From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9C24D471D1A for ; Wed, 2 Sep 2026 10:51:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788346292; cv=none; b=VWnAsMUNOCe1gsKgYjyPQAloS2xW7Y+qY0euavvlNRBlmdFoTTh25yNLy9H7CS2ge9vL9gqy8BTqjOcDWgmMRTER1PqBMIJ+z4pbz4G/W1soZJxeyZZFYh8LkJ6zoa9m/WcouVZ/RaambskpmoN4D7gokj36Yi1fXErf2NHQjP4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788346292; c=relaxed/simple; bh=nMu6uOIdcSiaN+JYugdLeZy5798bpsbb/pHYStuoqbU=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=BdTcz2gycj5BEoMh5+A2SCubzekVuOkJHjnKexSMc8D42Yan+rx5n6JDuw5J99rMHLtQmW2tZ5VuS4+zwpTwLen8uv53vhMUVdYNvEkK5RkkSi3LjneSy/1hGLit7yLT2rxfkFHCYE/aorbRAx+54ulsnb9b7ZlwqwFiK+jplgQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=u3PXF4vQ; arc=none smtp.client-ip=209.85.208.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="u3PXF4vQ" Received: by mail-ed1-f69.google.com with SMTP id 4fb4d7f45d1cf-6a125f5b317so1028984a12.1 for ; Wed, 02 Sep 2026 03:51:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1788346274; x=1788951074; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=gODwxuTtOVKQ6CMnGDMT0l3+wYWk2p1Ok9ZsUXJwJCE=; b=u3PXF4vQsvb9b6DDt1uaqig+t6k0iJ0rZtFkFFlH2UTJupC/ymMzaK/xSrL/FmcT2U 9ODi9WZk1WG4X9Jj4TF0vigTq6t0W1UMJ+iO3XibVmfxi9j3Q9s2gWWCug5u5JPX3sjI 8IZBH5AtoU3bnhtKn5NATG9NE1V29igdbUDAgOOk7tJug5lwPpUZgJTuo9z5WoaOuHs8 AVQBaf7aux7ECtZ5LCUXIGgsZ8NU/XxzqhUk9aBNSAk/jWH8CLCfDbIJVac9JZfd3wNd JT+KQrJfXC1Wo+vCqkRup/sf9vLdhJdEuqInv5MkEr1Du+rbQ6V53WxFD88ZS7fCnkQh yEEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788346274; x=1788951074; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=gODwxuTtOVKQ6CMnGDMT0l3+wYWk2p1Ok9ZsUXJwJCE=; b=Hedsikx4Ph9+uWO4uw5MatSAh84xWuWscNFA3qf10MnJq3Z7POd9ajzqcURg8SV/NP LTX54dYTmIJ52zdEuLLS5UraNLwVvQCEsoFyPqiiFf4JEZ9BOJGF+YyC1QrljRV03C/f x07xAzJ8YTJwwr2Vx1SylrHT9Aq2zcVLW9zkU+GzjzKL/fc8I4gufIukm2xM2GrPclLu ZuE2jZVRX5JkokNp6YGnZFXzB54L5w9FiX6g96zQLHlgcEyKgvfitde33WOdaQG0L3a2 YzOStd3K8B/9ug0e1UekLb/vmWIoVbpri0lEroPhT4RSnw0yoVyJahfLBF6BK+sb49Sk LLjw== X-Forwarded-Encrypted: i=1; AKwUvBy3NcMFvIONNA7pIjcda/TqWb3PsxhJdJ6oUPdKkAuucbVoub69t7yZyUh+S2JYBoSfkVwyRPwj9+2b@vger.kernel.org X-Gm-Message-State: AFuF++ls1zDg0eotMXt2WzJYFZC4rC7N3N2LwNb1qQMkyqQUjUxxZ67S Tjsd5atlL6Mbae4f9DnLR8CeX62Rwfdjb4D0w2EaK/crfPg7tmksIIT1IFpAquJqfD/9+1u5Cbq rf0q0NkLZfABKUuupklPgaw== X-Received: from edy6-n2.prod.google.com ([2002:a05:6402:5346:20b0:6a6:8ab2:8708]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6402:4284:b0:6a6:32f5:ff40 with SMTP id 4fb4d7f45d1cf-6a682af8134mr2906512a12.20.1788346274084; Wed, 02 Sep 2026 03:51:14 -0700 (PDT) Date: Wed, 2 Sep 2026 11:47:08 +0100 In-Reply-To: <20260902104712.2399797-1-vdonnefort@google.