X-Git-Url: https://git.stricted.de/?a=blobdiff_plain;f=kernel%2Frelay.c;h=ad855017bc59de72ebf592fda7576edf6e245bb4;hb=a4d63e729edad704af95e5f2a56e8c8eaaa5216b;hp=e61156ea4e2522c6ffdaf1dfdfc0c4b892c17d8d;hpb=8d62fdebdaf9b866c7e236a8f5cfe90e6dba5773;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git diff --git a/kernel/relay.c b/kernel/relay.c index e61156ea4e25..ad855017bc59 100644 --- a/kernel/relay.c +++ b/kernel/relay.c @@ -1,7 +1,7 @@ /* * Public API and common code for kernel->userspace relay file support. * - * See Documentation/filesystems/relayfs.txt for an overview of relayfs. + * See Documentation/filesystems/relay.txt for an overview. * * Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp * Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com) @@ -21,6 +21,7 @@ #include #include #include +#include /* list of open channels, for cpu hotplug */ static DEFINE_MUTEX(relay_channels_mutex); @@ -79,7 +80,7 @@ static struct vm_operations_struct relay_file_mmap_ops = { * * Caller should already have grabbed mmap_sem. */ -int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma) +static int relay_mmap_buf(struct rchan_buf *buf, struct vm_area_struct *vma) { unsigned long length = vma->vm_end - vma->vm_start; struct file *filp = vma->vm_file; @@ -121,6 +122,7 @@ static void *relay_alloc_buf(struct rchan_buf *buf, size_t *size) buf->page_array[i] = alloc_page(GFP_KERNEL); if (unlikely(!buf->page_array[i])) goto depopulate; + set_page_private(buf->page_array[i], (unsigned long)buf); } mem = vmap(buf->page_array, n_pages, VM_MAP, PAGE_KERNEL); if (!mem) @@ -143,7 +145,7 @@ depopulate: * * Returns channel buffer if successful, %NULL otherwise. */ -struct rchan_buf *relay_create_buf(struct rchan *chan) +static struct rchan_buf *relay_create_buf(struct rchan *chan) { struct rchan_buf *buf = kzalloc(sizeof(struct rchan_buf), GFP_KERNEL); if (!buf) @@ -173,7 +175,7 @@ free_buf: * * Should only be called from kref_put(). */ -void relay_destroy_channel(struct kref *kref) +static void relay_destroy_channel(struct kref *kref) { struct rchan *chan = container_of(kref, struct rchan, kref); kfree(chan); @@ -183,7 +185,7 @@ void relay_destroy_channel(struct kref *kref) * relay_destroy_buf - destroy an rchan_buf struct and associated buffer * @buf: the buffer struct */ -void relay_destroy_buf(struct rchan_buf *buf) +static void relay_destroy_buf(struct rchan_buf *buf) { struct rchan *chan = buf->chan; unsigned int i; @@ -208,7 +210,7 @@ void relay_destroy_buf(struct rchan_buf *buf) * rchan_buf_struct and the channel buffer. Should only be called from * kref_put(). */ -void relay_remove_buf(struct kref *kref) +static void relay_remove_buf(struct kref *kref) { struct rchan_buf *buf = container_of(kref, struct rchan_buf, kref); buf->chan->cb->remove_buf_file(buf->dentry); @@ -221,11 +223,10 @@ void relay_remove_buf(struct kref *kref) * * Returns 1 if the buffer is empty, 0 otherwise. */ -int relay_buf_empty(struct rchan_buf *buf) +static int relay_buf_empty(struct rchan_buf *buf) { return (buf->subbufs_produced - buf->subbufs_consumed) ? 