target/linux/generic/pending-4.4/093-MIPS-store-the-appended-dtb-address-in-a-variable.patch

   1 From 15f37e1588920e010f20b53f04af94e91b8ee714 Mon Sep 17 00:00:00 2001
   2 From: Jonas Gorski <jogo@openwrt.org>
   3 Date: Mon, 20 Jun 2016 11:27:37 +0200
   4 Subject: [PATCH] MIPS: store the appended dtb address in a variable
   5
   6 Instead of rewriting the arguments to match the UHI spec, store the
   7 address of a appended or UHI supplied dtb in fw_supplied_dtb.
   8
   9 That way the original bootloader arugments are kept intact while still
  10 making the use of an appended dtb invisible for mach code.
  11
  12 Mach code can still find out if it is an appended dtb by comparing
  13 fw_arg1 with fw_supplied_dtb.
  14
  15 Signed-off-by: Jonas Gorski <jogo@openwrt.org>
  16 Cc: Kevin Cernekee <cernekee@gmail.com>
  17 Cc: Florian Fainelli <f.fainelli@gmail.com>
  18 Cc: John Crispin <john@phrozen.org>
  19 Cc: Paul Burton <paul.burton@imgtec.com>
  20 Cc: James Hogan <james.hogan@imgtec.com>
  21 Cc: Alban Bedel <albeu@free.fr>
  22 Cc: Daniel Gimpelevich <daniel@gimpelevich.san-francisco.ca.us>
  23 Cc: Antony Pavlov <antonynpavlov@gmail.com>
  24 Cc: linux-mips@linux-mips.org
  25 Patchwork: https://patchwork.linux-mips.org/patch/13699/
  26 Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
  27 ---
  28  arch/mips/ath79/setup.c          |  4 ++--
  29  arch/mips/bmips/setup.c          |  4 ++--
  30  arch/mips/include/asm/bootinfo.h |  4 ++++
  31  arch/mips/kernel/head.S          | 21 ++++++++++++++-------
  32  arch/mips/kernel/setup.c         |  4 ++++
  33  arch/mips/lantiq/prom.c          |  4 ++--
  34  arch/mips/pic32/pic32mzda/init.c |  4 ++--
  35  7 files changed, 30 insertions(+), 15 deletions(-)
  36
  37 --- a/arch/mips/ath79/setup.c
  38 +++ b/arch/mips/ath79/setup.c
  39 @@ -207,6 +207,8 @@ void __init plat_mem_setup(void)
  40         fdt_start = fw_getenvl("fdt_start");
  41         if (fdt_start)
  42                 __dt_setup_arch((void *)KSEG0ADDR(fdt_start));
  43 +       else if (fw_passed_dtb)
  44 +               __dt_setup_arch((void *)KSEG0ADDR(fw_passed_dtb));
  45  #ifdef CONFIG_BUILTIN_DTB
  46         else
  47                 __dt_setup_arch(__dtb_start);
  48 --- a/arch/mips/bmips/setup.c
  49 +++ b/arch/mips/bmips/setup.c
  50 @@ -149,8 +149,8 @@ void __init plat_mem_setup(void)
  51         /* intended to somewhat resemble ARM; see Documentation/arm/Booting */
  52         if (fw_arg0 == 0 && fw_arg1 == 0xffffffff)
  53                 dtb = phys_to_virt(fw_arg2);
  54 -       else if (fw_arg0 == -2) /* UHI interface */
  55 -               dtb = (void *)fw_arg1;
  56 +       else if (fw_passed_dtb) /* UHI interface */
  57 +               dtb = (void *)fw_passed_dtb;
  58         else if (__dtb_start != __dtb_end)
  59                 dtb = (void *)__dtb_start;
  60         else
  61 --- a/arch/mips/include/asm/bootinfo.h
  62 +++ b/arch/mips/include/asm/bootinfo.h
  63 @@ -127,6 +127,10 @@ extern char arcs_cmdline[COMMAND_LINE_SI
  64   */
  65  extern unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;
  66
  67 +#ifdef CONFIG_USE_OF
  68 +extern unsigned long fw_passed_dtb;
  69 +#endif
  70 +
  71  /*
  72   * Platform memory detection hook called by setup_arch
  73   */
  74 --- a/arch/mips/kernel/head.S
  75 +++ b/arch/mips/kernel/head.S
  76 @@ -94,21 +94,24 @@ NESTED(kernel_entry, 16, sp)                        # kernel
  77         jr      t0
  78  0:
  79
  80 +#ifdef CONFIG_USE_OF
  81  #ifdef CONFIG_MIPS_RAW_APPENDED_DTB
  82 -       PTR_LA          t0, __appended_dtb
  83 +       PTR_LA          t2, __appended_dtb
  84
  85  #ifdef CONFIG_CPU_BIG_ENDIAN
  86         li              t1, 0xd00dfeed
  87  #else
  88         li              t1, 0xedfe0dd0
  89  #endif
  90 -       lw              t2, (t0)
  91 -       bne             t1, t2, not_found
  92 -        nop
  93 -
  94 -       move            a1, t0
  95 -       PTR_LI          a0, -2
  96 -not_found:
  97 +       lw              t0, (t2)
  98 +       beq             t0, t1, dtb_found
  99 +#endif
 100 +       li              t1, -2
 101 +       beq             a0, t1, dtb_found
 102 +       move            t2, a1
 103 +
 104 +       li              t2, 0
 105 +dtb_found:
 106  #endif
 107         PTR_LA          t0, __bss_start         # clear .bss
 108         LONG_S          zero, (t0)
 109 @@ -123,6 +126,10 @@ not_found:
 110         LONG_S          a2, fw_arg2
 111         LONG_S          a3, fw_arg3
 112
 113 +#ifdef CONFIG_USE_OF
 114 +       LONG_S          t2, fw_passed_dtb
 115 +#endif
 116 +
 117         MTC0            zero, CP0_CONTEXT       # clear context register
 118         PTR_LA          $28, init_thread_union
 119         /* Set the SP after an empty pt_regs.  */
 120 --- a/arch/mips/kernel/setup.c
 121 +++ b/arch/mips/kernel/setup.c
 122 @@ -886,6 +886,10 @@ void __init setup_arch(char **cmdline_p)
 123  unsigned long kernelsp[NR_CPUS];
 124  unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;
 125
 126 +#ifdef CONFIG_USE_OF
 127 +unsigned long fw_passed_dtb;
 128 +#endif
 129 +
 130  #ifdef CONFIG_DEBUG_FS
 131  struct dentry *mips_debugfs_dir;
 132  static int __init debugfs_mips(void)