Re: [PATCH 9/9] ARM: smp: remove arch-provided "pen_release"
From: Russell King - ARM Linux <linux@armlinux.org.uk>
Date: 2018-12-14 13:12:00
Also in:
linux-arm-msm, linux-omap, linux-samsung-soc
On Fri, Dec 14, 2018 at 10:09:23AM +0530, Viresh Kumar wrote:
On 13-12-18, 18:01, Russell King wrote:quoted
diff --git a/arch/arm/mach-spear/generic.h b/arch/arm/mach-spear/generic.h index 909b97c0b237..815333fc320c 100644 --- a/arch/arm/mach-spear/generic.h +++ b/arch/arm/mach-spear/generic.h@@ -20,6 +20,8 @@ #include <asm/mach/time.h> +extern volatile int prima2_pen_release;prima2 ? I haven't tried but this may cause build regressions as well, I am surprised on how this passed for you.
Thanks. These patches aren't all build tested - I don't see the point of wasting hours build testing when these platforms /really/ need something better. This is not supposed to be a finished patch, but a patch to get folk to do something about this issue. Please fix this issue properly. I can't give you a patch to do that, you need to sort it yourself, but failure to do anything _will_ result in an updated version of this patch being merged.
quoted
extern void spear13xx_timer_init(void); extern void spear3xx_timer_init(void); extern struct pl022_ssp_controller pl022_plat_data;diff --git a/arch/arm/mach-spear/headsmp.S b/arch/arm/mach-spear/headsmp.S index c52192dc3d9f..6e250b6c0aa2 100644 --- a/arch/arm/mach-spear/headsmp.S +++ b/arch/arm/mach-spear/headsmp.S@@ -43,5 +43,5 @@ pen: ldr r7, [r6] .align 1: .long . - .long pen_release + .long spear_pen_release ENDPROC(spear13xx_secondary_startup)diff --git a/arch/arm/mach-spear/hotplug.c b/arch/arm/mach-spear/hotplug.c index 12edd1cf8a12..0dd84f609627 100644 --- a/arch/arm/mach-spear/hotplug.c +++ b/arch/arm/mach-spear/hotplug.c@@ -16,6 +16,8 @@ #include <asm/cp15.h> #include <asm/smp_plat.h> +#include "generic.h" + static inline void cpu_enter_lowpower(void) { unsigned int v;@@ -57,7 +59,7 @@ static inline void spear13xx_do_lowpower(unsigned int cpu, int *spurious) for (;;) { wfi(); - if (pen_release == cpu) { + if (spear_pen_release == cpu) { /* * OK, proper wakeup, we're done */diff --git a/arch/arm/mach-spear/platsmp.c b/arch/arm/mach-spear/platsmp.c index 39038a03836a..b1ff4bb86f6d 100644 --- a/arch/arm/mach-spear/platsmp.c +++ b/arch/arm/mach-spear/platsmp.c@@ -20,16 +20,21 @@ #include <mach/spear.h> #include "generic.h" +/* XXX spear_pen_release is cargo culted code - DO NOT COPY XXX */ +volatile int spear_pen_release = -1; + /* - * Write pen_release in a way that is guaranteed to be visible to all - * observers, irrespective of whether they're taking part in coherency + * XXX CARGO CULTED CODE - DO NOT COPY XXX + * + * Write spear_pen_release in a way that is guaranteed to be visible to + * all observers, irrespective of whether they're taking part in coherency * or not. This is necessary for the hotplug code to work reliably. */ -static void write_pen_release(int val) +static void spear_write_pen_release(int val) { - pen_release = val; + spear_pen_release = val; smp_wmb(); - sync_cache_w(&pen_release); + sync_cache_w(&spear_pen_release); } static DEFINE_SPINLOCK(boot_lock);@@ -42,7 +47,7 @@ static void spear13xx_secondary_init(unsigned int cpu) * let the primary processor know we're out of the * pen, then head off into the C entry point */ - write_pen_release(-1); + spear_write_pen_release(-1); /* * Synchronise with the boot thread.@@ -64,17 +69,17 @@ static int spear13xx_boot_secondary(unsigned int cpu, struct task_struct *idle) /* * 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. + * that it has been released by resetting spear_pen_release. * - * Note that "pen_release" is the hardware CPU ID, whereas + * Note that "spear_pen_release" is the hardware CPU ID, whereas * "cpu" is Linux's internal ID. */ - write_pen_release(cpu); + spear_write_pen_release(cpu); timeout = jiffies + (1 * HZ); while (time_before(jiffies, timeout)) { smp_rmb(); - if (pen_release == -1) + if (spear_pen_release == -1) break; udelay(10);@@ -86,7 +91,7 @@ static int spear13xx_boot_secondary(unsigned int cpu, struct task_struct *idle) */ spin_unlock(&boot_lock); - return pen_release != -1 ? -ENOSYS : 0; + return spear_pen_release != -1 ? -ENOSYS : 0; } /*-- 2.7.4-- viresh _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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