![Finn Thain](/assets/img/avatar_default.png)
Adopt nvram module to reduce code duplication. This means CONFIG_NVRAM becomes available to PPC64 builds. Previously it was only available to PPC32 builds because it depended on CONFIG_GENERIC_NVRAM. The IOC_NVRAM_GET_OFFSET ioctl as implemented on PPC64 validates the offset returned by pmac_get_partition(). Do the same in the nvram module. Note that the old PPC32 generic_nvram module lacked this test. So when CONFIG_PPC32 && CONFIG_PPC_PMAC, the IOC_NVRAM_GET_OFFSET ioctl would have returned 0 (always). But when CONFIG_PPC64 && CONFIG_PPC_PMAC, the IOC_NVRAM_GET_OFFSET ioctl would have returned -1 (which is -EPERM) when the requested partition was not found. With this patch, the result is now -EINVAL on both PPC32 and PPC64 when the requested PowerMac NVRAM partition is not found. This is a userspace- visible change, in the non-existent partition case, which would be in an error path for an IOC_NVRAM_GET_OFFSET ioctl syscall. Tested-by: Stan Johnson <userm57@yahoo.com> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
549 lines
14 KiB
C
549 lines
14 KiB
C
/*
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* CMOS/NV-RAM driver for Linux
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*
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* Copyright (C) 1997 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
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* idea by and with help from Richard Jelinek <rj@suse.de>
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* Portions copyright (c) 2001,2002 Sun Microsystems (thockin@sun.com)
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*
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* This driver allows you to access the contents of the non-volatile memory in
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* the mc146818rtc.h real-time clock. This chip is built into all PCs and into
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* many Atari machines. In the former it's called "CMOS-RAM", in the latter
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* "NVRAM" (NV stands for non-volatile).
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*
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* The data are supplied as a (seekable) character device, /dev/nvram. The
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* size of this file is dependent on the controller. The usual size is 114,
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* the number of freely available bytes in the memory (i.e., not used by the
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* RTC itself).
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*
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* Checksums over the NVRAM contents are managed by this driver. In case of a
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* bad checksum, reads and writes return -EIO. The checksum can be initialized
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* to a sane state either by ioctl(NVRAM_INIT) (clear whole NVRAM) or
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* ioctl(NVRAM_SETCKS) (doesn't change contents, just makes checksum valid
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* again; use with care!)
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*
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* 1.1 Cesar Barros: SMP locking fixes
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* added changelog
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* 1.2 Erik Gilling: Cobalt Networks support
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* Tim Hockin: general cleanup, Cobalt support
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* 1.3 Wim Van Sebroeck: convert PRINT_PROC to seq_file
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*/
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#define NVRAM_VERSION "1.3"
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#include <linux/module.h>
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#include <linux/nvram.h>
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/miscdevice.h>
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#include <linux/ioport.h>
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#include <linux/fcntl.h>
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#include <linux/mc146818rtc.h>
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#include <linux/init.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/io.h>
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#include <linux/uaccess.h>
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#include <linux/mutex.h>
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#include <linux/pagemap.h>
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#ifdef CONFIG_PPC
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#include <asm/nvram.h>
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#endif
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static DEFINE_MUTEX(nvram_mutex);
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static DEFINE_SPINLOCK(nvram_state_lock);
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static int nvram_open_cnt; /* #times opened */
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static int nvram_open_mode; /* special open modes */
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static ssize_t nvram_size;
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#define NVRAM_WRITE 1 /* opened for writing (exclusive) */
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#define NVRAM_EXCL 2 /* opened with O_EXCL */
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#ifdef CONFIG_X86
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/*
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* These functions are provided to be called internally or by other parts of
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* the kernel. It's up to the caller to ensure correct checksum before reading
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* or after writing (needs to be done only once).
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*
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* It is worth noting that these functions all access bytes of general
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* purpose memory in the NVRAM - that is to say, they all add the
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* NVRAM_FIRST_BYTE offset. Pass them offsets into NVRAM as if you did not
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* know about the RTC cruft.
