[PATCH 3.13.y-ckt 014/121] ARM: pxa: fix hang on startup with DEBUG_LL

From: Kamal Mostafa
Date: Tue Dec 02 2014 - 15:00:52 EST

3.13.11-ckt12 -stable review patch. If anyone has any objections, please let me know.


From: Robert Jarzmik <robert.jarzmik@xxxxxxx>

commit cde7fc879969f933614b1256df2625d6ff637bab upstream.

The commit 2111667b4677 ("ARM: pxa: call debug_ll_io_init for
earlyprintk") triggers in the current kernel the attached backtrace on
PXA/tosa early in the boot time when DEBUG_LL is enabled.

It is due to overlap between uart virtual memory defined in
DEBUG_UART_VIRT and mapped by debug_ll_io_init() and peripheral bus
mapped by pxa_map_io at the same address, 0xf2100000.

As hinted by Arnd, map early virtual memory for low level debug on
address 0xf6200000, even if that means 2 virtual mappings will give
access to the pxa internal UARTs (FFUART, BTUART, STUART, ...).

------------[ cut here ]------------
kernel BUG at /home/lumag/linux/mm/vmalloc.c:1143!
Internal error: Oops - BUG: 0 [#1] PREEMPT ARM
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 3.17.0-00032-g8e0d202-dirty #23
task: c062a5a8 ti: c0620000 task.ti: c0620000
PC is at vm_area_add_early+0x54/0x84
LR is at add_static_vm_early+0xc/0x60
pc : [<c03e1100>] lr : [<c03d9ef4>] psr: 800001d3
sp : c0621f04 ip : c03efa74 fp : c03edf84
r10: c0637e98 r9 : 40000001 r8 : c03da57c
r7 : c3ffcfb0 r6 : 00000000 r5 : c3ffcfb0 r4 : 02000000
r3 : c3ffcfd8 r2 : f2100000 r1 : f4000000 r0 : c3ffcfb0
Flags: Nzcv IRQs off FIQs off Mode SVC_32 ISA ARM Segment kernel
Control: 00007977 Table: a0004000 DAC: 00000017
Process swapper (pid: 0, stack limit = 0xc06201c8)
Stack: (0xc0621f04 to 0xc0622000)
1f00: c3ffcfd8 40000001 c3ffcfd8 c03ee08c c03da570 c03db90c c0637d24
1f20: 00000000 c03ec7cc c066e654 a0700000 000a0700 c03db914 c03db90c c03daf84
1f40: 00000000 000a0000 c0000000 c03ec7cc 000a0700 c0700000 ffff1000 000a3fff
1f60: 00001000 00000007 00000000 c03ec7cc c0008000 c03ed748 c0621fd4 c03d5d18
1f80: 69052d00 a03ec48c 00000000 c03d8ad0 0000006c 00007977 c036c6e8 00000001
1fa0: c0621fd4 c03ed744 c0628000 a0004000 69052d00 a03ec48c 00000000 c03d68d4
1fc0: 00000000 00000000 00000000 00000000 00000000 c03ed748 c0649894 c062801c
1fe0: c03ed744 c062b2f0 a0004000 69052d00 a03ec48c a0008040 00000000 00000000
[<c03e1100>] (vm_area_add_early) from [<c03d9ef4>] (add_static_vm_early+0xc/0x60)
[<c03d9ef4>] (add_static_vm_early) from [<c03da570>] (iotable_init.part.6+0xa8/0xb4)
[<c03da570>] (iotable_init.part.6) from [<c03db914>] (pxa25x_map_io+0x8/0x24)
[<c03db914>] (pxa25x_map_io) from [<c03daf84>] (paging_init+0x744/0x8d8)
[<c03daf84>] (paging_init) from [<c03d8ad0>] (setup_arch+0x354/0x608)
[<c03d8ad0>] (setup_arch) from [<c03d68d4>] (start_kernel+0xa8/0x3dc)
[<c03d68d4>] (start_kernel) from [<a0008040>] (0xa0008040)
Code: e5904008 e0811004 e1520001 2a000005 (e7f001f2)
---[ end trace f24b6c88ae00fa9a ]---
Kernel panic - not syncing: Attempted to kill the idle task!
---[ end Kernel panic - not syncing: Attempted to kill the idle task!

Reported-by: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx>
Signed-off-by: Robert Jarzmik <robert.jarzmik@xxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
arch/arm/Kconfig.debug | 2 +-
arch/arm/mach-pxa/include/mach/addr-map.h | 5 +++++
2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 5765abf..ae15787 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -1033,7 +1033,7 @@ config DEBUG_UART_VIRT
default 0xf1600000 if ARCH_INTEGRATOR
default 0xf1c28000 if DEBUG_SUNXI_UART0
default 0xf1c28400 if DEBUG_SUNXI_UART1
- default 0xf2100000 if DEBUG_PXA_UART1
+ default 0xf6200000 if DEBUG_PXA_UART1
default 0xf4090000 if ARCH_LPC32XX
default 0xf4200000 if ARCH_GEMINI
default 0xf8009000 if DEBUG_VEXPRESS_UART0_CA9
diff --git a/arch/arm/mach-pxa/include/mach/addr-map.h b/arch/arm/mach-pxa/include/mach/addr-map.h
index bbf9df3..d28fe29 100644
--- a/arch/arm/mach-pxa/include/mach/addr-map.h
+++ b/arch/arm/mach-pxa/include/mach/addr-map.h
@@ -39,6 +39,11 @@
#define DMEMC_SIZE 0x00100000

+ * Reserved space for low level debug virtual addresses within
+ * 0xf6200000..0xf6201000
+ */
* Internal Memory Controller (PXA27x and later)
#define IMEMC_PHYS 0x58000000

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