#include "hyperv_vmbus.h"
-#define NUM_PAGES_SPANNED(addr, len) \
-((PAGE_ALIGN(addr + len) >> PAGE_SHIFT) - (addr >> PAGE_SHIFT))
+/*
+ * hv_gpadl_size - Return the real size of a gpadl, the size that Hyper-V uses
+ *
+ * For BUFFER gpadl, Hyper-V uses the exact same size as the guest does.
+ *
+ * For RING gpadl, in each ring, the guest uses one PAGE_SIZE as the header
+ * (because of the alignment requirement), however, the hypervisor only
+ * uses the first HV_HYP_PAGE_SIZE as the header, therefore leaving a
+ * (PAGE_SIZE - HV_HYP_PAGE_SIZE) gap. And since there are two rings in a
+ * ringbuffer, the total size for a RING gpadl that Hyper-V uses is the
+ * total size that the guest uses minus twice of the gap size.
+ */
+static inline u32 hv_gpadl_size(enum hv_gpadl_type type, u32 size)
+{
+ switch (type) {
+ case HV_GPADL_BUFFER:
+ return size;
+ case HV_GPADL_RING:
+ /* The size of a ringbuffer must be page-aligned */
+ BUG_ON(size % PAGE_SIZE);
+ /*
+ * Two things to notice here:
+ * 1) We're processing two ring buffers as a unit
+ * 2) We're skipping any space larger than HV_HYP_PAGE_SIZE in
+ * the first guest-size page of each of the two ring buffers.
+ * So we effectively subtract out two guest-size pages, and add
+ * back two Hyper-V size pages.
+ */
+ return size - 2 * (PAGE_SIZE - HV_HYP_PAGE_SIZE);
+ }
+ BUG();
+ return 0;
+}
-static unsigned long virt_to_hvpfn(void *addr)
+/*
+ * hv_ring_gpadl_send_hvpgoffset - Calculate the send offset (in unit of
+ * HV_HYP_PAGE) in a ring gpadl based on the
+ * offset in the guest
+ *
+ * @offset: the offset (in bytes) where the send ringbuffer starts in the
+ * virtual address space of the guest
+ */
+static inline u32 hv_ring_gpadl_send_hvpgoffset(u32 offset)
{
- phys_addr_t paddr;
- if (is_vmalloc_addr(addr))
- paddr = page_to_phys(vmalloc_to_page(addr)) +
- offset_in_page(addr);
- else
- paddr = __pa(addr);
+ /*
+ * For RING gpadl, in each ring, the guest uses one PAGE_SIZE as the
+ * header (because of the alignment requirement), however, the
+ * hypervisor only uses the first HV_HYP_PAGE_SIZE as the header,
+ * therefore leaving a (PAGE_SIZE - HV_HYP_PAGE_SIZE) gap.
+ *
+ * And to calculate the effective send offset in gpadl, we need to
+ * substract this gap.
