From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/mips/kernel/rtlx.c | 407 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 407 insertions(+) create mode 100644 arch/mips/kernel/rtlx.c (limited to 'arch/mips/kernel/rtlx.c') diff --git a/arch/mips/kernel/rtlx.c b/arch/mips/kernel/rtlx.c new file mode 100644 index 000000000..c5c4fd54d --- /dev/null +++ b/arch/mips/kernel/rtlx.c @@ -0,0 +1,407 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved. + * Copyright (C) 2005, 06 Ralf Baechle (ralf@linux-mips.org) + * Copyright (C) 2013 Imagination Technologies Ltd. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static int sp_stopping; +struct rtlx_info *rtlx; +struct chan_waitqueues channel_wqs[RTLX_CHANNELS]; +struct vpe_notifications rtlx_notify; +void (*aprp_hook)(void) = NULL; +EXPORT_SYMBOL(aprp_hook); + +static void __used dump_rtlx(void) +{ + int i; + + pr_info("id 0x%lx state %d\n", rtlx->id, rtlx->state); + + for (i = 0; i < RTLX_CHANNELS; i++) { + struct rtlx_channel *chan = &rtlx->channel[i]; + + pr_info(" rt_state %d lx_state %d buffer_size %d\n", + chan->rt_state, chan->lx_state, chan->buffer_size); + + pr_info(" rt_read %d rt_write %d\n", + chan->rt_read, chan->rt_write); + + pr_info(" lx_read %d lx_write %d\n", + chan->lx_read, chan->lx_write); + + pr_info(" rt_buffer <%s>\n", chan->rt_buffer); + pr_info(" lx_buffer <%s>\n", chan->lx_buffer); + } +} + +/* call when we have the address of the shared structure from the SP side. */ +static int rtlx_init(struct rtlx_info *rtlxi) +{ + if (rtlxi->id != RTLX_ID) { + pr_err("no valid RTLX id at 0x%p 0x%lx\n", rtlxi, rtlxi->id); + return -ENOEXEC; + } + + rtlx = rtlxi; + + return 0; +} + +/* notifications */ +void rtlx_starting(int vpe) +{ + int i; + sp_stopping = 0; + + /* force a reload of rtlx */ + rtlx = NULL; + + /* wake up any sleeping rtlx_open's */ + for (i = 0; i < RTLX_CHANNELS; i++) + wake_up_interruptible(&channel_wqs[i].lx_queue); +} + +void rtlx_stopping(int vpe) +{ + int i; + + sp_stopping = 1; + for (i = 0; i < RTLX_CHANNELS; i++) + wake_up_interruptible(&channel_wqs[i].lx_queue); +} + + +int rtlx_open(int index, int can_sleep) +{ + struct rtlx_info **p; + struct rtlx_channel *chan; + enum rtlx_state state; + int ret = 0; + + if (index >= RTLX_CHANNELS) { + pr_debug("rtlx_open index out of range\n"); + return -ENOSYS; + } + + if (atomic_inc_return(&channel_wqs[index].in_open) > 1) { + pr_debug("rtlx_open channel %d already opened\n", index); + ret = -EBUSY; + goto out_fail; + } + + if (rtlx == NULL) { + p = vpe_get_shared(aprp_cpu_index()); + if (p == NULL) { + if (can_sleep) { + ret = __wait_event_interruptible( + channel_wqs[index].lx_queue, + (p = vpe_get_shared(aprp_cpu_index()))); + if (ret) + goto out_fail; + } else { + pr_debug("No SP program loaded, and device opened with O_NONBLOCK\n"); + ret = -ENOSYS; + goto out_fail; + } + } + + smp_rmb(); + if (*p == NULL) { + if (can_sleep) { + DEFINE_WAIT(wait); + + for (;;) { + prepare_to_wait( + &channel_wqs[index].lx_queue, + &wait, TASK_INTERRUPTIBLE); + smp_rmb(); + if (*p != NULL) + break; + if (!signal_pending(current)) { + schedule(); + continue; + } + ret = -ERESTARTSYS; + goto out_fail; + } + finish_wait(&channel_wqs[index].lx_queue, + &wait); + } else { + pr_err(" *vpe_get_shared is NULL. Has an SP program been loaded?\n"); + ret = -ENOSYS; + goto out_fail; + } + } + + if ((unsigned int)*p < KSEG0) { + pr_warn("vpe_get_shared returned an invalid pointer maybe an error code %d\n", + (int)*p); + ret = -ENOSYS; + goto out_fail; + } + + ret = rtlx_init(*p); + if (ret < 0) + goto out_ret; + } + + chan = &rtlx->channel[index]; + + state = xchg(&chan->lx_state, RTLX_STATE_OPENED); + if (state == RTLX_STATE_OPENED) { + ret = -EBUSY; + goto out_fail; + } + +out_fail: + smp_mb(); + atomic_dec(&channel_wqs[index].in_open); + smp_mb(); + +out_ret: + return ret; +} + +int rtlx_release(int index) +{ + if (rtlx == NULL) { + pr_err("rtlx_release() with null rtlx\n"); + return 0; + } + rtlx->channel[index].lx_state = RTLX_STATE_UNUSED; + return 0; +} + +unsigned int rtlx_read_poll(int index, int can_sleep) +{ + struct rtlx_channel *chan; + + if (rtlx == NULL) + return 0; + + chan = &rtlx->channel[index]; + + /* data available to read? */ + if (chan->lx_read == chan->lx_write) { + if (can_sleep) { + int ret = __wait_event_interruptible( + channel_wqs[index].lx_queue, + (chan->lx_read != chan->lx_write) || + sp_stopping); + if (ret) + return ret; + + if (sp_stopping) + return 0; + } else + return 