diff options
Diffstat (limited to 'arch/arm64/include/asm/hardirq.h')
| -rw-r--r-- | arch/arm64/include/asm/hardirq.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/hardirq.h b/arch/arm64/include/asm/hardirq.h new file mode 100644 index 0000000000..cbfa7b6f2e --- /dev/null +++ b/arch/arm64/include/asm/hardirq.h @@ -0,0 +1,94 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2012 ARM Ltd. + */ +#ifndef __ASM_HARDIRQ_H +#define __ASM_HARDIRQ_H + +#include <linux/cache.h> +#include <linux/percpu.h> +#include <linux/threads.h> +#include <asm/barrier.h> +#include <asm/irq.h> +#include <asm/kvm_arm.h> +#include <asm/sysreg.h> + +#define ack_bad_irq ack_bad_irq +#include <asm-generic/hardirq.h> + +#define __ARCH_IRQ_EXIT_IRQS_DISABLED 1 + +struct nmi_ctx { + u64 hcr; + unsigned int cnt; +}; + +DECLARE_PER_CPU(struct nmi_ctx, nmi_contexts); + +#define arch_nmi_enter() \ +do { \ + struct nmi_ctx *___ctx; \ + u64 ___hcr; \ + \ + if (!is_kernel_in_hyp_mode()) \ + break; \ + \ + ___ctx = this_cpu_ptr(&nmi_contexts); \ + if (___ctx->cnt) { \ + ___ctx->cnt++; \ + break; \ + } \ + \ + ___hcr = read_sysreg(hcr_el2); \ + if (!(___hcr & HCR_TGE)) { \ + write_sysreg(___hcr | HCR_TGE, hcr_el2); \ + isb(); \ + } \ + /* \ + * Make sure the sysreg write is performed before ___ctx->cnt \ + * is set to 1. NMIs that see cnt == 1 will rely on us. \ + */ \ + barrier(); \ + ___ctx->cnt = 1; \ + /* \ + * Make sure ___ctx->cnt is set before we save ___hcr. We \ + * don't want ___ctx->hcr to be overwritten. \ + */ \ + barrier(); \ + ___ctx->hcr = ___hcr; \ +} while (0) + +#define arch_nmi_exit() \ +do { \ + struct nmi_ctx *___ctx; \ + u64 ___hcr; \ + \ + if (!is_kernel_in_hyp_mode()) \ + break; \ + \ + ___ctx = this_cpu_ptr(&nmi_contexts); \ + ___hcr = ___ctx->hcr; \ + /* \ + * Make sure we read ___ctx->hcr before we release \ + * ___ctx->cnt as it makes ___ctx->hcr updatable again. \ + */ \ + barrier(); \ + ___ctx->cnt--; \ + /* \ + * Make sure ___ctx->cnt release is visible before we \ + * restore the sysreg. Otherwise a new NMI occurring \ + * right after write_sysreg() can be fooled and think \ + * we secured things for it. \ + */ \ + barrier(); \ + if (!___ctx->cnt && !(___hcr & HCR_TGE)) \ + write_sysreg(___hcr, hcr_el2); \ +} while (0) + +static inline void ack_bad_irq(unsigned int irq) +{ + extern unsigned long irq_err_count; + irq_err_count++; +} + +#endif /* __ASM_HARDIRQ_H */ |