+ */
+ return (offset - (PAGE_SIZE - HV_HYP_PAGE_SIZE)) >> HV_HYP_PAGE_SHIFT;
+}
+
+/*
+ * hv_gpadl_hvpfn - Return the Hyper-V page PFN of the @i th Hyper-V page in
+ * the gpadl
+ *
+ * @type: the type of the gpadl
+ * @kbuffer: the pointer to the gpadl in the guest
+ * @size: the total size (in bytes) of the gpadl
+ * @send_offset: the offset (in bytes) where the send ringbuffer starts in the
+ * virtual address space of the guest
+ * @i: the index
+ */
+static inline u64 hv_gpadl_hvpfn(enum hv_gpadl_type type, void *kbuffer,
+ u32 size, u32 send_offset, int i)
+{
+ int send_idx = hv_ring_gpadl_send_hvpgoffset(send_offset);
+ unsigned long delta = 0UL;
+
+ switch (type) {
+ case HV_GPADL_BUFFER:
+ break;
+ case HV_GPADL_RING:
+ if (i == 0)
+ delta = 0;
+ else if (i <= send_idx)
+ delta = PAGE_SIZE - HV_HYP_PAGE_SIZE;
+ else
+ delta = 2 * (PAGE_SIZE - HV_HYP_PAGE_SIZE);
+ break;
+ default:
+ BUG();
+ break;
+ }
- return paddr >> PAGE_SHIFT;
+ return virt_to_hvpfn(kbuffer + delta + (HV_HYP_PAGE_SIZE * i));
}
/*
}
EXPORT_SYMBOL_GPL(vmbus_alloc_ring);
-static int __vmbus_open(struct vmbus_channel *newchannel,
- void *userdata, u32 userdatalen,
- void (*onchannelcallback)(void *context), void *context)
-{
- struct vmbus_channel_open_channel *open_msg;
- struct vmbus_channel_msginfo *open_info = NULL;
- struct page *page = newchannel->ringbuffer_page;
- u32 send_pages, recv_pages;
- unsigned long flags;
- int err;
-
- if (userdatalen > MAX_USER_DEFINED_BYTES)
- return -EINVAL;
-
- send_pages = newchannel->ringbuffer_send_offset;
- recv_pages = newchannel->ringbuffer_pagecount - send_pages;
-
- if (newchannel->state != CHANNEL_OPEN_STATE)
- return -EINVAL;
-
- newchannel->state = CHANNEL_OPENING_STATE;
- newchannel->onchannel_callback = onchannelcallback;
- newchannel->channel_callback_context = context;
-
- err = hv_ringbuffer_init(&newchannel->outbound, page, send_pages);
- if (err)
- goto error_clean_ring;
-
- err = hv_ringbuffer_init(&newchannel->inbound,
- &page[send_pages], recv_pages);
- if (err)
- goto error_clean_ring;
-
- /* Establish the gpadl for the ring buffer */
- newchannel->ringbuffer_gpadlhandle = 0;
-
- err = vmbus_establish_gpadl(newchannel,
- page_address(newchannel->ringbuffer_page),
- (send_pages + recv_pages) << PAGE_SHIFT,
- &newchannel->ringbuffer_gpadlhandle);
- if (err)
- goto error_clean_ring;
-
- /* Create and init the channel open message */
- open_info = kmalloc(sizeof(*open_info) +
- sizeof(struct vmbus_channel_open_channel),
- GFP_KERNEL);
- if (!open_info) {
- err = -ENOMEM;
- goto error_free_gpadl;
- }
-
- init_completion(&open_info->waitevent);
- open_info->waiting_channel = newchannel;
-
- open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
- open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
- open_msg->openid = newchannel->offermsg.child_relid;
- open_msg->child_relid = newchannel->offermsg.child_relid;
- open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
- open_msg->downstream_ringbuffer_pageoffset = newchannel->ringbuffer_send_offset;
- open_msg->target_vp = hv_cpu_number_to_vp_number(newchannel->target_cpu);
-
- if (userdatalen)
- memcpy(open_msg->userdata, userdata, userdatalen);
-
- spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
- list_add_tail(&open_info->msglistentry,
- &vmbus_connection.chn_msg_list);
- spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
-
- if (newchannel->rescind) {
- err = -ENODEV;
- goto error_free_info;
- }
-
- err = vmbus_post_msg(open_msg,
- sizeof(struct vmbus_channel_open_channel), true);
-
- trace_vmbus_open(open_msg, err);
-
- if (err != 0)
- goto error_clean_msglist;
-
- wait_for_completion(&open_info->waitevent);
-
- spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
- list_del(&open_info->msglistentry);
- spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
-
- if (newchannel->rescind) {
- err = -ENODEV;
- goto error_free_info;
- }
-
- if (open_info->response.open_result.status) {
- err = -EAGAIN;
- goto error_free_info;
- }
-
- newchannel->state = CHANNEL_OPENED_STATE;
- kfree(open_info);
- return 0;
-
-error_clean_msglist:
- spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
- list_del(&open_info->msglistentry);
- spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
-error_free_info:
- kfree(open_info);
-error_free_gpadl:
- vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
- newchannel->ringbuffer_gpadlhandle = 0;
-error_clean_ring:
- hv_ringbuffer_cleanup(&newchannel->outbound);
- hv_ringbuffer_cleanup(&newchannel->inbound);
- newchannel->state = CHANNEL_OPEN_STATE;
- return err;
-}
-
-/*
- * vmbus_connect_ring - Open the channel but reuse ring buffer
- */
-int vmbus_connect_ring(struct vmbus_channel *newchannel,
- void (*onchannelcallback)(void *context), void *context)
-{
- return __vmbus_open(newchannel, NULL, 0, onchannelcallback, context);
-}
-EXPORT_SYMBOL_GPL(vmbus_connect_ring);
-
-/*
- * vmbus_open - Open the specified channel.