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*/
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#define NVRAM_BYTES (128 - NVRAM_FIRST_BYTE)
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/* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with
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* rtc_lock held. Due to the index-port/data-port design of the RTC, we
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* don't want two different things trying to get to it at once. (e.g. the
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* periodic 11 min sync from kernel/time/ntp.c vs. this driver.)
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*/
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static unsigned char __nvram_read_byte(int i)
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{
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return CMOS_READ(NVRAM_FIRST_BYTE + i);
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}
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static unsigned char pc_nvram_read_byte(int i)
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{
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unsigned long flags;
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unsigned char c;
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spin_lock_irqsave(&rtc_lock, flags);
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c = __nvram_read_byte(i);
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spin_unlock_irqrestore(&rtc_lock, flags);
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return c;
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}
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/* This races nicely with trying to read with checksum checking (nvram_read) */
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static void __nvram_write_byte(unsigned char c, int i)
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{
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CMOS_WRITE(c, NVRAM_FIRST_BYTE + i);
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}
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static void pc_nvram_write_byte(unsigned char c, int i)
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{
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unsigned long flags;
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spin_lock_irqsave(&rtc_lock, flags);
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__nvram_write_byte(c, i);
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spin_unlock_irqrestore(&rtc_lock, flags);
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}
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/* On PCs, the checksum is built only over bytes 2..31 */
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#define PC_CKS_RANGE_START 2
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#define PC_CKS_RANGE_END 31
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#define PC_CKS_LOC 32
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static int __nvram_check_checksum(void)
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{
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int i;
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unsigned short sum = 0;
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unsigned short expect;
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for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
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sum += __nvram_read_byte(i);
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expect = __nvram_read_byte(PC_CKS_LOC)<<8 |
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__nvram_read_byte(PC_CKS_LOC+1);
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return (sum & 0xffff) == expect;
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}
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static void __nvram_set_checksum(void)
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{
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int i;
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unsigned short sum = 0;
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for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
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sum += __nvram_read_byte(i);
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__nvram_write_byte(sum >> 8, PC_CKS_LOC);
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__nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1);
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}
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static long pc_nvram_set_checksum(void)
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{
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spin_lock_irq(&rtc_lock);
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__nvram_set_checksum();
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spin_unlock_irq(&rtc_lock);
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return 0;
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}
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static long pc_nvram_initialize(void)
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{
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ssize_t i;
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spin_lock_irq(&rtc_lock);
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for (i = 0; i < NVRAM_BYTES; ++i)
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__nvram_write_byte(0, i);
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__nvram_set_checksum();
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spin_unlock_irq(&rtc_lock);
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return 0;
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}
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static ssize_t pc_nvram_get_size(void)
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{
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return NVRAM_BYTES;
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}
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static ssize_t pc_nvram_read(char *buf, size_t count, loff_t *ppos)
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{
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char *p = buf;
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loff_t i;
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spin_lock_irq(&rtc_lock);
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if (!__nvram_check_checksum()) {
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spin_unlock_irq(&rtc_lock);
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return -EIO;
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}
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for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p)
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*p = __nvram_read_byte(i);
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spin_unlock_irq(&rtc_lock);
