forked from Minki/linux
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>
82 lines
2.4 KiB
C
82 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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#ifndef VIRT_H
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#define VIRT_H
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#include <asm/ptrace.h>
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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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#ifndef __ASSEMBLY__
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#include <asm/cacheflush.h>
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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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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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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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#ifndef ZIMAGE
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void hyp_mode_check(void);
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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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/* 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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#endif /* __ASSEMBLY__ */
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#endif /* ! VIRT_H */
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