/* * * Copyright (c) 2009, Microsoft Corporation. * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 59 Temple * Place - Suite 330, Boston, MA 02111-1307 USA. * * Authors: * Haiyang Zhang <haiyangz@microsoft.com> * Hank Janssen <hjanssen@microsoft.com> * K. Y. Srinivasan <kys@microsoft.com> * */#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h>#include <linux/mm.h>#include <linux/hyperv.h>#include <linux/uio.h> #include "hyperv_vmbus.h" void hv_begin_read(struct hv_ring_buffer_info *rbi){ rbi->ring_buffer->interrupt_mask = 1; mb();} u32 hv_end_read(struct hv_ring_buffer_info *rbi){ u32 read; u32 write; rbi->ring_buffer->interrupt_mask = 0; mb(); /* * Now check to see if the ring buffer is still empty. * If it is not, we raced and we need to process new * incoming messages. */ hv_get_ringbuffer_availbytes(rbi, &read, &write); return read;} /* * When we write to the ring buffer, check if the host needs to * be signaled. Here is the details of this protocol: * * 1. The host guarantees that while it is draining the * ring buffer, it will set the interrupt_mask to * indicate it does not need to be interrupted when * new data is placed. * * 2. The host guarantees that it will completely drain * the ring buffer before exiting the read loop. Further, * once the ring buffer is empty, it will clear the * interrupt_mask and re-check to see if new data has * arrived. */ static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi){ mb(); if (rbi->ring_buffer->interrupt_mask) return false; /* check interrupt_mask before read_index */ rmb(); /* * This is the only case we need to signal when the * ring transitions from being empty to non-empty. */ if (old_write == rbi->ring_buffer->read_index) return true; return false;} /* * To optimize the flow management on the send-side, * when the sender is blocked because of lack of * sufficient space in the ring buffer, potential the * consumer of the ring buffer can signal the producer. * This is controlled by the following parameters: * * 1. pending_send_sz: This is the size in bytes that the * producer is trying to send. * 2. The feature bit feat_pending_send_sz set to indicate if * the consumer of the ring will signal when the ring * state transitions from being full to a state where * there is room for the producer to send the pending packet. */ static bool hv_need_to_signal_on_read(u32 old_rd, struct hv_ring_buffer_info *rbi){ u32 prev_write_sz; u32 cur_write_sz; u32 r_size; u32 write_loc = rbi->ring_buffer->write_index; 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 (pending_sz == 0) return false; r_size = rbi->ring_datasize; cur_write_sz = write_loc >= read_loc ? r_size - (write_loc - read_loc) : read_loc - write_loc; prev_write_sz = write_loc >= old_rd ? r_size - (write_loc - old_rd) : old_rd - write_loc; if ((prev_write_sz < pending_sz) && (cur_write_sz >= pending_sz)) return true; return false;} /* * hv_get_next_write_location() * * Get the next write location for the specified ring buffer * */static inline u32hv_get_next_write_location(struct hv_ring_buffer_info *ring_info){ u32 next = ring_info->ring_buffer->write_index; return next;} /* * hv_set_next_write_location() * * Set the next write location for the specified ring buffer * */static inline voidhv_set_next_write_location(struct hv_ring_buffer_info *ring_info, u32 next_write_location){ ring_info->ring_buffer->write_index = next_write_location;} /* * hv_get_next_read_location() * * Get the next read location for the specified ring buffer */static inline u32hv_get_next_read_location(struct hv_ring_buffer_info *ring_info){ u32 next = ring_info->ring_buffer->read_index; return next;} /* * hv_get_next_readlocation_withoffset() * * Get the next read location + offset for the specified ring buffer. * This allows the caller to skip */static inline u32hv_get_next_readlocation_withoffset(struct hv_ring_buffer_info *ring_info, u32 offset){ u32 next = ring_info->ring_buffer->read_index; next += offset; next %= ring_info->ring_datasize; return next;} /* * * hv_set_next_read_location() * * Set the next read location for the specified ring buffer * */static inline voidhv_set_next_read_location(struct hv_ring_buffer_info *ring_info, u32 next_read_location){ ring_info->ring_buffer->read_index = next_read_location;} /* * * hv_get_ring_buffer() * * Get the start of