handling PMC hardware

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The PMC module is used by perf_events, oprofile and watchdogs.

Signed-off-by: Zhigang Lu <zlu@tilera.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This commit is contained in:
Zhigang Lu 2014-01-27 15:11:07 +08:00 committed by Chris Metcalf
parent 2e285458e6
commit 8e3441ebab
6 changed files with 204 additions and 12 deletions
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4
arch/tile/Kconfig
View File

@ -66,6 +66,10 @@ config HUGETLB_SUPER_PAGES
config GENERIC_TIME_VSYSCALL
def_bool y
# Enable PMC if PERF_EVENTS, OPROFILE, or WATCHPOINTS are enabled.
config USE_PMC
bool
# FIXME: tilegx can implement a more efficient rwsem.
config RWSEM_GENERIC_SPINLOCK
def_bool y

64
arch/tile/include/asm/pmc.h Normal file
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@ -0,0 +1,64 @@
/*
* Copyright 2014 Tilera Corporation. All Rights Reserved.
*
* 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, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#ifndef _ASM_TILE_PMC_H
#define _ASM_TILE_PMC_H
#include <linux/ptrace.h>
#define TILE_BASE_COUNTERS 2
/* Bitfields below are derived from SPR PERF_COUNT_CTL*/
#ifndef __tilegx__
/* PERF_COUNT_CTL on TILEPro */
#define TILE_CTL_EXCL_USER (1 << 7) /* exclude user level */
#define TILE_CTL_EXCL_KERNEL (1 << 8) /* exclude kernel level */
#define TILE_CTL_EXCL_HV (1 << 9) /* exclude hypervisor level */
#define TILE_SEL_MASK 0x7f /* 7 bits for event SEL,
COUNT_0_SEL */
#define TILE_PLM_MASK 0x780 /* 4 bits priv level msks,
COUNT_0_MASK*/
#define TILE_EVENT_MASK (TILE_SEL_MASK | TILE_PLM_MASK)
#else /* __tilegx__*/
/* PERF_COUNT_CTL on TILEGx*/
#define TILE_CTL_EXCL_USER (1 << 10) /* exclude user level */
#define TILE_CTL_EXCL_KERNEL (1 << 11) /* exclude kernel level */
#define TILE_CTL_EXCL_HV (1 << 12) /* exclude hypervisor level */
#define TILE_SEL_MASK 0x3f /* 6 bits for event SEL,
COUNT_0_SEL*/
#define TILE_BOX_MASK 0x1c0 /* 3 bits box msks,
COUNT_0_BOX */
#define TILE_PLM_MASK 0x3c00 /* 4 bits priv level msks,
COUNT_0_MASK */
#define TILE_EVENT_MASK (TILE_SEL_MASK | TILE_BOX_MASK | TILE_PLM_MASK)
#endif /* __tilegx__*/
/* Takes register and fault number. Returns error to disable the interrupt. */
typedef int (*perf_irq_t)(struct pt_regs *, int);
int userspace_perf_handler(struct pt_regs *regs, int fault);
perf_irq_t reserve_pmc_hardware(perf_irq_t new_perf_irq);
void release_pmc_hardware(void);
unsigned long pmc_get_overflow(void);
void pmc_ack_overflow(unsigned long status);
void unmask_pmc_interrupts(void);
void mask_pmc_interrupts(void);
#endif /* _ASM_TILE_PMC_H */

1
arch/tile/kernel/Makefile
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@ -25,6 +25,7 @@ obj-$(CONFIG_PCI) += pci_gx.o
else
obj-$(CONFIG_PCI) += pci.o
endif
obj-$(CONFIG_USE_PMC) += pmc.o
obj-$(CONFIG_TILE_USB) += usb.o
obj-$(CONFIG_TILE_HVGLUE_TRACE) += hvglue_trace.o
obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o mcount_64.o

13
arch/tile/kernel/intvec_32.S
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@ -313,13 +313,13 @@ intvec_\vecname:
movei r3, 0
}
.else
.ifc \c_routine, op_handle_perf_interrupt
.ifc \c_routine, handle_perf_interrupt
{
mfspr r2, PERF_COUNT_STS
movei r3, -1 /* not used, but set for consistency */
}
.else
.ifc \c_routine, op_handle_aux_perf_interrupt
.ifc \c_routine, handle_perf_interrupt
{
mfspr r2, AUX_PERF_COUNT_STS
movei r3, -1 /* not used, but set for consistency */
@ -1835,8 +1835,9 @@ int_unalign:
/* Include .intrpt array of interrupt vectors */
.section ".intrpt", "ax"
#define op_handle_perf_interrupt bad_intr
#define op_handle_aux_perf_interrupt bad_intr
#ifndef CONFIG_USE_PMC
#define handle_perf_interrupt bad_intr
#endif
#ifndef CONFIG_HARDWALL
#define do_hardwall_trap bad_intr
@ -1877,7 +1878,7 @@ int_unalign:
int_hand INT_IDN_AVAIL, IDN_AVAIL, bad_intr
int_hand INT_UDN_AVAIL, UDN_AVAIL, bad_intr
int_hand INT_PERF_COUNT, PERF_COUNT, \
op_handle_perf_interrupt, handle_nmi
handle_perf_interrupt, handle_nmi
int_hand INT_INTCTRL_3, INTCTRL_3, bad_intr
#if CONFIG_KERNEL_PL == 2
dc_dispatch INT_INTCTRL_2, INTCTRL_2
@ -1902,7 +1903,7 @@ int_unalign:
int_hand INT_SN_CPL, SN_CPL, bad_intr
int_hand INT_DOUBLE_FAULT, DOUBLE_FAULT, do_trap
int_hand INT_AUX_PERF_COUNT, AUX_PERF_COUNT, \
op_handle_aux_perf_interrupt, handle_nmi
handle_perf_interrupt, handle_nmi
/* Synthetic interrupt delivered only by the simulator */
int_hand INT_BREAKPOINT, BREAKPOINT, do_breakpoint

