From a6341f000024cdf1ec14dc26743a409a17378db5 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Sat, 2 Apr 2016 17:59:46 -0700 Subject: Drivers: hv: vmbus: Introduce functions for estimating room in the ring buffer Introduce separate functions for estimating how much can be read from and written to the ring buffer. Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- include/linux/hyperv.h | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'include/linux/hyperv.h') diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index aa0fadce9308..66226ceade37 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -151,6 +151,33 @@ hv_get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi, *read = dsize - *write; } +static inline u32 hv_get_bytes_to_read(struct hv_ring_buffer_info *rbi) +{ + u32 read_loc, write_loc, dsize, read; + + dsize = rbi->ring_datasize; + read_loc = rbi->ring_buffer->read_index; + write_loc = READ_ONCE(rbi->ring_buffer->write_index); + + read = write_loc >= read_loc ? (write_loc - read_loc) : + (dsize - read_loc) + write_loc; + + return read; +} + +static inline u32 hv_get_bytes_to_write(struct hv_ring_buffer_info *rbi) +{ + u32 read_loc, write_loc, dsize, write; + + dsize = rbi->ring_datasize; + read_loc = READ_ONCE(rbi->ring_buffer->read_index); + write_loc = rbi->ring_buffer->write_index; + + write = write_loc >= read_loc ? dsize - (write_loc - read_loc) : + read_loc - write_loc; + return write; +} + /* * VMBUS version is 32 bit entity broken up into * two 16 bit quantities: major_number. minor_number. -- cgit v1.2.3-71-gd317 From 5cc472477f928fb8584eb8e08245c9cf9002d74a Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Sat, 2 Apr 2016 17:59:49 -0700 Subject: Drivers: hv: vmbus: Export the vmbus_set_event() API In preparation for moving some ring buffer functionality out of the vmbus driver, export the API for signaling the host. Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/connection.c | 1 + drivers/hv/hyperv_vmbus.h | 2 -- include/linux/hyperv.h | 1 + 3 files changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux/hyperv.h') diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index d02f1373dd98..fcf8a02dc0ea 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -495,3 +495,4 @@ void vmbus_set_event(struct vmbus_channel *channel) hv_do_hypercall(HVCALL_SIGNAL_EVENT, channel->sig_event, NULL); } +EXPORT_SYMBOL_GPL(vmbus_set_event); diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index 12321b93a756..e5c586fab0e5 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -667,8 +667,6 @@ void vmbus_disconnect(void); int vmbus_post_msg(void *buffer, size_t buflen); -void vmbus_set_event(struct vmbus_channel *channel); - void vmbus_on_event(unsigned long data); void vmbus_on_msg_dpc(unsigned long data); diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 66226ceade37..40fd608475f7 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1365,4 +1365,5 @@ extern __u32 vmbus_proto_version; int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id, const uuid_le *shv_host_servie_id); +void vmbus_set_event(struct vmbus_channel *channel); #endif /* _HYPERV_H */ -- cgit v1.2.3-71-gd317 From 687f32e6d9bd1d63c5e557e877809eb446f1a6e8 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Sat, 2 Apr 2016 17:59:50 -0700 Subject: Drivers: hv: vmbus: Move some ring buffer functions to hyperv.h In preparation for implementing APIs for in-place consumption of VMBUS packets, movve some ring buffer functionality into hyperv.h Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/ring_buffer.c | 55 ------------------------------------------------ include/linux/hyperv.h | 54 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 54 insertions(+), 55 deletions(-) (limited to 'include/linux/hyperv.h') diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index 8f518af3074d..dd255c9b9420 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -84,52 +84,6 @@ static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi) 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(struct hv_ring_buffer_info *rbi) -{ - u32 cur_write_sz; - u32 pending_sz; - - /* - * Issue a full memory barrier before making the signaling decision. - * Here is the reason for