^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /******************************************************************************
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * ring.h
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Shared producer-consumer ring macros.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Permission is hereby granted, free of charge, to any person obtaining a copy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * of this software and associated documentation files (the "Software"), to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * deal in the Software without restriction, including without limitation the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * sell copies of the Software, and to permit persons to whom the Software is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * furnished to do so, subject to the following conditions:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * The above copyright notice and this permission notice shall be included in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) * all copies or substantial portions of the Software.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * DEALINGS IN THE SOFTWARE.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) * Tim Deegan and Andrew Warfield November 2004.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #ifndef __XEN_PUBLIC_IO_RING_H__
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #define __XEN_PUBLIC_IO_RING_H__
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * When #include'ing this header, you need to provide the following
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) * declaration upfront:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * - standard integers types (uint8_t, uint16_t, etc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * They are provided by stdint.h of the standard headers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) * In addition, if you intend to use the FLEX macros, you also need to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) * provide the following, before invoking the FLEX macros:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) * - size_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) * - memcpy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * - grant_ref_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * These declarations are provided by string.h of the standard headers,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * and grant_table.h from the Xen public headers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) #include <xen/interface/grant_table.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) typedef unsigned int RING_IDX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) /* Round a 32-bit unsigned constant down to the nearest power of two. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) #define __RD2(_x) (((_x) & 0x00000002) ? 0x2 : ((_x) & 0x1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) #define __RD4(_x) (((_x) & 0x0000000c) ? __RD2((_x)>>2)<<2 : __RD2(_x))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) #define __RD8(_x) (((_x) & 0x000000f0) ? __RD4((_x)>>4)<<4 : __RD4(_x))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) #define __RD16(_x) (((_x) & 0x0000ff00) ? __RD8((_x)>>8)<<8 : __RD8(_x))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) #define __RD32(_x) (((_x) & 0xffff0000) ? __RD16((_x)>>16)<<16 : __RD16(_x))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * Calculate size of a shared ring, given the total available space for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * ring and indexes (_sz), and the name tag of the request/response structure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * A ring contains as many entries as will fit, rounded down to the nearest
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * power of two (so we can mask with (size-1) to loop around).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) #define __CONST_RING_SIZE(_s, _sz) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) (__RD32(((_sz) - offsetof(struct _s##_sring, ring)) / \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) sizeof(((struct _s##_sring *)0)->ring[0])))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) * The same for passing in an actual pointer instead of a name tag.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) #define __RING_SIZE(_s, _sz) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) (__RD32(((_sz) - (long)(_s)->ring + (long)(_s)) / sizeof((_s)->ring[0])))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) * Macros to make the correct C datatypes for a new kind of ring.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) * To make a new ring datatype, you need to have two message structures,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) * let's say request_t, and response_t already defined.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) * In a header where you want the ring datatype declared, you then do:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) * DEFINE_RING_TYPES(mytag, request_t, response_t);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * These expand out to give you a set of types, as you can see below.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) * The most important of these are:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * mytag_sring_t - The shared ring.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * mytag_front_ring_t - The 'front' half of the ring.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * mytag_back_ring_t - The 'back' half of the ring.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * To initialize a ring in your code you need to know the location and size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) * of the shared memory area (PAGE_SIZE, for instance). To initialise
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) * the front half:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) * mytag_front_ring_t front_ring;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) * SHARED_RING_INIT((mytag_sring_t *)shared_page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) * FRONT_RING_INIT(&front_ring, (mytag_sring_t *)shared_page, PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) * Initializing the back follows similarly (note that only the front
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * initializes the shared ring):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) * mytag_back_ring_t back_ring;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) * BACK_RING_INIT(&back_ring, (mytag_sring_t *)shared_page, PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) #define DEFINE_RING_TYPES(__name, __req_t, __rsp_t) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) /* Shared ring entry */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) union __name##_sring_entry { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) __req_t req; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) __rsp_t rsp; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) }; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) /* Shared ring page */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) struct __name##_sring { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) RING_IDX req_prod, req_event; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) RING_IDX rsp_prod, rsp_event; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) uint8_t __pad[48]; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) union __name##_sring_entry