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include: import Xen public headers to hw/xen/interface

Browse source 
There's already a partial set here; update them and pull in a more
complete set.

To start with, define __XEN_TOOLS__ in hw/xen/xen.h to ensure that any
internal definitions needed by Xen toolstack libraries are present
regardless of the order in which the headers are included. A reckoning
will come later, once we make the PV backends work in emulation and
untangle the headers for Xen-native vs. generic parts.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
[dwmw2: Update to Xen public headers from 4.16.2 release, add some in io/,
        define __XEN_TOOLS__ in hw/xen/xen.h, move to hw/xen/interface/]
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Paul Durrant <paul@xen.org>
This commit is contained in:
Joao Martins 2019-02-13 12:29:47 -05:00 • committed by David Woodhouse
parent 6276340310
commit 50c88402ca
28 changed files with 7134 additions and 136 deletions
Download patch file Download diff file Expand all files Collapse all files

99
include/hw/xen/interface/io/ring.h
View file

@ -1,6 +1,6 @@
/******************************************************************************
* ring.h
*
*
* Shared producer-consumer ring macros.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
@ -33,13 +33,6 @@
* - standard integers types (uint8_t, uint16_t, etc)
* They are provided by stdint.h of the standard headers.
*
* Before using the different macros, you need to provide the following
* macros:
* - xen_mb() a memory barrier
* - xen_rmb() a read memory barrier
* - xen_wmb() a write memory barrier
* Example of those can be found in xenctrl.h.
*
* In addition, if you intend to use the FLEX macros, you also need to
* provide the following, before invoking the FLEX macros:
* - size_t
@ -49,6 +42,14 @@
* and grant_table.h from the Xen public headers.
*/
#include "../xen-compat.h"
#if __XEN_INTERFACE_VERSION__ < 0x00030208
#define xen_mb() mb()
#define xen_rmb() rmb()
#define xen_wmb() wmb()
#endif
typedef unsigned int RING_IDX;
/* Round a 32-bit unsigned constant down to the nearest power of two. */
@ -61,12 +62,12 @@ typedef unsigned int RING_IDX;
/*
* Calculate size of a shared ring, given the total available space for the
* ring and indexes (_sz), and the name tag of the request/response structure.
* A ring contains as many entries as will fit, rounded down to the nearest
* A ring contains as many entries as will fit, rounded down to the nearest
* power of two (so we can mask with (size-1) to loop around).
*/
#define __CONST_RING_SIZE(_s, _sz) \
(__RD32(((_sz) - offsetof(struct _s##_sring, ring)) / \
sizeof_field(struct _s##_sring, ring[0])))
sizeof(((struct _s##_sring *)0)->ring[0])))
/*
* The same for passing in an actual pointer instead of a name tag.
*/
@ -75,7 +76,7 @@ typedef unsigned int RING_IDX;
/*
* Macros to make the correct C datatypes for a new kind of ring.
*
*
* To make a new ring datatype, you need to have two message structures,
* let's say request_t, and response_t already defined.
*
@ -85,7 +86,7 @@ typedef unsigned int RING_IDX;
*
* These expand out to give you a set of types, as you can see below.
* The most important of these are:
*
*
* mytag_sring_t - The shared ring.
* mytag_front_ring_t - The 'front' half of the ring.
* mytag_back_ring_t - The 'back' half of the ring.
@ -153,15 +154,15 @@ typedef struct __name##_back_ring __name##_back_ring_t
/*
* Macros for manipulating rings.
*
* FRONT_RING_whatever works on the "front end" of a ring: here
*
* FRONT_RING_whatever works on the "front end" of a ring: here
* requests are pushed on to the ring and responses taken off it.
*
* BACK_RING_whatever works on the "back end" of a ring: here
*
* BACK_RING_whatever works on the "back end" of a ring: here
* requests are taken off the ring and responses put on.
*
* N.B. these macros do NO INTERLOCKS OR FLOW CONTROL.
* This is OK in 1-for-1 request-response situations where the
*
* N.B. these macros do NO INTERLOCKS OR FLOW CONTROL.
* This is OK in 1-for-1 request-response situations where the
* requestor (front end) never has more than RING_SIZE()-1
* outstanding requests.
*/
@ -174,20 +175,24 @@ typedef struct __name##_back_ring __name##_back_ring_t
(void)memset((_s)->__pad, 0, sizeof((_s)->__pad)); \
} while(0)
#define FRONT_RING_INIT(_r, _s, __size) do { \