having this barrier: - * If the reading of the pend_sz (in this function) - * were to be reordered and read before we commit the new read - * index (in the calling function) we could - * have a problem. If the host were to set the pending_sz after we - * have sampled pending_sz and go to sleep before we commit the - * read index, we could miss sending the interrupt. Issue a full - * memory barrier to address this. - */ - virt_mb(); - - pending_sz = READ_ONCE(rbi->ring_buffer->pending_send_sz); - /* If the other end is not blocked on write don't bother. */ - if (pending_sz == 0) - return false; - - cur_write_sz = hv_get_bytes_to_write(rbi); - - if (cur_write_sz >= pending_sz) - return true; - - return false; -} - /* 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) @@ -180,15 +134,6 @@ hv_set_next_read_location(struct hv_ring_buffer_info *ring_info, ring_info->ring_buffer->read_index = next_read_location; } - -/* 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; -} - - /* Get the size of the ring buffer. */ static inline u32 hv_get_ring_buffersize(struct hv_ring_buffer_info *ring_info) diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 40fd608475f7..eb7c0b215ba4 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1366,4 +1366,58 @@ extern __u32 vmbus_proto_version; int vmbus_send_tl_connect_request(const uuid_le *shv_guest_servie_id, const uuid_le *shv_host_servie_id); void vmbus_set_event(struct vmbus_channel *channel); + +/* 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; +} + +/* + * 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 inline bool hv_need_to_signal_on_read(struct hv_ring_buffer_info *rbi) +{ + u32 cur_write_sz; + u32 pending_sz; + + /* + * Issue a full memory barrier before making the signaling decision. + * Here is the reason for having this barrier: + * If the reading of the pend_sz (in this function) + * were to be reordered and read before we commit the new read + * index (in the calling function) we could + * have a problem. If the host were to set the pending_sz after we + * have sampled pending_sz and go to sleep before we commit the + * read index, we could miss sending the interrupt. Issue a full + * memory barrier to address this. + */ + virt_mb(); + + pending_sz = READ_ONCE(rbi->ring_buffer->pending_send_sz); + /* If the other end is not blocked on write don't bother. */ + if (pending_sz == 0) + return false; + + cur_write_sz = hv_get_bytes_to_write(rbi); + + if (cur_write_sz >= pending_sz) + return true; + + return false; +} + #endif /* _HYPERV_H */ -- cgit v1.2.3-71-gd317 From ab028db41ca9174caab7f9e3fc0a2e7f4a418410 Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Sat, 2 Apr 2016 17:59:51 -0700 Subject: Drivers: hv: vmbus: Implement APIs to support "in place" consumption of vmbus packets Implement APIs for in-place consumption of vmbus packets. Currently, each packet is copied and processed one at a time and as part of processing each packet we potentially may signal the host (if it is waiting for room to produce a packet). These APIs help batched in-place processing of vmbus packets. We also optimize host signaling by having a separate API to signal the end of in-place consumption. With netvsc using these APIs, on an iperf run on average I see about 20X reduction in checks to signal the host. Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/ring_buffer.c | 1 + include/linux/hyperv.h | 86 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 87 insertions(+) (limited to 'include/linux/hyperv.h') diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index dd255c9b9420..fe586bf74e17 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -132,6 +132,7 @@ 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; + ring_info->priv_read_index = next_read_location; } /* Get the size of the ring buffer. */ diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index eb7c0b215ba4..590fee6a2e6f 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -126,6 +126,8 @@ struct hv_ring_buffer_info { u32 ring_datasize; /* < ring_size */ u32 ring_data_startoffset; + u32 priv_write_index; + u32 priv_read_index; }; /* @@ -1420,4 +1422,88 @@ static inline bool hv_need_to_signal_on_read(struct hv_ring_buffer_info *rbi) return