linux_dsm_epyc7002/tools/testing/selftests/rseq/rseq.h
Paul Burton 744f4be542
rseq/selftests: Implement MIPS support
Implement support for both MIPS32 & MIPS64 in the rseq selftests, in
order to sanity check the recently enabled rseq syscall.

The tests all pass on a MIPS Boston development board running either a
MIPS32r2 interAptiv CPU & a MIPS64r6 I6500 CPU, both of which were
configured with 2 cores each of which have 2 hardware threads (VP(E)s) -
ie. 4 CPUs.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Reviewed-by: James Hogan <jhogan@kernel.org>
Patchwork: https://patchwork.linux-mips.org/patch/19524/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
2018-06-19 21:14:19 -07:00

150 lines
3.8 KiB
C

/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* rseq.h
*
* (C) Copyright 2016-2018 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*/
#ifndef RSEQ_H
#define RSEQ_H
#include <stdint.h>
#include <stdbool.h>
#include <pthread.h>
#include <signal.h>
#include <sched.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <sched.h>
#include <linux/rseq.h>
/*
* Empty code injection macros, override when testing.
* It is important to consider that the ASM injection macros need to be
* fully reentrant (e.g. do not modify the stack).
*/
#ifndef RSEQ_INJECT_ASM
#define RSEQ_INJECT_ASM(n)
#endif
#ifndef RSEQ_INJECT_C
#define RSEQ_INJECT_C(n)
#endif
#ifndef RSEQ_INJECT_INPUT
#define RSEQ_INJECT_INPUT
#endif
#ifndef RSEQ_INJECT_CLOBBER
#define RSEQ_INJECT_CLOBBER
#endif
#ifndef RSEQ_INJECT_FAILED
#define RSEQ_INJECT_FAILED
#endif
extern __thread volatile struct rseq __rseq_abi;
#define rseq_likely(x) __builtin_expect(!!(x), 1)
#define rseq_unlikely(x) __builtin_expect(!!(x), 0)
#define rseq_barrier() __asm__ __volatile__("" : : : "memory")
#define RSEQ_ACCESS_ONCE(x) (*(__volatile__ __typeof__(x) *)&(x))
#define RSEQ_WRITE_ONCE(x, v) __extension__ ({ RSEQ_ACCESS_ONCE(x) = (v); })
#define RSEQ_READ_ONCE(x) RSEQ_ACCESS_ONCE(x)
#define __rseq_str_1(x) #x
#define __rseq_str(x) __rseq_str_1(x)
#define rseq_log(fmt, args...) \
fprintf(stderr, fmt "(in %s() at " __FILE__ ":" __rseq_str(__LINE__)"\n", \
## args, __func__)
#define rseq_bug(fmt, args...) \
do { \
rseq_log(fmt, ##args); \
abort(); \
} while (0)
#if defined(__x86_64__) || defined(__i386__)
#include <rseq-x86.h>
#elif defined(__ARMEL__)
#include <rseq-arm.h>
#elif defined(__PPC__)
#include <rseq-ppc.h>
#elif defined(__mips__)
#include <rseq-mips.h>
#else
#error unsupported target
#endif
/*
* Register rseq for the current thread. This needs to be called once
* by any thread which uses restartable sequences, before they start
* using restartable sequences, to ensure restartable sequences
* succeed. A restartable sequence executed from a non-registered
* thread will always fail.
*/
int rseq_register_current_thread(void);
/*
* Unregister rseq for current thread.
*/
int rseq_unregister_current_thread(void);
/*
* Restartable sequence fallback for reading the current CPU number.
*/
int32_t rseq_fallback_current_cpu(void);
/*
* Values returned can be either the current CPU number, -1 (rseq is
* uninitialized), or -2 (rseq initialization has failed).
*/
static inline int32_t rseq_current_cpu_raw(void)
{
return RSEQ_ACCESS_ONCE(__rseq_abi.cpu_id);
}
/*
* Returns a possible CPU number, which is typically the current CPU.
* The returned CPU number can be used to prepare for an rseq critical
* section, which will confirm whether the cpu number is indeed the
* current one, and whether rseq is initialized.
*
* The CPU number returned by rseq_cpu_start should always be validated
* by passing it to a rseq asm sequence, or by comparing it to the
* return value of rseq_current_cpu_raw() if the rseq asm sequence
* does not need to be invoked.
*/
static inline uint32_t rseq_cpu_start(void)
{
return RSEQ_ACCESS_ONCE(__rseq_abi.cpu_id_start);
}
static inline uint32_t rseq_current_cpu(void)
{
int32_t cpu;
cpu = rseq_current_cpu_raw();
if (rseq_unlikely(cpu < 0))
cpu = rseq_fallback_current_cpu();
return cpu;
}
/*
* rseq_prepare_unload() should be invoked by each thread using rseq_finish*()
* at least once between their last rseq_finish*() and library unload of the
* library defining the rseq critical section (struct rseq_cs). This also
* applies to use of rseq in code generated by JIT: rseq_prepare_unload()
* should be invoked at least once by each thread using rseq_finish*() before
* reclaim of the memory holding the struct rseq_cs.
*/
static inline void rseq_prepare_unload(void)
{
__rseq_abi.rseq_cs = 0;
}
#endif /* RSEQ_H_ */