ring[1]; /* variable-length */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) }; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) /* "Front" end's private variables */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) struct __name##_front_ring { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) RING_IDX req_prod_pvt; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) RING_IDX rsp_cons; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) unsigned int nr_ents; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) struct __name##_sring *sring; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) }; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) /* "Back" end's private variables */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) struct __name##_back_ring { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) RING_IDX rsp_prod_pvt; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) RING_IDX req_cons; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) unsigned int nr_ents; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) struct __name##_sring *sring; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) }; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) * Macros for manipulating rings.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * FRONT_RING_whatever works on the "front end" of a ring: here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) * requests are pushed on to the ring and responses taken off it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) * BACK_RING_whatever works on the "back end" of a ring: here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) * requests are taken off the ring and responses put on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) * N.B. these macros do NO INTERLOCKS OR FLOW CONTROL.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) * This is OK in 1-for-1 request-response situations where the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) * requestor (front end) never has more than RING_SIZE()-1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) * outstanding requests.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) /* Initialising empty rings */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) #define SHARED_RING_INIT(_s) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) (_s)->req_prod = (_s)->rsp_prod = 0; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) (_s)->req_event = (_s)->rsp_event = 1; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) (void)memset((_s)->__pad, 0, sizeof((_s)->__pad)); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) } while(0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) #define FRONT_RING_ATTACH(_r, _s, _i, __size) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) (_r)->req_prod_pvt = (_i); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) (_r)->rsp_cons = (_i); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) (_r)->nr_ents = __RING_SIZE(_s, __size); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) (_r)->sring = (_s); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) #define FRONT_RING_INIT(_r, _s, __size) FRONT_RING_ATTACH(_r, _s, 0, __size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) #define BACK_RING_ATTACH(_r, _s, _i, __size) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) (_r)->rsp_prod_pvt = (_i); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) (_r)->req_cons = (_i); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) (_r)->nr_ents = __RING_SIZE(_s, __size); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) (_r)->sring = (_s); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) #define BACK_RING_INIT(_r, _s, __size) BACK_RING_ATTACH(_r, _s, 0, __size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) /* How big is this ring? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) #define RING_SIZE(_r) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) ((_r)->nr_ents)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) /* Number of free requests (for use on front side only). */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) #define RING_FREE_REQUESTS(_r) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) (RING_SIZE(_r) - ((_r)->req_prod_pvt - (_r)->rsp_cons))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) /* Test if there is an empty slot available on the front ring.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) * (This is only meaningful from the front. )
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) #define RING_FULL(_r) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) (RING_FREE_REQUESTS(_r) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) /* Test if there are outstanding messages to be processed on a ring. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) #define RING_HAS_UNCONSUMED_RESPONSES(_r) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) ((_r)->sring->rsp_prod - (_r)->rsp_cons)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) #define RING_HAS_UNCONSUMED_REQUESTS(_r) ({ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) unsigned int req = (_r)->sring->req_prod - (_r)->req_cons; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) unsigned int rsp = RING_SIZE(_r) - \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) ((_r)->req_cons - (_r)->rsp_prod_pvt); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) req < rsp ? req : rsp; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) })
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) /* Direct access to individual ring elements, by index. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) #define RING_GET_REQUEST(_r, _idx) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) (&((_r)->sring->ring[((_idx) & (RING_SIZE(_r) - 1))].req))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) #define RING_GET_RESPONSE(_r, _idx) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) (&((_r)->sring->ring[((_idx) & (RING_SIZE(_r) - 1))].rsp))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) * Get a local copy of a request/response.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) * Use this in preference to RING_GET_{REQUEST,RESPONSE}() so all processing is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) * done on a local copy that cannot be modified by the other end.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) * Note that https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145 may cause this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) * to be ineffective where dest is a struct which consists of only bitfields.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) #define RING_COPY_(type, r, idx, dest) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) /* Use volatile to force the copy into dest. */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) *(dest) = *(volatile typeof(dest))RING_GET_##type(r, idx); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) #define RING_COPY_REQUEST(r, idx, req) RING_COPY_(REQUEST, r, idx, req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) #define RING_COPY_RESPONSE(r, idx, rsp) RING_COPY_(RESPONSE, r, idx, rsp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) /* Loop termination condition: Would the specified index overflow the ring? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) #define RING_REQUEST_CONS_OVERFLOW(_r, _cons) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) (((_cons) - (_r)->rsp_prod_pvt) >= RING_SIZE(_r))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) /* Ill-behaved frontend determination: Can there be this many requests? