diff options
Diffstat (limited to 'drivers/hv/ring_buffer.c')
| -rw-r--r-- | drivers/hv/ring_buffer.c | 218 |
1 files changed, 63 insertions, 155 deletions
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 70a1a9a22f87..b53702ce692f 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -112,9 +112,7 @@ static bool hv_need_to_signal_on_read(u32 prev_write_sz, u32 read_loc = rbi->ring_buffer->read_index; u32 pending_sz = rbi->ring_buffer->pending_send_sz; - /* - * If the other end is not blocked on write don't bother. - */ + /* If the other end is not blocked on write don't bother. */ if (pending_sz == 0) return false; @@ -128,12 +126,7 @@ static bool hv_need_to_signal_on_read(u32 prev_write_sz, return false; } -/* - * hv_get_next_write_location() - * - * Get the next write location for the specified ring buffer - * - */ +/* Get the next write location for the specified ring buffer. */ static inline u32 hv_get_next_write_location(struct hv_ring_buffer_info *ring_info) { @@ -142,12 +135,7 @@ hv_get_next_write_location(struct hv_ring_buffer_info *ring_info) return next; } -/* - * hv_set_next_write_location() - * - * Set the next write location for the specified ring buffer - * - */ +/* Set the next write location for the specified ring buffer. */ static inline void hv_set_next_write_location(struct hv_ring_buffer_info *ring_info, u32 next_write_location) @@ -155,11 +143,7 @@ hv_set_next_write_location(struct hv_ring_buffer_info *ring_info, ring_info->ring_buffer->write_index = next_write_location; } -/* - * hv_get_next_read_location() - * - * Get the next read location for the specified ring buffer - */ +/* Get the next read location for the specified ring buffer. */ static inline u32 hv_get_next_read_location(struct hv_ring_buffer_info *ring_info) { @@ -169,10 +153,8 @@ hv_get_next_read_location(struct hv_ring_buffer_info *ring_info) } /* - * hv_get_next_readlocation_withoffset() - * * Get the next read location + offset for the specified ring buffer. - * This allows the caller to skip + * This allows the caller to skip. */ static inline u32 hv_get_next_readlocation_withoffset(struct hv_ring_buffer_info *ring_info, @@ -186,13 +168,7 @@ hv_get_next_readlocation_withoffset(struct hv_ring_buffer_info *ring_info, return next; } -/* - * - * hv_set_next_read_location() - * - * Set the next read location for the specified ring buffer - * - */ +/* Set the next read location for the specified ring buffer. */ static inline void hv_set_next_read_location(struct hv_ring_buffer_info *ring_info, u32 next_read_location) @@ -201,12 +177,7 @@ hv_set_next_read_location(struct hv_ring_buffer_info *ring_info, } -/* - * - * hv_get_ring_buffer() - * - * Get the start of the ring buffer - */ +/* Get the start of the ring buffer. */ static inline void * hv_get_ring_buffer(struct hv_ring_buffer_info *ring_info) { @@ -214,25 +185,14 @@ hv_get_ring_buffer(struct hv_ring_buffer_info *ring_info) } -/* - * - * hv_get_ring_buffersize() - * - * Get the size of the ring buffer - */ +/* Get the size of the ring buffer. */ static inline u32 hv_get_ring_buffersize(struct hv_ring_buffer_info *ring_info) { return ring_info->ring_datasize; } -/* - * - * hv_get_ring_bufferindices() - * - * Get the read and write indices as u64 of the specified ring buffer - * - */ +/* Get the read and write indices as u64 of the specified ring buffer. */ static inline u64 hv_get_ring_bufferindices(struct hv_ring_buffer_info *ring_info) { @@ -240,12 +200,8 @@ hv_get_ring_bufferindices(struct hv_ring_buffer_info *ring_info) } /* - * - * hv_copyfrom_ringbuffer() - * * Helper routine to copy to source from ring buffer. * Assume there is enough room. Handles wrap-around in src case only!! - * */ static u32 hv_copyfrom_ringbuffer( struct hv_ring_buffer_info *ring_info, @@ -277,12 +233,8 @@ static u32 hv_copyfrom_ringbuffer( /* - * - * hv_copyto_ringbuffer() - * * Helper routine to copy from source to ring buffer. * Assume there is enough room. Handles wrap-around in dest case only!! - * */ static u32 hv_copyto_ringbuffer( struct hv_ring_buffer_info *ring_info, @@ -308,13 +260,7 @@ static u32 hv_copyto_ringbuffer( return start_write_offset; } -/* - * - * hv_ringbuffer_get_debuginfo() - * - * Get various debug metrics for the specified ring buffer - * - */ +/* Get various debug metrics for the specified ring buffer. */ void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, struct hv_ring_buffer_debug_info *debug_info) { @@ -337,13 +283,7 @@ void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, } } -/* - * - * hv_ringbuffer_init() - * - *Initialize the ring buffer - * - */ +/* Initialize the ring buffer. */ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, void *buffer, u32 buflen) { @@ -356,9 +296,7 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, ring_info->ring_buffer->read_index = ring_info->ring_buffer->write_index = 