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	On arm64, there is no need to add 2 bytes of padding to the start of each network buffer just to make the IP header appear 32-bit aligned. Since this might actually adversely affect DMA performance some platforms, let's override NET_IP_ALIGN to 0 to get rid of this padding. Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Tested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
		
			
				
	
	
		
			289 lines
		
	
	
	
		
			7.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			289 lines
		
	
	
	
		
			7.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Based on arch/arm/include/asm/processor.h
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 *
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 * Copyright (C) 1995-1999 Russell King
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 * Copyright (C) 2012 ARM Ltd.
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 *
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 * This program is free software; you can redistribute it and/or modify
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 * it under the terms of the GNU General Public License version 2 as
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 * published by the Free Software Foundation.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 * GNU General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public License
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 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
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 */
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#ifndef __ASM_PROCESSOR_H
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#define __ASM_PROCESSOR_H
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#define TASK_SIZE_64		(UL(1) << VA_BITS)
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#define KERNEL_DS	UL(-1)
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#define USER_DS		(TASK_SIZE_64 - 1)
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/*
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 * On arm64 systems, unaligned accesses by the CPU are cheap, and so there is
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 * no point in shifting all network buffers by 2 bytes just to make some IP
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 * header fields appear aligned in memory, potentially sacrificing some DMA
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 * performance on some platforms.
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 */
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#define NET_IP_ALIGN	0
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#ifndef __ASSEMBLY__
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#ifdef __KERNEL__
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#include <linux/build_bug.h>
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#include <linux/cache.h>
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#include <linux/init.h>
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#include <linux/stddef.h>
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#include <linux/string.h>
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#include <asm/alternative.h>
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#include <asm/cpufeature.h>
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#include <asm/hw_breakpoint.h>
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#include <asm/lse.h>
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#include <asm/pgtable-hwdef.h>
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#include <asm/ptrace.h>
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#include <asm/types.h>
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/*
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 * TASK_SIZE - the maximum size of a user space task.
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 * TASK_UNMAPPED_BASE - the lower boundary of the mmap VM area.
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 */
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#ifdef CONFIG_COMPAT
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#define TASK_SIZE_32		UL(0x100000000)
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#define TASK_SIZE		(test_thread_flag(TIF_32BIT) ? \
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				TASK_SIZE_32 : TASK_SIZE_64)
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#define TASK_SIZE_OF(tsk)	(test_tsk_thread_flag(tsk, TIF_32BIT) ? \
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				TASK_SIZE_32 : TASK_SIZE_64)
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#else
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#define TASK_SIZE		TASK_SIZE_64
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#endif /* CONFIG_COMPAT */
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#define TASK_UNMAPPED_BASE	(PAGE_ALIGN(TASK_SIZE / 4))
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#define STACK_TOP_MAX		TASK_SIZE_64
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#ifdef CONFIG_COMPAT
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#define AARCH32_VECTORS_BASE	0xffff0000
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#define STACK_TOP		(test_thread_flag(TIF_32BIT) ? \
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				AARCH32_VECTORS_BASE : STACK_TOP_MAX)
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#else
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#define STACK_TOP		STACK_TOP_MAX
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#endif /* CONFIG_COMPAT */
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extern phys_addr_t arm64_dma_phys_limit;
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#define ARCH_LOW_ADDRESS_LIMIT	(arm64_dma_phys_limit - 1)
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struct debug_info {
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#ifdef CONFIG_HAVE_HW_BREAKPOINT
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	/* Have we suspended stepping by a debugger? */
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	int			suspended_step;
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	/* Allow breakpoints and watchpoints to be disabled for this thread. */
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	int			bps_disabled;
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	int			wps_disabled;
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	/* Hardware breakpoints pinned to this task. */
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	struct perf_event	*hbp_break[ARM_MAX_BRP];
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	struct perf_event	*hbp_watch[ARM_MAX_WRP];
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#endif
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};
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struct cpu_context {
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	unsigned long x19;
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	unsigned long x20;
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	unsigned long x21;
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	unsigned long x22;
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	unsigned long x23;
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	unsigned long x24;
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	unsigned long x25;
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	unsigned long x26;
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	unsigned long x27;
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	unsigned long x28;
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	unsigned long fp;
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	unsigned long sp;
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	unsigned long pc;
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};
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struct thread_struct {
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	struct cpu_context	cpu_context;	/* cpu context */
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	/*
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	 * Whitelisted fields for hardened usercopy:
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	 * Maintainers must ensure manually that this contains no
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	 * implicit padding.
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	 */
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	struct {
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		unsigned long	tp_value;	/* TLS register */
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		unsigned long	tp2_value;
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		struct user_fpsimd_state fpsimd_state;
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	} uw;
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	unsigned int		fpsimd_cpu;
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	void			*sve_state;	/* SVE registers, if any */
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	unsigned int		sve_vl;		/* SVE vector length */
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	unsigned int		sve_vl_onexec;	/* SVE vl after next exec */
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	unsigned long		fault_address;	/* fault info */
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	unsigned long		fault_code;	/* ESR_EL1 value */
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	struct debug_info	debug;		/* debugging */
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};
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static inline void arch_thread_struct_whitelist(unsigned long *offset,
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						unsigned long *size)
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{
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	/* Verify that there is no padding among the whitelisted fields: */
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	BUILD_BUG_ON(sizeof_field(struct thread_struct, uw) !=
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		     sizeof_field(struct thread_struct, uw.tp_value) +
