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| author | Ian Campbell <ian.campbell@citrix.com> | 2013-02-20 15:48:06 +0400 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-02-20 17:45:07 +0400 |
| commit | c81611c4e96f595a80d8be9367c385d2c116428b (patch) | |
| tree | 94c1b31034506d8b73b6d9b2c2e0e2331d0fd450 /arch/arm/include | |
| parent | 76eaca031f0af2bb303e405986f637811956a422 (diff) | |
| download | linux-c81611c4e96f595a80d8be9367c385d2c116428b.tar.xz | |
xen: event channel arrays are xen_ulong_t and not unsigned long
On ARM we want these to be the same size on 32- and 64-bit.
This is an ABI change on ARM. X86 does not change.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Keir (Xen.org) <keir@xen.org>
Cc: Tim Deegan <tim@xen.org>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: xen-devel@lists.xen.org
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'arch/arm/include')
| -rw-r--r-- | arch/arm/include/asm/xen/events.h | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/arm/include/asm/xen/events.h b/arch/arm/include/asm/xen/events.h index 94b4e9020b02..5c27696de14f 100644 --- a/arch/arm/include/asm/xen/events.h +++ b/arch/arm/include/asm/xen/events.h @@ -15,4 +15,26 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) return raw_irqs_disabled_flags(regs->ARM_cpsr); } +/* + * We cannot use xchg because it does not support 8-byte + * values. However it is safe to use {ldr,dtd}exd directly because all + * platforms which Xen can run on support those instructions. + */ +static inline xen_ulong_t xchg_xen_ulong(xen_ulong_t *ptr, xen_ulong_t val) +{ + xen_ulong_t oldval; + unsigned int tmp; + + wmb(); + asm volatile("@ xchg_xen_ulong\n" + "1: ldrexd %0, %H0, [%3]\n" + " strexd %1, %2, %H2, [%3]\n" + " teq %1, #0\n" + " bne 1b" + : "=&r" (oldval), "=&r" (tmp) + : "r" (val), "r" (ptr) + : "memory", "cc"); + return oldval; +} + #endif /* _ASM_ARM_XEN_EVENTS_H */ |