From patchwork Sun Nov 19 16:57:11 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandru Elisei X-Patchwork-Id: 13460603 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E69C0C54E76 for ; Sun, 19 Nov 2023 16:59:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=a4xwCr4oH5Q1n+4U0BSilg7wisS1wR3slPxS2pXVZgM=; b=C+FEZUUmOJ6VcP 286q2WO1aV+A2MjowbZeANm6q4uhjjdKP7rfyc/oM7aReoOj8IY4202fANGPEVSkh/AILi/GhuAwx 2cJky4j6+iti37lGYKHc5tM+2XI5w3zOSU06ePb+fyLit0NjrVEcNbfKBmt6hawzBV10daOnfMhc+ oAkPQUFoBHclCffLrySoOmAV0HUu8AJjnkxx3hwD9wLwjbWtUbpo1tAVWrjsYWthpyxHi23Ru5ppi lxDJqjGmH14qcvd3HX9IRsk08cj99JF7T4EZIpBgejLZhZfZgVbe7rDa5fxOirXarcBIEZ0WlFipX xkJqX2CE4TMKgW54DA9Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r4l8c-00ARPx-33; Sun, 19 Nov 2023 16:59:15 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r4l8X-00ARJk-1m for linux-arm-kernel@lists.infradead.org; Sun, 19 Nov 2023 16:59:11 +0000 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 5E0701042; Sun, 19 Nov 2023 08:59:55 -0800 (PST) Received: from e121798.cable.virginm.net (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2A15B3F6C4; Sun, 19 Nov 2023 08:59:04 -0800 (PST) From: Alexandru Elisei To: catalin.marinas@arm.com, will@kernel.org, oliver.upton@linux.dev, maz@kernel.org, james.morse@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, arnd@arndb.de, akpm@linux-foundation.org, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, mhiramat@kernel.org, rppt@kernel.org, hughd@google.com Cc: pcc@google.com, steven.price@arm.com, anshuman.khandual@arm.com, vincenzo.frascino@arm.com, david@redhat.com, eugenis@google.com, kcc@google.com, hyesoo.yu@samsung.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org Subject: [PATCH RFC v2 17/27] arm64: mte: Perform CMOs for tag blocks on tagged page allocation/free Date: Sun, 19 Nov 2023 16:57:11 +0000 Message-Id: <20231119165721.9849-18-alexandru.elisei@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231119165721.9849-1-alexandru.elisei@arm.com> References: <20231119165721.9849-1-alexandru.elisei@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231119_085909_749392_E02677E7 X-CRM114-Status: GOOD ( 13.78 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Make sure the contents of the tag storage block is not corrupted by performing: 1. A tag dcache inval when the associated tagged pages are freed, to avoid dirty tag cache lines being evicted and corrupting the tag storage block when it's being used to store data. 2. A data cache inval when the tag storage block is being reserved, to ensure that no dirty data cache lines are present, which would trigger a writeback that could corrupt the tags stored in the block. Signed-off-by: Alexandru Elisei --- arch/arm64/include/asm/assembler.h | 10 ++++++++++ arch/arm64/include/asm/mte_tag_storage.h | 2 ++ arch/arm64/kernel/mte_tag_storage.c | 11 +++++++++++ arch/arm64/lib/mte.S | 16 ++++++++++++++++ 4 files changed, 39 insertions(+) diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index 376a980f2bad..8d41c8cfdc69 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -310,6 +310,16 @@ alternative_cb_end lsl \reg, \reg, \tmp // actual cache line size .endm +/* + * tcache_line_size - get the safe tag cache line size across all CPUs + */ + .macro tcache_line_size, reg, tmp + read_ctr \tmp + ubfm \tmp, \tmp, #32, #37 // tag cache line size encoding + mov \reg, #4 // bytes per word + lsl \reg, \reg, \tmp // actual tag cache line size + .endm + /* * raw_icache_line_size - get the minimum I-cache line size on this CPU * from the CTR register. diff --git a/arch/arm64/include/asm/mte_tag_storage.h b/arch/arm64/include/asm/mte_tag_storage.h index cab033b184ab..6e5d28e607bb 100644 --- a/arch/arm64/include/asm/mte_tag_storage.h +++ b/arch/arm64/include/asm/mte_tag_storage.h @@ -11,6 +11,8 @@ #include +extern void dcache_inval_tags_poc(unsigned long start, unsigned long end); + #ifdef CONFIG_ARM64_MTE_TAG_STORAGE DECLARE_STATIC_KEY_FALSE(tag_storage_enabled_key); diff --git a/arch/arm64/kernel/mte_tag_storage.c b/arch/arm64/kernel/mte_tag_storage.c index 9f8ef3116fc3..833480048170 100644 --- a/arch/arm64/kernel/mte_tag_storage.c +++ b/arch/arm64/kernel/mte_tag_storage.c @@ -19,6 +19,7 @@ #include #include +#include #include __ro_after_init DEFINE_STATIC_KEY_FALSE(tag_storage_enabled_key); @@ -431,8 +432,13 @@ static bool tag_storage_block_is_reserved(unsigned long block) static int tag_storage_reserve_block(unsigned long block, struct tag_region *region, int order) { + unsigned long block_va; int ret; + block_va = (unsigned long)page_to_virt(pfn_to_page(block)); + /* Avoid writeback of dirty data cache lines corrupting tags. */ + dcache_inval_poc(block_va, block_va + region->block_size * PAGE_SIZE); + ret = xa_err(xa_store(&tag_blocks_reserved, block, pfn_to_page(block), GFP_KERNEL)); if (!ret) block_ref_add(block, region, order); @@ -587,6 +593,7 @@ void free_tag_storage(struct page *page, int order) { unsigned long block, start_block, end_block; struct tag_region *region; + unsigned long page_va; unsigned long flags; int ret; @@ -594,6 +601,10 @@ void free_tag_storage(struct page *page, int order) if (WARN_ONCE(ret, "Missing tag storage block for pfn 0x%lx", page_to_pfn(page))) return; + page_va = (unsigned long)page_to_virt(page); + /* Avoid writeback of dirty tag cache lines corrupting data. */ + dcache_inval_tags_poc(page_va, page_va + (PAGE_SIZE << order)); + end_block = start_block + order_to_num_blocks(order) * region->block_size; xa_lock_irqsave(&tag_blocks_reserved, flags); diff --git a/arch/arm64/lib/mte.S b/arch/arm64/lib/mte.S index 9f623e9da09f..bc02b4e95062 100644 --- a/arch/arm64/lib/mte.S +++ b/arch/arm64/lib/mte.S @@ -175,3 +175,19 @@ SYM_FUNC_START(mte_copy_page_tags_from_buf) ret SYM_FUNC_END(mte_copy_page_tags_from_buf) + +/* + * dcache_inval_tags_poc(start, end) + * + * Ensure that any tags in the D-cache for the interval [start, end) + * are invalidated to PoC. + * + * - start - virtual start address of region + * - end - virtual end address of region + */ +SYM_FUNC_START(__pi_dcache_inval_tags_poc) + tcache_line_size x2, x3 + dcache_by_myline_op igvac, sy, x0, x1, x2, x3 + ret +SYM_FUNC_END(__pi_dcache_inval_tags_poc) +SYM_FUNC_ALIAS(dcache_inval_tags_poc, __pi_dcache_inval_tags_poc)