- */
-int vmbus_open(struct vmbus_channel *newchannel,
- u32 send_ringbuffer_size, u32 recv_ringbuffer_size,
- void *userdata, u32 userdatalen,
- void (*onchannelcallback)(void *context), void *context)
-{
- int err;
-
- err = vmbus_alloc_ring(newchannel, send_ringbuffer_size,
- recv_ringbuffer_size);
- if (err)
- return err;
-
- err = __vmbus_open(newchannel, userdata, userdatalen,
- onchannelcallback, context);
- if (err)
- vmbus_free_ring(newchannel);
-
- return err;
-}
-EXPORT_SYMBOL_GPL(vmbus_open);
-
/* Used for Hyper-V Socket: a guest client's connect() to the host */
int vmbus_send_tl_connect_request(const guid_t *shv_guest_servie_id,
const guid_t *shv_host_servie_id)
/*
* create_gpadl_header - Creates a gpadl for the specified buffer
*/
-static int create_gpadl_header(void *kbuffer, u32 size,
+static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer,
+ u32 size, u32 send_offset,
struct vmbus_channel_msginfo **msginfo)
{
int i;
int pfnsum, pfncount, pfnleft, pfncurr, pfnsize;
- pagecount = size >> PAGE_SHIFT;
+ pagecount = hv_gpadl_size(type, size) >> HV_HYP_PAGE_SHIFT;
/* do we need a gpadl body msg */
pfnsize = MAX_SIZE_CHANNEL_MESSAGE -
gpadl_header->range_buflen = sizeof(struct gpa_range) +
pagecount * sizeof(u64);
gpadl_header->range[0].byte_offset = 0;
- gpadl_header->range[0].byte_count = size;
+ gpadl_header->range[0].byte_count = hv_gpadl_size(type, size);
for (i = 0; i < pfncount; i++)
- gpadl_header->range[0].pfn_array[i] = virt_to_hvpfn(
- kbuffer + PAGE_SIZE * i);
+ gpadl_header->range[0].pfn_array[i] = hv_gpadl_hvpfn(
+ type, kbuffer, size, send_offset, i);
*msginfo = msgheader;
pfnsum = pfncount;
* so the hypervisor guarantees that this is ok.
*/
for (i = 0; i < pfncurr; i++)
- gpadl_body->pfn[i] = virt_to_hvpfn(
- kbuffer + PAGE_SIZE * (pfnsum + i));
+ gpadl_body->pfn[i] = hv_gpadl_hvpfn(type,
+ kbuffer, size, send_offset, pfnsum + i);
/* add to msg header */
list_add_tail(&msgbody->msglistentry,
gpadl_header->range_buflen = sizeof(struct gpa_range) +
pagecount * sizeof(u64);
gpadl_header->range[0].byte_offset = 0;
- gpadl_header->range[0].byte_count = size;
+ gpadl_header->range[0].byte_count = hv_gpadl_size(type, size);
for (i = 0; i < pagecount; i++)
- gpadl_header->range[0].pfn_array[i] = virt_to_hvpfn(
- kbuffer + PAGE_SIZE * i);
+ gpadl_header->range[0].pfn_array[i] = hv_gpadl_hvpfn(
+ type, kbuffer, size, send_offset, i);
*msginfo = msgheader;
}
}
/*
- * vmbus_establish_gpadl - Establish a GPADL for the specified buffer
+ * __vmbus_establish_gpadl - Establish a GPADL for a buffer or ringbuffer
*
* @channel: a channel
+ * @type: the type of the corresponding GPADL, only meaningful for the guest.
