diff options
| -rw-r--r-- | arch/mips/kernel/rtlx.c | 41 |
1 files changed, 24 insertions, 17 deletions
diff --git a/arch/mips/kernel/rtlx.c b/arch/mips/kernel/rtlx.c index 16d3fdecf3e..0441c7c1e44 100644 --- a/arch/mips/kernel/rtlx.c +++ b/arch/mips/kernel/rtlx.c @@ -306,7 +306,7 @@ static inline void copy_from(void *dst, void *src, size_t count, int user) ssize_t rtlx_read(int index, void *buff, size_t count, int user) { - size_t fl = 0L; + size_t lx_write, fl = 0L; struct rtlx_channel *lx; if (rtlx == NULL) @@ -314,23 +314,26 @@ ssize_t rtlx_read(int index, void *buff, size_t count, int user) lx = &rtlx->channel[index]; + smp_rmb(); + lx_write = lx->lx_write; + /* find out how much in total */ count = min(count, - (size_t)(lx->lx_write + lx->buffer_size - lx->lx_read) + (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); + fl = min(count, (size_t)lx->buffer_size - lx->lx_read); - copy_to(buff, &lx->lx_buffer[lx->lx_read], fl, user); + copy_to(buff, lx->lx_buffer + lx->lx_read, fl, user); /* and if there is anything left at the beginning of the buffer */ - if ( count - fl ) - copy_to (buff + fl, lx->lx_buffer, count - fl, user); + if (count - fl) + copy_to(buff + fl, lx->lx_buffer, count - fl, user); - /* update the index */ - lx->lx_read += count; - lx->lx_read %= lx->buffer_size; + smp_wmb(); + lx->lx_read = (lx->lx_read + count) % lx->buffer_size; + smp_wmb(); return count; } @@ -338,6 +341,7 @@ ssize_t rtlx_read(int index, void *buff, size_t count, int user) ssize_t rtlx_write(int index, void *buffer, size_t count, int user) { struct rtlx_channel *rt; + size_t rt_read; size_t fl; if (rtlx == NULL) @@ -345,24 +349,27 @@ ssize_t rtlx_write(int index, void *buffer, size_t count, int user) rt = &rtlx->channel[index]; + smp_rmb(); + rt_read = rt->rt_read; + /* total number of bytes to copy */ count = min(count, - (size_t)write_spacefree(rt->rt_read, rt->rt_write, - rt->buffer_size)); + (size_t)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); - copy_from (&rt->rt_buffer[rt->rt_write], buffer, fl, user); + copy_from(rt->rt_buffer + rt->rt_write, buffer, fl, user); /* if there's any left copy to the beginning of the buffer */ - if( count - fl ) - copy_from (rt->rt_buffer, buffer + fl, count - fl, user); + if (count - fl) + copy_from(rt->rt_buffer, buffer + fl, count - fl, user); - rt->rt_write += count; - rt->rt_write %= rt->buffer_size; + smp_wmb(); + rt->rt_write = (rt->rt_write + count) % rt->buffer_size; + smp_wmb(); - return(count); + return count; } |