From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1FBD72D949C; Mon, 13 Apr 2026 16:10:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776096651; cv=none; b=CjJs3D0wp0EvupIfWCZ8yW8itSO/oQ9vgb7/TyBCusvCQDCVu1ZyiutL/P4Td0lw1U3qePWSnX1SwwQAr9pCYlOUi0KYtuxvleab3ZqBP1P9Zyr4UUbjHrQf9s5RmeI/18EcGLFMBkXb4bm7YwF3y7YMGhsv2Yfcw9tuwQEQHgA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776096651; c=relaxed/simple; bh=BJ/J9O2+/26eycMmYVKd4e9UfTYEgARlHM6ZgZYoh1o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f4rmiiFUy977aUr9PdWJkCQP+1ysAj3M2mD1h29lcb1lbbuX/SArI8rg9i5IPWN2e/qS/qzkE2/hzORlyJUFcP7fN/3DLqAPAlzyjMt/FrBf+K6Y3S3AIYIoJF+gY8HhytHCaftUfYanCddymqlRKnPpTfQmTNeq7JEu13mPRx8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sGaJ/1Mq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="sGaJ/1Mq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6B590C2BCAF; Mon, 13 Apr 2026 16:10:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776096650; bh=BJ/J9O2+/26eycMmYVKd4e9UfTYEgARlHM6ZgZYoh1o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sGaJ/1MqrVKYeiXl3SviJ26l7bLt3yy1Vqeg9+9rId059+cDGy4co0HbL4NXSqErP zc1afKcnjyMaoJoPx5VUJPURoz50jmJHy/nChJRgjbYisCfLptLzmzco+h4daDs2ZC fZxtji8ImLcaQgMN54S3yeEa/Zl688OYzxAJHHLw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Maciej W. Rozycki" , Thomas Bogendoerfer , Sasha Levin Subject: [PATCH 6.12 10/70] MIPS: Always record SEGBITS in cpu_data.vmbits Date: Mon, 13 Apr 2026 18:00:05 +0200 Message-ID: <20260413155728.570965462@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260413155728.181580293@linuxfoundation.org> References: <20260413155728.181580293@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maciej W. Rozycki commit 8374c2cb83b95b3c92f129fd56527225c20a058c upstream. With a 32-bit kernel running on 64-bit MIPS hardware the hardcoded value of `cpu_vmbits' only records the size of compatibility useg and does not reflect the size of native xuseg or the complete range of values allowed in the VPN2 field of TLB entries. An upcoming change will need the actual VPN2 value range permitted even in 32-bit kernel configurations, so always include the `vmbits' member in `struct cpuinfo_mips' and probe for SEGBITS when running on 64-bit hardware and resorting to the currently hardcoded value of 31 on 32-bit processors. No functional change for users of `cpu_vmbits'. Signed-off-by: Maciej W. Rozycki Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin --- arch/mips/include/asm/cpu-features.h | 1 - arch/mips/include/asm/cpu-info.h | 2 -- arch/mips/include/asm/mipsregs.h | 2 ++ arch/mips/kernel/cpu-probe.c | 13 ++++++++----- arch/mips/kernel/cpu-r3k-probe.c | 2 ++ 5 files changed, 12 insertions(+), 8 deletions(-) diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h index 404390bb87eaf..3f11e5218e6c6 100644 --- a/arch/mips/include/asm/cpu-features.h +++ b/arch/mips/include/asm/cpu-features.h @@ -484,7 +484,6 @@ # endif # ifndef cpu_vmbits # define cpu_vmbits cpu_data[0].vmbits -# define __NEED_VMBITS_PROBE # endif #endif diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h index a600670d00e97..1aee44124f118 100644 --- a/arch/mips/include/asm/cpu-info.h +++ b/arch/mips/include/asm/cpu-info.h @@ -80,9 +80,7 @@ struct cpuinfo_mips { int srsets; /* Shadow register sets */ int package;/* physical package number */ unsigned int globalnumber; -#ifdef CONFIG_64BIT int vmbits; /* Virtual memory size in bits */ -#endif void *data; /* Additional data */ unsigned int watch_reg_count; /* Number that exist */ unsigned int watch_reg_use_cnt; /* Usable by ptrace */ diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h index 3c6ddc0c2c7ac..db8e02493eb89 100644 --- a/arch/mips/include/asm/mipsregs.h +++ b/arch/mips/include/asm/mipsregs.h @@ -1871,6 +1871,8 @@ do { \ #define read_c0_entryhi() __read_ulong_c0_register($10, 0) #define write_c0_entryhi(val) __write_ulong_c0_register($10, 0, val) +#define read_c0_entryhi_64() __read_64bit_c0_register($10, 0) +#define write_c0_entryhi_64(val) __write_64bit_c0_register($10, 0, val) #define read_c0_guestctl1() __read_32bit_c0_register($10, 4) #define write_c0_guestctl1(val) __write_32bit_c0_register($10, 4, val) diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index af7412549e6ea..3220e68bd12e8 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -207,11 +207,14 @@ static inline void set_elf_base_platform(const char *plat) static inline void cpu_probe_vmbits(struct cpuinfo_mips *c) { -#ifdef __NEED_VMBITS_PROBE - write_c0_entryhi(0x3fffffffffffe000ULL); - back_to_back_c0_hazard(); - c->vmbits = fls64(read_c0_entryhi() & 0x3fffffffffffe000ULL); -#endif + int vmbits = 31; + + if (cpu_has_64bits) { + write_c0_entryhi_64(0x3fffffffffffe000ULL); + back_to_back_c0_hazard(); + vmbits = fls64(read_c0_entryhi_64() & 0x3fffffffffffe000ULL); + } + c->vmbits = vmbits; } static void set_isa(struct cpuinfo_mips *c, unsigned int isa) diff --git a/arch/mips/kernel/cpu-r3k-probe.c b/arch/mips/kernel/cpu-r3k-probe.c index 0c826f729f752..edcf04de0a6fb 100644 --- a/arch/mips/kernel/cpu-r3k-probe.c +++ b/arch/mips/kernel/cpu-r3k-probe.c @@ -137,6 +137,8 @@ void cpu_probe(void) else cpu_set_nofpu_opts(c); + c->vmbits = 31; + reserve_exception_space(0, 0x400); } -- 2.53.0