diff options
Diffstat (limited to 'include/hw/xen/interface/io/ring.h')
| -rw-r--r-- | include/hw/xen/interface/io/ring.h | 49 |
1 files changed, 25 insertions, 24 deletions
diff --git a/include/hw/xen/interface/io/ring.h b/include/hw/xen/interface/io/ring.h index c486c457e0..025939278b 100644 --- a/include/hw/xen/interface/io/ring.h +++ b/include/hw/xen/interface/io/ring.h @@ -1,26 +1,9 @@ +/* SPDX-License-Identifier: MIT */ /****************************************************************************** * ring.h * * Shared producer-consumer ring macros. * - * Permission is hereby granted, free of charge, to any person obtaining a copy - * of this software and associated documentation files (the "Software"), to - * deal in the Software without restriction, including without limitation the - * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or - * sell copies of the Software, and to permit persons to whom the Software is - * furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE - * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER - * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING - * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER - * DEALINGS IN THE SOFTWARE. - * * Tim Deegan and Andrew Warfield November 2004. */ @@ -95,9 +78,8 @@ typedef unsigned int RING_IDX; * of the shared memory area (PAGE_SIZE, for instance). To initialise * the front half: * - * mytag_front_ring_t front_ring; - * SHARED_RING_INIT((mytag_sring_t *)shared_page); - * FRONT_RING_INIT(&front_ring, (mytag_sring_t *)shared_page, PAGE_SIZE); + * mytag_front_ring_t ring; + * XEN_FRONT_RING_INIT(&ring, (mytag_sring_t *)shared_page, PAGE_SIZE); * * Initializing the back follows similarly (note that only the front * initializes the shared ring): @@ -184,6 +166,11 @@ typedef struct __name##_back_ring __name##_back_ring_t #define FRONT_RING_INIT(_r, _s, __size) FRONT_RING_ATTACH(_r, _s, 0, __size) +#define XEN_FRONT_RING_INIT(r, s, size) do { \ + SHARED_RING_INIT(s); \ + FRONT_RING_INIT(r, s, size); \ +} while (0) + #define BACK_RING_ATTACH(_r, _s, _i, __size) do { \ (_r)->rsp_prod_pvt = (_i); \ (_r)->req_cons = (_i); \ @@ -208,11 +195,11 @@ typedef struct __name##_back_ring __name##_back_ring_t (RING_FREE_REQUESTS(_r) == 0) /* Test if there are outstanding messages to be processed on a ring. */ -#define RING_HAS_UNCONSUMED_RESPONSES(_r) \ +#define XEN_RING_NR_UNCONSUMED_RESPONSES(_r) \ ((_r)->sring->rsp_prod - (_r)->rsp_cons) #ifdef __GNUC__ -#define RING_HAS_UNCONSUMED_REQUESTS(_r) ({ \ +#define XEN_RING_NR_UNCONSUMED_REQUESTS(_r) ({ \ unsigned int req = (_r)->sring->req_prod - (_r)->req_cons; \ unsigned int rsp = RING_SIZE(_r) - \ ((_r)->req_cons - (_r)->rsp_prod_pvt); \ @@ -220,13 +207,27 @@ typedef struct __name##_back_ring __name##_back_ring_t }) #else /* Same as above, but without the nice GCC ({ ... }) syntax. */ -#define RING_HAS_UNCONSUMED_REQUESTS(_r) \ +#define XEN_RING_NR_UNCONSUMED_REQUESTS(_r) \ ((((_r)->sring->req_prod - (_r)->req_cons) < \ (RING_SIZE(_r) - ((_r)->req_cons - (_r)->rsp_prod_pvt))) ? \ ((_r)->sring->req_prod - (_r)->req_cons) : \ (RING_SIZE(_r) - ((_r)->req_cons - (_r)->rsp_prod_pvt))) #endif +#ifdef XEN_RING_HAS_UNCONSUMED_IS_BOOL +/* + * These variants should only be used in case no caller is abusing them for + * obtaining the number of unconsumed responses/requests. + */ +#define RING_HAS_UNCONSUMED_RESPONSES(_r) \ + (!!XEN_RING_NR_UNCONSUMED_RESPONSES(_r)) +#define RING_HAS_UNCONSUMED_REQUESTS(_r) \ + (!!XEN_RING_NR_UNCONSUMED_REQUESTS(_r)) +#else +#define RING_HAS_UNCONSUMED_RESPONSES(_r) XEN_RING_NR_UNCONSUMED_RESPONSES(_r) +#define RING_HAS_UNCONSUMED_REQUESTS(_r) XEN_RING_NR_UNCONSUMED_REQUESTS(_r) +#endif + /* Direct access to individual ring elements, by index. */ #define RING_GET_REQUEST(_r, _idx) \ (&((_r)->sring->ring[((_idx) & (RING_SIZE(_r) - 1))].req)) |