greybus: create a slab cache for operations

Everything we do on greybus will involve an operation, so create a
slab cache for that frequently-allocated data structure.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

diff --git a/drivers/staging/greybus/operation.c b/drivers/staging/greybus/operation.c
index 1176c97..da455f0 100644 (file)
--- a/drivers/staging/greybus/operation.c
+++ b/drivers/staging/greybus/operation.c
@@ -24,6 +24,8 @@
  */
 #define GB_OPERATION_MESSAGE_SIZE_MAX  4096
 
+static struct kmem_cache *gb_operation_cache;
+
 /* Workqueue to handle Greybus operation completions. */
 static struct workqueue_struct *gb_operation_recv_workqueue;
 
@@ -307,8 +309,7 @@ struct gb_operation *gb_operation_create(struct gb_connection *connection,
        gfp_t gfp_flags = response_size ? GFP_KERNEL : GFP_ATOMIC;
        bool outgoing = response_size != 0;
 
-       /* XXX Use a slab cache */
-       operation = kzalloc(sizeof(*operation), gfp_flags);
+       operation = kmem_cache_zalloc(gb_operation_cache, gfp_flags);
        if (!operation)
                return NULL;
        operation->connection = connection;             /* XXX refcount? */
@@ -316,10 +317,8 @@ struct gb_operation *gb_operation_create(struct gb_connection *connection,
        operation->request = gb_operation_gbuf_create(operation, type,
                                                        request_size,
                                                        outgoing);
-       if (!operation->request) {
-               kfree(operation);
-               return NULL;
-       }
+       if (!operation->request)
+               goto err_cache;
        operation->request_payload = operation->request->transfer_buffer +
                                        sizeof(struct gb_operation_msg_hdr);
        /* We always use the full request buffer */
@@ -330,11 +329,8 @@ struct gb_operation *gb_operation_create(struct gb_connection *connection,
                operation->response = gb_operation_gbuf_create(operation,
                                                type, response_size,
                                                false);
-               if (!operation->response) {
-                       greybus_free_gbuf(operation->request);
-                       kfree(operation);
-                       return NULL;
-               }
+               if (!operation->response)
+                       goto err_request;
                operation->response_payload =
                                operation->response->transfer_buffer +
                                sizeof(struct gb_operation_msg_hdr);
@@ -349,6 +345,13 @@ struct gb_operation *gb_operation_create(struct gb_connection *connection,
        spin_unlock_irq(&gb_operations_lock);
 
        return operation;
+
+err_request:
+       greybus_free_gbuf(operation->request);
+err_cache:
+       kmem_cache_free(gb_operation_cache, operation);
+
+       return NULL;
 }
 
 /*
@@ -367,7 +370,7 @@ void gb_operation_destroy(struct gb_operation *operation)
        greybus_free_gbuf(operation->response);
        greybus_free_gbuf(operation->request);
 
-       kfree(operation);
+       kmem_cache_free(gb_operation_cache, operation);
 }
 
 /*
@@ -470,14 +473,25 @@ void gb_connection_operation_recv(struct gb_connection *connection,
 
 int gb_operation_init(void)
 {
+       gb_operation_cache = kmem_cache_create("gb_operation_cache",
+                               sizeof(struct gb_operation), 0, 0, NULL);
+       if (!gb_operation_cache)
+               return -ENOMEM;
+
        gb_operation_recv_workqueue = alloc_workqueue("greybus_recv", 0, 1);
-       if (!gb_operation_recv_workqueue)
+       if (!gb_operation_recv_workqueue) {
+               kmem_cache_destroy(gb_operation_cache);
+               gb_operation_cache = NULL;
                return -ENOMEM;
+       }
 
        return 0;
 }
 
 void gb_operation_exit(void)
 {
+       kmem_cache_destroy(gb_operation_cache);
+       gb_operation_cache = NULL;
        destroy_workqueue(gb_operation_recv_workqueue);
+       gb_operation_recv_workqueue = NULL;
 }