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		     sizeof_field(struct thread_struct, uw.tp2_value) +
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		     sizeof_field(struct thread_struct, uw.fpsimd_state));
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	*offset = offsetof(struct thread_struct, uw);
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	*size = sizeof_field(struct thread_struct, uw);
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}
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#ifdef CONFIG_COMPAT
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#define task_user_tls(t)						\
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({									\
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	unsigned long *__tls;						\
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	if (is_compat_thread(task_thread_info(t)))			\
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		__tls = &(t)->thread.uw.tp2_value;			\
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	else								\
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		__tls = &(t)->thread.uw.tp_value;			\
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	__tls;								\
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 })
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#else
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#define task_user_tls(t)	(&(t)->thread.uw.tp_value)
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#endif
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/* Sync TPIDR_EL0 back to thread_struct for current */
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void tls_preserve_current_state(void);
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#define INIT_THREAD {				\
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	.fpsimd_cpu = NR_CPUS,			\
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}
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static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
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{
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	memset(regs, 0, sizeof(*regs));
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	forget_syscall(regs);
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	regs->pc = pc;
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}
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static inline void start_thread(struct pt_regs *regs, unsigned long pc,
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				unsigned long sp)
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{
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	start_thread_common(regs, pc);
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	regs->pstate = PSR_MODE_EL0t;
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	if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
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		regs->pstate |= PSR_SSBS_BIT;
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	regs->sp = sp;
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}
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#ifdef CONFIG_COMPAT
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static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
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				       unsigned long sp)
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{
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	start_thread_common(regs, pc);
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	regs->pstate = PSR_AA32_MODE_USR;
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	if (pc & 1)
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		regs->pstate |= PSR_AA32_T_BIT;
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#ifdef __AARCH64EB__
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	regs->pstate |= PSR_AA32_E_BIT;
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#endif
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	if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
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		regs->pstate |= PSR_AA32_SSBS_BIT;
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	regs->compat_sp = sp;
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}
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#endif
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/* Forward declaration, a strange C thing */
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struct task_struct;
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/* Free all resources held by a thread. */
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extern void release_thread(struct task_struct *);
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unsigned long get_wchan(struct task_struct *p);
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static inline void cpu_relax(void)
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{
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	asm volatile("yield" ::: "memory");
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}
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/* Thread switching */
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extern struct task_struct *cpu_switch_to(struct task_struct *prev,
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					 struct task_struct *next);
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#define task_pt_regs(p) \
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	((struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1)
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#define KSTK_EIP(tsk)	((unsigned long)task_pt_regs(tsk)->pc)
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#define KSTK_ESP(tsk)	user_stack_pointer(task_pt_regs(tsk))
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/*
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 * Prefetching support
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 */
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#define ARCH_HAS_PREFETCH
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static inline void prefetch(const void *ptr)
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{
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	asm volatile("prfm pldl1keep, %a0\n" : : "p" (ptr));
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}
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#define ARCH_HAS_PREFETCHW
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static inline void prefetchw(const void *ptr)
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{
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	asm volatile("prfm pstl1keep, %a0\n" : : "p" (ptr));
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}
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#define ARCH_HAS_SPINLOCK_PREFETCH
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static inline void spin_lock_prefetch(const void *ptr)
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{
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	asm volatile(ARM64_LSE_ATOMIC_INSN(
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		     "prfm pstl1strm, %a0",
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		     "nop") : : "p" (ptr));
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}
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#define HAVE_ARCH_PICK_MMAP_LAYOUT
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#endif
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extern unsigned long __ro_after_init signal_minsigstksz; /* sigframe size */
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extern void __init minsigstksz_setup(void);
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/*
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 * Not at the top of the file due to a direct #include cycle between
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 * <asm/fpsimd.h> and <asm/processor.h>.  Deferring this #include
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 * ensures that contents of processor.h are visible to fpsimd.h even if
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 * processor.h is included first.
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 *
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 * These prctl helpers are the only things in this file that require
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 * fpsimd.h.  The core code expects them to be in this header.
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 */
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#include <asm/fpsimd.h>
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/* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
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#define SVE_SET_VL(arg)	sve_set_current_vl(arg)
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#define SVE_GET_VL()	sve_get_current_vl()
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/*
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 * For CONFIG_GCC_PLUGIN_STACKLEAK
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 *
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 * These need to be macros because otherwise we get stuck in a nightmare
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 * of header definitions for the use of task_stack_page.
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 */
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#define current_top_of_stack()							\
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({										\
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	struct stack_info _info;						\
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	BUG_ON(!on_accessible_stack(current, current_stack_pointer, &_info));	\
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	_info.high;								\
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})
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#define on_thread_stack()	(on_task_stack(current, current_stack_pointer, NULL))
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#endif /* __ASSEMBLY__ */
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#endif /* __ASM_PROCESSOR_H */
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