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*ppos = i;
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return p - buf;
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}
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static ssize_t pc_nvram_write(char *buf, size_t count, loff_t *ppos)
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{
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char *p = buf;
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loff_t i;
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spin_lock_irq(&rtc_lock);
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if (!__nvram_check_checksum()) {
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spin_unlock_irq(&rtc_lock);
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return -EIO;
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}
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for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p)
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__nvram_write_byte(*p, i);
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__nvram_set_checksum();
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spin_unlock_irq(&rtc_lock);
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*ppos = i;
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return p - buf;
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}
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const struct nvram_ops arch_nvram_ops = {
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.read = pc_nvram_read,
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.write = pc_nvram_write,
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.read_byte = pc_nvram_read_byte,
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.write_byte = pc_nvram_write_byte,
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.get_size = pc_nvram_get_size,
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.set_checksum = pc_nvram_set_checksum,
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.initialize = pc_nvram_initialize,
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};
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EXPORT_SYMBOL(arch_nvram_ops);
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#endif /* CONFIG_X86 */
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/*
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* The are the file operation function for user access to /dev/nvram
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*/
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static loff_t nvram_misc_llseek(struct file *file, loff_t offset, int origin)
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{
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return generic_file_llseek_size(file, offset, origin, MAX_LFS_FILESIZE,
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nvram_size);
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}
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static ssize_t nvram_misc_read(struct file *file, char __user *buf,
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size_t count, loff_t *ppos)
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{
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char *tmp;
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ssize_t ret;
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if (!access_ok(buf, count))
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return -EFAULT;
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if (*ppos >= nvram_size)
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return 0;
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count = min_t(size_t, count, nvram_size - *ppos);
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count = min_t(size_t, count, PAGE_SIZE);
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tmp = kmalloc(count, GFP_KERNEL);
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if (!tmp)
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return -ENOMEM;
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ret = nvram_read(tmp, count, ppos);
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if (ret <= 0)
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goto out;
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if (copy_to_user(buf, tmp, ret)) {
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*ppos -= ret;
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ret = -EFAULT;
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}
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out:
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kfree(tmp);
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return ret;
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}
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static ssize_t nvram_misc_write(struct file *file, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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char *tmp;
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ssize_t ret;
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if (!access_ok(buf, count))
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return -EFAULT;
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if (*ppos >= nvram_size)
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return 0;
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count = min_t(size_t, count, nvram_size - *ppos);
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count = min_t(size_t, count, PAGE_SIZE);
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tmp = memdup_user(buf, count);
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if (IS_ERR(tmp))
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return PTR_ERR(tmp);
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ret = nvram_write(tmp, count, ppos);
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kfree(tmp);
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return ret;
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}
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static long nvram_misc_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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long ret = -ENOTTY;
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switch (cmd) {
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#ifdef CONFIG_PPC
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case OBSOLETE_PMAC_NVRAM_GET_OFFSET:
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pr_warn("nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n");
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/* fall through */
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case IOC_NVRAM_GET_OFFSET:
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ret = -EINVAL;
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#ifdef CONFIG_PPC_PMAC
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if (machine_is(powermac)) {
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int part, offset;
