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>
1 parent 8426191
Raw File
scsi_transport_sas.h
#ifndef SCSI_TRANSPORT_SAS_H
#define SCSI_TRANSPORT_SAS_H

#include <linux/transport_class.h>
#include <linux/types.h>
#include <linux/mutex.h>
#include <scsi/sas.h>

struct scsi_transport_template;
struct sas_rphy;
struct request;

static inline int sas_protocol_ata(enum sas_protocol proto)
{
	return ((proto & SAS_PROTOCOL_SATA) ||
		(proto & SAS_PROTOCOL_STP))? 1 : 0;
}

enum sas_linkrate {
	/* These Values are defined in the SAS standard */
	SAS_LINK_RATE_UNKNOWN = 0,
	SAS_PHY_DISABLED = 1,
	SAS_PHY_RESET_PROBLEM = 2,
	SAS_SATA_SPINUP_HOLD = 3,
	SAS_SATA_PORT_SELECTOR = 4,
	SAS_PHY_RESET_IN_PROGRESS = 5,
	SAS_LINK_RATE_1_5_GBPS = 8,
	SAS_LINK_RATE_G1 = SAS_LINK_RATE_1_5_GBPS,
	SAS_LINK_RATE_3_0_GBPS = 9,
	SAS_LINK_RATE_G2 = SAS_LINK_RATE_3_0_GBPS,
	SAS_LINK_RATE_6_0_GBPS = 10,
	SAS_LINK_RATE_12_0_GBPS = 11,
	/* These are virtual to the transport class and may never
	 * be signalled normally since the standard defined field
	 * is only 4 bits */
	SAS_LINK_RATE_FAILED = 0x10,
	SAS_PHY_VIRTUAL = 0x11,
};

struct sas_identify {
	enum sas_device_type	device_type;
	enum sas_protocol	initiator_port_protocols;
	enum sas_protocol	target_port_protocols;
	u64			sas_address;
	u8			phy_identifier;
};

struct sas_phy {
	struct device		dev;
	int			number;
	int			enabled;

	/* phy identification */
	struct sas_identify	identify;

	/* phy attributes */
	enum sas_linkrate	negotiated_linkrate;
	enum sas_linkrate	minimum_linkrate_hw;
	enum sas_linkrate	minimum_linkrate;
	enum sas_linkrate	maximum_linkrate_hw;
	enum sas_linkrate	maximum_linkrate;

	/* link error statistics */
	u32			invalid_dword_count;
	u32			running_disparity_error_count;
	u32			loss_of_dword_sync_count;
	u32			phy_reset_problem_count;

	/* for the list of phys belonging to a port */
	struct list_head	port_siblings;

	/* available to the lldd */
	void			*hostdata;
};

#define dev_to_phy(d) \
	container_of((d), struct sas_phy, dev)
#define transport_class_to_phy(dev) \
	dev_to_phy((dev)->parent)
#define phy_to_shost(phy) \
	dev_to_shost((phy)->dev.parent)

struct request_queue;
struct sas_rphy {
	struct device		dev;
	struct sas_identify	identify;
	struct list_head	list;
	struct request_queue	*q;
	u32			scsi_target_id;
};

#define dev_to_rphy(d) \
	container_of((d), struct sas_rphy, dev)
#define transport_class_to_rphy(dev) \
	dev_to_rphy((dev)->parent)
#define rphy_to_shost(rphy) \
	dev_to_shost((rphy)->dev.parent)
#define target_to_rphy(targ) \
	dev_to_rphy((targ)->dev.parent)

struct sas_end_device {
	struct sas_rphy		rphy;
	/* flags */
	unsigned		ready_led_meaning:1;
	unsigned		tlr_supported:1;
	unsigned		tlr_enabled:1;
	/* parameters */
	u16			I_T_nexus_loss_timeout;
	u16			initiator_response_timeout;
};
#define rphy_to_end_device(r) \
	container_of((r), struct sas_end_device, rphy)

struct sas_expander_device {
	int    level;
	int    next_port_id;

	#define SAS_EXPANDER_VENDOR_ID_LEN	8
	char   vendor_id[SAS_EXPANDER_VENDOR_ID_LEN+1];
	#define SAS_EXPANDER_PRODUCT_ID_LEN	16
	char   product_id[SAS_EXPANDER_PRODUCT_ID_LEN+1];
	#define SAS_EXPANDER_PRODUCT_REV_LEN	4
	char   product_rev[SAS_EXPANDER_PRODUCT_REV_LEN+1];
	#define SAS_EXPANDER_COMPONENT_VENDOR_ID_LEN	8
	char   component_vendor_id[SAS_EXPANDER_COMPONENT_VENDOR_ID_LEN+1];
	u16    component_id;
	u8     component_revision_id;

	struct sas_rphy		rphy;

