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linux/drivers/s390/block/dasd_eckd.h
Stefan Haberland 59a9ed5f87 s390/dasd: reorder lcu and device lock 
Reorder lcu and device lock to get rid of the error-prone trylock
mechanism.

The locking order is lcu lock -> device lock.
This protects against changes to the lcu device lists and enables us
to iterate over the devices, take the cdev lock and make changes to
the device structures.

The complicated part is the summary unit check handler that gets an
interrupt on one device of the lcu that leads to structural changes of
the whole lcu itself. This work needs to be done even if devices on
the lcu disappear. So a device independent worker is used.
The old approach tried to update some lcu structures and set up the
lcu worker in the interrupt context with the device lock held.
But this forced the lock order "cdev lock -> lcu lock" that made it
hard to have the lcu lock held and iterate over all devices and change
them.

The new approach is to schedule a device specific worker that gets
out of the interrupt context and rid of the device lock for summary
unit checks. This worker is able to take the lcu lock and schedule the
lcu worker that updates all devices. The time between interrupt and
worker execution is no problem because the devices in the lcu reject
all I/O in this time with an appropriate error. The dasd driver can
deal with this situation and re-drive the I/O later on.

Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-03-17 13:18:25 +01:00

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/*
* Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
* Horst Hummel <Horst.Hummel@de.ibm.com>
* Bugreports.to..: <Linux390@de.ibm.com>
* Copyright IBM Corp. 1999, 2000
*
*/
#ifndef DASD_ECKD_H
#define DASD_ECKD_H
/*****************************************************************************
* SECTION: CCW Definitions
****************************************************************************/
#define DASD_ECKD_CCW_WRITE 0x05
#define DASD_ECKD_CCW_READ 0x06
#define DASD_ECKD_CCW_WRITE_HOME_ADDRESS 0x09
#define DASD_ECKD_CCW_READ_HOME_ADDRESS 0x0a
#define DASD_ECKD_CCW_WRITE_KD 0x0d
#define DASD_ECKD_CCW_READ_KD 0x0e
#define DASD_ECKD_CCW_ERASE 0x11
#define DASD_ECKD_CCW_READ_COUNT 0x12
#define DASD_ECKD_CCW_SLCK 0x14
#define DASD_ECKD_CCW_WRITE_RECORD_ZERO 0x15
#define DASD_ECKD_CCW_READ_RECORD_ZERO 0x16
#define DASD_ECKD_CCW_WRITE_CKD 0x1d
#define DASD_ECKD_CCW_READ_CKD 0x1e
#define DASD_ECKD_CCW_PSF 0x27
#define DASD_ECKD_CCW_SNID 0x34
#define DASD_ECKD_CCW_RSSD 0x3e
#define DASD_ECKD_CCW_LOCATE_RECORD 0x47
#define DASD_ECKD_CCW_SNSS 0x54
#define DASD_ECKD_CCW_DEFINE_EXTENT 0x63
#define DASD_ECKD_CCW_WRITE_MT 0x85
#define DASD_ECKD_CCW_READ_MT 0x86
#define DASD_ECKD_CCW_WRITE_KD_MT 0x8d
#define DASD_ECKD_CCW_READ_KD_MT 0x8e
#define DASD_ECKD_CCW_RELEASE 0x94
#define DASD_ECKD_CCW_WRITE_FULL_TRACK 0x95
#define DASD_ECKD_CCW_READ_CKD_MT 0x9e
#define DASD_ECKD_CCW_WRITE_CKD_MT 0x9d
#define DASD_ECKD_CCW_WRITE_TRACK_DATA 0xA5
#define DASD_ECKD_CCW_READ_TRACK_DATA 0xA6
#define DASD_ECKD_CCW_RESERVE 0xB4
#define DASD_ECKD_CCW_READ_TRACK 0xDE
#define DASD_ECKD_CCW_PFX 0xE7
#define DASD_ECKD_CCW_PFX_READ 0xEA
#define DASD_ECKD_CCW_RSCK 0xF9
#define DASD_ECKD_CCW_RCD 0xFA
/*
* Perform Subsystem Function / Sub-Orders
*/
#define PSF_ORDER_PRSSD 0x18
#define PSF_ORDER_CUIR_RESPONSE 0x1A
#define PSF_ORDER_SSC 0x1D
/*
* CUIR response condition codes
*/
#define PSF_CUIR_INVALID 0x00
