 8fbac214e5
			
		
	
	
	8fbac214e5
	
	
	
		
			
			Secondary CPUs write to __boot_cpu_mode with caches disabled, and thus a cached value of __boot_cpu_mode may be incoherent with that in memory. This could lead to a failure to detect mismatched boot modes. This patch adds flushing to ensure that writes by secondaries to __boot_cpu_mode are made visible before we test against it. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <cdall@cs.columbia.edu> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
		
			
				
	
	
		
			81 lines
		
	
	
	
		
			2.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			81 lines
		
	
	
	
		
			2.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2012 Linaro Limited.
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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 as published by
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|  * the Free Software Foundation; either version 2 of the License, or
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|  * (at your option) any later version.
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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 along
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|  * with this program; if not, write to the Free Software Foundation, Inc.,
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|  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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|  */
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| 
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| #ifndef VIRT_H
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| #define VIRT_H
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| 
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| #include <asm/ptrace.h>
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| 
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| /*
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|  * Flag indicating that the kernel was not entered in the same mode on every
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|  * CPU.  The zImage loader stashes this value in an SPSR, so we need an
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|  * architecturally defined flag bit here.
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|  */
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| #define BOOT_CPU_MODE_MISMATCH	PSR_N_BIT
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| 
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| #ifndef __ASSEMBLY__
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| #include <asm/cacheflush.h>
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| 
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| #ifdef CONFIG_ARM_VIRT_EXT
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| /*
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|  * __boot_cpu_mode records what mode the primary CPU was booted in.
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|  * A correctly-implemented bootloader must start all CPUs in the same mode:
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|  * if it fails to do this, the flag BOOT_CPU_MODE_MISMATCH is set to indicate
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|  * that some CPU(s) were booted in a different mode.
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|  *
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|  * This allows the kernel to flag an error when the secondaries have come up.
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|  */
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| extern int __boot_cpu_mode;
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| 
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| static inline void sync_boot_mode(void)
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| {
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| 	/*
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| 	 * As secondaries write to __boot_cpu_mode with caches disabled, we
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| 	 * must flush the corresponding cache entries to ensure the visibility
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| 	 * of their writes.
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| 	 */
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| 	sync_cache_r(&__boot_cpu_mode);
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| }
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| 
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| void __hyp_set_vectors(unsigned long phys_vector_base);
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| unsigned long __hyp_get_vectors(void);
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| #else
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| #define __boot_cpu_mode	(SVC_MODE)
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| #define sync_boot_mode()
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| #endif
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| 
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| #ifndef ZIMAGE
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| void hyp_mode_check(void);
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| 
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| /* Reports the availability of HYP mode */
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| static inline bool is_hyp_mode_available(void)
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| {
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| 	return ((__boot_cpu_mode & MODE_MASK) == HYP_MODE &&
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| 		!(__boot_cpu_mode & BOOT_CPU_MODE_MISMATCH));
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| }
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| 
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| /* Check if the bootloader has booted CPUs in different modes */
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| static inline bool is_hyp_mode_mismatched(void)
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| {
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| 	return !!(__boot_cpu_mode & BOOT_CPU_MODE_MISMATCH);
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| }
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| #endif
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| 
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| #endif /* __ASSEMBLY__ */
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| 
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| #endif /* ! VIRT_H */
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