};
#define rphy_to_expander_device(r) \
	container_of((r), struct sas_expander_device, rphy)

struct sas_port {
	struct device		dev;

	int			port_identifier;
	int			num_phys;
	/* port flags */
	unsigned int		is_backlink:1;

	/* the other end of the link */
	struct sas_rphy		*rphy;

	struct mutex		phy_list_mutex;
	struct list_head	phy_list;
};

#define dev_to_sas_port(d) \
	container_of((d), struct sas_port, dev)
#define transport_class_to_sas_port(dev) \
	dev_to_sas_port((dev)->parent)

struct sas_phy_linkrates {
	enum sas_linkrate maximum_linkrate;
	enum sas_linkrate minimum_linkrate;
};

/* The functions by which the transport class and the driver communicate */
struct sas_function_template {
	int (*get_linkerrors)(struct sas_phy *);
	int (*get_enclosure_identifier)(struct sas_rphy *, u64 *);
	int (*get_bay_identifier)(struct sas_rphy *);
	int (*phy_reset)(struct sas_phy *, int);
	int (*phy_enable)(struct sas_phy *, int);
	int (*phy_setup)(struct sas_phy *);
	void (*phy_release)(struct sas_phy *);
	int (*set_phy_speed)(struct sas_phy *, struct sas_phy_linkrates *);
	int (*smp_handler)(struct Scsi_Host *, struct sas_rphy *, struct request *);
};


void sas_remove_children(struct device *);
extern void sas_remove_host(struct Scsi_Host *);

extern struct sas_phy *sas_phy_alloc(struct device *, int);
extern void sas_phy_free(struct sas_phy *);
extern int sas_phy_add(struct sas_phy *);
extern void sas_phy_delete(struct sas_phy *);
extern int scsi_is_sas_phy(const struct device *);

unsigned int sas_tlr_supported(struct scsi_device *);
unsigned int sas_is_tlr_enabled(struct scsi_device *);
void sas_disable_tlr(struct scsi_device *);
void sas_enable_tlr(struct scsi_device *);

extern struct sas_rphy *sas_end_device_alloc(struct sas_port *);
extern struct sas_rphy *sas_expander_alloc(struct sas_port *, enum sas_device_type);
void sas_rphy_free(struct sas_rphy *);
extern int sas_rphy_add(struct sas_rphy *);
extern void sas_rphy_remove(struct sas_rphy *);
extern void sas_rphy_delete(struct sas_rphy *);
extern void sas_rphy_unlink(struct sas_rphy *);
extern int scsi_is_sas_rphy(const struct device *);

struct sas_port *sas_port_alloc(struct device *, int);
struct sas_port *sas_port_alloc_num(struct device *);
int sas_port_add(struct sas_port *);
void sas_port_free(struct sas_port *);
void sas_port_delete(struct sas_port *);
void sas_port_add_phy(struct sas_port *, struct sas_phy *);
void sas_port_delete_phy(struct sas_port *, struct sas_phy *);
void sas_port_mark_backlink(struct sas_port *);
int scsi_is_sas_port(const struct device *);
struct sas_phy *sas_port_get_phy(struct sas_port *port);
static inline void sas_port_put_phy(struct sas_phy *phy)
{
	if (phy)
		put_device(&phy->dev);
}

extern struct scsi_transport_template *
sas_attach_transport(struct sas_function_template *);
extern void sas_release_transport(struct scsi_transport_template *);
int sas_read_port_mode_page(struct scsi_device *);

static inline int
scsi_is_sas_expander_device(struct device *dev)
{
	struct sas_rphy *rphy;
	if (!scsi_is_sas_rphy(dev))
		return 0;
	rphy = dev_to_rphy(dev);
	return rphy->identify.device_type == SAS_FANOUT_EXPANDER_DEVICE ||
		rphy->identify.device_type == SAS_EDGE_EXPANDER_DEVICE;
}

#define scsi_is_sas_phy_local(phy)	scsi_is_host_device((phy)->dev.parent)

#endif /* SCSI_TRANSPORT_SAS_H */
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