From 000a42b35a54372597f0657f6b9875b38c641864 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Thu, 9 Jul 2020 08:59:41 +0530 Subject: powerpc/book3s64/keys/kuap: Reset AMR/IAMR values on kexec As we kexec across kernels that use AMR/IAMR for different purposes we need to ensure that new kernels get kexec'd with a reset value of AMR/IAMR. For ex: the new kernel can use key 0 for kernel mapping and the old AMR value prevents access to key 0. This patch also removes reset if IAMR and AMOR in kexec_sequence. Reset of AMOR is not needed and the IAMR reset is partial (it doesn't do the reset on secondary cpus) and is redundant with this patch. Signed-off-by: Aneesh Kumar K.V Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200709032946.881753-19-aneesh.kumar@linux.ibm.com --- arch/powerpc/include/asm/book3s/64/kexec.h | 23 +++++++++++++++++++++++ arch/powerpc/include/asm/kexec.h | 12 ++++++++++++ 2 files changed, 35 insertions(+) create mode 100644 arch/powerpc/include/asm/book3s/64/kexec.h (limited to 'arch/powerpc/include') diff --git a/arch/powerpc/include/asm/book3s/64/kexec.h b/arch/powerpc/include/asm/book3s/64/kexec.h new file mode 100644 index 000000000000..6b5c3a248ba2 --- /dev/null +++ b/arch/powerpc/include/asm/book3s/64/kexec.h @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _ASM_POWERPC_BOOK3S_64_KEXEC_H_ +#define _ASM_POWERPC_BOOK3S_64_KEXEC_H_ + + +#define reset_sprs reset_sprs +static inline void reset_sprs(void) +{ + if (cpu_has_feature(CPU_FTR_ARCH_206)) { + mtspr(SPRN_AMR, 0); + mtspr(SPRN_UAMOR, 0); + } + + if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + mtspr(SPRN_IAMR, 0); + } + + /* Do we need isync()? We are going via a kexec reset */ + isync(); +} + +#endif diff --git a/arch/powerpc/include/asm/kexec.h b/arch/powerpc/include/asm/kexec.h index c68476818753..89f7e3462292 100644 --- a/arch/powerpc/include/asm/kexec.h +++ b/arch/powerpc/include/asm/kexec.h @@ -150,6 +150,18 @@ static inline void crash_send_ipi(void (*crash_ipi_callback)(struct pt_regs *)) } #endif /* CONFIG_KEXEC_CORE */ + +#ifdef CONFIG_PPC_BOOK3S_64 +#include +#endif + +#ifndef reset_sprs +#define reset_sprs reset_sprs +static inline void reset_sprs(void) +{ +} +#endif + #endif /* ! __ASSEMBLY__ */ #endif /* __KERNEL__ */ #endif /* _ASM_POWERPC_KEXEC_H */ -- cgit v1.2.3