mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-12 12:06:44 +07:00
347ba8a588
Fixed data reading bug by replacing binary attribute with device one. Switching the sysfs read from bin_attribute to device_attribute. The data is far under PAGE_SIZE so the binary interface isn't required. As the device_attribute interface will make one call to w1_therm_read per file open and buffer, the result is, the following problems go away. buffer overflow: Execute a short read on w1_slave and w1_therm_read_bin would still return the full string size worth of data clobbering the user space buffer when it returned. Switching to device_attribute avoids the buffer overflow problems. With the snprintf formatted output dealing with short reads without doing a conversion per read would have been difficult. bad behavior: `cat w1_slave` would cause two temperature conversions to take place. Previously the code assumed W1_SLAVE_DATA_SIZE would be returned with each read. It would not return 0 unless the offset was less than W1_SLAVE_DATA_SIZE. The result was the first read did a temperature conversion, filled the buffer and returned, the offset in the second read would be less than W1_SLAVE_DATA_SIZE and also fill the buffer and return, the third read would finnally have a big enough offset to return 0 and cause cat to stop. Now w1_therm_read will be called at most once per open. Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
243 lines
6.1 KiB
C
243 lines
6.1 KiB
C
/*
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* w1.h
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*
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* Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifndef __W1_H
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#define __W1_H
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struct w1_reg_num
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{
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#if defined(__LITTLE_ENDIAN_BITFIELD)
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__u64 family:8,
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id:48,
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crc:8;
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#elif defined(__BIG_ENDIAN_BITFIELD)
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__u64 crc:8,
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id:48,
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family:8;
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#else
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#error "Please fix <asm/byteorder.h>"
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#endif
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};
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#ifdef __KERNEL__
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#include <linux/completion.h>
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#include <linux/device.h>
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#include <linux/mutex.h>
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#include "w1_family.h"
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#define W1_MAXNAMELEN 32
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#define W1_SEARCH 0xF0
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#define W1_ALARM_SEARCH 0xEC
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#define W1_CONVERT_TEMP 0x44
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#define W1_SKIP_ROM 0xCC
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#define W1_READ_SCRATCHPAD 0xBE
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#define W1_READ_ROM 0x33
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#define W1_READ_PSUPPLY 0xB4
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#define W1_MATCH_ROM 0x55
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#define W1_SLAVE_ACTIVE 0
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struct w1_slave
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{
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struct module *owner;
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unsigned char name[W1_MAXNAMELEN];
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struct list_head w1_slave_entry;
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struct w1_reg_num reg_num;
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atomic_t refcnt;
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u8 rom[9];
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u32 flags;
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int ttl;
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struct w1_master *master;
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struct w1_family *family;
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void *family_data;
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struct device dev;
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struct completion released;
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};
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typedef void (*w1_slave_found_callback)(struct w1_master *, u64);
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/**
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* Note: read_bit and write_bit are very low level functions and should only
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* be used with hardware that doesn't really support 1-wire operations,
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* like a parallel/serial port.
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* Either define read_bit and write_bit OR define, at minimum, touch_bit and
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* reset_bus.
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*/
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struct w1_bus_master
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{
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/** the first parameter in all the functions below */
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void *data;
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/**
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* Sample the line level
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* @return the level read (0 or 1)
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*/
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u8 (*read_bit)(void *);
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/** Sets the line level */
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void (*write_bit)(void *, u8);
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/**
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* touch_bit is the lowest-level function for devices that really
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* support the 1-wire protocol.
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* touch_bit(0) = write-0 cycle
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* touch_bit(1) = write-1 / read cycle
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* @return the bit read (0 or 1)
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*/
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u8 (*touch_bit)(void *, u8);
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/**
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* Reads a bytes. Same as 8 touch_bit(1) calls.
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* @return the byte read
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*/
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u8 (*read_byte)(void *);
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/**
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* Writes a byte. Same as 8 touch_bit(x) calls.
