Revision bce0b6c51ac76fc0e763262a6c2a9d05e486f0d8 authored by Steven Rostedt (Red Hat) on 21 August 2014, 03:57:04 UTC, committed by Steven Rostedt on 22 August 2014, 19:24:12 UTC
Now that a ftrace_hash can be shared by multiple ftrace_ops, they can dec the rec->flags by more than once (one per those that share the ftrace_hash). This means that the tramp_hash may not have a hash item when it was added. For example, if two ftrace_ops share a hash for a ftrace record, and the first ops has a trampoline, when it adds itself it will set the rec->flags TRAMP flag and increments its nr_trampolines counter. When the second ops is added, it must clear that tramp flag but also decrement the other ops that shares its hash. As the update to the function callbacks has not yet been performed, the other ops will not have the tramp hash set yet and it can not be used to know to decrement its nr_trampolines. Luckily, the tramp_hash does not need to be used. As the ftrace_mutex is held, a ops with a trampoline to a record during an update of another ops that shares the record will have its func_hash pointing to it. Since a trampoline can only be set for a record if only one ops is attached to it, we can just check if the record has a trampoline (the FTRACE_FL_TRAMP flag is set) and then find the ops that has this record in its hashes. Also added some output to help debug when things go wrong. Cc: stable@vger.kernel.org # 3.16+ (apply after 3.17-rc4 is out) Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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scsi_transport_spi.h
/*
* Parallel SCSI (SPI) transport specific attributes exported to sysfs.
*
* Copyright (c) 2003 Silicon Graphics, Inc. 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; either version 2 of the License, or
* (at your option) any later version.
*
* 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. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef SCSI_TRANSPORT_SPI_H
#define SCSI_TRANSPORT_SPI_H
#include <linux/transport_class.h>
#include <linux/mutex.h>
struct scsi_transport_template;
struct scsi_target;
struct scsi_device;
struct Scsi_Host;
struct spi_transport_attrs {
int period; /* value in the PPR/SDTR command */
int min_period;
int offset;
int max_offset;
unsigned int width:1; /* 0 - narrow, 1 - wide */
unsigned int max_width:1;
unsigned int iu:1; /* Information Units enabled */
unsigned int max_iu:1;
unsigned int dt:1; /* DT clocking enabled */
unsigned int qas:1; /* Quick Arbitration and Selection enabled */
unsigned int max_qas:1;
unsigned int wr_flow:1; /* Write Flow control enabled */
unsigned int rd_strm:1; /* Read streaming enabled */
unsigned int rti:1; /* Retain Training Information */
unsigned int pcomp_en:1;/* Precompensation enabled */
unsigned int hold_mcs:1;/* Hold Margin Control Settings */
unsigned int initial_dv:1; /* DV done to this target yet */
unsigned long flags; /* flags field for drivers to use */
/* Device Properties fields */
unsigned int support_sync:1; /* synchronous support */
unsigned int support_wide:1; /* wide support */
unsigned int support_dt:1; /* allows DT phases */
unsigned int support_dt_only; /* disallows ST phases */
unsigned int support_ius; /* support Information Units */
unsigned int support_qas; /* supports quick arbitration and selection */
/* Private Fields */
unsigned int dv_pending:1; /* Internal flag: DV Requested */
unsigned int dv_in_progress:1; /* Internal: DV started */
struct mutex dv_mutex; /* semaphore to serialise dv */
};
enum spi_signal_type {
SPI_SIGNAL_UNKNOWN = 1,
SPI_SIGNAL_SE,
SPI_SIGNAL_LVD,
SPI_SIGNAL_HVD,
};
struct spi_host_attrs {
enum spi_signal_type signalling;
};
/* accessor functions */
#define spi_period(x) (((struct spi_transport_attrs *)&(x)->starget_data)->period)
#define spi_min_period(x) (((struct spi_transport_attrs *)&(x)->starget_data)->min_period)
#define spi_offset(x) (((struct spi_transport_attrs *)&(x)->starget_data)->offset)
#define spi_max_offset(x) (((struct spi_transport_attrs *)&(x)->starget_data)->max_offset)
#define spi_width(x) (((struct spi_transport_attrs *)&(x)->starget_data)->width)
