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From: Toshi Kani <toshi.kani@hp.com>
To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com,
	akpm@linux-foundation.org
Cc: travis@sgi.com, roland@purestorage.com, dan.j.williams@intel.com,
	mcgrof@suse.com, x86@kernel.org, linux-kernel@vger.kernel.org,
	linux-mm@kvack.org
Subject: [PATCH RESEND 0/3] mm, x86: Fix ioremap RAM check interfaces
Date: Thu, 16 Jul 2015 17:23:13 -0600	[thread overview]
Message-ID: <1437088996-28511-1-git-send-email-toshi.kani@hp.com> (raw)

ioremap() checks if a target range is in RAM and fails the request
if true.  There are multiple issues in the iormap RAM check interfaces.

 1. region_is_ram() always fails with -1.
 2. The check calls two functions, region_is_ram() and
    walk_system_ram_range(), which are redundant as both walk the
    same iomem_resource table.
 3. walk_system_ram_range() requires RAM ranges be page-aligned in
    the iomem_resource table to work properly.  This restriction
    has allowed multiple ioremaps to RAM which are page-unaligned.

This patchset solves issue 1 and 2.  It does not address issue 3,
but continues to allow the existing ioremaps to work until it is
addressed.

---
resend:
 - Rebased to 4.2-rc2 (no change needed). Modified change logs.

---
Toshi Kani (3):
  1/3 mm, x86: Fix warning in ioremap RAM check
  2/3 mm, x86: Remove region_is_ram() call from ioremap
  3/3 mm: Fix bugs in region_is_ram()

---
 arch/x86/mm/ioremap.c | 23 ++++++-----------------
 kernel/resource.c     |  6 +++---
 2 files changed, 9 insertions(+), 20 deletions(-)

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             reply	other threads:[~2015-07-16 23:24 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-16 23:23 Toshi Kani [this message]
2015-07-16 23:23 ` [PATCH RESEND 1/3] mm, x86: Fix warning in ioremap RAM check Toshi Kani
2015-07-16 23:23 ` [PATCH RESEND 2/3] mm, x86: Remove region_is_ram() call from ioremap Toshi Kani
2015-07-21 14:31   ` Thomas Gleixner
2015-07-21 15:07     ` Toshi Kani
2015-07-16 23:23 ` [PATCH RESEND 3/3] mm: Fix bugs in region_is_ram() Toshi Kani
2015-07-18  1:23 ` [PATCH RESEND 0/3] mm, x86: Fix ioremap RAM check interfaces Dan Williams

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