target/linux/ipq806x/patches/0002-ARM-msm-Remove-pen_release-usage.patch

   1 From 18d53dfa103e63154fb8e548d55016d6ad210d28 Mon Sep 17 00:00:00 2001
   2 From: Rohit Vaswani <rvaswani@codeaurora.org>
   3 Date: Fri, 21 Jun 2013 12:17:37 -0700
   4 Subject: [PATCH 002/182] ARM: msm: Remove pen_release usage
   5
   6 pen_release is no longer required as the synchronization
   7 is now managed by generic arm code.
   8 This is done as suggested in https://lkml.org/lkml/2013/6/4/184
   9
  10 Cc: Russell King <linux@arm.linux.org.uk>
  11 Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>
  12 Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
  13 Signed-off-by: Kumar Gala <galak@codeaurora.org>
  14 ---
  15  arch/arm/mach-msm/Makefile  |    2 +-
  16  arch/arm/mach-msm/headsmp.S |   39 ---------------------------------------
  17  arch/arm/mach-msm/hotplug.c |   31 ++++---------------------------
  18  arch/arm/mach-msm/platsmp.c |   37 +++----------------------------------
  19  4 files changed, 8 insertions(+), 101 deletions(-)
  20  delete mode 100644 arch/arm/mach-msm/headsmp.S
  21
  22 --- a/arch/arm/mach-msm/Makefile
  23 +++ b/arch/arm/mach-msm/Makefile
  24 @@ -19,7 +19,7 @@ obj-$(CONFIG_MSM_SCM) += scm.o scm-boot.
  25  CFLAGS_scm.o :=$(call as-instr,.arch_extension sec,-DREQUIRES_SEC=1)
  26
  27  obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
  28 -obj-$(CONFIG_SMP) += headsmp.o platsmp.o
  29 +obj-$(CONFIG_SMP) += platsmp.o
  30
  31  obj-$(CONFIG_MACH_TROUT) += board-trout.o board-trout-gpio.o board-trout-mmc.o devices-msm7x00.o
  32  obj-$(CONFIG_MACH_TROUT) += board-trout.o board-trout-gpio.o board-trout-mmc.o board-trout-panel.o devices-msm7x00.o
  33 --- a/arch/arm/mach-msm/headsmp.S
  34 +++ /dev/null
  35 @@ -1,39 +0,0 @@
  36 -/*
  37 - *  linux/arch/arm/mach-realview/headsmp.S
  38 - *
  39 - *  Copyright (c) 2003 ARM Limited
  40 - *  All Rights Reserved
  41 - *
  42 - * This program is free software; you can redistribute it and/or modify
  43 - * it under the terms of the GNU General Public License version 2 as
  44 - * published by the Free Software Foundation.
  45 - */
  46 -#include <linux/linkage.h>
  47 -#include <linux/init.h>
  48 -
  49 -/*
  50 - * MSM specific entry point for secondary CPUs.  This provides
  51 - * a "holding pen" into which all secondary cores are held until we're
  52 - * ready for them to initialise.
  53 - */
  54 -ENTRY(msm_secondary_startup)
  55 -       mrc     p15, 0, r0, c0, c0, 5
  56 -       and     r0, r0, #15
  57 -       adr     r4, 1f
  58 -       ldmia   r4, {r5, r6}
  59 -       sub     r4, r4, r5
  60 -       add     r6, r6, r4
  61 -pen:   ldr     r7, [r6]
  62 -       cmp     r7, r0
  63 -       bne     pen
  64 -
  65 -       /*
  66 -        * we've been released from the holding pen: secondary_stack
  67 -        * should now contain the SVC stack for this core
  68 -        */
  69 -       b       secondary_startup
  70 -ENDPROC(msm_secondary_startup)
  71 -
  72 -       .align
  73 -1:     .long   .