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if (copy_from_user(&part, (void __user *)arg,
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sizeof(part)) != 0)
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return -EFAULT;
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if (part < pmac_nvram_OF || part > pmac_nvram_NR)
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return -EINVAL;
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offset = pmac_get_partition(part);
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if (offset < 0)
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return -EINVAL;
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if (copy_to_user((void __user *)arg,
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&offset, sizeof(offset)) != 0)
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return -EFAULT;
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ret = 0;
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}
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#endif
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break;
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#ifdef CONFIG_PPC32
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case IOC_NVRAM_SYNC:
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if (ppc_md.nvram_sync != NULL) {
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mutex_lock(&nvram_mutex);
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ppc_md.nvram_sync();
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mutex_unlock(&nvram_mutex);
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}
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ret = 0;
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break;
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#endif
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#elif defined(CONFIG_X86) || defined(CONFIG_M68K)
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case NVRAM_INIT:
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/* initialize NVRAM contents and checksum */
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if (!capable(CAP_SYS_ADMIN))
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return -EACCES;
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if (arch_nvram_ops.initialize != NULL) {
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mutex_lock(&nvram_mutex);
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ret = arch_nvram_ops.initialize();
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mutex_unlock(&nvram_mutex);
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}
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break;
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case NVRAM_SETCKS:
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/* just set checksum, contents unchanged (maybe useful after
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* checksum garbaged somehow...) */
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if (!capable(CAP_SYS_ADMIN))
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return -EACCES;
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if (arch_nvram_ops.set_checksum != NULL) {
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mutex_lock(&nvram_mutex);
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ret = arch_nvram_ops.set_checksum();
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mutex_unlock(&nvram_mutex);
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}
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break;
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#endif /* CONFIG_X86 || CONFIG_M68K */
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}
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return ret;
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}
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static int nvram_misc_open(struct inode *inode, struct file *file)
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{
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spin_lock(&nvram_state_lock);
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/* Prevent multiple readers/writers if desired. */
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if ((nvram_open_cnt && (file->f_flags & O_EXCL)) ||
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(nvram_open_mode & NVRAM_EXCL)) {
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spin_unlock(&nvram_state_lock);
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return -EBUSY;
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}
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#if defined(CONFIG_X86) || defined(CONFIG_M68K)
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/* Prevent multiple writers if the set_checksum ioctl is implemented. */
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if ((arch_nvram_ops.set_checksum != NULL) &&
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(file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE)) {
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spin_unlock(&nvram_state_lock);
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return -EBUSY;
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}
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#endif
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if (file->f_flags & O_EXCL)
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nvram_open_mode |= NVRAM_EXCL;
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if (file->f_mode & FMODE_WRITE)
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nvram_open_mode |= NVRAM_WRITE;
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nvram_open_cnt++;
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spin_unlock(&nvram_state_lock);
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return 0;
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}
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static int nvram_misc_release(struct inode *inode, struct file *file)
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{
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spin_lock(&nvram_state_lock);
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nvram_open_cnt--;
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/* if only one instance is open, clear the EXCL bit */
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if (nvram_open_mode & NVRAM_EXCL)
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nvram_open_mode &= ~NVRAM_EXCL;
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if (file->f_mode & FMODE_WRITE)
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nvram_open_mode &= ~NVRAM_WRITE;
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spin_unlock(&nvram_state_lock);
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return 0;
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}
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#if defined(CONFIG_X86) && defined(CONFIG_PROC_FS)
