Kernel/linux-next
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git synced 2025-01-01 10:42:11 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Drivers: hv: vmbus: Introduce vmbus_request_addr_match()

Browse Source 
The function can be used to retrieve and clear/remove a transation ID
from a channel requestor, provided the memory address corresponding to
the ID equals a specified address.  The function, and its 'lockless'
variant __vmbus_request_addr_match(), will be used by hv_pci.

Refactor vmbus_request_addr() to reuse the 'newly' introduced code.

No functional change.

Suggested-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20220419122325.10078-5-parri.andrea@gmail.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
This commit is contained in:
Andrea Parri (Microsoft) 2022-04-19 14:23:23 +02:00 committed by Wei Liu
parent b03afa57c6
commit 0aadb6a7bb
2 changed files with 53 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

67
drivers/hv/channel.c
View File

@ -1279,17 +1279,11 @@ u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
}
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.
* @channel: Pointer to the VMbus channel struct
* @trans_id: Request id sent back from Hyper-V. Becomes the requestor's
* next request id.
*/
u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id)
/* As in vmbus_request_addr_match() but without the requestor lock */
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;
/* Check rqstor has been initialized */
@ -1300,25 +1294,60 @@ u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id)
if (!trans_id)
return VMBUS_RQST_ERROR;
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);
if (trans_id >= rqstor->size || !test_bit(trans_id, rqstor->req_bitmap))
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;
if (rqst_addr == VMBUS_RQST_ADDR_ANY || req_addr == rqst_addr) {
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);
/* 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_match);
/*
* vmbus_request_addr_match - Clears/removes @trans_id from the @channel's
* requestor, provided the memory address stored at @trans_id equals @rqst_addr
* (or provided @rqst_addr matches the sentinel value VMBUS_RQST_ADDR_ANY).
*
* Returns the memory address stored at @trans_id, or VMBUS_RQST_ERROR if
* @trans_id is not contained in the requestor.
*
* Acquires and releases the requestor spin lock.
*/
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);
req_addr = __vmbus_request_addr_match(channel, trans_id, rqst_addr);
spin_unlock_irqrestore(&rqstor->req_lock, flags);
return req_addr;
}
EXPORT_SYMBOL_GPL(vmbus_request_addr_match);
/*
* vmbus_request_addr - Returns the memory address stored at @trans_id
* in @rqstor. Uses a spin lock to avoid race conditions.
* @channel: Pointer to the VMbus channel struct
* @trans_id: Request id sent back from Hyper-V. Becomes the requestor's
* next request id.
*/
u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id)
{
return vmbus_request_addr_match(channel, trans_id, VMBUS_RQST_ADDR_ANY);
}
EXPORT_SYMBOL_GPL(vmbus_request_addr);

5
include/linux/hyperv.h
View File

@ -788,6 +788,7 @@ struct vmbus_requestor {
#define VMBUS_NO_RQSTOR U64_MAX
#define VMBUS_RQST_ERROR (U64_MAX - 1)
#define VMBUS_RQST_ADDR_ANY U64_MAX
/* NetVSC-specific */
#define VMBUS_RQST_ID_NO_RESPONSE (U64_MAX - 2)
/* StorVSC-specific */
@ -1042,6 +1043,10 @@ struct vmbus_channel {
};
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);
u64 vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
u64 rqst_addr);
u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id);
static inline bool is_hvsock_channel(const struct vmbus_channel *c)