OXIESEC PANEL

Name	Size	Modified	Perms
📁 ..	-	11/17/2022 06:42:15 AM	rwxr-xr-x
📄 Kbuild	568 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 arch_gicv3.h	9.05 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 arch_timer.h	2.48 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 arm-cci.h	1.05 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 asm-offsets.h	35 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 assembler.h	10.46 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 atomic.h	13.22 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 auxvec.h	29 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 bL_switcher.h	2.28 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 barrier.h	2.84 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 bitops.h	8.62 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 bitrev.h	451 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 bug.h	2.46 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 bugs.h	546 bytes	11/01/2022 04:52:05 PM	rw-r--r--
📄 cache.h	813 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 cacheflush.h	15.54 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 cachetype.h	2.71 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 checksum.h	3.71 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 clocksource.h	153 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 cmpxchg.h	6.14 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 compiler.h	978 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 cp15.h	3.84 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 cpu.h	533 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 cpufeature.h	1.4 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 cpuidle.h	1.33 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 cputype.h	8.42 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 cti.h	3.62 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 dcc.h	1.01 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 delay.h	2.83 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 device.h	771 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 div64.h	3.17 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 dma-contiguous.h	265 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 dma-iommu.h	1.01 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 dma-mapping.h	7.44 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 dma.h	4.18 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 dmi.h	528 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 domain.h	3.65 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 ecard.h	5.98 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 edac.h	1.51 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 efi.h	3.04 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 elf.h	4.52 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 entry-macro-multi.S	726 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 exception.h	571 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 fb.h	375 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 fiq.h	1.36 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 firmware.h	1.82 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 fixmap.h	1.84 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 flat.h	915 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 floppy.h	3.61 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 fncpy.h	3.08 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 fpstate.h	1.73 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 ftrace.h	1.92 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 futex.h	4.24 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 glue-cache.h	3.51 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 glue-df.h	2.2 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 glue-pf.h	1.12 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 glue-proc.h	4.46 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 glue.h	759 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 gpio.h	693 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 hardirq.h	803 bytes	11/01/2022 04:52:05 PM	rw-r--r--
📁 hardware	-	11/17/2022 06:42:18 AM	rwxr-xr-x
📄 highmem.h	2.15 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 hugetlb-3level.h	2.03 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 hugetlb.h	1.78 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 hw_breakpoint.h	3.53 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 hw_irq.h	349 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 hwcap.h	378 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 hypervisor.h	140 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 ide.h	566 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 idmap.h	355 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 insn.h	636 bytes	11/01/2022 04:52:05 PM	rw-r--r--
📄 io.h	15.96 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 irq.h	1015 bytes	11/01/2022 04:52:05 PM	rw-r--r--
📄 irq_work.h	234 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 irqflags.h	3.88 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 jump_label.h	1009 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 kexec-internal.h	272 bytes	11/01/2022 04:52:05 PM	rw-r--r--
📄 kexec.h	2.3 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 kgdb.h	2.72 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 kmap_types.h	190 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 kprobes.h	2.65 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 kvm_arm.h	7.6 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 kvm_asm.h	2.84 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 kvm_coproc.h	1.99 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 kvm_emulate.h	7.84 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 kvm_host.h	10.31 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 kvm_hyp.h	4.49 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 kvm_mmio.h	1.34 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 kvm_mmu.h	7.27 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 limits.h	166 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 linkage.h	216 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📁 mach	-	11/17/2022 06:42:18 AM	rwxr-xr-x
📄 mc146818rtc.h	720 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 mcpm.h	11.92 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 mcs_spinlock.h	570 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 memblock.h	248 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 memory.h	10.12 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 mmu.h	953 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 mmu_context.h	3.94 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 module.h	1.57 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 mpu.h	2.15 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 mtd-xip.h	666 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 neon.h	1.16 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 nwflash.h	252 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 opcodes-sec.h	742 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 opcodes-virt.h	1.32 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 opcodes.h	8.07 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 outercache.h	3.78 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 page-nommu.h	957 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 page.h	3.61 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 paravirt.h	454 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 patch.h	438 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 pci.h	956 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 percpu.h	1.56 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 perf_event.h	850 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 pgalloc.h	3.79 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 pgtable-2level-hwdef.h	3.45 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 pgtable-2level-types.h	1.84 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 pgtable-2level.h	8.51 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 pgtable-3level-hwdef.h	3.95 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 pgtable-3level-types.h	1.89 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 pgtable-3level.h	9.54 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 pgtable-hwdef.h	467 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 pgtable-nommu.h	2.66 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 pgtable.h	11.68 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 probes.h	1.73 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 proc-fns.h	4.79 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 processor.h	3.4 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 procinfo.h	1.27 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 prom.h	715 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 psci.h	771 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 ptrace.h	4.89 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 sections.h	189 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 set_memory.h	1.04 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 setup.h	934 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 shmparam.h	419 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 signal.h	500 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 smp.h	3.1 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 smp_plat.h	2.48 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 smp_scu.h	1.32 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 smp_twd.h	908 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 sparsemem.h	716 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 spectre.h	906 bytes	11/01/2022 04:52:05 PM	rw-r--r--
📄 spinlock.h	5.49 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 spinlock_types.h	541 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 stackprotector.h	1.09 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 stacktrace.h	742 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 stage2_pgtable.h	2.12 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 string.h	1.43 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 suspend.h	369 bytes	11/01/2022 04:52:05 PM	rw-r--r--
📄 swab.h	1005 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 switch_to.h	1.03 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 sync_bitops.h	1.03 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 syscall.h	2.48 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 system_info.h	763 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 system_misc.h	1.14 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 tcm.h	937 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 therm.h	655 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 thread_info.h	5.2 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 thread_notify.h	1.2 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 timex.h	577 bytes	11/01/2022 04:52:05 PM	rw-r--r--
📄 tlb.h	7.37 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 tlbflush.h	17.88 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 tls.h	3.09 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 topology.h	1.18 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 traps.h	1.17 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 trusted_foundations.h	2.29 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 uaccess-asm.h	2.83 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 uaccess.h	16.22 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 ucontext.h	2.98 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 unaligned.h	846 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 unified.h	1.61 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 unistd.h	1.68 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 unwind.h	1.71 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 uprobes.h	1.07 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 user.h	4.2 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 v7m.h	2.93 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 vdso.h	507 bytes	11/01/2022 04:52:05 PM	rw-r--r--
📄 vdso_datapage.h	1.69 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 vfp.h	2.86 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 vfpmacros.h	2.1 KB	11/01/2022 04:52:05 PM	rw-r--r--
📄 vga.h	305 bytes	01/28/2018 09:20:33 PM	rw-r--r--
📄 virt.h	2.9 KB	01/28/2018 09:20:33 PM	rw-r--r--
📄 word-at-a-time.h	2.08 KB	01/28/2018 09:20:33 PM	rw-r--r--
📁 xen	-	11/17/2022 06:42:18 AM	rwxr-xr-x
📄 xor.h	5.22 KB	01/28/2018 09:20:33 PM	rw-r--r--