the ring buffer */static inline void *hv_get_ring_buffer(struct hv_ring_buffer_info *ring_info){ return (void *)ring_info->ring_buffer->buffer;} /* * * hv_get_ring_buffersize() * * Get the size of the ring buffer */static inline u32hv_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 * */static inline u64hv_get_ring_bufferindices(struct hv_ring_buffer_info *ring_info){ return (u64)ring_info->ring_buffer->write_index << 32;} /* * * 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, void *dest, u32 destlen, u32 start_read_offset){ void *ring_buffer = hv_get_ring_buffer(ring_info); u32 ring_buffer_size = hv_get_ring_buffersize(ring_info); u32 frag_len; /* wrap-around detected at the src */ if (destlen > ring_buffer_size - start_read_offset) { frag_len = ring_buffer_size - start_read_offset; memcpy(dest, ring_buffer + start_read_offset, frag_len); memcpy(dest + frag_len, ring_buffer, destlen - frag_len); } else memcpy(dest, ring_buffer + start_read_offset, destlen); start_read_offset += destlen; start_read_offset %= ring_buffer_size; return start_read_offset;} /* * * 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, u32 start_write_offset, void *src, u32 srclen){ void *ring_buffer = hv_get_ring_buffer(ring_info); u32 ring_buffer_size = hv_get_ring_buffersize(ring_info); u32 frag_len; /* wrap-around detected! */ if (srclen > ring_buffer_size - start_write_offset) { frag_len = ring_buffer_size - start_write_offset; memcpy(ring_buffer + start_write_offset, src, frag_len); memcpy(ring_buffer, src + frag_len, srclen - frag_len); } else memcpy(ring_buffer + start_write_offset, src, srclen); start_write_offset += srclen; start_write_offset %= ring_buffer_size; return start_write_offset;} /* * * hv_ringbuffer_get_debuginfo() * * 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){ u32 bytes_avail_towrite; u32 bytes_avail_toread; if (ring_info->ring_buffer) { hv_get_ringbuffer_availbytes(ring_info, &bytes_avail_toread, &bytes_avail_towrite); debug_info->bytes_avail_toread = bytes_avail_toread; debug_info->bytes_avail_towrite = bytes_avail_towrite; debug_info->current_read_index = ring_info->ring_buffer->read_index; debug_info->current_write_index = ring_info->ring_buffer->write_index; debug_info->current_interrupt_mask = ring_info->ring_buffer->interrupt_mask; }} /* * * hv_ringbuffer_init() * *Initialize the ring buffer * */int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, void *buffer, u32 buflen){ if (sizeof(struct hv_ring_buffer) != PAGE_SIZE) return -EINVAL; memset(ring_info, 0, sizeof(struct hv_ring_buffer_info)); ring_info->ring_buffer = (struct hv_ring_buffer *)buffer; ring_info->ring_buffer->read_index = ring_info->ring_buffer->write_index = 0; /* * Set the feature bit for enabling flow control. */ ring_info->ring_buffer->feature_bits.value = 1; ring_info->ring_size = buflen; ring_info->ring_datasize = buflen - sizeof(struct hv_ring_buffer); spin_lock_init(&ring_info->ring_lock); return 0;} /* * * hv_ringbuffer_cleanup() * * Cleanup the ring buffer * */void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info){} /* * * hv_ringbuffer_write() * * 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){ int i = 0; u32 bytes_avail_towrite; u32 bytes_avail_toread; u32 totalbytes_towrite = 0; u32 next_write_location; u32 old_write; u64 prev_indices = 0; unsigned long flags; for (i = 0; i < kv_count; i++) totalbytes_towrite += kv_list[i].iov_len; totalbytes_towrite += sizeof(u64); spin_lock_irqsave(&outring_info->ring_lock, flags); hv_get_ringbuffer_availbytes(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 (bytes_avail_towrite <= totalbytes_towrite) { spin_unlock_irqrestore(&outring_info->ring_lock, flags); return -EAGAIN; } /* Write to the ring buffer */ next_write_location = hv_get_next_write_location(outring_info); old_write = next_write_location; for (i = 0; i < kv_count; i++) { next_write_location = hv_copyto_ringbuffer(outring_info, next_write_location, kv_list[i].iov_base, kv_list[i].iov_len); } /* Set previous packet start */ prev_indices = hv_get_ring_bufferindices(outring_info); next_write_location = hv_copyto_ringbuffer(outring_info, next_write_location, &prev_indices, sizeof(u64)); /* Issue a full memory barrier before updating the write index */ mb(); /* Now, update the write location */ hv_set_next_write_location(outring_info, next_write_location); spin_unlock_irqrestore(&outring_info->ring_lock, flags); *signal = hv_need_to_signal(old_write, 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); Lines 1–500 of 566. 