0; - /* - * Set the feature bit for enabling flow control. - */ + /* Set the feature bit for enabling flow control. */ ring_info->ring_buffer->feature_bits.value = 1; ring_info->ring_size = buflen; @@ -369,24 +307,12 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, return 0; } -/* - * - * hv_ringbuffer_cleanup() - * - * Cleanup the ring buffer - * - */ +/* Cleanup the ring buffer. */ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info) { } -/* - * - * hv_ringbuffer_write() - * - * Write to the ring buffer - * - */ +/* Write to the ring buffer. */ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info, struct kvec *kv_list, u32 kv_count, bool *signal) { @@ -411,10 +337,11 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info, &bytes_avail_toread, &bytes_avail_towrite); - - /* If there is only room for the packet, assume it is full. */ - /* Otherwise, the next time around, we think the ring buffer */ - /* is empty since the read index == write index */ + /* + * If there is only room for the packet, assume it is full. + * Otherwise, the next time around, we think the ring buffer + * is empty since the read index == write index. + */ if (bytes_avail_towrite <= totalbytes_towrite) { spin_unlock_irqrestore(&outring_info->ring_lock, flags); return -EAGAIN; @@ -453,80 +380,59 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info, return 0; } - -/* - * - * hv_ringbuffer_peek() - * - * Read without advancing the read index - * - */ -int hv_ringbuffer_peek(struct hv_ring_buffer_info *Inring_info, - void *Buffer, u32 buflen) -{ - u32 bytes_avail_towrite; - u32 bytes_avail_toread; - u32 next_read_location = 0; - unsigned long flags; - - spin_lock_irqsave(&Inring_info->ring_lock, flags); - - hv_get_ringbuffer_availbytes(Inring_info, - &bytes_avail_toread, - &bytes_avail_towrite); - - /* Make sure there is something to read */ - if (bytes_avail_toread < buflen) { - - spin_unlock_irqrestore(&Inring_info->ring_lock, flags); - - return -EAGAIN; - } - - /* Convert to byte offset */ - next_read_location = hv_get_next_read_location(Inring_info); - - next_read_location = hv_copyfrom_ringbuffer(Inring_info, - Buffer, - buflen, - next_read_location); - - spin_unlock_irqrestore(&Inring_info->ring_lock, flags); - - return 0; -} - - -/* - * - * hv_ringbuffer_read() - * - * Read and advance the read index - * - */ -int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, - u32 buflen, u32 offset, bool *signal) +int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, + void *buffer, u32 buflen, u32 *buffer_actual_len, + u64 *requestid, bool *signal, bool raw) { u32 bytes_avail_towrite; u32 bytes_avail_toread; u32 next_read_location = 0; u64 prev_indices = 0; unsigned long flags; + struct vmpacket_descriptor desc; + u32 offset; + u32 packetlen; + int ret = 0; if (buflen <= 0) return -EINVAL; spin_lock_irqsave(&inring_info->ring_lock, flags); + *buffer_actual_len = 0; + *requestid = 0; + hv_get_ringbuffer_availbytes(inring_info, &bytes_avail_toread, &bytes_avail_towrite); /* Make sure there is something to read */ - if (bytes_avail_toread < buflen) { - spin_unlock_irqrestore(&inring_info->ring_lock, flags); + if (bytes_avail_toread < sizeof(desc)) { + /* + * No error is set when there is even no header, drivers are + * supposed to analyze buffer_actual_len. + */ + goto out_unlock; + } - return -EAGAIN; + next_read_location = hv_get_next_read_location(inring_info); + next_read_location = hv_copyfrom_ringbuffer(inring_info, &desc, + sizeof(desc), + next_read_location); + + offset = raw ? 0 : (desc.offset8 << 3); + packetlen = (desc.len8 << 3) - offset; + *buffer_actual_len = packetlen; + *requestid = desc.trans_id; + + if (bytes_avail_toread < packetlen + offset) { + ret = -EAGAIN; + goto out_unlock; + } + + if (packetlen > buflen) { + ret = -ENOBUFS; + goto out_unlock; } next_read_location = @@ -534,7 +440,7 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, next_read_location = hv_copyfrom_ringbuffer(inring_info, buffer, - buflen, + packetlen, next_read_location); next_read_location = hv_copyfrom_ringbuffer(inring_info, @@ -542,17 +448,19 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, void *buffer, sizeof(u64), next_read_location); - /* Make sure all reads are done before we update the read index since */ - /* the writer may start writing to the read area once the read index */ - /*is updated */ + /* + * Make sure all reads are done before we update the read index since + * the writer may start writing to the read area once the read index + * is updated. + */ mb(); /* Update the read index */ hv_set_next_read_location(inring_info, next_read_location); - spin_unlock_irqrestore(&inring_info->ring_lock, flags); - *signal = hv_need_to_signal_on_read(bytes_avail_towrite, inring_info); - return 0; +out_unlock: + spin_unlock_irqrestore(&inring_info->ring_lock, flags); + return ret; } |