diff options
Diffstat (limited to 'arch/x86/lguest/boot.c')
| -rw-r--r-- | arch/x86/lguest/boot.c | 45 |
1 files changed, 16 insertions, 29 deletions
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index 37b8c1d3e022..514f4d0d2bfa 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -179,7 +179,7 @@ static void lguest_end_context_switch(struct task_struct *next) paravirt_end_context_switch(next); } -/*G:033 +/*G:032 * After that diversion we return to our first native-instruction * replacements: four functions for interrupt control. * @@ -199,41 +199,28 @@ static unsigned long save_fl(void) { return lguest_data.irq_enabled; } -PV_CALLEE_SAVE_REGS_THUNK(save_fl); - -/* restore_flags() just sets the flags back to the value given. */ -static void restore_fl(unsigned long flags) -{ - lguest_data.irq_enabled = flags; - mb(); - /* Null hcall forces interrupt delivery now, if irq_pending is - * set to X86_EFLAGS_IF (ie. an interrupt is pending, and flags - * enables interrupts. */ - if (flags & lguest_data.irq_pending) - kvm_hypercall0(LHCALL_SEND_INTERRUPTS); -} -PV_CALLEE_SAVE_REGS_THUNK(restore_fl); /* Interrupts go off... */ static void irq_disable(void) { lguest_data.irq_enabled = 0; } -PV_CALLEE_SAVE_REGS_THUNK(irq_disable); -/* Interrupts go on... */ -static void irq_enable(void) -{ - lguest_data.irq_enabled = X86_EFLAGS_IF; - mb(); - /* Null hcall forces interrupt delivery now. */ - if (lguest_data.irq_pending) - kvm_hypercall0(LHCALL_SEND_INTERRUPTS); +/* Let's pause a moment. Remember how I said these are called so often? + * Jeremy Fitzhardinge optimized them so hard early in 2009 that he had to + * break some rules. In particular, these functions are assumed to save their + * own registers if they need to: normal C functions assume they can trash the + * eax register. To use normal C functions, we use + * PV_CALLEE_SAVE_REGS_THUNK(), which pushes %eax onto the stack, calls the + * C function, then restores it. */ +PV_CALLEE_SAVE_REGS_THUNK(save_fl); +PV_CALLEE_SAVE_REGS_THUNK(irq_disable); +/*:*/ -} -PV_CALLEE_SAVE_REGS_THUNK(irq_enable); +/* These are in i386_head.S */ +extern void lg_irq_enable(void); +extern void lg_restore_fl(unsigned long flags); -/*:*/ /*M:003 Note that we don't check for outstanding interrupts when we re-enable * them (or when we unmask an interrupt). This seems to work for the moment, * since interrupts are rare and we'll just get the interrupt on the next timer @@ -1041,9 +1028,9 @@ __init void lguest_init(void) /* interrupt-related operations */ pv_irq_ops.init_IRQ = lguest_init_IRQ; pv_irq_ops.save_fl = PV_CALLEE_SAVE(save_fl); - pv_irq_ops.restore_fl = PV_CALLEE_SAVE(restore_fl); + pv_irq_ops.restore_fl = __PV_IS_CALLEE_SAVE(lg_restore_fl); pv_irq_ops.irq_disable = PV_CALLEE_SAVE(irq_disable); - pv_irq_ops.irq_enable = PV_CALLEE_SAVE(irq_enable); + pv_irq_ops.irq_enable = __PV_IS_CALLEE_SAVE(lg_irq_enable); pv_irq_ops.safe_halt = lguest_safe_halt; /* init-time operations */ |