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/* * * Copyright (c) 2009, Microsoft Corporation. * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 59 Temple * Place - Suite 330, Boston, MA 02111-1307 USA. * * Authors: * Haiyang Zhang <haiyangz@microsoft.com> * Hank Janssen <hjanssen@microsoft.com> * K. Y. Srinivasan <kys@microsoft.com> * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h> #include <linux/mm.h> #include <linux/hyperv.h> #include <linux/uio.h> #include "hyperv_vmbus.h" void hv_begin_read(struct hv_ring_buffer_info *rbi) { rbi->ring_buffer->interrupt_mask = 1; mb(); } u32 hv_end_read(struct hv_ring_buffer_info *rbi) { u32 read; u32 write; rbi->ring_buffer->interrupt_mask = 0; mb(); /* * Now check to see if the ring buffer is still empty. * If it is not, we raced and we need to process new * incoming messages. */ hv_get_ringbuffer_availbytes(rbi, &read, &write); return read; } /* * When we write to the ring buffer, check if the host needs to * be signaled. Here is the details of this protocol: * * 1. The host guarantees that while it is draining the * ring buffer, it will set the interrupt_mask to * indicate it does not need to be interrupted when * new data is placed. * * 2. The host guarantees that it will completely drain * the ring buffer before exiting the read loop. Further, * once the ring buffer is empty, it will clear the * interrupt_mask and re-check to see if new data has * arrived. */ static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi) { mb(); if (rbi->ring_buffer->interrupt_mask) return false; /* check interrupt_mask before read_index */ rmb(); /* * This is the only case we need to signal when the * ring transitions from being empty to non-empty. */ if (old_write == rbi->ring_buffer->read_index) return true; return false; } /* * To optimize the flow management on the send-side, * when the sender is blocked because of lack of * sufficient space in the ring buffer, potential the * consumer of the ring buffer can signal the producer. * This is controlled by the following parameters: * * 1. pending_send_sz: This is the size in bytes that the * producer is trying to send. * 2. The feature bit feat_pending_send_sz set to indicate if * the consumer of the ring will signal when the ring * state transitions from being full to a state where * there is room for the producer to send the pending packet. */ static bool hv_need_to_signal_on_read(u32 old_rd, struct hv_ring_buffer_info *rbi) { u32 prev_write_sz; u32 cur_write_sz; u32 r_size; u32 write_loc = rbi->ring_buffer->write_index; 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 (pending_sz == 0) return false; r_size = rbi->ring_datasize; cur_write_sz = write_loc >= read_loc ? r_size - (write_loc - read_loc) : read_loc - write_loc; prev_write_sz = write_loc >= old_rd ? r_size - (write_loc - old_rd) : old_rd - write_loc; if ((prev_write_sz < pending_sz) && (cur_write_sz >= pending_sz)) return true; return false; } /* * hv_get_next_write_location() * * 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) { u32 next = ring_info->ring_buffer->write_index; return next; } /* * hv_set_next_write_location() * * 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) { ring_info->ring_buffer->write_index = next_write_location; } /* * hv_get_next_read_location() * * 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) { u32 next = ring_info->ring_buffer->read_index; return next; } /* * hv_get_next_readlocation_withoffset() * * Get the next read location + offset for the specified ring buffer. * This allows the caller to skip */ static inline u32 hv_get_next_readlocation_withoffset(struct hv_ring_buffer_info *ring_info, u32 offset) { u32 next = ring_info->ring_buffer->read_index; next += offset; next %= ring_info->ring_datasize; return next; } /* * * hv_set_next_read_location() * * 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) { ring_info->ring_buffer->read_index = next_read_location; } /* * * hv_get_ring_buffer() * * Get the start of the ring buffer */ static inline void * hv_get_ring_buffer(struct hv_ring_buffer_info *ring_info) { return (void *)ring_info->ring_buffer->buffer; } /* * * hv_get_ring_buffersize() * * 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 * */ static inline u64 hv_get_ring_bufferindices(struct hv_ring_buffer_info *ring_info) { return (u64)ring_info->ring_buffer->write_index << 32; } /* * * 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, void *dest, u32 destlen, u32 start_read_offset) { void *ring_buffer = hv_get_ring_buffer(ring_info); u32 ring_buffer_size = hv_get_ring_buffersize(ring_info); u32 frag_len; /* wrap-around detected at the src */ if (destlen > ring_buffer_size - start_read_offset) { frag_len = ring_buffer_size - start_read_offset; memcpy(dest, ring_buffer + start_read_offset, frag_len); memcpy(dest + frag_len, ring_buffer, destlen - frag_len); } else memcpy(dest, ring_buffer + start_read_offset, destlen); start_read_offset += destlen; start_read_offset %= ring_buffer_size; return start_read_offset; } /* * * 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, u32 start_write_offset, void *src, u32 srclen) { void *ring_buffer = hv_get_ring_buffer(ring_info); u32 ring_buffer_size = hv_get_ring_buffersize(ring_info); u32 frag_len; /* wrap-around detected! */ if (srclen > ring_buffer_size - start_write_offset) { frag_len = ring_buffer_size - start_write_offset; memcpy(ring_buffer + start_write_offset, src, frag_len); memcpy(ring_buffer, src + frag_len, srclen - frag_len); } else memcpy(ring_buffer + start_write_offset, src, srclen); start_write_offset += srclen; start_write_offset %= ring_buffer_size; return start_write_offset; } /* * * hv_ringbuffer_get_debuginfo() * * 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) { u32 bytes_avail_towrite; u32 bytes_avail_toread; if (ring_info->ring_buffer) { hv_get_ringbuffer_availbytes(ring_info, &bytes_avail_toread, &bytes_avail_towrite); debug_info->bytes_avail_toread = bytes_avail_toread; debug_info->bytes_avail_towrite = bytes_avail_towrite; debug_info->current_read_index = ring_info->ring_buffer->read_index; debug_info->current_write_index = ring_info->ring_buffer->write_index; debug_info->current_interrupt_mask = ring_info->ring_buffer->interrupt_mask; } } /* * * hv_ringbuffer_init() * *Initialize the ring buffer * */ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, void *buffer, u32 buflen) { if (sizeof(struct hv_ring_buffer) != PAGE_SIZE) return -EINVAL; memset(ring_info, 0, sizeof(struct hv_ring_buffer_info)); ring_info->ring_buffer = (struct hv_ring_buffer *)buffer; ring_info->ring_buffer->read_index = ring_info->ring_buffer->write_index = 0; /* * Set the feature bit for enabling flow control. */ ring_info->ring_buffer->feature_bits.value = 1; ring_info->ring_size = buflen; ring_info->ring_datasize = buflen - sizeof(struct hv_ring_buffer); spin_lock_init(&ring_info->ring_lock); return 0; } /* * * hv_ringbuffer_cleanup() * * Cleanup the ring buffer * */ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info) { } /* * * hv_ringbuffer_write() * * 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) { int i = 0; u32 bytes_avail_towrite; u32 bytes_avail_toread; u32 totalbytes_towrite = 0; u32 next_write_location; u32 old_write; u64 prev_indices = 0; unsigned long flags; for (i = 0; i < kv_count; i++) totalbytes_towrite += kv_list[i].iov_len; totalbytes_towrite += sizeof(u64); spin_lock_irqsave(&outring_info->ring_lock, flags); hv_get_ringbuffer_availbytes(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 (bytes_avail_towrite <= totalbytes_towrite) { spin_unlock_irqrestore(&outring_info->ring_lock, flags); return -EAGAIN; } /* Write to the ring buffer */ next_write_location = hv_get_next_write_location(outring_info); old_write = next_write_location; for (i = 0; i < kv_count; i++) { next_write_location = hv_copyto_ringbuffer(outring_info, next_write_location, kv_list[i].iov_base, kv_list[i].iov_len); } /* Set previous packet start */ prev_indices = hv_get_ring_bufferindices(outring_info); next_write_location = hv_copyto_ringbuffer(outring_info, next_write_location, &prev_indices, sizeof(u64)); /* Issue a full memory barrier before updating the write index */ mb(); /* Now, update the write location */ hv_set_next_write_location(outring_info, next_write_location); spin_unlock_irqrestore(&outring_info->ring_lock, flags); *signal = hv_need_to_signal(old_write, 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);