linux/arch/arm64/include/asm/traps.h
Alexandru Elisei 8d56e5c5a9 arm64: Treat ESR_ELx as a 64-bit register
In the initial release of the ARM Architecture Reference Manual for
ARMv8-A, the ESR_ELx registers were defined as 32-bit registers. This
changed in 2018 with version D.a (ARM DDI 0487D.a) of the architecture,
when they became 64-bit registers, with bits [63:32] defined as RES0. In
version G.a, a new field was added to ESR_ELx, ISS2, which covers bits
[36:32].  This field is used when the Armv8.7 extension FEAT_LS64 is
implemented.

As a result of the evolution of the register width, Linux stores it as
both a 64-bit value and a 32-bit value, which hasn't affected correctness
so far as Linux only uses the lower 32 bits of the register.

Make the register type consistent and always treat it as 64-bit wide. The
register is redefined as an "unsigned long", which is an unsigned
double-word (64-bit quantity) for the LP64 machine (aapcs64 [1], Table 1,
page 14). The type was chosen because "unsigned int" is the most frequent
type for ESR_ELx and because FAR_ELx, which is used together with ESR_ELx
in exception handling, is also declared as "unsigned long". The 64-bit type
also makes adding support for architectural features that use fields above
bit 31 easier in the future.

The KVM hypervisor will receive a similar update in a subsequent patch.

[1] https://github.com/ARM-software/abi-aa/releases/download/2021Q3/aapcs64.pdf

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220425114444.368693-4-alexandru.elisei@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2022-04-29 19:26:27 +01:00

104 lines
2.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Based on arch/arm/include/asm/traps.h
*
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_TRAP_H
#define __ASM_TRAP_H
#include <linux/list.h>
#include <asm/esr.h>
#include <asm/sections.h>
struct pt_regs;
struct undef_hook {
struct list_head node;
u32 instr_mask;
u32 instr_val;
u64 pstate_mask;
u64 pstate_val;
int (*fn)(struct pt_regs *regs, u32 instr);
};
void register_undef_hook(struct undef_hook *hook);
void unregister_undef_hook(struct undef_hook *hook);
void force_signal_inject(int signal, int code, unsigned long address, unsigned long err);
void arm64_notify_segfault(unsigned long addr);
void arm64_force_sig_fault(int signo, int code, unsigned long far, const char *str);
void arm64_force_sig_mceerr(int code, unsigned long far, short lsb, const char *str);
void arm64_force_sig_ptrace_errno_trap(int errno, unsigned long far, const char *str);
/*
* Move regs->pc to next instruction and do necessary setup before it
* is executed.
*/
void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size);
static inline int __in_irqentry_text(unsigned long ptr)
{
return ptr >= (unsigned long)&__irqentry_text_start &&
ptr < (unsigned long)&__irqentry_text_end;
}
static inline int in_entry_text(unsigned long ptr)
{
return ptr >= (unsigned long)&__entry_text_start &&
ptr < (unsigned long)&__entry_text_end;
}
/*
* CPUs with the RAS extensions have an Implementation-Defined-Syndrome bit
* to indicate whether this ESR has a RAS encoding. CPUs without this feature
* have a ISS-Valid bit in the same position.
* If this bit is set, we know its not a RAS SError.
* If its clear, we need to know if the CPU supports RAS. Uncategorized RAS
* errors share the same encoding as an all-zeros encoding from a CPU that
* doesn't support RAS.
*/
static inline bool arm64_is_ras_serror(unsigned long esr)
{
WARN_ON(preemptible());
if (esr & ESR_ELx_IDS)
return false;
if (this_cpu_has_cap(ARM64_HAS_RAS_EXTN))
return true;
else
return false;
}
/*
* Return the AET bits from a RAS SError's ESR.
*
* It is implementation defined whether Uncategorized errors are containable.
* We treat them as Uncontainable.
* Non-RAS SError's are reported as Uncontained/Uncategorized.
*/
static inline unsigned long arm64_ras_serror_get_severity(unsigned long esr)
{
unsigned long aet = esr & ESR_ELx_AET;
if (!arm64_is_ras_serror(esr)) {
/* Not a RAS error, we can't interpret the ESR. */
return ESR_ELx_AET_UC;
}
/*
* AET is RES0 if 'the value returned in the DFSC field is not
* [ESR_ELx_FSC_SERROR]'
*/
if ((esr & ESR_ELx_FSC) != ESR_ELx_FSC_SERROR) {
/* No severity information : Uncategorized */
return ESR_ELx_AET_UC;
}
return aet;
}
bool arm64_is_fatal_ras_serror(struct pt_regs *regs, unsigned long esr);
void __noreturn arm64_serror_panic(struct pt_regs *regs, unsigned long esr);
#endif