Editing: spinlock.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_SPINLOCK_H
#define __ASM_SPINLOCK_H

#if __LINUX_ARM_ARCH__ < 6
#error SMP not supported on pre-ARMv6 CPUs
#endif

#include <linux/prefetch.h>
#include <asm/barrier.h>
#include <asm/processor.h>

/*
 * sev and wfe are ARMv6K extensions.  Uniprocessor ARMv6 may not have the K
 * extensions, so when running on UP, we have to patch these instructions away.
 */
#ifdef CONFIG_THUMB2_KERNEL
/*
 * For Thumb-2, special care is needed to ensure that the conditional WFE
 * instruction really does assemble to exactly 4 bytes (as required by
 * the SMP_ON_UP fixup code).   By itself "wfene" might cause the
 * assembler to insert a extra (16-bit) IT instruction, depending on the
 * presence or absence of neighbouring conditional instructions.
 *
 * To avoid this unpredictableness, an approprite IT is inserted explicitly:
 * the assembler won't change IT instructions which are explicitly present
 * in the input.
 */
#define WFE(cond)	__ALT_SMP_ASM(		\
	"it " cond "\n\t"			\
	"wfe" cond ".n",			\
						\
	"nop.w"					\
)
#else
#define WFE(cond)	__ALT_SMP_ASM("wfe" cond, "nop")
#endif

#define SEV		__ALT_SMP_ASM(WASM(sev), WASM(nop))

static inline void dsb_sev(void)
{

dsb(ishst);
	__asm__(SEV);
}

/*
 * ARMv6 ticket-based spin-locking.
 *
 * A memory barrier is required after we get a lock, and before we
 * release it, because V6 CPUs are assumed to have weakly ordered
 * memory.
 */

static inline void arch_spin_lock(arch_spinlock_t *lock)
{
	unsigned long tmp;
	u32 newval;
	arch_spinlock_t lockval;

prefetchw(&lock->slock);
	__asm__ __volatile__(
"1:	ldrex	%0, [%3]\n"
"	add	%1, %0, %4\n"
"	strex	%2, %1, [%3]\n"
"	teq	%2, #0\n"
"	bne	1b"
	: "=&r" (lockval), "=&r" (newval), "=&r" (tmp)
	: "r" (&lock->slock), "I" (1 << TICKET_SHIFT)
	: "cc");

while (lockval.tickets.next != lockval.tickets.owner) {
		wfe();
		lockval.tickets.owner = READ_ONCE(lock->tickets.owner);
	}

smp_mb();
}

static inline int arch_spin_trylock(arch_spinlock_t *lock)
{
	unsigned long contended, res;
	u32 slock;