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) #define RING_REQUEST_PROD_OVERFLOW(_r, _prod) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) (((_prod) - (_r)->rsp_prod_pvt) > RING_SIZE(_r))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) /* Ill-behaved backend determination: Can there be this many responses? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) #define RING_RESPONSE_PROD_OVERFLOW(_r, _prod) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) (((_prod) - (_r)->rsp_cons) > RING_SIZE(_r))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) #define RING_PUSH_REQUESTS(_r) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) virt_wmb(); /* back sees requests /before/ updated producer index */\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) (_r)->sring->req_prod = (_r)->req_prod_pvt; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) #define RING_PUSH_RESPONSES(_r) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) virt_wmb(); /* front sees resps /before/ updated producer index */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) (_r)->sring->rsp_prod = (_r)->rsp_prod_pvt; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) * Notification hold-off (req_event and rsp_event):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) * When queueing requests or responses on a shared ring, it may not always be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) * necessary to notify the remote end. For example, if requests are in flight
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) * in a backend, the front may be able to queue further requests without
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) * notifying the back (if the back checks for new requests when it queues
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) * responses).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) * When enqueuing requests or responses:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) * Use RING_PUSH_{REQUESTS,RESPONSES}_AND_CHECK_NOTIFY(). The second argument
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) * is a boolean return value. True indicates that the receiver requires an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) * asynchronous notification.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) * After dequeuing requests or responses (before sleeping the connection):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) * Use RING_FINAL_CHECK_FOR_REQUESTS() or RING_FINAL_CHECK_FOR_RESPONSES().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) * The second argument is a boolean return value. True indicates that there
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) * are pending messages on the ring (i.e., the connection should not be put
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) * to sleep).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) * These macros will set the req_event/rsp_event field to trigger a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) * notification on the very next message that is enqueued. If you want to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) * create batches of work (i.e., only receive a notification after several
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) * messages have been enqueued) then you will need to create a customised
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) * version of the FINAL_CHECK macro in your own code, which sets the event
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) * field appropriately.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) #define RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(_r, _notify) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) RING_IDX __old = (_r)->sring->req_prod; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) RING_IDX __new = (_r)->req_prod_pvt; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) virt_wmb(); /* back sees requests /before/ updated producer index */\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) (_r)->sring->req_prod = __new; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) virt_mb(); /* back sees new requests /before/ we check req_event */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) (_notify) = ((RING_IDX)(__new - (_r)->sring->req_event) < \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) (RING_IDX)(__new - __old)); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) #define RING_PUSH_RESPONSES_AND_CHECK_NOTIFY(_r, _notify) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) RING_IDX __old = (_r)->sring->rsp_prod; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) RING_IDX __new = (_r)->rsp_prod_pvt; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) virt_wmb(); /* front sees resps /before/ updated producer index */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) (_r)->sring->rsp_prod = __new; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) virt_mb(); /* front sees new resps /before/ we check rsp_event */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) (_notify) = ((RING_IDX)(__new - (_r)->sring->rsp_event) < \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) (RING_IDX)(__new - __old)); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) #define RING_FINAL_CHECK_FOR_REQUESTS(_r, _work_to_do) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) (_work_to_do) = RING_HAS_UNCONSUMED_REQUESTS(_r); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) if (_work_to_do) break; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) (_r)->sring->req_event = (_r)->req_cons + 1; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) virt_mb(); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) (_work_to_do) = RING_HAS_UNCONSUMED_REQUESTS(_r); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) #define RING_FINAL_CHECK_FOR_RESPONSES(_r, _work_to_do) do { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) (_work_to_do) = RING_HAS_UNCONSUMED_RESPONSES(_r); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) if (_work_to_do) break; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) (_r)->sring->rsp_event = (_r)->rsp_cons + 1; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) virt_mb(); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) (_work_to_do) = RING_HAS_UNCONSUMED_RESPONSES(_r); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) } while (0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) * DEFINE_XEN_FLEX_RING_AND_INTF defines two monodirectional rings and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) * functions to check if there is data on the ring, and to read and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) * write to them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) * DEFINE_XEN_FLEX_RING is similar to DEFINE_XEN_FLEX_RING_AND_INTF, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) * does not define the indexes page. As different protocols can have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) * extensions to the basic format, this macro allow them to define their
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) * own struct.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) * XEN_FLEX_RING_SIZE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) * Convenience macro to calculate the size of one of the two rings
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) * from the overall order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) * $NAME_mask
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) * Function to apply the size mask to an index, to reduce the index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) * within the range [0-size].