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260902104712.2399797-1-vdonnefort@google.com> X-Mailer: git-send-email 2.55.0.970.g62bdec98f9-goog Message-ID: <20260902104712.2399797-7-vdonnefort@google.com> Subject: [PATCH v9 06/10] arm64: Implement can_set_direct_map_range() From: Vincent Donnefort To: catalin.marinas@arm.com, will@kernel.org, rppt@kernel.org, akpm@linux-foundation.org, sudeep.holla@kernel.org, jenswi@kernel.org, robh@kernel.org Cc: mark.rutland@arm.com, sumit.garg@kernel.org, ardb@kernel.org, thierry.reding@kernel.org, david@kernel.org, danielmentz@google.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, op-tee@lists.trustedfirmware.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" For systems where can_set_direct_map() is false, it is still possible that a subregion of the direct map can be modified if it is mapped at the last-level. Add an implementation for can_set_direct_map_range(). It falls back to a page table walk to verify the mapping level if can_set_direct_map() is false. Signed-off-by: Vincent Donnefort diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h index 90f61b17275e..1a37f4ef130b 100644 --- a/arch/arm64/include/asm/set_memory.h +++ b/arch/arm64/include/asm/set_memory.h @@ -9,6 +9,9 @@ bool can_set_direct_map(void); #define can_set_direct_map can_set_direct_map +bool can_set_direct_map_range(struct page *page, unsigned long nr_pages); +#define can_set_direct_map_range can_set_direct_map_range + int set_memory_valid(unsigned long addr, int numpages, int enable); int set_direct_map_invalid_noflush(struct page *page); diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c index 58898ae53f5d..c59ef17eb0d0 100644 --- a/arch/arm64/mm/pageattr.c +++ b/arch/arm64/mm/pageattr.c @@ -103,6 +103,48 @@ bool can_set_direct_map(void) system_supports_bbml3(); } +bool can_set_direct_map_range(struct page *page, unsigned long nr_pages) +{ + unsigned long addr = (unsigned long)page_address(page); + unsigned long end = addr + nr_pages * PAGE_SIZE; + + if (can_set_direct_map()) + return true; + + /* + * If !can_set_direct_map() then no one can split blocks and it is safe + * to walk the page-table lockless. + */ + while (addr < end) { + pud_t *pudp, pud; + pmd_t *pmdp, pmd; + pgd_t *pgdp; + p4d_t *p4dp; + + pgdp = pgd_offset_k(addr); + if (pgd_none(READ_ONCE(*pgdp))) + return false; + + p4dp = p4d_offset(pgdp, addr); + if (p4d_none(READ_ONCE(*p4dp))) + return false; + + pudp = pud_offset(p4dp, addr); + pud = READ_ONCE(*pudp); + if (pud_none(pud) || pud_leaf(pud)) + return false; + + pmdp = pmd_offset(pudp, addr); + pmd = READ_ONCE(*pmdp); + if (pmd_none(pmd) || pmd_leaf(pmd)) + return false; + + addr = pmd_addr_end(addr, end); + } + + return true; +} + static int update_range_prot(unsigned long start, unsigned long size, pgprot_t set_mask, pgprot_t clear_mask) { -- 2.55.0.970.g62bdec98f9-goog