linux-kernel - [PATCH] fsl: mpc85xx: call k(un)map

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Message-ID: <1425285335-21753-1-git-send-email-yanjiang.jin@windriver.com>
Date:	Mon, 2 Mar 2015 16:35:35 +0800
From:	<yanjiang.jin@...driver.com>
To:	<mpe@...erman.id.au>, <scottwood@...escale.com>
CC:	<msm@...escale.com>, <galak@...nel.crashing.org>,
	<benh@...nel.crashing.org>, <linuxppc-dev@...ts.ozlabs.org>,
	<linux-kernel@...r.kernel.org>
Subject: [PATCH] fsl: mpc85xx: call k(un)map_atomic other than k(un)map

From: Yanjiang Jin <yanjiang.jin@...driver.com>

The k(un)map function may be called in atomic context in the
function map_and_flush(), so use k(un)map_atomic to replace it,
else we would get the below warning during kdump:

BUG: sleeping function called from invalid context at include/linux/highmem.h:58
in_atomic(): 1, irqs_disabled(): 1, pid: 736, name: sh
INFO: lockdep is turned off.
irq event stamp: 0
hardirqs last  enabled at (0): [<          (null)>]           (null)
hardirqs last disabled at (0): [<c000000000066d1c>] .copy_process.part.44+0x50c/0x1360
softirqs last  enabled at (0): [<c000000000066d1c>] .copy_process.part.44+0x50c/0x1360
softirqs last disabled at (0): [<          (null)>]           (null)
CPU: 1 PID: 736 Comm: sh Tainted: G      D W    3.10.62-ltsi-WR6.0.0.0_standard #2
Call Trace:
[c0000000f47cf120] [c00000000000b150] .show_stack+0x170/0x290 (unreliable)
[c0000000f47cf210] [c000000000b71334] .dump_stack+0x28/0x3c
[c0000000f47cf280] [c0000000000bb5d8] .__might_sleep+0x1a8/0x270
[c0000000f47cf310] [c0000000000440cc] .map_and_flush+0x4c/0xc0
[c0000000f47cf390] [c0000000000441cc] .mpc85xx_smp_machine_kexec+0x8c/0xec0
[c0000000f47cf420] [c00000000002ae00] .machine_kexec+0x60/0x90
[c0000000f47cf4b0] [c00000000010957c] .crash_kexec+0x8c/0x100
[c0000000f47cf6a0] [c000000000015df8] .die+0x348/0x450
[c0000000f47cf740] [c00000000002f3a0] .bad_page_fault+0xe0/0x130
[c0000000f47cf7c0] [c00000000001f3e4] storage_fault_common+0x40/0x44

Signed-off-by: Yanjiang Jin <yanjiang.jin@...driver.com>
---
 arch/powerpc/platforms/85xx/smp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
index d7c1e69..8631ac5 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -360,10 +360,10 @@ static void mpc85xx_smp_kexec_down(void *arg)
 static void map_and_flush(unsigned long paddr)
 {
 	struct page *page = pfn_to_page(paddr >> PAGE_SHIFT);
-	unsigned long kaddr  = (unsigned long)kmap(page);
+	unsigned long kaddr  = (unsigned long)kmap_atomic(page);
 
 	flush_dcache_range(kaddr, kaddr + PAGE_SIZE);
-	kunmap(page);
+	kunmap_atomic((void *)kaddr);
 }
 
 /**
-- 
1.9.1

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