* @kbuffer: from kmalloc or vmalloc
* @size: page-size multiple
+ * @send_offset: the offset (in bytes) where the send ring buffer starts,
+ * should be 0 for BUFFER type gpadl
* @gpadl_handle: some funky thing
*/
-int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
- u32 size, u32 *gpadl_handle)
+static int __vmbus_establish_gpadl(struct vmbus_channel *channel,
+ enum hv_gpadl_type type, void *kbuffer,
+ u32 size, u32 send_offset,
+ u32 *gpadl_handle)
{
struct vmbus_channel_gpadl_header *gpadlmsg;
struct vmbus_channel_gpadl_body *gpadl_body;
next_gpadl_handle =
(atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1);
- ret = create_gpadl_header(kbuffer, size, &msginfo);
+ ret = create_gpadl_header(type, kbuffer, size, send_offset, &msginfo);
if (ret)
return ret;
kfree(msginfo);
return ret;
}
+
+/*
+ * vmbus_establish_gpadl - Establish a GPADL for the specified buffer
+ *
+ * @channel: a channel
+ * @kbuffer: from kmalloc or vmalloc
+ * @size: page-size multiple
+ * @gpadl_handle: some funky thing
+ */
+int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer,
+ u32 size, u32 *gpadl_handle)
+{
+ return __vmbus_establish_gpadl(channel, HV_GPADL_BUFFER, kbuffer, size,
+ 0U, gpadl_handle);
+}
EXPORT_SYMBOL_GPL(vmbus_establish_gpadl);
+/**
+ * request_arr_init - Allocates memory for the requestor array. Each slot
+ * keeps track of the next available slot in the array. Initially, each
+ * slot points to the next one (as in a Linked List). The last slot
+ * does not point to anything, so its value is U64_MAX by default.
+ * @size The size of the array
+ */
+static u64 *request_arr_init(u32 size)
+{
+ int i;
+ u64 *req_arr;
+
+ req_arr = kcalloc(size, sizeof(u64), GFP_KERNEL);
+ if (!req_arr)
+ return NULL;
+
+ for (i = 0; i < size - 1; i++)
+ req_arr[i] = i + 1;
+
+ /* Last slot (no more available slots) */
+ req_arr[i] = U64_MAX;
+
+ return req_arr;
+}
+
+/*
+ * vmbus_alloc_requestor - Initializes @rqstor's fields.
