releases/4.8.5/soc-fsl-qe-fix-oops-on-cpm1-and-likely-cpm2.patch

   1 From 4d486e0083796b54d5aeddd7a5794f897fca1008 Mon Sep 17 00:00:00 2001
   2 From: Christophe Leroy <christophe.leroy@c-s.fr>
   3 Date: Tue, 16 Aug 2016 08:26:20 +0200
   4 Subject: soc/fsl/qe: fix Oops on CPM1 (and likely CPM2)
   5
   6 From: Christophe Leroy <christophe.leroy@c-s.fr>
   7
   8 commit 4d486e0083796b54d5aeddd7a5794f897fca1008 upstream.
   9
  10 Commit 0e6e01ff694ee ("CPM/QE: use genalloc to manage CPM/QE muram")
  11 has changed the way muram is managed.
  12 genalloc uses kmalloc(), hence requires the SLAB to be up and running.
  13
  14 On powerpc 8xx, cpm_reset() is called early during startup.
  15 cpm_reset() then calls cpm_muram_init() before SLAB is available,
  16 hence the following Oops.
  17
  18 cpm_reset() cannot be called during initcalls because the CPM is
  19 needed for console.
  20
  21 This patch removes the call to cpm_muram_init() from cpm_reset().
  22 cpm_muram_init() will be called from a new function called cpm_init()
  23 which is declared as subsys_initcall, unless cpm_muram_alloc() is
  24 called earlier for the serial console in which case cpm_muram_init()
  25 will be called from there.
  26
  27 The reason for calling it from two places is that some drivers
  28 (e.g. i2c-cpm) need some of the initialisations done by
  29 cpm_muram_init() but don't call cpm_muram_alloc(). The console
  30 driver calls cpm_muram_alloc() but some platforms might not use
  31 the CPM serial ports for console.
  32
  33 [    0.000000] Unable to handle kernel paging request for data at address 0x00000008
  34 [    0.000000] Faulting instruction address: 0xc01acce0
  35 [    0.000000] Oops: Kernel access of bad area, sig: 11 [#1]
  36 [    0.000000] PREEMPT CMPC885
  37 [    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.4.14-g0886ed8 #5
  38 [    0.000000] task: c05183e0 ti: c0536000 task.ti: c0536000
  39 [    0.000000] NIP: c01acce0 LR: c0011068 CTR: 00000000
  40 [    0.000000] REGS: c0537e50 TRAP: 0300   Not tainted (4.4.14-s3k-dev-g0886ed8-svn)
  41 [    0.000000] MSR: 00001032 <ME,IR,DR,RI>  CR: 28044428  XER: 00000000
  42 [    0.000000] DAR: 00000008 DSISR: c0000000
  43 GPR00: c0011068 c0537f00 c05183e0 00000000 00009000 ffffffff 00000bc0 ffffffff
  44 GPR08: ff003000 ff00b000 ff003bbf 00000000 22044422 100d43a8 00000000 07ff94e8
  45 GPR16: 00000000 07bb5d70 00000000 07ff81f4 07ff81f4 07ff81f4 00000000 00000000
  46 GPR24: 07ffb3a0 07fe7628 c0550000 c7ffa190 c0540000 ff003bbf 00000000 00000001
  47 [    0.000000] NIP [c01acce0] gen_pool_add_virt+0x14/0xdc
  48 [    0.000000] LR [c0011068] cpm_muram_init+0xd4/0x18c
  49 [    0.000000] Call Trace:
  50 [    0.000000] [c0537f00] [00000200] 0x200 (unreliable)
  51 [    0.000000] [c0537f20] [c0011068] cpm_muram_init+0xd4/0x18c
  52 [    0.000000] [c0537f70] [c0494684] cpm_reset+0xb4/0xc8
  53 [    0.000000] [c0537f90] [c0494c64] cmpc885_setup_arch+0x10/0x30
  54 [    0.000000] [c0537fa0] [c0493cd4] setup_arch+0x130/0x168
  55 [    0.000000] [c0537fb0] [c04906bc] start_kernel+0x88/0x380
  56 [    0.000000] [c0537ff0] [c0002224] start_here+0x38/0x98
  57 [    0.000000] Instruction dump:
  58 [    0.000000] 91430010 91430014 80010014 83e1000c 7c0803a6 38210010 4e800020 7c0802a6