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) * $NAME_read_packet
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) * Function to read data from the ring. The amount of data to read is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) * specified by the "size" argument.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) * $NAME_write_packet
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) * Function to write data to the ring. The amount of data to write is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) * specified by the "size" argument.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) * $NAME_get_ring_ptr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) * Convenience function that returns a pointer to read/write to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) * ring at the right location.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) * $NAME_data_intf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) * Indexes page, shared between frontend and backend. It also
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) * contains the array of grant refs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) * $NAME_queued
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) * Function to calculate how many bytes are currently on the ring,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) * ready to be read. It can also be used to calculate how much free
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) * space is currently on the ring (XEN_FLEX_RING_SIZE() -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) * $NAME_queued()).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) #ifndef XEN_PAGE_SHIFT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) /* The PAGE_SIZE for ring protocols and hypercall interfaces is always
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) * 4K, regardless of the architecture, and page granularity chosen by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) * operating systems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) #define XEN_PAGE_SHIFT 12
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) #define XEN_FLEX_RING_SIZE(order) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) (1UL << ((order) + XEN_PAGE_SHIFT - 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) #define DEFINE_XEN_FLEX_RING(name) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) static inline RING_IDX name##_mask(RING_IDX idx, RING_IDX ring_size) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) return idx & (ring_size - 1); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) } \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) static inline unsigned char *name##_get_ring_ptr(unsigned char *buf, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) RING_IDX idx, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) RING_IDX ring_size) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) return buf + name##_mask(idx, ring_size); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) } \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) static inline void name##_read_packet(void *opaque, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) const unsigned char *buf, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) size_t size, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) RING_IDX masked_prod, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) RING_IDX *masked_cons, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) RING_IDX ring_size) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) if (*masked_cons < masked_prod || \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) size <= ring_size - *masked_cons) { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) memcpy(opaque, buf + *masked_cons, size); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) } else { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) memcpy(opaque, buf + *masked_cons, ring_size - *masked_cons); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) memcpy((unsigned char *)opaque + ring_size - *masked_cons, buf, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) size - (ring_size - *masked_cons)); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) } \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) *masked_cons = name##_mask(*masked_cons + size, ring_size); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) } \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) static inline void name##_write_packet(unsigned char *buf, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) const void *opaque, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) size_t size, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) RING_IDX *masked_prod, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) RING_IDX masked_cons, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) RING_IDX ring_size) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) if (*masked_prod < masked_cons || \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) size <= ring_size - *masked_prod) { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) memcpy(buf + *masked_prod, opaque, size); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) } else { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) memcpy(buf + *masked_prod, opaque, ring_size - *masked_prod); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) memcpy(buf, (unsigned char *)opaque + (ring_size - *masked_prod), \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) size - (ring_size - *masked_prod)); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) } \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) *masked_prod = name##_mask(*masked_prod + size, ring_size); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) } \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) static inline RING_IDX name##_queued(RING_IDX prod, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) RING_IDX cons, \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) RING_IDX ring_size) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) RING_IDX size; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) if (prod == cons) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) return 0; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) prod = name##_mask(prod, ring_size); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) cons = name##_mask(cons, ring_size); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) if (prod == cons) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) return ring_size; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) if (prod > cons) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) size = prod - cons; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) else \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) size = ring_size - (cons - prod); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) return size; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) } \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) struct name##_data { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) unsigned char *in; /* half of the allocation */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) unsigned char *out; /* half of the allocation */ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) #define DEFINE_XEN_FLEX_RING_AND_INTF(name) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) struct name##_data_intf { \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) RING_IDX in_cons, in_prod; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) uint8_t pad1[56]; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) RING_IDX out_cons, out_prod; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) uint8_t pad2[56]; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) RING_IDX ring_order; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) grant_ref_t ref[]; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) }; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) DEFINE_XEN_FLEX_RING(name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) #endif /* __XEN_PUBLIC_IO_RING_H__ */
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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