+ * Index 0 is the first free slot
+ * @size: Size of the requestor array
+ */
+static int vmbus_alloc_requestor(struct vmbus_requestor *rqstor, u32 size)
+{
+ u64 *rqst_arr;
+ unsigned long *bitmap;
+
+ rqst_arr = request_arr_init(size);
+ if (!rqst_arr)
+ return -ENOMEM;
+
+ bitmap = bitmap_zalloc(size, GFP_KERNEL);
+ if (!bitmap) {
+ kfree(rqst_arr);
+ return -ENOMEM;
+ }
+
+ rqstor->req_arr = rqst_arr;
+ rqstor->req_bitmap = bitmap;
+ rqstor->size = size;
+ rqstor->next_request_id = 0;
+ spin_lock_init(&rqstor->req_lock);
+
+ return 0;
+}
+
+/*
+ * vmbus_free_requestor - Frees memory allocated for @rqstor
+ * @rqstor: Pointer to the requestor struct
+ */
+static void vmbus_free_requestor(struct vmbus_requestor *rqstor)
+{
+ kfree(rqstor->req_arr);
+ bitmap_free(rqstor->req_bitmap);
+}
+
+static int __vmbus_open(struct vmbus_channel *newchannel,
+ void *userdata, u32 userdatalen,
+ void (*onchannelcallback)(void *context), void *context)
+{
+ struct vmbus_channel_open_channel *open_msg;
+ struct vmbus_channel_msginfo *open_info = NULL;
+ struct page *page = newchannel->ringbuffer_page;
+ u32 send_pages, recv_pages;
+ unsigned long flags;
+ int err;
+
+ if (userdatalen > MAX_USER_DEFINED_BYTES)
+ return -EINVAL;
+
+ send_pages = newchannel->ringbuffer_send_offset;
+ recv_pages = newchannel->ringbuffer_pagecount - send_pages;
+
+ if (newchannel->state != CHANNEL_OPEN_STATE)
+ return -EINVAL;
+
+ /* Create and init requestor */
+ if (newchannel->rqstor_size) {
+ if (vmbus_alloc_requestor(&newchannel->requestor, newchannel->rqstor_size))
+ return -ENOMEM;
+ }
+
+ newchannel->state = CHANNEL_OPENING_STATE;
+ newchannel->onchannel_callback = onchannelcallback;
+ newchannel->channel_callback_context = context;
+
+ err = hv_ringbuffer_init(&newchannel->outbound, page, send_pages);
+ if (err)
+ goto error_clean_ring;
+
+ err = hv_ringbuffer_init(&newchannel->inbound,
+ &page[send_pages], recv_pages);
+ if (err)
+ goto error_clean_ring;
+
+ /* Establish the gpadl for the ring buffer */
+ newchannel->ringbuffer_gpadlhandle = 0;
+
+ err = __vmbus_establish_gpadl(newchannel, HV_GPADL_RING,
+ page_address(newchannel->ringbuffer_page),
+ (send_pages + recv_pages) << PAGE_SHIFT,
+ newchannel->ringbuffer_send_offset << PAGE_SHIFT,
+ &newchannel->ringbuffer_gpadlhandle);
+ if (err)
+ goto error_clean_ring;
+
+ /* Create and init the channel open message */
+ open_info = kmalloc(sizeof(*open_info) +
+ sizeof(struct vmbus_channel_open_channel),
+ GFP_KERNEL);
+ if (!open_info) {
+ err = -ENOMEM;
+ goto error_free_gpadl;
+ }
+
+ init_completion(&open_info->waitevent);
+ open_info->waiting_channel = newchannel;
+
+ open_msg = (struct vmbus_channel_open_channel *)open_info->msg;
+ open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL;
+ open_msg->openid = newchannel->offermsg.child_relid;
+ open_msg->child_relid = newchannel->offermsg.child_relid;
+ open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
+ /*
+ * The unit of ->downstream_ringbuffer_pageoffset is HV_HYP_PAGE and
+ * the unit of ->ringbuffer_send_offset (i.e. send_pages) is PAGE, so
+ * here we calculate it into HV_HYP_PAGE.
