From 9988ce685676cebe0b14dc128f00e1ae9cd1a4fa Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Fri, 2 Sep 2016 05:58:20 -0700 Subject: [PATCH] Drivers: hv: ring_buffer: wrap around mappings for ring buffers Make it possible to always use a single memcpy() or to provide a direct link to a packet on the ring buffer by creating virtual mapping for two copies of the ring buffer with vmap(). Utilize currently empty hv_ringbuffer_cleanup() to do the unmap. While on it, replace sizeof(struct hv_ring_buffer) check in hv_ringbuffer_init() with BUILD_BUG_ON() as it is a compile time check. Signed-off-by: Vitaly Kuznetsov Tested-by: Dexuan Cui Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/channel.c | 29 ++++++++++++++--------------- drivers/hv/hyperv_vmbus.h | 4 ++-- drivers/hv/ring_buffer.c | 39 +++++++++++++++++++++++++++++++++------ 3 files changed, 49 insertions(+), 23 deletions(-) diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c index 15e8330..16f91c8 100644 --- a/drivers/hv/channel.c +++ b/drivers/hv/channel.c @@ -75,7 +75,6 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size, { struct vmbus_channel_open_channel *open_msg; struct vmbus_channel_msginfo *open_info = NULL; - void *in, *out; unsigned long flags; int ret, err = 0; struct page *page; @@ -112,23 +111,21 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size, goto error_set_chnstate; } - out = page_address(page); - in = (void *)((unsigned long)out + send_ringbuffer_size); - - newchannel->ringbuffer_pages = out; + newchannel->ringbuffer_pages = page_address(page); newchannel->ringbuffer_pagecount = (send_ringbuffer_size + recv_ringbuffer_size) >> PAGE_SHIFT; - ret = hv_ringbuffer_init( - &newchannel->outbound, out, send_ringbuffer_size); + ret = hv_ringbuffer_init(&newchannel->outbound, page, + send_ringbuffer_size >> PAGE_SHIFT); if (ret != 0) { err = ret; goto error_free_pages; } - ret = hv_ringbuffer_init( - &newchannel->inbound, in, recv_ringbuffer_size); + ret = hv_ringbuffer_init(&newchannel->inbound, + &page[send_ringbuffer_size >> PAGE_SHIFT], + recv_ringbuffer_size >> PAGE_SHIFT); if (ret != 0) { err = ret; goto error_free_pages; @@ -139,10 +136,10 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size, newchannel->ringbuffer_gpadlhandle = 0; ret = vmbus_establish_gpadl(newchannel, - newchannel->outbound.ring_buffer, - send_ringbuffer_size + - recv_ringbuffer_size, - &newchannel->ringbuffer_gpadlhandle); + page_address(page), + send_ringbuffer_size + + recv_ringbuffer_size, + &newchannel->ringbuffer_gpadlhandle); if (ret != 0) { err = ret; @@ -214,8 +211,10 @@ error_free_gpadl: vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle); kfree(open_info); error_free_pages: - free_pages((unsigned long)out, - get_order(send_ringbuffer_size + recv_ringbuffer_size)); + hv_ringbuffer_cleanup(&newchannel->outbound); + hv_ringbuffer_cleanup(&newchannel->inbound); + __free_pages(page, + get_order(send_ringbuffer_size + recv_ringbuffer_size)); error_set_chnstate: newchannel->state = CHANNEL_OPEN_STATE; return err; diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index ddcc348..a5b4442 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -522,8 +522,8 @@ extern unsigned int host_info_edx; /* Interface */ -int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, void *buffer, - u32 buflen); +int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, + struct page *pages, u32 pagecnt); void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info); diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c index e3edcae..7e21c2c 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -27,6 +27,8 @@ #include #include #include +#include +#include #include "hyperv_vmbus.h" @@ -243,22 +245,46 @@ void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info, /* Initialize the ring buffer. */ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, - void *buffer, u32 buflen) + struct page *pages, u32 page_cnt) { - if (sizeof(struct hv_ring_buffer) != PAGE_SIZE) - return -EINVAL; + int i; + struct page **pages_wraparound; + + BUILD_BUG_ON((sizeof(struct hv_ring_buffer) != PAGE_SIZE)); memset(ring_info, 0, sizeof(struct hv_ring_buffer_info)); - ring_info->ring_buffer = (struct hv_ring_buffer *)buffer; + /* + * First page holds struct hv_ring_buffer, do wraparound mapping for + * the rest. + */ + pages_wraparound = kzalloc(sizeof(struct page *) * (page_cnt * 2 - 1), + GFP_KERNEL); + if (!pages_wraparound) + return -ENOMEM; + + pages_wraparound[0] = pages; + for (i = 0; i < 2 * (page_cnt - 1); i++) + pages_wraparound[i + 1] = &pages[i % (page_cnt - 1) + 1]; + + ring_info->ring_buffer = (struct hv_ring_buffer *) + vmap(pages_wraparound, page_cnt * 2 - 1, VM_MAP, PAGE_KERNEL); + + kfree(pages_wraparound); + + + if (!ring_info->ring_buffer) + return -ENOMEM; + 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); + ring_info->ring_size = page_cnt << PAGE_SHIFT; + ring_info->ring_datasize = ring_info->ring_size - + sizeof(struct hv_ring_buffer); spin_lock_init(&ring_info->ring_lock); @@ -268,6 +294,7 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, /* Cleanup the ring buffer. */ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info) { + vunmap(ring_info->ring_buffer); } /* Write to the ring buffer. */ -- 2.7.4