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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-06 09:41:23 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-06 09:41:23 -0700 |
commit | 049711bf3cc59501ebeae621aa22acd3918ebd79 (patch) | |
tree | d6168b7bb3d8cee71a4a4e43a85cfaf2a3ef1a0a /arch/sparc/kernel/mdesc.c | |
parent | ae045e2455429c418a418a3376301a9e5753a0a8 (diff) | |
parent | 5b6ff9df056b69a3b65708bfb9923af41146c8c8 (diff) | |
download | op-kernel-dev-049711bf3cc59501ebeae621aa22acd3918ebd79.zip op-kernel-dev-049711bf3cc59501ebeae621aa22acd3918ebd79.tar.gz |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next
Pull sparc updates from David Miller:
1) Add sparc RAM output to /proc/iomem, from Bob Picco.
2) Allow seeks on /dev/mdesc, from Khalid Aziz.
3) Cleanup sparc64 I/O accessors, from Sam Ravnborg.
4) If update_mmu_cache{,_pmd}() is called with an not-valid mapping, do
not insert it into the TLB miss hash tables otherwise we'll
livelock. Based upon work by Christopher Alexander Tobias Schulze.
5) Fix BREAK detection in sunsab driver when no actual characters are
pending, from Christopher Alexander Tobias Schulze.
6) Because we have modules --> openfirmware --> vmalloc ordering of
virtual memory, the lazy VMAP TLB flusher can cons up an invocation
of flush_tlb_kernel_range() that covers the openfirmware address
range. Unfortunately this will flush out the firmware's locked TLB
mapping which causes all kinds of trouble. Just split up the flush
request if this happens, but in the long term the lazy VMAP flusher
should probably be made a little bit smarter.
Based upon work by Christopher Alexander Tobias Schulze.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next:
sparc64: Fix up merge thinko.
sparc: Add "install" target
arch/sparc/math-emu/math_32.c: drop stray break operator
sparc64: ldc_connect() should not return EINVAL when handshake is in progress.
sparc64: Guard against flushing openfirmware mappings.
sunsab: Fix detection of BREAK on sunsab serial console
bbc-i2c: Fix BBC I2C envctrl on SunBlade 2000
sparc64: Do not insert non-valid PTEs into the TSB hash table.
sparc64: avoid code duplication in io_64.h
sparc64: reorder functions in io_64.h
sparc64: drop unused SLOW_DOWN_IO definitions
sparc64: remove macro indirection in io_64.h
sparc64: update IO access functions in PeeCeeI
sparcspkr: use sbus_*() primitives for IO
sparc: Add support for seek and shorter read to /dev/mdesc
sparc: use %s for unaligned panic
drivers/sbus/char: Micro-optimization in display7seg.c
display7seg: Introduce the use of the managed version of kzalloc
sparc64 - add mem to iomem resource
Diffstat (limited to 'arch/sparc/kernel/mdesc.c')
-rw-r--r-- | arch/sparc/kernel/mdesc.c | 82 |
1 files changed, 69 insertions, 13 deletions
diff --git a/arch/sparc/kernel/mdesc.c b/arch/sparc/kernel/mdesc.c index a1a4400..99632a8 100644 --- a/arch/sparc/kernel/mdesc.c +++ b/arch/sparc/kernel/mdesc.c @@ -906,29 +906,85 @@ void mdesc_fill_in_cpu_data(cpumask_t *mask) smp_fill_in_sib_core_maps(); } -static ssize_t mdesc_read(struct file *file, char __user *buf, - size_t len, loff_t *offp) +/* mdesc_open() - Grab a reference to mdesc_handle when /dev/mdesc is + * opened. Hold this reference until /dev/mdesc is closed to ensure + * mdesc data structure is not released underneath us. Store the + * pointer to mdesc structure in private_data for read and seek to use + */ +static int mdesc_open(struct inode *inode, struct file *file) { struct mdesc_handle *hp = mdesc_grab(); - int err; if (!hp) return -ENODEV; - err = hp->handle_size; - if (len < hp->handle_size) - err = -EMSGSIZE; - else if (copy_to_user(buf, &hp->mdesc, hp->handle_size)) - err = -EFAULT; - mdesc_release(hp); + file->private_data = hp; + + return 0; +} + +static ssize_t mdesc_read(struct file *file, char __user *buf, + size_t len, loff_t *offp) +{ + struct mdesc_handle *hp = file->private_data; + unsigned char *mdesc; + int bytes_left, count = len; + + if (*offp >= hp->handle_size) + return 0; + + bytes_left = hp->handle_size - *offp; + if (count > bytes_left) + count = bytes_left; + + mdesc = (unsigned char *)&hp->mdesc; + mdesc += *offp; + if (!copy_to_user(buf, mdesc, count)) { + *offp += count; + return count; + } else { + return -EFAULT; + } +} - return err; +static loff_t mdesc_llseek(struct file *file, loff_t offset, int whence) +{ + struct mdesc_handle *hp; + + switch (whence) { + case SEEK_CUR: + offset += file->f_pos; + break; + case SEEK_SET: + break; + default: + return -EINVAL; + } + + hp = file->private_data; + if (offset > hp->handle_size) + return -EINVAL; + else + file->f_pos = offset; + + return offset; +} + +/* mdesc_close() - /dev/mdesc is being closed, release the reference to + * mdesc structure. + */ +static int mdesc_close(struct inode *inode, struct file *file) +{ + mdesc_release(file->private_data); + return 0; } static const struct file_operations mdesc_fops = { - .read = mdesc_read, - .owner = THIS_MODULE, - .llseek = noop_llseek, + .open = mdesc_open, + .read = mdesc_read, + .llseek = mdesc_llseek, + .release = mdesc_close, + .owner = THIS_MODULE, }; static struct miscdevice mdesc_misc = { |