+ */
+ open_msg->downstream_ringbuffer_pageoffset =
+ hv_ring_gpadl_send_hvpgoffset(send_pages << PAGE_SHIFT);
+ open_msg->target_vp = hv_cpu_number_to_vp_number(newchannel->target_cpu);
+
+ if (userdatalen)
+ memcpy(open_msg->userdata, userdata, userdatalen);
+
+ spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+ list_add_tail(&open_info->msglistentry,
+ &vmbus_connection.chn_msg_list);
+ spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+
+ if (newchannel->rescind) {
+ err = -ENODEV;
+ goto error_free_info;
+ }
+
+ err = vmbus_post_msg(open_msg,
+ sizeof(struct vmbus_channel_open_channel), true);
+
+ trace_vmbus_open(open_msg, err);
+
+ if (err != 0)
+ goto error_clean_msglist;
+
+ wait_for_completion(&open_info->waitevent);
+
+ spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+ list_del(&open_info->msglistentry);
+ spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+
+ if (newchannel->rescind) {
+ err = -ENODEV;
+ goto error_free_info;
+ }
+
+ if (open_info->response.open_result.status) {
+ err = -EAGAIN;
+ goto error_free_info;
+ }
+
+ newchannel->state = CHANNEL_OPENED_STATE;
+ kfree(open_info);
+ return 0;
+
+error_clean_msglist:
+ spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
+ list_del(&open_info->msglistentry);
+ spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+error_free_info:
+ kfree(open_info);
+error_free_gpadl:
+ vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
+ newchannel->ringbuffer_gpadlhandle = 0;
+error_clean_ring:
+ hv_ringbuffer_cleanup(&newchannel->outbound);
+ hv_ringbuffer_cleanup(&newchannel->inbound);
+ vmbus_free_requestor(&newchannel->requestor);
+ newchannel->state = CHANNEL_OPEN_STATE;
+ return err;
+}
+
+/*
+ * vmbus_connect_ring - Open the channel but reuse ring buffer
+ */
+int vmbus_connect_ring(struct vmbus_channel *newchannel,
+ void (*onchannelcallback)(void *context), void *context)
+{
+ return __vmbus_open(newchannel, NULL, 0, onchannelcallback, context);
+}
+EXPORT_SYMBOL_GPL(vmbus_connect_ring);
+
+/*
+ * vmbus_open - Open the specified channel.
+ */
+int vmbus_open(struct vmbus_channel *newchannel,
+ u32 send_ringbuffer_size, u32 recv_ringbuffer_size,
+ void *userdata, u32 userdatalen,
+ void (*onchannelcallback)(void *context), void *context)
+{
+ int err;
+
+ err = vmbus_alloc_ring(newchannel, send_ringbuffer_size,
+ recv_ringbuffer_size);
+ if (err)
+ return err;
+
+ err = __vmbus_open(newchannel, userdata, userdatalen,
+ onchannelcallback, context);
+ if (err)
+ vmbus_free_ring(newchannel);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(vmbus_open);
+
/*
* vmbus_teardown_gpadl -Teardown the specified GPADL handle
*/
channel->ringbuffer_gpadlhandle = 0;
}
+ if (!ret)
+ vmbus_free_requestor(&channel->requestor);
+
return ret;
}
/* in 8-bytes granularity */
desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3;
desc.len8 = (u16)(packetlen_aligned >> 3);
- desc.trans_id = requestid;
+ desc.trans_id = VMBUS_RQST_ERROR; /* will be updated in hv_ringbuffer_write() */
bufferlist[0].iov_base = &desc;
bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor);
bufferlist[2].iov_base = &aligned_data;
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
- return hv_ringbuffer_write(channel, bufferlist, num_vecs);
+ return hv_ringbuffer_write(channel, bufferlist, num_vecs, requestid);
}
EXPORT_SYMBOL(vmbus_sendpacket);
desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
desc.dataoffset8 = descsize >> 3; /* in 8-bytes granularity */
desc.length8 = (u16)(packetlen_aligned >> 3);
- desc.transactionid = requestid;
+ desc.transactionid = VMBUS_RQST_ERROR; /* will be updated in hv_ringbuffer_write() */
desc.reserved = 0;
desc.rangecount = pagecount;
bufferlist[2].iov_base = &aligned_data;
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
- return hv_ringbuffer_write(channel, bufferlist, 3);
+ return hv_ringbuffer_write(channel, bufferlist, 3, requestid);
}
EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED;
desc->dataoffset8 = desc_size >> 3; /* in 8-bytes granularity */
desc->length8 = (u16)(packetlen_aligned >> 3);
- desc->transactionid = requestid;
+ desc->transactionid = VMBUS_RQST_ERROR; /* will be updated in hv_ringbuffer_write() */
desc->reserved = 0;
desc->rangecount = 1;
bufferlist[2].iov_base = &aligned_data;
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
- return hv_ringbuffer_write(channel, bufferlist, 3);
+ return hv_ringbuffer_write(channel, bufferlist, 3, requestid);
}
EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
buffer_actual_len, requestid, true);
}
EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw);
+
+/*
+ * vmbus_next_request_id - Returns a new request id. It is also
+ * the index at which the guest memory address is stored.
