@@ -208,11 +208,11 @@ 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 +220,27 @@ 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))
Today RING_HAS_UNCONSUMED_*() macros are returning the number of unconsumed requests or responses instead of a boolean as the name of the macros would imply. As this "feature" is already being used, rename the macros to XEN_RING_NR_UNCONSUMED_*() and define the RING_HAS_UNCONSUMED_*() macros by using the new XEN_RING_NR_UNCONSUMED_*() macros. In order to avoid future misuse let RING_HAS_UNCONSUMED_*() optionally really return a boolean (can be activated by defining XEN_RING_HAS_UNCONSUMED_IS_BOOL). Note that the known misuses need to be switched to the new XEN_RING_NR_UNCONSUMED_*() macros when using the RING_HAS_UNCONSUMED_*() variants returning a boolean value. Cc: Roger Pau Monne <roger.pau@citrix.com> Cc: Manuel Bouyer <bouyer@antioche.eu.org> Cc: Simon Kuenzer <simon.kuenzer@neclab.eu> Cc: Paul Durrant <paul@xen.org> Signed-off-by: Juergen Gross <jgross@suse.com> --- V3: - add XEN_ prefix to new macros (Jan Beulich) --- xen/include/public/io/ring.h | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-)