linux-kernel - [PATCH v3 RESEND 16/17] ARM: mm: cleanup checks for membank overlap with vmalloc area

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Message-ID: <1348242975-19184-17-git-send-email-cyril@ti.com>
Date:	Fri, 21 Sep 2012 11:56:14 -0400
From:	Cyril Chemparathy <cyril@...com>
To:	<linux@....linux.org.uk>
CC:	<linux-arm-kernel@...ts.infradead.org>,
	<linux-kernel@...r.kernel.org>, <arnd@...db.de>,
	<catalin.marinas@....com>, <davidb@...eaurora.org>,
	<frank.rowand@...sony.com>, <hsweeten@...ionengravers.com>,
	<linus.walleij@...aro.org>, <marc.zyngier@....com>,
	<nico@...aro.org>, <paul.gortmaker@...driver.com>,
	<plagnioj@...osoft.com>, <rabin@....in>, <rmallon@...il.com>,
	<rob.herring@...xeda.com>, <sboyd@...eaurora.org>,
	<sjg@...omium.org>, <tglx@...utronix.de>, <tj@...nel.org>,
	<vincent.guittot@...aro.org>, <vitalya@...com>,
	<will.deacon@....com>, <grant.likely@...retlab.ca>,
	Cyril Chemparathy <cyril@...com>
Subject: [PATCH v3 RESEND 16/17] ARM: mm: cleanup checks for membank overlap with vmalloc area

On Keystone platforms, physical memory is entirely outside the 32-bit
addressible range.  Therefore, the (bank->start > ULONG_MAX) check below marks
the entire system memory as highmem, and this causes unpleasentness all over.

This patch eliminates the extra bank start check (against ULONG_MAX) by
checking bank->start against the physical address corresponding to vmalloc_min
instead.

In the process, this patch also cleans up parts of the highmem sanity check
code by removing what has now become a redundant check for banks that entirely
overlap with the vmalloc range.

Signed-off-by: Cyril Chemparathy <cyril@...com>
Signed-off-by: Vitaly Andrianov <vitalya@...com>
Acked-by: Nicolas Pitre <nico@...aro.org>
---
 arch/arm/mm/mmu.c |   19 +------------------
 1 file changed, 1 insertion(+), 18 deletions(-)

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index fcdc185..e631f73 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -901,15 +901,12 @@ void __init sanity_check_meminfo(void)
 		struct membank *bank = &meminfo.bank[j];
 		*bank = meminfo.bank[i];
 
-		if (bank->start > ULONG_MAX)
-			highmem = 1;
-
-#ifdef CONFIG_HIGHMEM
 		if (bank->start >= vmalloc_limit)
 			highmem = 1;
 
 		bank->highmem = highmem;
 
+#ifdef CONFIG_HIGHMEM
 		/*
 		 * Split those memory banks which are partially overlapping
 		 * the vmalloc area greatly simplifying things later.
@@ -932,8 +929,6 @@ void __init sanity_check_meminfo(void)
 			bank->size = vmalloc_limit - bank->start;
 		}
 #else
-		bank->highmem = highmem;
-
 		/*
 		 * Highmem banks not allowed with !CONFIG_HIGHMEM.
 		 */
@@ -946,18 +941,6 @@ void __init sanity_check_meminfo(void)
 		}
 
 		/*
-		 * Check whether this memory bank would entirely overlap
-		 * the vmalloc area.
-		 */
-		if (bank->start >= vmalloc_limit) {
-			printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx "
-			       "(vmalloc region overlap).\n",
-			       (unsigned long long)bank->start,
-			       (unsigned long long)bank->start + bank->size - 1);
-			continue;
-		}
-
-		/*
 		 * Check whether this memory bank would partially overlap
 		 * the vmalloc area.
 		 */
-- 
1.7.9.5

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