diff options
Diffstat (limited to 'arch/x86/xen')
| -rw-r--r-- | arch/x86/xen/enlighten.c | 3 | ||||
| -rw-r--r-- | arch/x86/xen/spinlock.c | 64 | ||||
| -rw-r--r-- | arch/x86/xen/xen-asm_64.S | 28 | ||||
| -rw-r--r-- | arch/x86/xen/xen-ops.h | 2 |
4 files changed, 71 insertions, 26 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 53233a9beea9..a8f57a94785a 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1181,10 +1181,11 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = { .read_tscp = native_read_tscp, .iret = xen_iret, - .irq_enable_sysexit = xen_sysexit, #ifdef CONFIG_X86_64 .usergs_sysret32 = xen_sysret32, .usergs_sysret64 = xen_sysret64, +#else + .irq_enable_sysexit = xen_sysexit, #endif .load_tr_desc = paravirt_nop, diff --git a/arch/x86/xen/spinlock.c b/arch/x86/xen/spinlock.c index 956374c1edbc..9e2ba5c6e1dd 100644 --- a/arch/x86/xen/spinlock.c +++ b/arch/x86/xen/spinlock.c @@ -17,6 +17,56 @@ #include "xen-ops.h" #include "debugfs.h" +static DEFINE_PER_CPU(int, lock_kicker_irq) = -1; +static DEFINE_PER_CPU(char *, irq_name); +static bool xen_pvspin = true; + +#ifdef CONFIG_QUEUED_SPINLOCKS + +#include <asm/qspinlock.h> + +static void xen_qlock_kick(int cpu) +{ + xen_send_IPI_one(cpu, XEN_SPIN_UNLOCK_VECTOR); +} + +/* + * Halt the current CPU & release it back to the host + */ +static void xen_qlock_wait(u8 *byte, u8 val) +{ + int irq = __this_cpu_read(lock_kicker_irq); + + /* If kicker interrupts not initialized yet, just spin */ + if (irq == -1) + return; + + /* clear pending */ + xen_clear_irq_pending(irq); + barrier(); + + /* + * We check the byte value after clearing pending IRQ to make sure + * that we won't miss a wakeup event because of the clearing. + * + * The sync_clear_bit() call in xen_clear_irq_pending() is atomic. + * So it is effectively a memory barrier for x86. + */ + if (READ_ONCE(*byte) != val) + return; + + /* + * If an interrupt happens here, it will leave the wakeup irq + * pending, which will cause xen_poll_irq() to return + * immediately. + */ + + /* Block until irq becomes pending (or perhaps a spurious wakeup) */ + xen_poll_irq(irq); +} + +#else /* CONFIG_QUEUED_SPINLOCKS */ + enum xen_contention_stat { TAKEN_SLOW, TAKEN_SLOW_PICKUP, @@ -100,12 +150,9 @@ struct xen_lock_waiting { __ticket_t want; }; -static DEFINE_PER_CPU(int, lock_kicker_irq) = -1; -static DEFINE_PER_CPU(char *, irq_name); static DEFINE_PER_CPU(struct xen_lock_waiting, lock_waiting); static cpumask_t waiting_cpus; -static bool xen_pvspin = true; __visible void xen_lock_spinning(struct arch_spinlock *lock, __ticket_t want) { int irq = __this_cpu_read(lock_kicker_irq); @@ -217,6 +264,7 @@ static void xen_unlock_kick(struct arch_spinlock *lock, __ticket_t next) } } } +#endif /* CONFIG_QUEUED_SPINLOCKS */ static irqreturn_t dummy_handler(int irq, void *dev_id) { @@ -280,8 +328,16 @@ void __init xen_init_spinlocks(void) return; } printk(KERN_DEBUG "xen: PV spinlocks enabled\n"); +#ifdef CONFIG_QUEUED_SPINLOCKS + __pv_init_lock_hash(); + pv_lock_ops.queued_spin_lock_slowpath = __pv_queued_spin_lock_slowpath; + pv_lock_ops.queued_spin_unlock = PV_CALLEE_SAVE(__pv_queued_spin_unlock); + pv_lock_ops.wait = xen_qlock_wait; + pv_lock_ops.kick = xen_qlock_kick; +#else pv_lock_ops.lock_spinning = PV_CALLEE_SAVE(xen_lock_spinning); pv_lock_ops.unlock_kick = xen_unlock_kick; +#endif } /* @@ -310,7 +366,7 @@ static __init int xen_parse_nopvspin(char *arg) } early_param("xen_nopvspin", xen_parse_nopvspin); -#ifdef CONFIG_XEN_DEBUG_FS +#if defined(CONFIG_XEN_DEBUG_FS) && !defined(CONFIG_QUEUED_SPINLOCKS) static struct dentry *d_spin_debug; diff --git a/arch/x86/xen/xen-asm_64.S b/arch/x86/xen/xen-asm_64.S index 985fc3ee0973..f22667abf7b9 100644 --- a/arch/x86/xen/xen-asm_64.S +++ b/arch/x86/xen/xen-asm_64.S @@ -15,6 +15,8 @@ #include <asm/percpu.h> #include <asm/processor-flags.h> #include <asm/segment.h> +#include <asm/asm-offsets.h> +#include <asm/thread_info.h> #include <xen/interface/xen.h> @@ -47,29 +49,13 @@ ENTRY(xen_iret) ENDPATCH(xen_iret) RELOC(xen_iret, 1b+1) -/* - * sysexit is not used for 64-bit processes, so it's only ever used to - * return to 32-bit compat userspace. - */ -ENTRY(xen_sysexit) - pushq $__USER32_DS - pushq %rcx - pushq $X86_EFLAGS_IF - pushq $__USER32_CS - pushq %rdx - - pushq $0 -1: jmp hypercall_iret -ENDPATCH(xen_sysexit) -RELOC(xen_sysexit, 1b+1) - ENTRY(xen_sysret64) /* * We're already on the usermode stack at this point, but * still with the kernel gs, so we can easily switch back */ movq %rsp, PER_CPU_VAR(rsp_scratch) - movq PER_CPU_VAR(kernel_stack), %rsp + movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp pushq $__USER_DS pushq PER_CPU_VAR(rsp_scratch) @@ -88,7 +74,7 @@ ENTRY(xen_sysret32) * still with the kernel gs, so we can easily switch back */ movq %rsp, PER_CPU_VAR(rsp_scratch) - movq PER_CPU_VAR(kernel_stack), %rsp + movq PER_CPU_VAR(cpu_current_top_of_stack), %rsp pushq $__USER32_DS pushq PER_CPU_VAR(rsp_scratch) @@ -128,7 +114,7 @@ RELOC(xen_sysret32, 1b+1) /* Normal 64-bit system call target */ ENTRY(xen_syscall_target) undo_xen_syscall - jmp system_call_after_swapgs + jmp entry_SYSCALL_64_after_swapgs ENDPROC(xen_syscall_target) #ifdef CONFIG_IA32_EMULATION @@ -136,13 +122,13 @@ ENDPROC(xen_syscall_target) /* 32-bit compat syscall target */ ENTRY(xen_syscall32_target) undo_xen_syscall - jmp ia32_cstar_target + jmp entry_SYSCALL_compat ENDPROC(xen_syscall32_target) /* 32-bit compat sysenter target */ ENTRY(xen_sysenter_target) undo_xen_syscall - jmp ia32_sysenter_target + jmp entry_SYSENTER_compat ENDPROC(xen_sysenter_target) #else /* !CONFIG_IA32_EMULATION */ diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index 9e195c683549..c20fe29e65f4 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -134,7 +134,9 @@ DECL_ASM(void, xen_restore_fl_direct, unsigned long); /* These are not functions, and cannot be called normally */ __visible void xen_iret(void); +#ifdef CONFIG_X86_32 __visible void xen_sysexit(void); +#endif __visible void xen_sysret32(void); __visible void xen_sysret64(void); __visible void xen_adjust_exception_frame(void); |