From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZp48UndNz88A8B6xFBKFeIkuNkAT67M/LhZ6qP4mdtrFvnlxP9yfOWSk/OPfRQhC03pQH0h ARC-Seal: i=1; a=rsa-sha256; t=1525916690; cv=none; d=google.com; s=arc-20160816; b=yLVqnWlNmPO3SAsspZQ4rIusgu4/6YL1Xn+7yV5f0JnXiXUUUyYCeO6JzADK7BiOcd 5xVpgNJzlPTba61Lk15aKZaevTsdFov89l3vyPlFZAc3SCv9iDyRzI67GpevNnvcJtLP EYmkATc7u5buNCek57YsgCaJZmndZzkvlvY1KZ5QhKqfCRvfHDGlH/Gw1ksqAuNcayyC 1n93kN27EpOKaiIE5S3OVTAlzGGC9WVM8B4/zBh8vXRg+wcqE86ebXdudj2aCQLw2li1 792bY+uJRQ0lzGVrQYO4wxL0D6jww5NQj1u7A7pyDvJ/jJ/S3ouWSC+snPxnE8GXjVRd NuMw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature:arc-authentication-results; bh=1K+9TNjwLVRAkCgZ5vXSneAJWIs9CpFSOGSiRhWSunw=; b=SBG3KUu2KVEoinGAOApv0jaGwd8aG3YfDkMH8DIIt6jIjvNfKyMwAoaPyu0wFg65KS yfBW8/nbX1a9VG8TNRp6y2PkW5tZD3FHmIvF/uEXlNaIQagdGMG0OroflNzvvn+roDiZ 9f9D6Q5SKxSsvcka3Qvj5wIThtCmUss0km/3OszCjOSNQsHDSLe5sKdriFHvUf1ODHns TiHfa57UGnNaOW48PQN+6uVrtKgAZbcYKVdOZkQnaVP+RaeCN/wU+aTM1dtAVGxpDOKd 9zNdlylPYyAMGYxr/T2BOJ3YDI6HtzGV65cmmE53CoovHiNQ3M6JwmS8da1bp1w6qXm/ CK5w== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=b5llzdOD; spf=pass (google.com: domain of mcgrof@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=mcgrof@kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=b5llzdOD; spf=pass (google.com: domain of mcgrof@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=mcgrof@kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org From: "Luis R. Rodriguez" To: arnd@arndb.de Cc: gregkh@linuxfoundation.org, willy@infradead.org, geert@linux-m68k.org, linux-m68k@lists.linux-m68k.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Luis R. Rodriguez" Subject: [PATCH v2 1/2] mm: provide a fallback for PAGE_KERNEL_RO for architectures Date: Wed, 9 May 2018 18:44:46 -0700 Message-Id: <20180510014447.15989-2-mcgrof@kernel.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180510014447.15989-1-mcgrof@kernel.org> References: <20180510014447.15989-1-mcgrof@kernel.org> X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1598946836077947117?= X-GMAIL-MSGID: =?utf-8?q?1600039619497041853?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Some architectures do not define certain PAGE_KERNEL_* flags, this is either because: a) The way to implement some these flags is *not yet ported*, or b) The architecture *has no way* to describe them Over time we have accumulated a few PAGE_KERNEL_* fallback work arounds for architectures in the kernel which do not define them using *relatively safe* equivalents. Move these scattered fallback hacks into asm-generic and document which architectures needs further evaluation for which PAGE_KERNEL_* flag. We start off with PAGE_KERNEL_RO using PAGE_KERNEL as a fallback. This has been in place on the firmware loader for years. Move the fallback into the respective asm-generic header. Architectures which don't define this yet: o alpha o ia64 o m68k o mips o sparc64 o sparc Signed-off-by: Luis R. Rodriguez --- drivers/base/firmware_loader/fallback.c | 5 ----- include/asm-generic/pgtable.h | 24 ++++++++++++++++++++++++ 2 files changed, 24 insertions(+), 5 deletions(-) diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c index 358354148dec..36f016b753e0 100644 --- a/drivers/base/firmware_loader/fallback.c +++ b/drivers/base/firmware_loader/fallback.c @@ -219,11 +219,6 @@ static ssize_t firmware_loading_show(struct device *dev, return sprintf(buf, "%d\n", loading); } -/* Some architectures don't have PAGE_KERNEL_RO */ -#ifndef PAGE_KERNEL_RO -#define PAGE_KERNEL_RO PAGE_KERNEL -#endif - /* one pages buffer should be mapped/unmapped only once */ static int map_fw_priv_pages(struct fw_priv *fw_priv) { diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index f59639afaa39..890fc54f4713 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -1083,6 +1083,30 @@ int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, static inline void init_espfix_bsp(void) { } #endif +/* + * Architecture PAGE_KERNEL_* fallbacks + * + * Some architectures don't define certain PAGE_KERNEL_* flags. This is either + * because they really don't support them, or the port needs to be updated to + * reflect the required functionality. Below are a set of relatively safe + * fallbacks, as best effort, which we can count on in lieu of the architectures + * not defining them on their own yet. + */ + +/* + * Current architectures known to not define PAGE_KERNEL_RO: + * + * o alpha + * o ia64 + * o m68k + * o mips + * o sparc64 + * o sparc + */ +#ifndef PAGE_KERNEL_RO +# define PAGE_KERNEL_RO PAGE_KERNEL +#endif + #endif /* !__ASSEMBLY__ */ #ifndef io_remap_pfn_range -- 2.17.0