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*/
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void (*write_byte)(void *, u8);
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/**
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* Same as a series of read_byte() calls
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* @return the number of bytes read
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*/
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u8 (*read_block)(void *, u8 *, int);
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/** Same as a series of write_byte() calls */
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void (*write_block)(void *, const u8 *, int);
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/**
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* Combines two reads and a smart write for ROM searches
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* @return bit0=Id bit1=comp_id bit2=dir_taken
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*/
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u8 (*triplet)(void *, u8);
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/**
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* long write-0 with a read for the presence pulse detection
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* @return -1=Error, 0=Device present, 1=No device present
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*/
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u8 (*reset_bus)(void *);
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/**
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* Put out a strong pull-up pulse of the specified duration.
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* @return -1=Error, 0=completed
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*/
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u8 (*set_pullup)(void *, int);
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/** Really nice hardware can handles the different types of ROM search
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* w1_master* is passed to the slave found callback.
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*/
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void (*search)(void *, struct w1_master *,
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u8, w1_slave_found_callback);
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};
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struct w1_master
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{
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struct list_head w1_master_entry;
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struct module *owner;
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unsigned char name[W1_MAXNAMELEN];
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struct list_head slist;
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int max_slave_count, slave_count;
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unsigned long attempts;
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int slave_ttl;
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int initialized;
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u32 id;
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int search_count;
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atomic_t refcnt;
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void *priv;
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int priv_size;
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/** 5V strong pullup enabled flag, 1 enabled, zero disabled. */
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int enable_pullup;
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/** 5V strong pullup duration in milliseconds, zero disabled. */
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int pullup_duration;
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struct task_struct *thread;
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struct mutex mutex;
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struct device_driver *driver;
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struct device dev;
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struct w1_bus_master *bus_master;
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u32 seq;
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};
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int w1_create_master_attributes(struct w1_master *);
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void w1_destroy_master_attributes(struct w1_master *master);
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void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
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void w1_search_devices(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb);
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struct w1_slave *w1_search_slave(struct w1_reg_num *id);
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void w1_search_process(struct w1_master *dev, u8 search_type);
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struct w1_master *w1_search_master_id(u32 id);
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/* Disconnect and reconnect devices in the given family. Used for finding
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* unclaimed devices after a family has been registered or releasing devices
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* after a family has been unregistered. Set attach to 1 when a new family
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* has just been registered, to 0 when it has been unregistered.
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*/
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void w1_reconnect_slaves(struct w1_family *f, int attach);
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void w1_slave_detach(struct w1_slave *sl);
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u8 w1_triplet(struct w1_master *dev, int bdir);
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void w1_write_8(struct w1_master *, u8);
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int w1_reset_bus(struct w1_master *);
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u8 w1_calc_crc8(u8 *, int);
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void w1_write_block(struct w1_master *, const u8 *, int);
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u8 w1_read_block(struct w1_master *, u8 *, int);
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int w1_reset_select_slave(struct w1_slave *sl);
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void w1_next_pullup(struct w1_master *, int);
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static inline struct w1_slave* dev_to_w1_slave(struct device *dev)
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{
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return container_of(dev, struct w1_slave, dev);
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}
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static inline struct w1_slave* kobj_to_w1_slave(struct kobject *kobj)
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{
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return dev_to_w1_slave(container_of(kobj, struct device, kobj));
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}
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static inline struct w1_master* dev_to_w1_master(struct device *dev)
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{
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return container_of(dev, struct w1_master, dev);
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}
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extern struct device_driver w1_master_driver;
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extern struct device w1_master_device;
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extern int w1_max_slave_count;
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extern int w1_max_slave_ttl;
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extern struct list_head w1_masters;
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extern struct mutex w1_mlock;
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extern int w1_process(void *);
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#endif /* __KERNEL__ */
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#endif /* __W1_H */
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