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89b3098703
Current arch_cpu_idle() is called with IRQs disabled, but will return with IRQs enabled. However, the very first thing the generic code does after calling arch_cpu_idle() is raw_local_irq_disable(). This means that architectures that can idle with IRQs disabled end up doing a pointless 'enable-disable' dance. Therefore, push this IRQ disabling into the idle function, meaning that those architectures can avoid the pointless IRQ state flipping. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com> Acked-by: Mark Rutland <mark.rutland@arm.com> [arm64] Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Guo Ren <guoren@kernel.org> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230112195540.618076436@infradead.org
64 lines
1.5 KiB
C
64 lines
1.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Gemini Device Tree boot support
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <asm/mach/arch.h>
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#include <asm/mach/map.h>
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#include <asm/system_misc.h>
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#include <asm/proc-fns.h>
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#ifdef CONFIG_DEBUG_GEMINI
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/* This is needed for LL-debug/earlyprintk/debug-macro.S */
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static struct map_desc gemini_io_desc[] __initdata = {
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{
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.virtual = CONFIG_DEBUG_UART_VIRT,
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.pfn = __phys_to_pfn(CONFIG_DEBUG_UART_PHYS),
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.length = SZ_4K,
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.type = MT_DEVICE,
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},
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};
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static void __init gemini_map_io(void)
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{
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iotable_init(gemini_io_desc, ARRAY_SIZE(gemini_io_desc));
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}
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#else
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#define gemini_map_io NULL
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#endif
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static void gemini_idle(void)
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{
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/*
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* Because of broken hardware we have to enable interrupts or the CPU
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* will never wakeup... Acctualy it is not very good to enable
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* interrupts first since scheduler can miss a tick, but there is
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* no other way around this. Platforms that needs it for power saving
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* should enable it in init code, since by default it is
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* disabled.
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*/
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/* FIXME: Enabling interrupts here is racy! */
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raw_local_irq_enable();
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cpu_do_idle();
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raw_local_irq_disable();
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}
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static void __init gemini_init_machine(void)
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{
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arm_pm_idle = gemini_idle;
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}
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static const char *gemini_board_compat[] = {
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"cortina,gemini",
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NULL,
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};
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DT_MACHINE_START(GEMINI_DT, "Gemini (Device Tree)")
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.map_io = gemini_map_io,
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.init_machine = gemini_init_machine,
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.dt_compat = gemini_board_compat,
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MACHINE_END
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