forked from Minki/linux
79e9aa59dc
When CONFIG_UNMAP_KERNEL_AT_EL0 is set the SDEI entry point and the rest of the kernel may be unmapped when we take an event. If this may be the case, use an entry trampoline that can switch to the kernel page tables. We can't use the provided PSTATE to determine whether to switch page tables as we may have interrupted the kernel's entry trampoline, (or a normal-priority event that interrupted the kernel's entry trampoline). Instead test for a user ASID in ttbr1_el1. Save a value in regs->addr_limit to indicate whether we need to restore the original ASID when returning from this event. This value is only used by do_page_fault(), which we don't call with the SDEI regs. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
58 lines
1.5 KiB
C
58 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2017 Arm Ltd.
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#ifndef __ASM_SDEI_H
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#define __ASM_SDEI_H
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/* Values for sdei_exit_mode */
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#define SDEI_EXIT_HVC 0
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#define SDEI_EXIT_SMC 1
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#define SDEI_STACK_SIZE IRQ_STACK_SIZE
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#ifndef __ASSEMBLY__
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#include <linux/linkage.h>
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#include <linux/preempt.h>
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#include <linux/types.h>
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#include <asm/virt.h>
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extern unsigned long sdei_exit_mode;
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/* Software Delegated Exception entry point from firmware*/
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asmlinkage void __sdei_asm_handler(unsigned long event_num, unsigned long arg,
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unsigned long pc, unsigned long pstate);
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/* and its CONFIG_UNMAP_KERNEL_AT_EL0 trampoline */
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asmlinkage void __sdei_asm_entry_trampoline(unsigned long event_num,
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unsigned long arg,
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unsigned long pc,
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unsigned long pstate);
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/*
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* The above entry point does the minimum to call C code. This function does
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* anything else, before calling the driver.
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*/
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struct sdei_registered_event;
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asmlinkage unsigned long __sdei_handler(struct pt_regs *regs,
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struct sdei_registered_event *arg);
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unsigned long sdei_arch_get_entry_point(int conduit);
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#define sdei_arch_get_entry_point(x) sdei_arch_get_entry_point(x)
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bool _on_sdei_stack(unsigned long sp);
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static inline bool on_sdei_stack(unsigned long sp)
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{
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if (!IS_ENABLED(CONFIG_VMAP_STACK))
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return false;
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if (!IS_ENABLED(CONFIG_ARM_SDE_INTERFACE))
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return false;
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if (in_nmi())
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return _on_sdei_stack(sp);
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return false;
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}
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#endif /* __ASSEMBLY__ */
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#endif /* __ASM_SDEI_H */
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