#define spi_max_width(x) (((struct spi_transport_attrs *)&(x)->starget_data)->max_width)
#define spi_iu(x) (((struct spi_transport_attrs *)&(x)->starget_data)->iu)
#define spi_max_iu(x) (((struct spi_transport_attrs *)&(x)->starget_data)->max_iu)
#define spi_dt(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dt)
#define spi_qas(x) (((struct spi_transport_attrs *)&(x)->starget_data)->qas)
#define spi_max_qas(x) (((struct spi_transport_attrs *)&(x)->starget_data)->max_qas)
#define spi_wr_flow(x) (((struct spi_transport_attrs *)&(x)->starget_data)->wr_flow)
#define spi_rd_strm(x) (((struct spi_transport_attrs *)&(x)->starget_data)->rd_strm)
#define spi_rti(x) (((struct spi_transport_attrs *)&(x)->starget_data)->rti)
#define spi_pcomp_en(x) (((struct spi_transport_attrs *)&(x)->starget_data)->pcomp_en)
#define spi_hold_mcs(x) (((struct spi_transport_attrs *)&(x)->starget_data)->hold_mcs)
#define spi_initial_dv(x) (((struct spi_transport_attrs *)&(x)->starget_data)->initial_dv)
#define spi_dv_pending(x) (((struct spi_transport_attrs *)&(x)->starget_data)->dv_pending)
#define spi_support_sync(x) (((struct spi_transport_attrs *)&(x)->starget_data)->support_sync)
#define spi_support_wide(x) (((struct spi_transport_attrs *)&(x)->starget_data)->support_wide)
#define spi_support_dt(x) (((struct spi_transport_attrs *)&(x)->starget_data)->support_dt)
#define spi_support_dt_only(x) (((struct spi_transport_attrs *)&(x)->starget_data)->support_dt_only)
#define spi_support_ius(x) (((struct spi_transport_attrs *)&(x)->starget_data)->support_ius)
#define spi_support_qas(x) (((struct spi_transport_attrs *)&(x)->starget_data)->support_qas)
#define spi_flags(x) (((struct spi_transport_attrs *)&(x)->starget_data)->flags)
#define spi_signalling(h) (((struct spi_host_attrs *)(h)->shost_data)->signalling)
/* The functions by which the transport class and the driver communicate */
struct spi_function_template {
void (*get_period)(struct scsi_target *);
void (*set_period)(struct scsi_target *, int);
void (*get_offset)(struct scsi_target *);
void (*set_offset)(struct scsi_target *, int);
void (*get_width)(struct scsi_target *);
void (*set_width)(struct scsi_target *, int);
void (*get_iu)(struct scsi_target *);
void (*set_iu)(struct scsi_target *, int);
void (*get_dt)(struct scsi_target *);
void (*set_dt)(struct scsi_target *, int);
void (*get_qas)(struct scsi_target *);
void (*set_qas)(struct scsi_target *, int);
void (*get_wr_flow)(struct scsi_target *);
void (*set_wr_flow)(struct scsi_target *, int);
void (*get_rd_strm)(struct scsi_target *);
void (*set_rd_strm)(struct scsi_target *, int);
void (*get_rti)(struct scsi_target *);
void (*set_rti)(struct scsi_target *, int);
void (*get_pcomp_en)(struct scsi_target *);
void (*set_pcomp_en)(struct scsi_target *, int);
void (*get_hold_mcs)(struct scsi_target *);
void (*set_hold_mcs)(struct scsi_target *, int);
void (*get_signalling)(struct Scsi_Host *);
void (*set_signalling)(struct Scsi_Host *, enum spi_signal_type);
int (*deny_binding)(struct scsi_target *);
/* The driver sets these to tell the transport class it
* wants the attributes displayed in sysfs. If the show_ flag
* is not set, the attribute will be private to the transport
* class */
unsigned long show_period:1;
unsigned long show_offset:1;
unsigned long show_width:1;
unsigned long show_iu:1;
unsigned long show_dt:1;
unsigned long show_qas:1;
unsigned long show_wr_flow:1;
unsigned long show_rd_strm:1;
unsigned long show_rti:1;
unsigned long show_pcomp_en:1;
unsigned long show_hold_mcs:1;
};
struct scsi_transport_template *spi_attach_transport(struct spi_function_template *);
void spi_release_transport(struct scsi_transport_template *);
void spi_schedule_dv_device(struct scsi_device *);
void spi_dv_device(struct scsi_device *);
void spi_display_xfer_agreement(struct scsi_target *);
int spi_print_msg(const unsigned char *);
int spi_populate_width_msg(unsigned char *msg, int width);
int spi_populate_sync_msg(unsigned char *msg, int period, int offset);
int spi_populate_ppr_msg(unsigned char *msg, int period, int offset, int width,
int options);
#endif /* SCSI_TRANSPORT_SPI_H */
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