target/linux/bcm53xx/patches-4.4/300-ARM-BCM5301X-Disable-MMU-and-Dcache-for-decompression.patch

   1 From: Florian Fainelli <f.fainelli@gmail.com>
   2 Subject: [PATCH] ARM: BCM5301x: Disable MMU and Dcache during decompression
   3 Date: Tue, 14 Jul 2015 16:12:08 -0700
   4
   5 Use the existing __armv7_mmu_cache_flush() to perform the cache flush
   6 since this does what we are after.
   7
   8 Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
   9 ---
  10  arch/arm/boot/compressed/Makefile                |  4 +++
  11  arch/arm/boot/compressed/head-bcm_5301x-mpcore.S | 37 ++++++++++++++++++++++++
  12  arch/arm/boot/compressed/head.S                  |  2 ++
  13  3 files changed, 43 insertions(+)
  14  create mode 100644 arch/arm/boot/compressed/head-bcm_5301x-mpcore.S
  15
  16 --- a/arch/arm/boot/compressed/Makefile
  17 +++ b/arch/arm/boot/compressed/Makefile
  18 @@ -31,6 +31,10 @@ ifeq ($(CONFIG_ARCH_ACORN),y)
  19  OBJS           += ll_char_wr.o font.o
  20  endif
  21
  22 +ifeq ($(CONFIG_ARCH_BCM_5301X),y)
  23 +OBJS           += head-bcm_5301x-mpcore.o
  24 +endif
  25 +
  26  ifeq ($(CONFIG_ARCH_SA1100),y)
  27  OBJS           += head-sa1100.o
  28  endif
  29 --- /dev/null
  30 +++ b/arch/arm/boot/compressed/head-bcm_5301x-mpcore.S
  31 @@ -0,0 +1,37 @@
  32 +/*
  33 + *
  34 + * Platform specific tweaks.  This is merged into head.S by the linker.
  35 + *
  36 + */
  37 +
  38 +#include <linux/linkage.h>
  39 +#include <asm/assembler.h>
  40 +#include <asm/cp15.h>
  41 +
  42 +               .section        ".start", "ax"
  43 +
  44 +/*
  45 + * This code section is spliced into the head code by the linker
  46 + */
  47 +
  48 +__plat_uncompress_start:
  49 +
  50 +       @ Preserve r8/r7 i.e. kernel entry values
  51 +       mov     r12, r8
  52 +
  53 +       @ Clear MMU enable and Dcache enable bits
  54 +       mrc     p15, 0, r0, c1, c0, 0           @ Read SCTLR
  55 +       bic     r0, #CR_C|CR_M
  56 +       mcr     p15, 0, r0, c1, c0, 0           @ Write SCTLR
  57 +       nop
  58 +
  59 +       @ Call the cache invalidation routine
  60 +       bl      __armv7_mmu_cache_flush_fn
  61 +       nop
  62 +       mov     r0,#0
  63 +       ldr     r3, =0x19022000                 @ L2 cache controller, control reg
  64 +       str     r0, [r3, #0x100]                @ Disable L2 cache
  65 +       nop
  66 +
  67 +       @ Restore
  68 +       mov     r8, r12
  69 --- a/arch/arm/boot/compressed/head.S
  70 +++ b/arch/arm/boot/compressed/head.S
  71 @@ -1152,6 +1152,7 @@ __armv7_mmu_cache_flush:
  72  hierarchical:
  73                 mcr     p15, 0, r10, c7, c10, 5 @ DMB
  74                 stmfd   sp!, {r0-r7, r9-r11}
  75 +ENTRY(__armv7_mmu_cache_flush_fn)
  76                 mrc     p15, 1, r0, c0, c0, 1   @ read clidr
  77                 ands    r3, r0, #0x7000000      @ extract loc from clidr
  78                 mov     r3, r3, lsr #23         @ left align loc bit field
  79 @@ -1201,6 +1202,7 @@ iflush:
  80                 mcr     p15, 0, r10, c7, c10, 4 @ DSB
  81                 mcr     p15, 0, r10, c7, c5, 4  @ ISB
  82                 mov     pc, lr
  83 +ENDPROC(__armv7_mmu_cache_flush_fn)
  84
  85  __armv5tej_mmu_cache_flush:
  86                 tst     r4, #1