0 : 1; } -EXPORT_SYMBOL_GPL(relay_buf_empty); /** * relay_buf_full - boolean, is the channel buffer full? @@ -425,6 +426,7 @@ static struct rchan_buf *relay_open_buf(struct rchan *chan, unsigned int cpu) free_buf: relay_destroy_buf(buf); + buf = NULL; free_name: kfree(tmpname); end: @@ -812,7 +814,10 @@ static void relay_file_read_consume(struct rchan_buf *buf, } buf->bytes_consumed += bytes_consumed; - read_subbuf = read_pos / buf->chan->subbuf_size; + if (!read_pos) + read_subbuf = buf->subbufs_consumed % n_subbufs; + else + read_subbuf = read_pos / buf->chan->subbuf_size; if (buf->bytes_consumed + buf->padding[read_subbuf] == subbuf_size) { if ((read_subbuf == buf->subbufs_produced % n_subbufs) && (buf->offset == subbuf_size)) @@ -841,8 +846,9 @@ static int relay_file_read_avail(struct rchan_buf *buf, size_t read_pos) } if (unlikely(produced - consumed >= n_subbufs)) { - consumed = (produced / n_subbufs) * n_subbufs; + consumed = produced - n_subbufs + 1; buf->subbufs_consumed = consumed; + buf->bytes_consumed = 0; } produced = (produced % n_subbufs) * subbuf_size + buf->offset; @@ -966,43 +972,6 @@ static int subbuf_read_actor(size_t read_start, return ret; } -/* - * subbuf_send_actor - send up to one subbuf's worth of data - */ -static int subbuf_send_actor(size_t read_start, - struct rchan_buf *buf, - size_t avail, - read_descriptor_t *desc, - read_actor_t actor) -{ - unsigned long pidx, poff; - unsigned int subbuf_pages; - int ret = 0; - - subbuf_pages = buf->chan->alloc_size >> PAGE_SHIFT; - pidx = (read_start / PAGE_SIZE) % subbuf_pages; - poff = read_start & ~PAGE_MASK; - while (avail) { - struct page *p = buf->page_array[pidx]; - unsigned int len; - - len = PAGE_SIZE - poff; - if (len > avail) - len = avail; - - len = actor(desc, p, poff, len); - if (desc->error) - break; - - avail -= len; - ret += len; - poff = 0; - pidx = (pidx + 1) % subbuf_pages; - } - - return ret; -} - typedef int (*subbuf_actor_t) (size_t read_start, struct rchan_buf *buf, size_t avail, @@ -1063,19 +1032,161 @@ static ssize_t relay_file_read(struct file *filp, NULL, &desc); } -static ssize_t relay_file_sendfile(struct file *filp, - loff_t *ppos, - size_t count, - read_actor_t actor, - void *target) +static void relay_consume_bytes(struct rchan_buf *rbuf, int bytes_consumed) { - read_descriptor_t desc; - desc.written = 0; - desc.count = count; - desc.arg.data = target; - desc.error = 0; - return relay_file_read_subbufs(filp, ppos, subbuf_send_actor, - actor, &desc); + rbuf->bytes_consumed += bytes_consumed; + + if (rbuf->bytes_consumed >= rbuf->chan->subbuf_size) { + relay_subbufs_consumed(rbuf->chan, rbuf->cpu, 1); + rbuf->bytes_consumed %= rbuf->chan->subbuf_size; + } +} + +static void relay_pipe_buf_release(struct pipe_inode_info *pipe, + struct pipe_buffer *buf) +{ + struct rchan_buf *rbuf; + + rbuf = (struct rchan_buf *)page_private(buf->page); + relay_consume_bytes(rbuf, buf->private); +} + +static struct pipe_buf_operations relay_pipe_buf_ops = { + .can_merge = 0, + .map = generic_pipe_buf_map, + .unmap = generic_pipe_buf_unmap, + .confirm = generic_pipe_buf_confirm, + .release = relay_pipe_buf_release, + .steal = generic_pipe_buf_steal, + .get = generic_pipe_buf_get, +}; + +/* + * subbuf_splice_actor - splice up to one