(_r)->req_prod_pvt = 0; \
(_r)->rsp_cons = 0; \
#define FRONT_RING_ATTACH(_r, _s, _i, __size) do { \
(_r)->req_prod_pvt = (_i); \
(_r)->rsp_cons = (_i); \
(_r)->nr_ents = __RING_SIZE(_s, __size); \
(_r)->sring = (_s); \
} while (0)
#define BACK_RING_INIT(_r, _s, __size) do { \
(_r)->rsp_prod_pvt = 0; \
(_r)->req_cons = 0; \
#define FRONT_RING_INIT(_r, _s, __size) FRONT_RING_ATTACH(_r, _s, 0, __size)
#define BACK_RING_ATTACH(_r, _s, _i, __size) do { \
(_r)->rsp_prod_pvt = (_i); \
(_r)->req_cons = (_i); \
(_r)->nr_ents = __RING_SIZE(_s, __size); \
(_r)->sring = (_s); \
} while (0)
#define BACK_RING_INIT(_r, _s, __size) BACK_RING_ATTACH(_r, _s, 0, __size)
/* How big is this ring? */
#define RING_SIZE(_r) \
((_r)->nr_ents)
@ -206,33 +211,45 @@ typedef struct __name##_back_ring __name##_back_ring_t
#define RING_HAS_UNCONSUMED_RESPONSES(_r) \
((_r)->sring->rsp_prod - (_r)->rsp_cons)
#ifdef __GNUC__
#define RING_HAS_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); \
req < rsp ? req : rsp; \
})
#else
/* Same as above, but without the nice GCC ({ ... }) syntax. */
#define RING_HAS_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
/* Direct access to individual ring elements, by index. */
#define RING_GET_REQUEST(_r, _idx) \
(&((_r)->sring->ring[((_idx) & (RING_SIZE(_r) - 1))].req))
#define RING_GET_RESPONSE(_r, _idx) \
(&((_r)->sring->ring[((_idx) & (RING_SIZE(_r) - 1))].rsp))
/*
* Get a local copy of a request.
* Get a local copy of a request/response.
*
* Use this in preference to RING_GET_REQUEST() so all processing is
* Use this in preference to RING_GET_{REQUEST,RESPONSE}() so all processing is
* done on a local copy that cannot be modified by the other end.
*
* Note that https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145 may cause this
* to be ineffective where _req is a struct which consists of only bitfields.
* to be ineffective where dest is a struct which consists of only bitfields.
*/
#define RING_COPY_REQUEST(_r, _idx, _req) do { \
/* Use volatile to force the copy into _req. */ \
*(_req) = *(volatile typeof(_req))RING_GET_REQUEST(_r, _idx); \
#define RING_COPY_(type, r, idx, dest) do { \
/* Use volatile to force the copy into dest. */ \
*(dest) = *(volatile __typeof__(dest))RING_GET_##type(r, idx); \
} while (0)
#define RING_GET_RESPONSE(_r, _idx) \
(&((_r)->sring->ring[((_idx) & (RING_SIZE(_r) - 1))].rsp))
#define RING_COPY_REQUEST(r, idx, req) RING_COPY_(REQUEST, r, idx, req)
#define RING_COPY_RESPONSE(r, idx, rsp) RING_COPY_(RESPONSE, r, idx, rsp)
/* Loop termination condition: Would the specified index overflow the ring? */
#define RING_REQUEST_CONS_OVERFLOW(_r, _cons) \
@ -242,6 +259,10 @@ typedef struct __name##_back_ring __name##_back_ring_t
#define RING_REQUEST_PROD_OVERFLOW(_r, _prod) \
(((_prod) - (_r)->rsp_prod_pvt) > RING_SIZE(_r))
/* Ill-behaved backend determination: Can there be this many responses? */
#define RING_RESPONSE_PROD_OVERFLOW(_r, _prod) \
(((_prod) - (_r)->rsp_cons) > RING_SIZE(_r))
#define RING_PUSH_REQUESTS(_r) do { \
xen_wmb(); /* back sees requests /before/ updated producer index */ \
(_r)->sring->req_prod = (_r)->req_prod_pvt; \
@ -254,26 +275,26 @@ typedef struct __name##_back_ring __name##_back_ring_t
/*
* Notification hold-off (req_event and rsp_event):
*
*
* When queueing requests or responses on a shared ring, it may not always be
* necessary to notify the remote end. For example, if requests are in flight
* in a backend, the front may be able to queue further requests without
* notifying the back (if the back checks for new requests when it queues
* responses).
*
*
* When enqueuing requests or responses:
*
*
* Use RING_PUSH_{REQUESTS,RESPONSES}_AND_CHECK_NOTIFY(). The second argument
* is a boolean return value. True indicates that the receiver requires an
* asynchronous notification.
*
*
* After dequeuing requests or responses (before sleeping the connection):
*
*
* Use RING_FINAL_CHECK_FOR_REQUESTS() or RING_FINAL_CHECK_FOR_RESPONSES().
* The second argument is a boolean return value. True indicates that there
* are pending messages on the ring (i.e., the connection should not be put
* to sleep).
*
*
* These macros will set the req_event/rsp_event field to trigger a
* notification on the very next message that is enqueued. If you want to
* create batches of work (i.e., only receive a notification after several