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a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1700843736; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+/V2DhDdOUNGu2LVBZcNgVrXs2fIvsaw6cBdbj+wY14=; b=xluI8XpUYoMnZ/ONjdydcDCaR4xzytw3ZKB1gJCmEtPkFksLS9v6A8SkD+7rPWGUyPucO6 2DaSv+CLYgVSsFleS8E+tGS9Jyz3LsWifdbSJpZtl4PigTvVmZmT39FufGvdqvBgXnJ7eG 2T5/hY22yhOqvV35f5t7snVtK12QZVw= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5D8C81BD0; Fri, 24 Nov 2023 08:36:21 -0800 (PST) Received: from e124191.cambridge.arm.com (e124191.cambridge.arm.com [10.1.197.45]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AE04C3F73F; Fri, 24 Nov 2023 08:35:32 -0800 (PST) From: Joey Gouly To: linux-arm-kernel@lists.infradead.org Cc: akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com, broonie@kernel.org, catalin.marinas@arm.com, dave.hansen@linux.intel.com, joey.gouly@arm.com, maz@kernel.org, oliver.upton@linux.dev, shuah@kernel.org, will@kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, James Morse , Suzuki K Poulose , Zenghui Yu Subject: [PATCH v3 05/25] arm64: context switch POR_EL0 register Date: Fri, 24 Nov 2023 16:34:50 +0000 Message-Id: <20231124163510.1835740-6-joey.gouly@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231124163510.1835740-1-joey.gouly@arm.com> References: <20231124163510.1835740-1-joey.gouly@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: E66B840003 X-Stat-Signature: xkhpu347r75uz5qat8wb1a6uywn3rkik X-Rspam-User: X-HE-Tag: 1700843735-935988 X-HE-Meta: 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 /ouxx2hU 1NYBbTMWtqiMjGZKszzlq0awr5jNCbELgzeBnG55qiA4q2Gb+O8bBgwV7V/Es3G5KI3EW5NOMu6A5jYk6/tbGl03rVWg4MGsnccgBJH1CnVl1rVD5iOAV0yfd6HAjKTMriA04GTWAGj8antiB16eVNmczN81Z5eW0dxgGuIjBFI00RjqHckjf1y92oTLw18ClaYwsPVGc5KFConV5o/PPB29VZDSEqojGwk1xmohdQ0snVJtcnfqYN4W/pw3BD1tUbytPHQL1NBR/+Dc= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: POR_EL0 is a register that can be modified by userspace directly, so it must be context switched. Signed-off-by: Joey Gouly Cc: Catalin Marinas Cc: Will Deacon --- arch/arm64/include/asm/cpufeature.h | 6 ++++++ arch/arm64/include/asm/processor.h | 1 + arch/arm64/include/asm/sysreg.h | 3 +++ arch/arm64/kernel/process.c | 22 ++++++++++++++++++++++ 4 files changed, 32 insertions(+) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index f6d416fe49b0..6870e4d46334 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -819,6 +819,12 @@ static inline bool system_supports_tlb_range(void) return alternative_has_cap_unlikely(ARM64_HAS_TLB_RANGE); } +static inline bool system_supports_poe(void) +{ + return IS_ENABLED(CONFIG_ARM64_POE) && + alternative_has_cap_unlikely(ARM64_HAS_S1POE); +} + int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt); bool try_emulate_mrs(struct pt_regs *regs, u32 isn); diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index e5bc54522e71..b3ad719c2d0c 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -179,6 +179,7 @@ struct thread_struct { u64 sctlr_user; u64 svcr; u64 tpidr2_el0; + u64 por_el0; }; static inline unsigned int thread_get_vl(struct thread_struct *thread, diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 9c2caf0efdc7..77a4797d0d54 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -1052,6 +1052,9 @@ #define POE_RXW UL(0x7) #define POE_MASK UL(0xf) +/* Initial value for Permission Overlay Extension for EL0 */ +#define POR_EL0_INIT POE_RXW + #define ARM64_FEATURE_FIELD_BITS 4 /* Defined for compatibility only, do not add new users. */ diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 7387b68c745b..fc899c12d759 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -271,12 +271,19 @@ static void flush_tagged_addr_state(void) clear_thread_flag(TIF_TAGGED_ADDR); } +static void flush_poe(void) +{ + if (system_supports_poe()) + write_sysreg_s(POR_EL0_INIT, SYS_POR_EL0); +} + void flush_thread(void) { fpsimd_flush_thread(); tls_thread_flush(); flush_ptrace_hw_breakpoint(current); flush_tagged_addr_state(); + flush_poe(); } void arch_release_task_struct(struct task_struct *tsk) @@ -374,6 +381,9 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) if (system_supports_tpidr2()) p->thread.tpidr2_el0 = read_sysreg_s(SYS_TPIDR2_EL0); + if (system_supports_poe()) + p->thread.por_el0 = read_sysreg_s(SYS_POR_EL0); + if (stack_start) { if (is_compat_thread(task_thread_info(p))) childregs->compat_sp = stack_start; @@ -498,6 +508,17 @@ static void erratum_1418040_new_exec(void) preempt_enable(); } +static void permission_overlay_switch(struct task_struct *next) +{ + if (system_supports_poe()) { + current->thread.por_el0 = read_sysreg_s(SYS_POR_EL0); + if (current->thread.por_el0 != next->thread.por_el0) { + write_sysreg_s(next->thread.por_el0, SYS_POR_EL0); + isb(); + } + } +} + /* * __switch_to() checks current->thread.sctlr_user as an optimisation. Therefore * this function must be called with preemption disabled and the update to @@ -533,6 +554,7 @@ struct task_struct *__switch_to(struct task_struct *prev, ssbs_thread_switch(next); erratum_1418040_thread_switch(next); ptrauth_thread_switch_user(next); + permission_overlay_switch(next); /* * Complete any pending TLB or cache maintenance on this CPU in case -- 2.25.1