[PATCH 5/6] Drivers: hv: vmbus: Introduce {lock,unlock}_requestor()

Andrea Parri (Microsoft)
2022-04-07T04:32:53Z

To abtract the lock and unlock operations on the requestor spin lock.
The helpers will come in handy in hv_pci.

No functional change.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
---
drivers/hv/channel.c | 11 +++++------
include/linux/hyperv.h | 15 +++++++++++++++
2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 49f10a603a091..56f7e06c673e4 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -1252,12 +1252,12 @@ u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
if (!channel->rqstor_size)
return VMBUS_NO_RQSTOR;

- spin_lock_irqsave(&rqstor->req_lock, flags);
+ lock_requestor(channel, flags);
current_id = rqstor->next_request_id;

/* Requestor array is full */
if (current_id >= rqstor->size) {
- spin_unlock_irqrestore(&rqstor->req_lock, flags);
+ unlock_requestor(channel, flags);
return VMBUS_RQST_ERROR;
}

@@ -1267,7 +1267,7 @@ u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
/* The already held spin lock provides atomicity */
bitmap_set(rqstor->req_bitmap, current_id, 1);

- spin_unlock_irqrestore(&rqstor->req_lock, flags);
+ unlock_requestor(channel, flags);

/*
* Cannot return an ID of 0, which is reserved for an unsolicited
@@ -1327,13 +1327,12 @@ EXPORT_SYMBOL_GPL(__vmbus_request_addr_match);
u64 vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
u64 rqst_addr)
{
- struct vmbus_requestor *rqstor = &channel->requestor;
unsigned long flags;
u64 req_addr;

- spin_lock_irqsave(&rqstor->req_lock, flags);
+ lock_requestor(channel, flags);
req_addr = __vmbus_request_addr_match(channel, trans_id, rqst_addr);
- spin_unlock_irqrestore(&rqstor->req_lock, flags);
+ unlock_requestor(channel, flags);

return req_addr;
}
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index c77d78f34b96a..015e4ceb43029 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -1042,6 +1042,21 @@ struct vmbus_channel {
u32 max_pkt_size;
};

+#define lock_requestor(channel, flags) \
+do { \
+ struct vmbus_requestor *rqstor = &(channel)->requestor; \
+ \
+ spin_lock_irqsave(&rqstor->req_lock, flags); \
+} while (0)
+
+static __always_inline void unlock_requestor(struct vmbus_channel *channel,
+ unsigned long flags)
+{
+ struct vmbus_requestor *rqstor = &channel->requestor;
+
+ spin_unlock_irqrestore(&rqstor->req_lock, flags);
+}
+
u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr);
u64 __vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
u64 rqst_addr);
--
2.25.1