prefetchw(&lock->slock);
	do {
		__asm__ __volatile__(
		"	ldrex	%0, [%3]\n"
		"	mov	%2, #0\n"
		"	subs	%1, %0, %0, ror #16\n"
		"	addeq	%0, %0, %4\n"
		"	strexeq	%2, %0, [%3]"
		: "=&r" (slock), "=&r" (contended), "=&r" (res)
		: "r" (&lock->slock), "I" (1 << TICKET_SHIFT)
		: "cc");
	} while (res);

if (!contended) {
		smp_mb();
		return 1;
	} else {
		return 0;
	}
}

static inline void arch_spin_unlock(arch_spinlock_t *lock)
{
	smp_mb();
	lock->tickets.owner++;
	dsb_sev();
}

static inline int arch_spin_value_unlocked(arch_spinlock_t lock)
{
	return lock.tickets.owner == lock.tickets.next;
}

static inline int arch_spin_is_locked(arch_spinlock_t *lock)
{
	return !arch_spin_value_unlocked(READ_ONCE(*lock));
}

static inline int arch_spin_is_contended(arch_spinlock_t *lock)
{
	struct __raw_tickets tickets = READ_ONCE(lock->tickets);
	return (tickets.next - tickets.owner) > 1;
}
#define arch_spin_is_contended	arch_spin_is_contended

/*
 * RWLOCKS
 *
 *
 * Write locks are easy - we just set bit 31.  When unlocking, we can
 * just write zero since the lock is exclusively held.
 */

static inline void arch_write_lock(arch_rwlock_t *rw)
{
	unsigned long tmp;

prefetchw(&rw->lock);
	__asm__ __volatile__(
"1:	ldrex	%0, [%1]\n"
"	teq	%0, #0\n"
	WFE("ne")
"	strexeq	%0, %2, [%1]\n"
"	teq	%0, #0\n"
"	bne	1b"
	: "=&r" (tmp)
	: "r" (&rw->lock), "r" (0x80000000)
	: "cc");

smp_mb();
}

static inline int arch_write_trylock(arch_rwlock_t *rw)
{
	unsigned long contended, res;

prefetchw(&rw->lock);
	do {
		__asm__ __volatile__(
		"	ldrex	%0, [%2]\n"
		"	mov	%1, #0\n"
		"	teq	%0, #0\n"
		"	strexeq	%1, %3, [%2]"
		: "=&r" (contended), "=&r" (res)
		: "r" (&rw->lock), "r" (0x80000000)
		: "cc");
	} while (res);

if (!contended) {
		smp_mb();
		return 1;
	} else {
		return 0;
	}
}

static inline void arch_write_unlock(arch_rwlock_t *rw)
{
	smp_mb();

__asm__ __volatile__(
	"str	%1, [%0]\n"
	:
	: "r" (&rw->lock), "r" (0)
	: "cc");

dsb_sev();
}

/*
 * Read locks are a bit more hairy:
 *  - Exclusively load the lock value.
 *  - Increment it.
 *  - Store new lock value if positive, and we still own this location.
 *    If the value is negative, we've already failed.
 *  - If we failed to store the value, we want a negative result.
 *  - If we failed, try again.
 * Unlocking is similarly hairy.  We may have multiple read locks
 * currently active.  However, we know we won't have any write
 * locks.
 */
static inline void arch_read_lock(arch_rwlock_t *rw)
{
	unsigned long tmp, tmp2;

prefetchw(&rw->lock);
	__asm__ __volatile__(
"1:	ldrex	%0, [%2]\n"
"	adds	%0, %0, #1\n"
"	strexpl	%1, %0, [%2]\n"
	WFE("mi")
"	rsbpls	%0, %1, #0\n"
"	bmi	1b"
	: "=&r" (tmp), "=&r" (tmp2)
	: "r" (&rw->lock)
	: "cc");

smp_mb();
}

static inline void arch_read_unlock(arch_rwlock_t *rw)
{
	unsigned long tmp, tmp2;

smp_mb();

prefetchw(&rw->lock);
	__asm__ __volatile__(
"1:	ldrex	%0, [%2]\n"
"	sub	%0, %0, #1\n"
"	strex	%1, %0, [%2]\n"
"	teq	%1, #0\n"
"	bne	1b"
	: "=&r" (tmp), "=&r" (tmp2)
	: "r" (&rw->lock)
	: "cc");

if (tmp == 0)
		dsb_sev();
}

static inline int arch_read_trylock(arch_rwlock_t *rw)
{
	unsigned long contended, res;

prefetchw(&rw->lock);
	do {
		__asm__ __volatile__(
		"	ldrex	%0, [%2]\n"
		"	mov	%1, #0\n"
		"	adds	%0, %0, #1\n"
		"	strexpl	%1, %0, [%2]"
		: "=&r" (contended), "=&r" (res)
		: "r" (&rw->lock)
		: "cc");
	} while (res);

/* If the lock is negative, then it is already held for write. */
	if (contended < 0x80000000) {
		smp_mb();
		return 1;
	} else {
		return 0;
	}
}

#endif /* __ASM_SPINLOCK_H */