  74 -       .long   pen_release
  75 --- a/arch/arm/mach-msm/hotplug.c
  76 +++ b/arch/arm/mach-msm/hotplug.c
  77 @@ -24,33 +24,10 @@ static inline void cpu_leave_lowpower(vo
  78
  79  static inline void platform_do_lowpower(unsigned int cpu)
  80  {
  81 -       /* Just enter wfi for now. TODO: Properly shut off the cpu. */
  82 -       for (;;) {
  83 -               /*
  84 -                * here's the WFI
  85 -                */
  86 -               asm("wfi"
  87 -                   :
  88 -                   :
  89 -                   : "memory", "cc");
  90 -
  91 -               if (pen_release == cpu_logical_map(cpu)) {
  92 -                       /*
  93 -                        * OK, proper wakeup, we're done
  94 -                        */
  95 -                       break;
  96 -               }
  97 -
  98 -               /*
  99 -                * getting here, means that we have come out of WFI without
 100 -                * having been woken up - this shouldn't happen
 101 -                *
 102 -                * The trouble is, letting people know about this is not really
 103 -                * possible, since we are currently running incoherently, and
 104 -                * therefore cannot safely call printk() or anything else
 105 -                */
 106 -               pr_debug("CPU%u: spurious wakeup call\n", cpu);
 107 -       }
 108 +       asm("wfi"
 109 +           :
 110 +           :
 111 +           : "memory", "cc");
 112  }
 113
 114  /*
 115 --- a/arch/arm/mach-msm/platsmp.c
 116 +++ b/arch/arm/mach-msm/platsmp.c
 117 @@ -12,13 +12,10 @@
 118  #include <linux/errno.h>
 119  #include <linux/delay.h>
 120  #include <linux/device.h>
 121 -#include <linux/jiffies.h>
 122  #include <linux/smp.h>
 123  #include <linux/io.h>
 124
 125 -#include <asm/cacheflush.h>
 126  #include <asm/cputype.h>
 127 -#include <asm/mach-types.h>
 128  #include <asm/smp_plat.h>
 129
 130  #include "scm-boot.h"
 131 @@ -28,7 +25,7 @@
 132  #define SCSS_CPU1CORE_RESET 0xD80
 133  #define SCSS_DBG_STATUS_CORE_PWRDUP 0xE64
 134
 135 -extern void msm_secondary_startup(void);
 136 +extern void secondary_startup(void);
 137
 138  static DEFINE_SPINLOCK(boot_lock);
 139
 140 @@ -41,13 +38,6 @@ static inline int get_core_count(void)
 141  static void msm_secondary_init(unsigned int cpu)
 142  {
 143         /*
 144 -        * let the primary processor know we're out of the
 145 -        * pen, then head off into the C entry point
 146 -        */
 147 -       pen_release = -1;
 148 -       smp_wmb();
 149 -
 150 -       /*
 151          * Synchronise with the boot thread.
 152          */
 153         spin_lock(&boot_lock);
 154 @@ -57,7 +47,7 @@ static void msm_secondary_init(unsigned
 155  static void prepare_cold_cpu(unsigned int cpu)
 156  {
 157         int ret;
 158 -       ret = scm_set_boot_addr(virt_to_phys(msm_secondary_startup),
 159 +       ret = scm_set_boot_addr(virt_to_phys(secondary_startup),
 160                                 SCM_FLAG_COLDBOOT_CPU1);
 161         if (ret == 0) {
 162                 void __iomem *sc1_base_ptr;
 163 @@ -75,7 +65,6 @@ static void prepare_cold_cpu(unsigned in
 164
 165  static int msm_boot_secondary(unsigned int cpu, struct task_struct *idle)
 166  {
 167 -       unsigned long timeout;
 168         static int cold_boot_done;
 169
 170         /* Only need to bring cpu out of reset this way once */
 171 @@ -91,39 +80,19 @@ static int msm_boot_secondary(unsigned i
 172         spin_lock(&boot_lock);
 173
 174         /*
 175 -        * The secondary processor is waiting to be released from
 176 -        * the holding pen - release it, then wait for it to flag
 177 -        * that it has been released by resetting pen_release.
 178 -        *
 179 -        * Note that "pen_release" is the hardware CPU ID, whereas
 180 -        * "cpu" is Linux's internal ID.
 181 -        */
 182 -       pen_release = cpu_logical_map(cpu);
 183 -       sync_cache_w(&pen_release);
 184 -
 185 -       /*
 186          * Send the secondary CPU a soft interrupt, thereby causing
 187          * the boot monitor to read the system wide flags register,
 188          * and branch to the address found there.
 189          */
 190         arch_send_wakeup_ipi_mask(cpumask_of(cpu));
 191
 192 -       timeout = jiffies + (1 * HZ);
 193 -       while (time_before(jiffies, timeout)) {
 194 -               smp_rmb();
 195 -               if (pen_release == -1)
 196 -                       break;
 197 -
 198 -               udelay(10);
 199 -       }
 200 -
 201         /*
 202          * now the secondary core is starting up let it run its
 203          * calibrations, then wait for it to finish
 204          */
 205         spin_unlock(&boot_lock);
 206
 207 -       return pen_release != -1 ? -ENOSYS : 0;
 208 +       return 0;
 209  }
 210
 211  /*