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static const char * const floppy_types[] = {
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"none", "5.25'' 360k", "5.25'' 1.2M", "3.5'' 720k", "3.5'' 1.44M",
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"3.5'' 2.88M", "3.5'' 2.88M"
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};
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static const char * const gfx_types[] = {
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"EGA, VGA, ... (with BIOS)",
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"CGA (40 cols)",
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"CGA (80 cols)",
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"monochrome",
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};
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static void pc_nvram_proc_read(unsigned char *nvram, struct seq_file *seq,
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void *offset)
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{
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int checksum;
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int type;
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spin_lock_irq(&rtc_lock);
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checksum = __nvram_check_checksum();
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spin_unlock_irq(&rtc_lock);
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seq_printf(seq, "Checksum status: %svalid\n", checksum ? "" : "not ");
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seq_printf(seq, "# floppies : %d\n",
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(nvram[6] & 1) ? (nvram[6] >> 6) + 1 : 0);
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seq_printf(seq, "Floppy 0 type : ");
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type = nvram[2] >> 4;
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if (type < ARRAY_SIZE(floppy_types))
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seq_printf(seq, "%s\n", floppy_types[type]);
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else
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seq_printf(seq, "%d (unknown)\n", type);
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seq_printf(seq, "Floppy 1 type : ");
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type = nvram[2] & 0x0f;
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if (type < ARRAY_SIZE(floppy_types))
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seq_printf(seq, "%s\n", floppy_types[type]);
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else
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seq_printf(seq, "%d (unknown)\n", type);
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seq_printf(seq, "HD 0 type : ");
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type = nvram[4] >> 4;
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if (type)
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seq_printf(seq, "%02x\n", type == 0x0f ? nvram[11] : type);
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else
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seq_printf(seq, "none\n");
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seq_printf(seq, "HD 1 type : ");
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type = nvram[4] & 0x0f;
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if (type)
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seq_printf(seq, "%02x\n", type == 0x0f ? nvram[12] : type);
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else
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seq_printf(seq, "none\n");
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seq_printf(seq, "HD type 48 data: %d/%d/%d C/H/S, precomp %d, lz %d\n",
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nvram[18] | (nvram[19] << 8),
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nvram[20], nvram[25],
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nvram[21] | (nvram[22] << 8), nvram[23] | (nvram[24] << 8));
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seq_printf(seq, "HD type 49 data: %d/%d/%d C/H/S, precomp %d, lz %d\n",
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nvram[39] | (nvram[40] << 8),
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nvram[41], nvram[46],
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nvram[42] | (nvram[43] << 8), nvram[44] | (nvram[45] << 8));
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seq_printf(seq, "DOS base memory: %d kB\n", nvram[7] | (nvram[8] << 8));
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seq_printf(seq, "Extended memory: %d kB (configured), %d kB (tested)\n",
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nvram[9] | (nvram[10] << 8), nvram[34] | (nvram[35] << 8));
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seq_printf(seq, "Gfx adapter : %s\n",
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gfx_types[(nvram[6] >> 4) & 3]);
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seq_printf(seq, "FPU : %sinstalled\n",
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(nvram[6] & 2) ? "" : "not ");
|
|
|
|
return;
|
|
}
|
|
|
|
static int nvram_proc_read(struct seq_file *seq, void *offset)
|
|
{
|
|
unsigned char contents[NVRAM_BYTES];
|
|
int i = 0;
|
|
|
|
spin_lock_irq(&rtc_lock);
|
|
for (i = 0; i < NVRAM_BYTES; ++i)
|
|
contents[i] = __nvram_read_byte(i);
|
|
spin_unlock_irq(&rtc_lock);
|
|
|
|
pc_nvram_proc_read(contents, seq, offset);
|
|
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_X86 && CONFIG_PROC_FS */
|
|
|
|
static const struct file_operations nvram_misc_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = nvram_misc_llseek,
|
|
.read = nvram_misc_read,
|
|
.write = nvram_misc_write,
|
|
.unlocked_ioctl = nvram_misc_ioctl,
|
|
.open = nvram_misc_open,
|
|
.release = nvram_misc_release,
|
|
};
|
|
|
|
static struct miscdevice nvram_misc = {
|
|
NVRAM_MINOR,
|
|
"nvram",
|
|
&nvram_misc_fops,
|
|
};
|
|
|
|
static int __init nvram_module_init(void)
|
|
{
|
|
int ret;
|
|
|
|
nvram_size = nvram_get_size();
|
|
if (nvram_size < 0)
|
|
return nvram_size;
|
|
|
|
ret = misc_register(&nvram_misc);
|
|
if (ret) {
|
|
pr_err("nvram: can't misc_register on minor=%d\n", NVRAM_MINOR);
|
|
return ret;
|
|
}
|
|
|
|
#if defined(CONFIG_X86) && defined(CONFIG_PROC_FS)
|
|
if (!proc_create_single("driver/nvram", 0, NULL, nvram_proc_read)) {
|
|
pr_err("nvram: can't create /proc/driver/nvram\n");
|
|
misc_deregister(&nvram_misc);
|
|
return -ENOMEM;
|
|
}
|
|
#endif
|
|
|
|
pr_info("Non-volatile memory driver v" NVRAM_VERSION "\n");
|
|
return 0;
|
|
}
|
|
|
|
static void __exit nvram_module_exit(void)
|
|
{
|
|
#if defined(CONFIG_X86) && defined(CONFIG_PROC_FS)
|
|
remove_proc_entry("driver/nvram", NULL);
|
|
#endif
|
|
misc_deregister(&nvram_misc);
|
|
}
|
|
|
|
module_init(nvram_module_init);
|
|
module_exit(nvram_module_exit);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_MISCDEV(NVRAM_MINOR);
|
|
MODULE_ALIAS("devname:nvram");
|