#define PSF_CUIR_COMPLETED 0x01
#define PSF_CUIR_NOT_SUPPORTED 0x02
#define PSF_CUIR_ERROR_IN_REQ 0x03
#define PSF_CUIR_DENIED 0x04
#define PSF_CUIR_LAST_PATH 0x05
#define PSF_CUIR_DEVICE_ONLINE 0x06
#define PSF_CUIR_VARY_FAILURE 0x07
#define PSF_CUIR_SOFTWARE_FAILURE 0x08
#define PSF_CUIR_NOT_RECOGNIZED 0x09
/*
* CUIR codes
*/
#define CUIR_QUIESCE 0x01
#define CUIR_RESUME 0x02
/*
* attention message definitions
*/
#define ATTENTION_LENGTH_CUIR 0x0e
#define ATTENTION_FORMAT_CUIR 0x01
/*
* Size that is reportet for large volumes in the old 16-bit no_cyl field
*/
#define LV_COMPAT_CYL 0xFFFE
#define FCX_MAX_DATA_FACTOR 65536
#define DASD_ECKD_RCD_DATA_SIZE 256
/*****************************************************************************
* SECTION: Type Definitions
****************************************************************************/
struct eckd_count {
__u16 cyl;
__u16 head;
__u8 record;
__u8 kl;
__u16 dl;
} __attribute__ ((packed));
struct ch_t {
__u16 cyl;
__u16 head;
} __attribute__ ((packed));
struct chs_t {
__u16 cyl;
__u16 head;
__u32 sector;
} __attribute__ ((packed));
struct chr_t {
__u16 cyl;
__u16 head;
__u8 record;
} __attribute__ ((packed));
struct geom_t {
__u16 cyl;
__u16 head;
__u32 sector;
} __attribute__ ((packed));
struct eckd_home {
__u8 skip_control[14];
__u16 cell_number;
__u8 physical_addr[3];
__u8 flag;
struct ch_t track_addr;
__u8 reserved;
__u8 key_length;
__u8 reserved2[2];
} __attribute__ ((packed));
struct DE_eckd_data {
struct {
unsigned char perm:2; /* Permissions on this extent */
unsigned char reserved:1;
unsigned char seek:2; /* Seek control */
unsigned char auth:2; /* Access authorization */
unsigned char pci:1; /* PCI Fetch mode */
} __attribute__ ((packed)) mask;
struct {
unsigned char mode:2; /* Architecture mode */
unsigned char ckd:1; /* CKD Conversion */
unsigned char operation:3; /* Operation mode */
unsigned char cfw:1; /* Cache fast write */
unsigned char dfw:1; /* DASD fast write */
} __attribute__ ((packed)) attributes;
__u16 blk_size; /* Blocksize */
__u16 fast_write_id;
__u8 ga_additional; /* Global Attributes Additional */
__u8 ga_extended; /* Global Attributes Extended */
struct ch_t beg_ext;
struct ch_t end_ext;
unsigned long long ep_sys_time; /* Ext Parameter - System Time Stamp */
__u8 ep_format; /* Extended Parameter format byte */
__u8 ep_prio; /* Extended Parameter priority I/O byte */
__u8 ep_reserved1; /* Extended Parameter Reserved */
__u8 ep_rec_per_track; /* Number of records on a track */
__u8 ep_reserved[4]; /* Extended Parameter Reserved */
} __attribute__ ((packed));
struct LO_eckd_data {
struct {
unsigned char orientation:2;
unsigned char operation:6;
} __attribute__ ((packed)) operation;
struct {
unsigned char last_bytes_used:1;
unsigned char reserved:6;
unsigned char read_count_suffix:1;
} __attribute__ ((packed)) auxiliary;
__u8 unused;
__u8 count;
struct ch_t seek_addr;
struct chr_t search_arg;
__u8 sector;
__u16 length;
} __attribute__ ((packed));
struct LRE_eckd_data {
struct {
unsigned char orientation:2;
unsigned char operation:6;
} __attribute__ ((packed)) operation;
struct {
unsigned char length_valid:1;
unsigned char length_scope:1;
unsigned char imbedded_ccw_valid:1;
unsigned char check_bytes:2;
unsigned char imbedded_count_valid:1;
unsigned char reserved:1;
unsigned char read_count_suffix:1;
} __attribute__ ((packed)) auxiliary;
__u8 imbedded_ccw;
__u8 count;
struct ch_t seek_addr;
struct chr_t search_arg;
