From 4d486e0083796b54d5aeddd7a5794f897fca1008 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Tue, 16 Aug 2016 08:26:20 +0200 Subject: soc/fsl/qe: fix Oops on CPM1 (and likely CPM2) Commit 0e6e01ff694ee ("CPM/QE: use genalloc to manage CPM/QE muram") has changed the way muram is managed. genalloc uses kmalloc(), hence requires the SLAB to be up and running. On powerpc 8xx, cpm_reset() is called early during startup. cpm_reset() then calls cpm_muram_init() before SLAB is available, hence the following Oops. cpm_reset() cannot be called during initcalls because the CPM is needed for console. This patch removes the call to cpm_muram_init() from cpm_reset(). cpm_muram_init() will be called from a new function called cpm_init() which is declared as subsys_initcall, unless cpm_muram_alloc() is called earlier for the serial console in which case cpm_muram_init() will be called from there. The reason for calling it from two places is that some drivers (e.g. i2c-cpm) need some of the initialisations done by cpm_muram_init() but don't call cpm_muram_alloc(). The console driver calls cpm_muram_alloc() but some platforms might not use the CPM serial ports for console. [ 0.000000] Unable to handle kernel paging request for data at address 0x00000008 [ 0.000000] Faulting instruction address: 0xc01acce0 [ 0.000000] Oops: Kernel access of bad area, sig: 11 [#1] [ 0.000000] PREEMPT CMPC885 [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.14-g0886ed8 #5 [ 0.000000] task: c05183e0 ti: c0536000 task.ti: c0536000 [ 0.000000] NIP: c01acce0 LR: c0011068 CTR: 00000000 [ 0.000000] REGS: c0537e50 TRAP: 0300 Not tainted (4.4.14-s3k-dev-g0886ed8-svn) [ 0.000000] MSR: 00001032 CR: 28044428 XER: 00000000 [ 0.000000] DAR: 00000008 DSISR: c0000000 GPR00: c0011068 c0537f00 c05183e0 00000000 00009000 ffffffff 00000bc0 ffffffff GPR08: ff003000 ff00b000 ff003bbf 00000000 22044422 100d43a8 00000000 07ff94e8 GPR16: 00000000 07bb5d70 00000000 07ff81f4 07ff81f4 07ff81f4 00000000 00000000 GPR24: 07ffb3a0 07fe7628 c0550000 c7ffa190 c0540000 ff003bbf 00000000 00000001 [ 0.000000] NIP [c01acce0] gen_pool_add_virt+0x14/0xdc [ 0.000000] LR [c0011068] cpm_muram_init+0xd4/0x18c [ 0.000000] Call Trace: [ 0.000000] [c0537f00] [00000200] 0x200 (unreliable) [ 0.000000] [c0537f20] [c0011068] cpm_muram_init+0xd4/0x18c [ 0.000000] [c0537f70] [c0494684] cpm_reset+0xb4/0xc8 [ 0.000000] [c0537f90] [c0494c64] cmpc885_setup_arch+0x10/0x30 [ 0.000000] [c0537fa0] [c0493cd4] setup_arch+0x130/0x168 [ 0.000000] [c0537fb0] [c04906bc] start_kernel+0x88/0x380 [ 0.000000] [c0537ff0] [c0002224] start_here+0x38/0x98 [ 0.000000] Instruction dump: [ 0.000000] 91430010 91430014 80010014 83e1000c 7c0803a6 38210010 4e800020 7c0802a6 [ 0.000000] 9421ffe0 bf61000c 90010024 7c7e1b78 <80630008> 7c9c2378 7cc31c30 3863001f [ 0.000000] ---[ end trace dc8fa200cb88537f ]--- fixes: 0e6e01ff694ee ("CPM/QE: use genalloc to manage CPM/QE muram") Cc: stable@vger.linux.org Signed-off-by: Christophe Leroy [scottwood: Removed some string changes unrelated to bugfix] Signed-off-by: Scott Wood --- arch/powerpc/sysdev/cpm_common.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'arch/powerpc/sysdev/cpm_common.c') diff --git a/arch/powerpc/sysdev/cpm_common.c b/arch/powerpc/sysdev/cpm_common.c index 947f42007734..51bf749a4f3a 100644 --- a/arch/powerpc/sysdev/cpm_common.c +++ b/arch/powerpc/sysdev/cpm_common.c @@ -37,6 +37,21 @@ #include #endif +static int __init cpm_init(void) +{ + struct device_node *np; + + np = of_find_compatible_node(NULL, NULL, "fsl,cpm1"); + if (!np) + np = of_find_compatible_node(NULL, NULL, "fsl,cpm2"); + if (!np) + return -ENODEV; + cpm_muram_init(); + of_node_put(np); + return 0; +} +subsys_initcall(cpm_init); + #ifdef CONFIG_PPC_EARLY_DEBUG_CPM static u32 __iomem *cpm_udbg_txdesc; static u8 __iomem *cpm_udbg_txbuf; -- cgit v1.2.3-59-g8ed1b