13
arch/tile/kernel/intvec_64.S
View File

@ -509,10 +509,10 @@ intvec_\vecname:
.ifc \c_routine, do_trap
mfspr r2, GPV_REASON
.else
.ifc \c_routine, op_handle_perf_interrupt
.ifc \c_routine, handle_perf_interrupt
mfspr r2, PERF_COUNT_STS
.else
.ifc \c_routine, op_handle_aux_perf_interrupt
.ifc \c_routine, handle_perf_interrupt
mfspr r2, AUX_PERF_COUNT_STS
.endif
.endif
@ -1491,8 +1491,9 @@ STD_ENTRY(fill_ra_stack)
.global intrpt_start
intrpt_start:
#define op_handle_perf_interrupt bad_intr
#define op_handle_aux_perf_interrupt bad_intr
#ifndef CONFIG_USE_PMC
#define handle_perf_interrupt bad_intr
#endif
#ifndef CONFIG_HARDWALL
#define do_hardwall_trap bad_intr
@ -1540,9 +1541,9 @@ intrpt_start:
#endif
int_hand INT_IPI_0, IPI_0, bad_intr
int_hand INT_PERF_COUNT, PERF_COUNT, \
op_handle_perf_interrupt, handle_nmi
handle_perf_interrupt, handle_nmi
int_hand INT_AUX_PERF_COUNT, AUX_PERF_COUNT, \
op_handle_perf_interrupt, handle_nmi
handle_perf_interrupt, handle_nmi
int_hand INT_INTCTRL_3, INTCTRL_3, bad_intr
#if CONFIG_KERNEL_PL == 2
dc_dispatch INT_INTCTRL_2, INTCTRL_2

121
arch/tile/kernel/pmc.c Normal file
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@ -0,0 +1,121 @@
/*
* Copyright 2014 Tilera Corporation. All Rights Reserved.
*
* 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, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#include <linux/errno.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/atomic.h>
#include <linux/interrupt.h>
#include <asm/processor.h>
#include <asm/pmc.h>
perf_irq_t perf_irq = NULL;
int handle_perf_interrupt(struct pt_regs *regs, int fault)
{
int retval;
if (!perf_irq)
panic("Unexpected PERF_COUNT interrupt %d\n", fault);
nmi_enter();
retval = perf_irq(regs, fault);
nmi_exit();
return retval;
}
/* Reserve PMC hardware if it is available. */
perf_irq_t reserve_pmc_hardware(perf_irq_t new_perf_irq)
{
return cmpxchg(&perf_irq, NULL, new_perf_irq);
}
EXPORT_SYMBOL(reserve_pmc_hardware);
/* Release PMC hardware. */
void release_pmc_hardware(void)
{
perf_irq = NULL;
}
EXPORT_SYMBOL(release_pmc_hardware);
/*
* Get current overflow status of each performance counter,
* and auxiliary performance counter.
*/
unsigned long
pmc_get_overflow(void)
{
unsigned long status;
/*
* merge base+aux into a single vector
*/
status = __insn_mfspr(SPR_PERF_COUNT_STS);
status |= __insn_mfspr(SPR_AUX_PERF_COUNT_STS) << TILE_BASE_COUNTERS;
return status;
}
/*
* Clear the status bit for the corresponding counter, if written
* with a one.
*/
void
pmc_ack_overflow(unsigned long status)
{
/*
* clear overflow status by writing ones
*/
__insn_mtspr(SPR_PERF_COUNT_STS, status);
__insn_mtspr(SPR_AUX_PERF_COUNT_STS, status >> TILE_BASE_COUNTERS);
}
/*
* The perf count interrupts are masked and unmasked explicitly,
* and only here. The normal irq_enable() does not enable them,
* and irq_disable() does not disable them. That lets these
* routines drive the perf count interrupts orthogonally.
*
* We also mask the perf count interrupts on entry to the perf count
* interrupt handler in assembly code, and by default unmask them
* again (with interrupt critical section protection) just before
* returning from the interrupt. If the perf count handler returns
* a non-zero error code, then we don't re-enable them before returning.
*
* For Pro, we rely on both interrupts being in the same word to update
* them atomically so we never have one enabled and one disabled.
*/
#if CHIP_HAS_SPLIT_INTR_MASK()
# if INT_PERF_COUNT < 32 || INT_AUX_PERF_COUNT < 32
# error Fix assumptions about which word PERF_COUNT interrupts are in
# endif
#endif
static inline unsigned long long pmc_mask(void)
{
unsigned long long mask = 1ULL << INT_PERF_COUNT;
mask |= 1ULL << INT_AUX_PERF_COUNT;
return mask;
}
void unmask_pmc_interrupts(void)
{
interrupt_mask_reset_mask(pmc_mask());
}
void mask_pmc_interrupts(void)
{
interrupt_mask_set_mask(pmc_mask());
}