提交 667c78af 编写于 作者: J Jeremy Fitzhardinge 提交者: Linus Torvalds

xen: Provide a variant of __RING_SIZE() that is an integer constant expression

Without this, gcc 4.5 won't compile xen-netfront and xen-blkfront, where
this is being used to specify array sizes.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: David Miller <davem@davemloft.net>
Cc: Stable Kernel <stable@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 6c965ff5
...@@ -72,7 +72,7 @@ struct blk_shadow { ...@@ -72,7 +72,7 @@ struct blk_shadow {
static DEFINE_MUTEX(blkfront_mutex); static DEFINE_MUTEX(blkfront_mutex);
static const struct block_device_operations xlvbd_block_fops; static const struct block_device_operations xlvbd_block_fops;
#define BLK_RING_SIZE __RING_SIZE((struct blkif_sring *)0, PAGE_SIZE) #define BLK_RING_SIZE __CONST_RING_SIZE(blkif, PAGE_SIZE)
/* /*
* We have one of these per vbd, whether ide, scsi or 'other'. They * We have one of these per vbd, whether ide, scsi or 'other'. They
......
...@@ -66,8 +66,8 @@ struct netfront_cb { ...@@ -66,8 +66,8 @@ struct netfront_cb {
#define GRANT_INVALID_REF 0 #define GRANT_INVALID_REF 0
#define NET_TX_RING_SIZE __RING_SIZE((struct xen_netif_tx_sring *)0, PAGE_SIZE) #define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
#define NET_RX_RING_SIZE __RING_SIZE((struct xen_netif_rx_sring *)0, PAGE_SIZE) #define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
#define TX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256) #define TX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
struct netfront_info { struct netfront_info {
......
...@@ -24,8 +24,15 @@ typedef unsigned int RING_IDX; ...@@ -24,8 +24,15 @@ typedef unsigned int RING_IDX;
* 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). * power of two (so we can mask with (size-1) to loop around).
*/ */
#define __RING_SIZE(_s, _sz) \ #define __CONST_RING_SIZE(_s, _sz) \
(__RD32(((_sz) - (long)&(_s)->ring + (long)(_s)) / sizeof((_s)->ring[0]))) (__RD32(((_sz) - offsetof(struct _s##_sring, ring)) / \
sizeof(((struct _s##_sring *)0)->ring[0])))
/*
* The same for passing in an actual pointer instead of a name tag.
*/
#define __RING_SIZE(_s, _sz) \
(__RD32(((_sz) - (long)&(_s)->ring + (long)(_s)) / sizeof((_s)->ring[0])))
/* /*
* Macros to make the correct C datatypes for a new kind of ring. * Macros to make the correct C datatypes for a new kind of ring.
......
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