false; } +/* + * An API to support in-place processing of incoming VMBUS packets. + */ +#define VMBUS_PKT_TRAILER 8 + +static inline struct vmpacket_descriptor * +get_next_pkt_raw(struct vmbus_channel *channel) +{ + struct hv_ring_buffer_info *ring_info = &channel->inbound; + u32 read_loc = ring_info->priv_read_index; + void *ring_buffer = hv_get_ring_buffer(ring_info); + struct vmpacket_descriptor *cur_desc; + u32 packetlen; + u32 dsize = ring_info->ring_datasize; + u32 delta = read_loc - ring_info->ring_buffer->read_index; + u32 bytes_avail_toread = (hv_get_bytes_to_read(ring_info) - delta); + + if (bytes_avail_toread < sizeof(struct vmpacket_descriptor)) + return NULL; + + if ((read_loc + sizeof(*cur_desc)) > dsize) + return NULL; + + cur_desc = ring_buffer + read_loc; + packetlen = cur_desc->len8 << 3; + + /* + * If the packet under consideration is wrapping around, + * return failure. + */ + if ((read_loc + packetlen + VMBUS_PKT_TRAILER) > (dsize - 1)) + return NULL; + + return cur_desc; +} + +/* + * A helper function to step through packets "in-place" + * This API is to be called after each successful call + * get_next_pkt_raw(). + */ +static inline void put_pkt_raw(struct vmbus_channel *channel, + struct vmpacket_descriptor *desc) +{ + struct hv_ring_buffer_info *ring_info = &channel->inbound; + u32 read_loc = ring_info->priv_read_index; + u32 packetlen = desc->len8 << 3; + u32 dsize = ring_info->ring_datasize; + + if ((read_loc + packetlen + VMBUS_PKT_TRAILER) > dsize) + BUG(); + /* + * Include the packet trailer. + */ + ring_info->priv_read_index += packetlen + VMBUS_PKT_TRAILER; +} + +/* + * This call commits the read index and potentially signals the host. + * Here is the pattern for using the "in-place" consumption APIs: + * + * while (get_next_pkt_raw() { + * process the packet "in-place"; + * put_pkt_raw(); + * } + * if (packets processed in place) + * commit_rd_index(); + */ +static inline void commit_rd_index(struct vmbus_channel *channel) +{ + struct hv_ring_buffer_info *ring_info = &channel->inbound; + /* + * 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. + */ + virt_rmb(); + ring_info->ring_buffer->read_index = ring_info->priv_read_index; + + if (hv_need_to_signal_on_read(ring_info)) + vmbus_set_event(channel); +} + + #endif /* _HYPERV_H */ -- cgit v1.2.3-71-gd317 From 97fb77dc87582300fa3c141b63699f853576cab1 Mon Sep 17 00:00:00 2001 From: Jake Oshins Date: Tue, 5 Apr 2016 10:22:51 -0700 Subject: drivers:hv: Make a function to free mmio regions through vmbus This patch introduces a function that reverses everything done by vmbus_allocate_mmio(). Existing code just called release_mem_region(). Future patches in this series require a more complex sequence of actions, so this function is introduced to wrap those actions. Signed-off-by: Jake Oshins Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/vmbus_drv.c | 15 +++++++++++++++ include/linux/hyperv.h | 2 +- 2 files changed, 16 insertions(+), 1 deletion(-) (limited to 'include/linux/hyperv.h') diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 799518b3cdc5..60553c156f90 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1187,6 +1187,21 @@ exit: } EXPORT_SYMBOL_GPL(vmbus_allocate_mmio); +/** + * vmbus_free_mmio() - Free a memory-mapped I/O range. + * @start: Base address of region to release. + * @size: Size of the range to be allocated + * + * This function releases anything requested by + * vmbus_mmio_allocate(). + */ +void vmbus_free_mmio(resource_size_t start, resource_size_t size) +{ + release_mem_region(start, size); + +} +EXPORT_SYMBOL_GPL(vmbus_free_mmio); + /** * vmbus_cpu_number_to_vp_number() - Map CPU to VP. * @cpu_number: CPU number in Linux terms diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 590fee6a2e6f..b10954a66939 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -1120,7 +1120,7 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj, resource_size_t min, resource_size_t max, resource_size_t size, resource_size_t align, bool fb_overlap_ok); - +void vmbus_free_mmio(resource_size_t start, resource_size_t size); int vmbus_cpu_number_to_vp_number(int cpu_number); u64 hv_do_hypercall(u64 control, void *input, void *output); -- cgit v1.2.3-71-gd317