+ * Uses a spin lock to avoid race conditions.
+ * @rqstor: Pointer to the requestor struct
+ * @rqst_add: Guest memory address to be stored in the array
+ */
+u64 vmbus_next_request_id(struct vmbus_requestor *rqstor, u64 rqst_addr)
+{
+ unsigned long flags;
+ u64 current_id;
+ const struct vmbus_channel *channel =
+ container_of(rqstor, const struct vmbus_channel, requestor);
+
+ /* Check rqstor has been initialized */
+ if (!channel->rqstor_size)
+ return VMBUS_NO_RQSTOR;
+
+ spin_lock_irqsave(&rqstor->req_lock, flags);
+ current_id = rqstor->next_request_id;
+
+ /* Requestor array is full */
+ if (current_id >= rqstor->size) {
+ spin_unlock_irqrestore(&rqstor->req_lock, flags);
+ return VMBUS_RQST_ERROR;
+ }
+
+ rqstor->next_request_id = rqstor->req_arr[current_id];
+ rqstor->req_arr[current_id] = rqst_addr;
+
+ /* The already held spin lock provides atomicity */
+ bitmap_set(rqstor->req_bitmap, current_id, 1);
+
+ spin_unlock_irqrestore(&rqstor->req_lock, flags);
+
+ /*
+ * Cannot return an ID of 0, which is reserved for an unsolicited
+ * message from Hyper-V.
+ */
+ return current_id + 1;
+}
+EXPORT_SYMBOL_GPL(vmbus_next_request_id);
+
+/*
+ * vmbus_request_addr - Returns the memory address stored at @trans_id
+ * in @rqstor. Uses a spin lock to avoid race conditions.
+ * @rqstor: Pointer to the requestor struct
+ * @trans_id: Request id sent back from Hyper-V. Becomes the requestor's
+ * next request id.
+ */
+u64 vmbus_request_addr(struct vmbus_requestor *rqstor, u64 trans_id)
+{
+ unsigned long flags;
+ u64 req_addr;
+ const struct vmbus_channel *channel =
+ container_of(rqstor, const struct vmbus_channel, requestor);
+
+ /* Check rqstor has been initialized */
+ if (!channel->rqstor_size)
+ return VMBUS_NO_RQSTOR;
+
+ /* Hyper-V can send an unsolicited message with ID of 0 */
+ if (!trans_id)
+ return trans_id;
+
+ spin_lock_irqsave(&rqstor->req_lock, flags);
+
+ /* Data corresponding to trans_id is stored at trans_id - 1 */
+ trans_id--;
+
+ /* Invalid trans_id */
+ if (trans_id >= rqstor->size || !test_bit(trans_id, rqstor->req_bitmap)) {
+ spin_unlock_irqrestore(&rqstor->req_lock, flags);
+ return VMBUS_RQST_ERROR;
+ }
+
+ req_addr = rqstor->req_arr[trans_id];
+ rqstor->req_arr[trans_id] = rqstor->next_request_id;
+ rqstor->next_request_id = trans_id;
+
+ /* The already held spin lock provides atomicity */
+ bitmap_clear(rqstor->req_bitmap, trans_id, 1);
+
+ spin_unlock_irqrestore(&rqstor->req_lock, flags);
+ return req_addr;
+}
+EXPORT_SYMBOL_GPL(vmbus_request_addr);
projects / linux-2.6-microblaze.git / blobdiff