  59 [    0.000000] 9421ffe0 bf61000c 90010024 7c7e1b78 <80630008> 7c9c2378 7cc31c30 3863001f
  60 [    0.000000] ---[ end trace dc8fa200cb88537f ]---
  61
  62 fixes: 0e6e01ff694ee ("CPM/QE: use genalloc to manage CPM/QE muram")
  63 Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
  64 [scottwood: Removed some string changes unrelated to bugfix]
  65 Signed-off-by: Scott Wood <oss@buserror.net>
  66 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  67
  68 ---
  69  arch/powerpc/sysdev/cpm1.c       |    2 --
  70  arch/powerpc/sysdev/cpm2.c       |    4 ----
  71  arch/powerpc/sysdev/cpm_common.c |   15 +++++++++++++++
  72  drivers/soc/fsl/qe/qe_common.c   |    8 ++++++++
  73  4 files changed, 23 insertions(+), 6 deletions(-)
  74
  75 --- a/arch/powerpc/sysdev/cpm1.c
  76 +++ b/arch/powerpc/sysdev/cpm1.c
  77 @@ -233,8 +233,6 @@ void __init cpm_reset(void)
  78         else
  79                 out_be32(&siu_conf->sc_sdcr, 1);
  80         immr_unmap(siu_conf);
  81 -
  82 -       cpm_muram_init();
  83  }
  84
  85  static DEFINE_SPINLOCK(cmd_lock);
  86 --- a/arch/powerpc/sysdev/cpm2.c
  87 +++ b/arch/powerpc/sysdev/cpm2.c
  88 @@ -66,10 +66,6 @@ void __init cpm2_reset(void)
  89         cpm2_immr = ioremap(get_immrbase(), CPM_MAP_SIZE);
  90  #endif
  91
  92 -       /* Reclaim the DP memory for our use.
  93 -        */
  94 -       cpm_muram_init();
  95 -
  96         /* Tell everyone where the comm processor resides.
  97          */
  98         cpmp = &cpm2_immr->im_cpm;
  99 --- a/arch/powerpc/sysdev/cpm_common.c
 100 +++ b/arch/powerpc/sysdev/cpm_common.c
 101 @@ -37,6 +37,21 @@
 102  #include <linux/of_gpio.h>
 103  #endif
 104
 105 +static int __init cpm_init(void)
 106 +{
 107 +       struct device_node *np;
 108 +
 109 +       np = of_find_compatible_node(NULL, NULL, "fsl,cpm1");
 110 +       if (!np)
 111 +               np = of_find_compatible_node(NULL, NULL, "fsl,cpm2");
 112 +       if (!np)
 113 +               return -ENODEV;
 114 +       cpm_muram_init();
 115 +       of_node_put(np);
 116 +       return 0;
 117 +}
 118 +subsys_initcall(cpm_init);
 119 +
 120  #ifdef CONFIG_PPC_EARLY_DEBUG_CPM
 121  static u32 __iomem *cpm_udbg_txdesc;
 122  static u8 __iomem *cpm_udbg_txbuf;
 123 --- a/drivers/soc/fsl/qe/qe_common.c
 124 +++ b/drivers/soc/fsl/qe/qe_common.c
 125 @@ -70,6 +70,11 @@ int cpm_muram_init(void)
 126         }
 127
 128         muram_pool = gen_pool_create(0, -1);
 129 +       if (!muram_pool) {
 130 +               pr_err("Cannot allocate memory pool for CPM/QE muram");
 131 +               ret = -ENOMEM;
 132 +               goto out_muram;
 133 +       }
 134         muram_pbase = of_translate_address(np, zero);
 135         if (muram_pbase == (phys_addr_t)OF_BAD_ADDR) {
 136                 pr_err("Cannot translate zero through CPM muram node");
 137 @@ -116,6 +121,9 @@ static unsigned long cpm_muram_alloc_com
 138         struct muram_block *entry;
 139         unsigned long start;
 140
 141 +       if (!muram_pool && cpm_muram_init())
 142 +               goto out2;
 143 +
 144         start = gen_pool_alloc_algo(muram_pool, size, algo, data);
 145         if (!start)
 146                 goto out2;