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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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a695f16729
If user space opens a unit record device node then vmur is leaving the kernel with lock open_mutex still held to prevent other processes from opening the device simultaneously. This causes lockdep to complain about a lock held when returning to user space. Now the mutex is replaced by a wait queue to serialize device open. Signed-off-by: Frank Munzert <munzert@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
111 lines
3.0 KiB
C
111 lines
3.0 KiB
C
/*
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* Linux driver for System z and s390 unit record devices
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* (z/VM virtual punch, reader, printer)
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*
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* Copyright IBM Corp. 2001, 2007
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* Authors: Malcolm Beattie <beattiem@uk.ibm.com>
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* Michael Holzheu <holzheu@de.ibm.com>
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* Frank Munzert <munzert@de.ibm.com>
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*/
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#ifndef _VMUR_H_
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#define _VMUR_H_
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#define DEV_CLASS_UR_I 0x20 /* diag210 unit record input device class */
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#define DEV_CLASS_UR_O 0x10 /* diag210 unit record output device class */
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/*
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* we only support z/VM's default unit record devices:
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* both in SPOOL directory control statement and in CP DEFINE statement
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* RDR defaults to 2540 reader
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* PUN defaults to 2540 punch
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* PRT defaults to 1403 printer
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*/
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#define READER_PUNCH_DEVTYPE 0x2540
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#define PRINTER_DEVTYPE 0x1403
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/* z/VM spool file control block SFBLOK */
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struct file_control_block {
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char reserved_1[8];
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char user_owner[8];
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char user_orig[8];
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__s32 data_recs;
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__s16 rec_len;
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__s16 file_num;
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__u8 file_stat;
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__u8 dev_type;
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char reserved_2[6];
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char file_name[12];
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char file_type[12];
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char create_date[8];
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char create_time[8];
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char reserved_3[6];
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__u8 file_class;
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__u8 sfb_lok;
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__u64 distr_code;
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__u32 reserved_4;
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__u8 current_starting_copy_number;
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__u8 sfblock_cntrl_flags;
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__u8 reserved_5;
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__u8 more_status_flags;
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char rest[200];
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} __attribute__ ((packed));
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#define FLG_SYSTEM_HOLD 0x04
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#define FLG_CP_DUMP 0x10
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#define FLG_USER_HOLD 0x20
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#define FLG_IN_USE 0x80
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/*
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* A struct urdev is created for each ur device that is made available
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* via the ccw_device driver model.
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*/
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struct urdev {
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struct ccw_device *cdev; /* Backpointer to ccw device */
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struct mutex io_mutex; /* Serialises device IO */
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struct completion *io_done; /* do_ur_io waits; irq completes */
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struct device *device;
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struct cdev *char_device;
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struct ccw_dev_id dev_id; /* device id */
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size_t reclen; /* Record length for *write* CCWs */
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int class; /* VM device class */
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int io_request_rc; /* return code from I/O request */
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atomic_t ref_count; /* reference counter */
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wait_queue_head_t wait; /* wait queue to serialize open */
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int open_flag; /* "urdev is open" flag */
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spinlock_t open_lock; /* serialize critical sections */
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};
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/*
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* A struct urfile is allocated at open() time for each device and
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* freed on release().
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*/
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struct urfile {
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struct urdev *urd;
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unsigned int flags;
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size_t dev_reclen;
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__u16 file_reclen;
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};
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/*
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* Device major/minor definitions.
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*/
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#define UR_MAJOR 0 /* get dynamic major */
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/*
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* We map minor numbers directly to device numbers (0-FFFF) for simplicity.
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* This avoids having to allocate (and manage) slot numbers.
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*/
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#define NUM_MINORS 65536
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/* Limiting each I/O to 511 records limits chan prog to 4KB (511 r/w + 1 NOP) */
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#define MAX_RECS_PER_IO 511
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#define WRITE_CCW_CMD 0x01
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#define TRACE(x...) debug_sprintf_event(vmur_dbf, 1, x)
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#define CCWDEV_CU_DI(cutype, di) \
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CCW_DEVICE(cutype, 0x00), .driver_info = (di)
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#define FILE_RECLEN_OFFSET 4064 /* reclen offset in spool data block */
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#endif /* _VMUR_H_ */
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