__u8 sector;
__u16 length;
__u8 imbedded_count;
__u8 extended_operation;
__u16 extended_parameter_length;
__u8 extended_parameter[0];
} __attribute__ ((packed));
/* Prefix data for format 0x00 and 0x01 */
struct PFX_eckd_data {
unsigned char format;
struct {
unsigned char define_extent:1;
unsigned char time_stamp:1;
unsigned char verify_base:1;
unsigned char hyper_pav:1;
unsigned char reserved:4;
} __attribute__ ((packed)) validity;
__u8 base_address;
__u8 aux;
__u8 base_lss;
__u8 reserved[7];
struct DE_eckd_data define_extent;
struct LRE_eckd_data locate_record;
} __attribute__ ((packed));
struct dasd_eckd_characteristics {
__u16 cu_type;
struct {
unsigned char support:2;
unsigned char async:1;
unsigned char reserved:1;
unsigned char cache_info:1;
unsigned char model:3;
} __attribute__ ((packed)) cu_model;
__u16 dev_type;
__u8 dev_model;
struct {
unsigned char mult_burst:1;
unsigned char RT_in_LR:1;
unsigned char reserved1:1;
unsigned char RD_IN_LR:1;
unsigned char reserved2:4;
unsigned char reserved3:8;
unsigned char defect_wr:1;
unsigned char XRC_supported:1;
unsigned char reserved4:1;
unsigned char striping:1;
unsigned char reserved5:4;
unsigned char cfw:1;
unsigned char reserved6:2;
unsigned char cache:1;
unsigned char dual_copy:1;
unsigned char dfw:1;
unsigned char reset_alleg:1;
unsigned char sense_down:1;
} __attribute__ ((packed)) facilities;
__u8 dev_class;
__u8 unit_type;
__u16 no_cyl;
__u16 trk_per_cyl;
__u8 sec_per_trk;
__u8 byte_per_track[3];
__u16 home_bytes;
__u8 formula;
union {
struct {
__u8 f1;
__u16 f2;
__u16 f3;
} __attribute__ ((packed)) f_0x01;
struct {
__u8 f1;
__u8 f2;
__u8 f3;
__u8 f4;
__u8 f5;
} __attribute__ ((packed)) f_0x02;
} __attribute__ ((packed)) factors;
__u16 first_alt_trk;
__u16 no_alt_trk;
__u16 first_dia_trk;
__u16 no_dia_trk;
__u16 first_sup_trk;
__u16 no_sup_trk;
__u8 MDR_ID;
__u8 OBR_ID;
__u8 director;
__u8 rd_trk_set;
__u16 max_rec_zero;
__u8 reserved1;
__u8 RWANY_in_LR;
__u8 factor6;
__u8 factor7;
__u8 factor8;
__u8 reserved2[3];
__u8 reserved3[6];
__u32 long_no_cyl;
} __attribute__ ((packed));
/* elements of the configuration data */
struct dasd_ned {
struct {
__u8 identifier:2;
__u8 token_id:1;
__u8 sno_valid:1;
__u8 subst_sno:1;
__u8 recNED:1;
__u8 emuNED:1;
__u8 reserved:1;
} __attribute__ ((packed)) flags;
__u8 descriptor;
__u8 dev_class;
__u8 reserved;
__u8 dev_type[6];
__u8 dev_model[3];
__u8 HDA_manufacturer[3];
__u8 HDA_location[2];
__u8 HDA_seqno[12];
__u8 ID;
__u8 unit_addr;
} __attribute__ ((packed));
struct dasd_sneq {
struct {
__u8 identifier:2;
__u8 reserved:6;
} __attribute__ ((packed)) flags;
__u8 res1;
__u16 format;
__u8 res2[4]; /* byte 4- 7 */
__u8 sua_flags; /* byte 8 */
__u8 base_unit_addr; /* byte 9 */
__u8 res3[22]; /* byte 10-31 */
} __attribute__ ((packed));
struct vd_sneq {
struct {
__u8 identifier:2;
__u8 reserved:6;
} __attribute__ ((packed)) flags;
__u8 res1;
__u16 format;
__u8 res2[4]; /* byte 4- 7 */
__u8 uit[16]; /* byte 8-23 */
__u8 res3[8]; /* byte 24-31 */
} __attribute__ ((packed));
struct dasd_gneq {
struct {
__u8 identifier:2;
__u8 reserved:6;
} __attribute__ ((packed)) flags;
__u8 record_selector;
__u8 reserved[4];
struct {
__u8 value:2;
__u8 number:6;
} __attribute__ ((packed)) timeout;
__u8 reserved3;
__u16 subsystemID;
__u8 reserved2[22];
} __attribute__ ((packed));
struct dasd_rssd_features {
char feature[256];
} __attribute__((packed));
struct dasd_rssd_messages {
__u16 length;
__u8 format;
__u8 code;
__u32 message_id;
__u8 flags;
char messages[4087];
} __packed;
struct dasd_cuir_message {
