Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751680AbWEIIyw (ORCPT ); Tue, 9 May 2006 04:54:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751700AbWEIIyV (ORCPT ); Tue, 9 May 2006 04:54:21 -0400 Received: from 216-99-217-87.dsl.aracnet.com ([216.99.217.87]:58755 "EHLO sous-sol.org") by vger.kernel.org with ESMTP id S1751539AbWEIItU (ORCPT ); Tue, 9 May 2006 04:49:20 -0400 Message-Id: <20060509085154.095325000@sous-sol.org> References: <20060509084945.373541000@sous-sol.org> Date: Tue, 09 May 2006 00:00:15 -0700 From: Chris Wright To: linux-kernel@vger.kernel.org Cc: virtualization@lists.osdl.org, xen-devel@lists.xensource.com, Ian Pratt , Christian Limpach Subject: [RFC PATCH 15/35] subarch support for controlling interrupt delivery Content-Disposition: inline; filename=i386-interrupt-control Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6432 Lines: 182 Abstract the code that controls interrupt delivery, and add a separate subarch implementation for Xen that manipulates a shared-memory event delivery mask. Signed-off-by: Ian Pratt Signed-off-by: Christian Limpach Signed-off-by: Chris Wright --- include/asm-i386/mach-default/mach_system.h | 24 ++++++ include/asm-i386/mach-xen/mach_system.h | 103 ++++++++++++++++++++++++++++ include/asm-i386/system.h | 20 ----- 3 files changed, 128 insertions(+), 19 deletions(-) --- linus-2.6.orig/include/asm-i386/system.h +++ linus-2.6/include/asm-i386/system.h @@ -490,25 +490,7 @@ static inline unsigned long long __cmpxc #define set_wmb(var, value) do { var = value; wmb(); } while (0) -/* interrupt control.. */ -#define local_save_flags(x) do { typecheck(unsigned long,x); __asm__ __volatile__("pushfl ; popl %0":"=g" (x): /* no input */); } while (0) -#define local_irq_restore(x) do { typecheck(unsigned long,x); __asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"g" (x):"memory", "cc"); } while (0) -#define local_irq_disable() __asm__ __volatile__("cli": : :"memory") -#define local_irq_enable() __asm__ __volatile__("sti": : :"memory") -/* used in the idle loop; sti takes one instruction cycle to complete */ -#define safe_halt() __asm__ __volatile__("sti; hlt": : :"memory") -/* used when interrupts are already enabled or to shutdown the processor */ -#define halt() __asm__ __volatile__("hlt": : :"memory") - -#define irqs_disabled() \ -({ \ - unsigned long flags; \ - local_save_flags(flags); \ - !(flags & (1<<9)); \ -}) - -/* For spinlocks etc */ -#define local_irq_save(x) __asm__ __volatile__("pushfl ; popl %0 ; cli":"=g" (x): /* no input */ :"memory") +#include /* * disable hlt during certain critical i/o operations --- /dev/null +++ linus-2.6/include/asm-i386/mach-default/mach_system.h @@ -0,0 +1,24 @@ +#ifndef __ASM_MACH_SYSTEM_H +#define __ASM_MACH_SYSTEM_H + +/* interrupt control.. */ +#define local_save_flags(x) do { typecheck(unsigned long,x); __asm__ __volatile__("pushfl ; popl %0":"=g" (x): /* no input */); } while (0) +#define local_irq_restore(x) do { typecheck(unsigned long,x); __asm__ __volatile__("pushl %0 ; popfl": /* no output */ :"g" (x):"memory", "cc"); } while (0) +#define local_irq_disable() __asm__ __volatile__("cli": : :"memory") +#define local_irq_enable() __asm__ __volatile__("sti": : :"memory") +/* used in the idle loop; sti takes one instruction cycle to complete */ +#define safe_halt() __asm__ __volatile__("sti; hlt": : :"memory") +/* used when interrupts are already enabled or to shutdown the processor */ +#define halt() __asm__ __volatile__("hlt": : :"memory") + +#define irqs_disabled() \ +({ \ + unsigned long flags; \ + local_save_flags(flags); \ + !