subbuf's worth of data + */ +static int subbuf_splice_actor(struct file *in, + loff_t *ppos, + struct pipe_inode_info *pipe, + size_t len, + unsigned int flags, + int *nonpad_ret) +{ + unsigned int pidx, poff, total_len, subbuf_pages, ret; + struct rchan_buf *rbuf = in->private_data; + unsigned int subbuf_size = rbuf->chan->subbuf_size; + uint64_t pos = (uint64_t) *ppos; + uint32_t alloc_size = (uint32_t) rbuf->chan->alloc_size; + size_t read_start = (size_t) do_div(pos, alloc_size); + size_t read_subbuf = read_start / subbuf_size; + size_t padding = rbuf->padding[read_subbuf]; + size_t nonpad_end = read_subbuf * subbuf_size + subbuf_size - padding; + struct page *pages[PIPE_BUFFERS]; + struct partial_page partial[PIPE_BUFFERS]; + struct splice_pipe_desc spd = { + .pages = pages, + .nr_pages = 0, + .partial = partial, + .flags = flags, + .ops = &relay_pipe_buf_ops, + }; + + if (rbuf->subbufs_produced == rbuf->subbufs_consumed) + return 0; + + /* + * Adjust read len, if longer than what is available + */ + if (len > (subbuf_size - read_start % subbuf_size)) + len = subbuf_size - read_start % subbuf_size; + + subbuf_pages = rbuf->chan->alloc_size >> PAGE_SHIFT; + pidx = (read_start / PAGE_SIZE) % subbuf_pages; + poff = read_start & ~PAGE_MASK; + + for (total_len = 0; spd.nr_pages < subbuf_pages; spd.nr_pages++) { + unsigned int this_len, this_end, private; + unsigned int cur_pos = read_start + total_len; + + if (!len) + break; + + this_len = min_t(unsigned long, len, PAGE_SIZE - poff); + private = this_len; + + spd.pages[spd.nr_pages] = rbuf->page_array[pidx]; + spd.partial[spd.nr_pages].offset = poff; + + this_end = cur_pos + this_len; + if (this_end >= nonpad_end) { + this_len = nonpad_end - cur_pos; + private = this_len + padding; + } + spd.partial[spd.nr_pages].len = this_len; + spd.partial[spd.nr_pages].private = private; + + len -= this_len; + total_len += this_len; + poff = 0; + pidx = (pidx + 1) % subbuf_pages; + + if (this_end >= nonpad_end) { + spd.nr_pages++; + break; + } + } + + if (!spd.nr_pages) + return 0; + + ret = *nonpad_ret = splice_to_pipe(pipe, &spd); + if (ret < 0 || ret < total_len) + return ret; + + if (read_start + ret == nonpad_end) + ret += padding; + + return ret; +} + +static ssize_t relay_file_splice_read(struct file *in, + loff_t *ppos, + struct pipe_inode_info *pipe, + size_t len, + unsigned int flags) +{ + ssize_t spliced; + int ret; + int nonpad_ret = 0; + + ret = 0; + spliced = 0; + + while (len) { + ret = subbuf_splice_actor(in, ppos, pipe, len, flags, &nonpad_ret); + if (ret < 0) + break; + else if (!ret) { + if (spliced) + break; + if (flags & SPLICE_F_NONBLOCK) { + ret = -EAGAIN; + break; + } + } + + *ppos += ret; + if (ret > len) + len = 0; + else + len -= ret; + spliced += nonpad_ret; + nonpad_ret = 0; + } + + if (spliced) + return spliced; + + return ret; } const struct file_operations relay_file_operations = { @@ -1085,7 +1196,7 @@ const struct file_operations relay_file_operations = { .read = relay_file_read, .llseek = no_llseek, .release = relay_file_release, - .sendfile = relay_file_sendfile, + .splice_read = relay_file_splice_read, }; EXPORT_SYMBOL_GPL(relay_file_operations);