0; + } + + return (chan->lx_write + chan->buffer_size - chan->lx_read) + % chan->buffer_size; +} + +static inline int write_spacefree(int read, int write, int size) +{ + if (read == write) { + /* + * Never fill the buffer completely, so indexes are always + * equal if empty and only empty, or !equal if data available + */ + return size - 1; + } + + return ((read + size - write) % size) - 1; +} + +unsigned int rtlx_write_poll(int index) +{ + struct rtlx_channel *chan = &rtlx->channel[index]; + + return write_spacefree(chan->rt_read, chan->rt_write, + chan->buffer_size); +} + +ssize_t rtlx_read(int index, void __user *buff, size_t count) +{ + size_t lx_write, fl = 0L; + struct rtlx_channel *lx; + unsigned long failed; + + if (rtlx == NULL) + return -ENOSYS; + + lx = &rtlx->channel[index]; + + mutex_lock(&channel_wqs[index].mutex); + smp_rmb(); + lx_write = lx->lx_write; + + /* find out how much in total */ + count = min(count, + (size_t)(lx_write + lx->buffer_size - lx->lx_read) + % lx->buffer_size); + + /* then how much from the read pointer onwards */ + fl = min(count, (size_t)lx->buffer_size - lx->lx_read); + + failed = copy_to_user(buff, lx->lx_buffer + lx->lx_read, fl); + if (failed) + goto out; + + /* and if there is anything left at the beginning of the buffer */ + if (count - fl) + failed = copy_to_user(buff + fl, lx->lx_buffer, count - fl); + +out: + count -= failed; + + smp_wmb(); + lx->lx_read = (lx->lx_read + count) % lx->buffer_size; + smp_wmb(); + mutex_unlock(&channel_wqs[index].mutex); + + return count; +} + +ssize_t rtlx_write(int index, const void __user *buffer, size_t count) +{ + struct rtlx_channel *rt; + unsigned long failed; + size_t rt_read; + size_t fl; + + if (rtlx == NULL) + return -ENOSYS; + + rt = &rtlx->channel[index]; + + mutex_lock(&channel_wqs[index].mutex); + smp_rmb(); + rt_read = rt->rt_read; + + /* total number of bytes to copy */ + count = min_t(size_t, count, write_spacefree(rt_read, rt->rt_write, + rt->buffer_size)); + + /* first bit from write pointer to the end of the buffer, or count */ + fl = min(count, (size_t) rt->buffer_size - rt->rt_write); + + failed = copy_from_user(rt->rt_buffer + rt->rt_write, buffer, fl); + if (failed) + goto out; + + /* if there's any left copy to the beginning of the buffer */ + if (count - fl) + failed = copy_from_user(rt->rt_buffer, buffer + fl, count - fl); + +out: + count -= failed; + + smp_wmb(); + rt->rt_write = (rt->rt_write + count) % rt->buffer_size; + smp_wmb(); + mutex_unlock(&channel_wqs[index].mutex); + + _interrupt_sp(); + + return count; +} + + +static int file_open(struct inode *inode, struct file *filp) +{ + return rtlx_open(iminor(inode), (filp->f_flags & O_NONBLOCK) ? 0 : 1); +} + +static int file_release(struct inode *inode, struct file *filp) +{ + return rtlx_release(iminor(inode)); +} + +static unsigned int file_poll(struct file *file, poll_table *wait) +{ + int minor = iminor(file_inode(file)); + unsigned int mask = 0; + + poll_wait(file, &channel_wqs[minor].rt_queue, wait); + poll_wait(file, &channel_wqs[minor].lx_queue, wait); + + if (rtlx == NULL) + return 0; + + /* data available to read? */ + if (rtlx_read_poll(minor, 0)) + mask |= POLLIN | POLLRDNORM; + + /* space to write */ + if (rtlx_write_poll(minor)) + mask |= POLLOUT | POLLWRNORM; + + return mask; +} + +static ssize_t file_read(struct file *file, char __user *buffer, size_t count, + loff_t *ppos) +{ + int minor = iminor(file_inode(file)); + + /* data available? */ + if (!rtlx_read_poll(minor, (file->f_flags & O_NONBLOCK) ? 0 : 1)) + return 0; /* -EAGAIN makes 'cat' whine */ + + return rtlx_read(minor, buffer, count); +} + +static ssize_t file_write(struct file *file, const char __user *buffer, + size_t count, loff_t *ppos) +{ + int minor = iminor(file_inode(file)); + + /* any space left... */ + if (!rtlx_write_poll(minor)) { + int ret; + + if (file->f_flags & O_NONBLOCK) + return -EAGAIN; + + ret = __wait_event_interruptible(channel_wqs[minor].rt_queue, + rtlx_write_poll(minor)); + if (ret) + return ret; + } + + return rtlx_write(minor, buffer, count); +} + +const struct file_operations rtlx_fops = { + .owner = THIS_MODULE, + .open = file_open, + .release = file_release, + .write = file_write, + .read = file_read, + .poll = file_poll, + .llseek = noop_llseek, +}; + +module_init(rtlx_module_init); +module_exit(rtlx_module_exit); + +MODULE_DESCRIPTION("MIPS RTLX"); +MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc."); +MODULE_LICENSE("GPL"); -- cgit v1.2.3-54-g00ecf