__u16 length;
__u8 format;
__u8 code;
__u32 message_id;
__u8 flags;
__u8 neq_map[3];
__u8 ned_map;
__u8 record_selector;
} __packed;
struct dasd_psf_cuir_response {
__u8 order;
__u8 flags;
__u8 cc;
__u8 chpid;
__u16 device_nr;
__u16 reserved;
__u32 message_id;
__u64 system_id;
__u8 cssid;
__u8 ssid;
} __packed;
/*
* Perform Subsystem Function - Prepare for Read Subsystem Data
*/
struct dasd_psf_prssd_data {
unsigned char order;
unsigned char flags;
unsigned char reserved[4];
unsigned char suborder;
unsigned char varies[5];
} __attribute__ ((packed));
/*
* Perform Subsystem Function - Set Subsystem Characteristics
*/
struct dasd_psf_ssc_data {
unsigned char order;
unsigned char flags;
unsigned char cu_type[4];
unsigned char suborder;
unsigned char reserved[59];
} __attribute__((packed));
/*
* some structures and definitions for alias handling
*/
struct dasd_unit_address_configuration {
struct {
char ua_type;
char base_ua;
} unit[256];
} __attribute__((packed));
#define MAX_DEVICES_PER_LCU 256
/* flags on the LCU */
#define NEED_UAC_UPDATE 0x01
#define UPDATE_PENDING 0x02
enum pavtype {NO_PAV, BASE_PAV, HYPER_PAV};
struct alias_root {
struct list_head serverlist;
spinlock_t lock;
};
struct alias_server {
struct list_head server;
struct dasd_uid uid;
struct list_head lculist;
};
struct summary_unit_check_work_data {
char reason;
struct dasd_device *device;
struct work_struct worker;
};
struct read_uac_work_data {
struct dasd_device *device;
struct delayed_work dwork;
};
struct alias_lcu {
struct list_head lcu;
struct dasd_uid uid;
enum pavtype pav;
char flags;
spinlock_t lock;
struct list_head grouplist;
struct list_head active_devices;
struct list_head inactive_devices;
struct dasd_unit_address_configuration *uac;
struct summary_unit_check_work_data suc_data;
struct read_uac_work_data ruac_data;
struct dasd_ccw_req *rsu_cqr;
struct completion lcu_setup;
};
struct alias_pav_group {
struct list_head group;
struct dasd_uid uid;
struct alias_lcu *lcu;
struct list_head baselist;
struct list_head aliaslist;
struct dasd_device *next;
};
struct dasd_conf_data {
struct dasd_ned neds[5];
u8 reserved[64];
struct dasd_gneq gneq;
} __packed;
struct dasd_eckd_private {
struct dasd_eckd_characteristics rdc_data;
u8 *conf_data;
int conf_len;
/* per path configuration data */
struct dasd_conf_data *path_conf_data[8];
/* pointers to specific parts in the conf_data */
struct dasd_ned *ned;
struct dasd_sneq *sneq;
struct vd_sneq *vdsneq;
struct dasd_gneq *gneq;
struct eckd_count count_area[5];
int init_cqr_status;
int uses_cdl;
struct attrib_data_t attrib; /* e.g. cache operations */
struct dasd_rssd_features features;
u32 real_cyl;
/* alias managemnet */
struct dasd_uid uid;
struct alias_pav_group *pavgroup;
struct alias_lcu *lcu;
int count;
u32 fcx_max_data;
char suc_reason;
};
int dasd_alias_make_device_known_to_lcu(struct dasd_device *);
void dasd_alias_disconnect_device_from_lcu(struct dasd_device *);
int dasd_alias_add_device(struct dasd_device *);
int dasd_alias_remove_device(struct dasd_device *);
struct dasd_device *dasd_alias_get_start_dev(struct dasd_device *);
void dasd_alias_handle_summary_unit_check(struct work_struct *);
void dasd_eckd_reset_ccw_to_base_io(struct dasd_ccw_req *);
void dasd_alias_lcu_setup_complete(struct dasd_device *);
void dasd_alias_wait_for_lcu_setup(struct dasd_device *);
int dasd_alias_update_add_device(struct dasd_device *);
#endif /* DASD_ECKD_H */
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