From: "Luis R. Rodriguez" <mcgrof@kernel.org>
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" <mcgrof@kernel.org>
Subject: [PATCH v3 1/2] mm: provide a fallback for PAGE_KERNEL_RO for architectures
Date: Thu, 10 May 2018 11:55:06 -0700 [thread overview]
Message-ID: <20180510185507.2439-2-mcgrof@kernel.org> (raw)
In-Reply-To: <20180510185507.2439-1-mcgrof@kernel.org>
Some architectures do not define certain PAGE_KERNEL_* flags, this is
either because:
a) The way to implement some of 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.
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.
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
---
drivers/base/firmware_loader/fallback.c | 5 -----
include/asm-generic/pgtable.h | 14 ++++++++++++++
2 files changed, 14 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..4e310e543fc8 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -1083,6 +1083,20 @@ 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.
+ */
+
+#ifndef PAGE_KERNEL_RO
+# define PAGE_KERNEL_RO PAGE_KERNEL
+#endif
+
#endif /* !__ASSEMBLY__ */
#ifndef io_remap_pfn_range
--
2.17.0
next prev parent reply other threads:[~2018-05-10 18:55 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-10 18:55 [PATCH v3 0/2] mm: PAGE_KERNEL_* fallbacks Luis R. Rodriguez
2018-05-10 18:55 ` Luis R. Rodriguez [this message]
2018-05-10 18:55 ` [PATCH v3 2/2] mm: provide a fallback for PAGE_KERNEL_EXEC for architectures Luis R. Rodriguez
2018-05-16 16:44 ` [PATCH v3 0/2] mm: PAGE_KERNEL_* fallbacks Luis R. Rodriguez
2018-05-23 21:35 ` Luis R. Rodriguez
2018-05-30 19:55 ` Luis R. Rodriguez
2018-05-30 20:06 ` Greg KH
2018-05-30 20:21 ` Luis R. Rodriguez
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180510185507.2439-2-mcgrof@kernel.org \
--to=mcgrof@kernel.org \
--cc=arnd@arndb.de \
--cc=geert@linux-m68k.org \
--cc=gregkh@linuxfoundation.org \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-m68k@lists.linux-m68k.org \
--cc=linux-mm@kvack.org \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).