(flags & (1<<9)); \ +}) + +/* For spinlocks etc */ +#define local_irq_save(x) __asm__ __volatile__("pushfl ; popl %0 ; cli":"=g" (x): /* no input */ :"memory") + +#endif /* __ASM_MACH_SYSTEM_H */ --- /dev/null +++ linus-2.6/include/asm-i386/mach-xen/mach_system.h @@ -0,0 +1,103 @@ +#ifndef __ASM_MACH_SYSTEM_H +#define __ASM_MACH_SYSTEM_H + +#ifdef __KERNEL__ + +#include + +#ifdef CONFIG_SMP +#define __vcpu_id smp_processor_id() +#else +#define __vcpu_id 0 +#endif + +/* interrupt control.. */ + +/* + * The use of 'barrier' in the following reflects their use as local-lock + * operations. Reentrancy must be prevented (e.g., __cli()) /before/ following + * critical operations are executed. All critical operations must complete + * /before/ reentrancy is permitted (e.g., __sti()). Alpha architecture also + * includes these barriers, for example. + */ + +#define __cli() \ +do { \ + struct vcpu_info *_vcpu; \ + preempt_disable(); \ + _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id]; \ + _vcpu->evtchn_upcall_mask = 1; \ + preempt_enable_no_resched(); \ + barrier(); \ +} while (0) + +#define __sti() \ +do { \ + struct vcpu_info *_vcpu; \ + barrier(); \ + preempt_disable(); \ + _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id]; \ + _vcpu->evtchn_upcall_mask = 0; \ + barrier(); /* unmask then check (avoid races) */ \ + if (unlikely(_vcpu->evtchn_upcall_pending)) \ + force_evtchn_callback(); \ + preempt_enable(); \ +} while (0) + +#define __save_flags(x) \ +do { \ + struct vcpu_info *_vcpu; \ + preempt_disable(); \ + _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id]; \ + (x) = _vcpu->evtchn_upcall_mask; \ + preempt_enable(); \ +} while (0) + +#define __restore_flags(x) \ +do { \ + struct vcpu_info *_vcpu; \ + barrier(); \ + preempt_disable(); \ + _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id]; \ + if ((_vcpu->evtchn_upcall_mask = (x)) == 0) { \ + barrier(); /* unmask then check (avoid races) */ \ + if (unlikely(_vcpu->evtchn_upcall_pending)) \ + force_evtchn_callback(); \ + preempt_enable(); \ + } else \ + preempt_enable_no_resched(); \ +} while (0) + +#define safe_halt() ((void)0) +#define halt() ((void)0) + +#define __save_and_cli(x) \ +do { \ + struct vcpu_info *_vcpu; \ + preempt_disable(); \ + _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id]; \ + (x) = _vcpu->evtchn_upcall_mask; \ + _vcpu->evtchn_upcall_mask = 1; \ + preempt_enable_no_resched(); \ + barrier(); \ +} while (0) + +#define local_irq_save(x) __save_and_cli(x) +#define local_irq_restore(x) __restore_flags(x) +#define local_save_flags(x) __save_flags(x) +#define local_irq_disable() __cli() +#define local_irq_enable() __sti() + +/* Cannot use preempt_enable() here as we would recurse in preempt_sched(). */ +#define irqs_disabled() \ +({ int ___x; \ + struct vcpu_info *_vcpu; \ + preempt_disable(); \ + _vcpu = &HYPERVISOR_shared_info->vcpu_info[__vcpu_id]; \ + ___x = (_vcpu->evtchn_upcall_mask != 0); \ + preempt_enable_no_resched(); \ + ___x; }) + +#endif /* __KERNEL__ */ + +#endif /* __ASM_MACH_SYSTEM_H */ -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/