From 18d53dfa103e63154fb8e548d55016d6ad210d28 Mon Sep 17 00:00:00 2001 From: Rohit Vaswani Date: Fri, 21 Jun 2013 12:17:37 -0700 Subject: [PATCH 002/182] ARM: msm: Remove pen_release usage pen_release is no longer required as the synchronization is now managed by generic arm code. This is done as suggested in https://lkml.org/lkml/2013/6/4/184 Cc: Russell King Signed-off-by: Rohit Vaswani Signed-off-by: Stephen Boyd Signed-off-by: Kumar Gala --- arch/arm/mach-msm/Makefile | 2 +- arch/arm/mach-msm/headsmp.S | 39 --------------------------------------- arch/arm/mach-msm/hotplug.c | 31 ++++--------------------------- arch/arm/mach-msm/platsmp.c | 37 +++---------------------------------- 4 files changed, 8 insertions(+), 101 deletions(-) delete mode 100644 arch/arm/mach-msm/headsmp.S --- a/arch/arm/mach-msm/Makefile +++ b/arch/arm/mach-msm/Makefile @@ -19,7 +19,7 @@ obj-$(CONFIG_MSM_SCM) += scm.o scm-boot. CFLAGS_scm.o :=$(call as-instr,.arch_extension sec,-DREQUIRES_SEC=1) obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o -obj-$(CONFIG_SMP) += headsmp.o platsmp.o +obj-$(CONFIG_SMP) += platsmp.o obj-$(CONFIG_MACH_TROUT) += board-trout.o board-trout-gpio.o board-trout-mmc.o devices-msm7x00.o obj-$(CONFIG_MACH_TROUT) += board-trout.o board-trout-gpio.o board-trout-mmc.o board-trout-panel.o devices-msm7x00.o --- a/arch/arm/mach-msm/headsmp.S +++ /dev/null @@ -1,39 +0,0 @@ -/* - * linux/arch/arm/mach-realview/headsmp.S - * - * Copyright (c) 2003 ARM Limited - * All Rights Reserved - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ -#include -#include - -/* - * MSM specific entry point for secondary CPUs. This provides - * a "holding pen" into which all secondary cores are held until we're - * ready for them to initialise. - */ -ENTRY(msm_secondary_startup) - mrc p15, 0, r0, c0, c0, 5 - and r0, r0, #15 - adr r4, 1f - ldmia r4, {r5, r6} - sub r4, r4, r5 - add r6, r6, r4 -pen: ldr r7, [r6] - cmp r7, r0 - bne pen - - /* - * we've been released from the holding pen: secondary_stack - * should now contain the SVC stack for this core - */ - b secondary_startup -ENDPROC(msm_secondary_startup) - - .align -1: .long . - .long pen_release --- a/arch/arm/mach-msm/hotplug.c +++ b/arch/arm/mach-msm/hotplug.c @@ -24,33 +24,10 @@ static inline void cpu_leave_lowpower(vo static inline void platform_do_lowpower(unsigned int cpu) { - /* Just enter wfi for now. TODO: Properly shut off the cpu. */ - for (;;) { - /* - * here's the WFI - */ - asm("wfi" - : - : - : "memory", "cc"); - - if (pen_release == cpu_logical_map(cpu)) { - /* - * OK, proper wakeup, we're done - */ - break; - } - - /* - * getting here, means that we have come out of WFI without - * having been woken up - this shouldn't happen - * - * The trouble is, letting people know about this is not really - * possible, since we are currently running incoherently, and - * therefore cannot safely call printk() or anything else - */ - pr_debug("CPU%u: spurious wakeup call\n", cpu); - } + asm("wfi" + : + : + : "memory", "cc"); } /* --- a/arch/arm/mach-msm/platsmp.c +++ b/arch/arm/mach-msm/platsmp.c @@ -12,13 +12,10 @@ #include #include #include -#include #include #include -#include #include -#include #include #include "scm-boot.h" @@ -28,7 +25,7 @@ #define SCSS_CPU1CORE_RESET 0xD80 #define SCSS_DBG_STATUS_CORE_PWRDUP 0xE64 -extern void msm_secondary_startup(void); +extern void secondary_startup(void); static DEFINE_SPINLOCK(boot_lock); @@ -41,13 +38,6 @@ static inline int get_core_count(void) static void msm_secondary_init(unsigned int cpu) { /* - * let the primary processor know we're out of the - * pen, then head off into the C entry point - */ - pen_release = -1; - smp_wmb(); - - /* * Synchronise with the boot thread. */ spin_lock(&boot_lock); @@ -57,7 +47,7 @@ static void msm_secondary_init(unsigned static void prepare_cold_cpu(unsigned int cpu) { int ret; - ret = scm_set_boot_addr(virt_to_phys(msm_secondary_startup), + ret = scm_set_boot_addr(virt_to_phys(secondary_startup), SCM_FLAG_COLDBOOT_CPU1); if (ret == 0) { void __iomem *sc1_base_ptr; @@ -75,7 +65,6 @@ static void prepare_cold_cpu(unsigned in static int msm_boot_secondary(unsigned int cpu, struct task_struct *idle) { - unsigned long timeout; static int cold_boot_done; /* Only need to bring cpu out of reset this way once */ @@ -91,39 +80,19 @@ static int msm_boot_secondary(unsigned i spin_lock(&boot_lock); /* - * The secondary processor is waiting to be released from - * the holding pen - release it, then wait for it to flag - * that it has been released by resetting pen_release. - * - * Note that "pen_release" is the hardware CPU ID, whereas - * "cpu" is Linux's internal ID. - */ - pen_release = cpu_logical_map(cpu); - sync_cache_w(&pen_release); - - /* * Send the secondary CPU a soft interrupt, thereby causing * the boot monitor to read the system wide flags register, * and branch to the address found there. */ arch_send_wakeup_ipi_mask(cpumask_of(cpu)); - timeout = jiffies + (1 * HZ); - while (time_before(jiffies, timeout)) { - smp_rmb(); - if (pen_release == -1) - break; - - udelay(10); - } - /* * now the secondary core is starting up let it run its * calibrations, then wait for it to finish */ spin_unlock(&boot_lock); - return pen_release != -1 ? -ENOSYS : 0; + return 0; } /*