It turns out that the logical CPU mapping is useful even when !CONFIG_SMP for manipulation of devices like interrupt and power controllers when running a UP kernel on a CPU other than 0. This can happen when kexecing a UP image from an SMP kernel. In the future, multi-cluster systems running AMP configurations will require something similar for mapping cluster IDs, so it makes sense to decouple this logic in preparation for this support. Acked-by: Yang Bai <hamo.by@gmail.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reported-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
		
			
				
	
	
		
			75 lines
		
	
	
	
		
			1.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			75 lines
		
	
	
	
		
			1.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright 2011 Freescale Semiconductor, Inc.
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 * Copyright 2011 Linaro Ltd.
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 *
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 * The code contained herein is licensed under the GNU General Public
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 * License. You may obtain a copy of the GNU General Public License
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 * Version 2 or later at the following locations:
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 *
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 * http://www.opensource.org/licenses/gpl-license.html
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 * http://www.gnu.org/copyleft/gpl.html
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 */
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#include <linux/init.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/smp.h>
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#include <asm/smp_plat.h>
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#define SRC_SCR				0x000
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#define SRC_GPR1			0x020
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#define BP_SRC_SCR_WARM_RESET_ENABLE	0
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#define BP_SRC_SCR_CORE1_RST		14
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#define BP_SRC_SCR_CORE1_ENABLE		22
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static void __iomem *src_base;
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void imx_enable_cpu(int cpu, bool enable)
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{
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	u32 mask, val;
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	cpu = cpu_logical_map(cpu);
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	mask = 1 << (BP_SRC_SCR_CORE1_ENABLE + cpu - 1);
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	val = readl_relaxed(src_base + SRC_SCR);
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	val = enable ? val | mask : val & ~mask;
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	writel_relaxed(val, src_base + SRC_SCR);
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}
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void imx_set_cpu_jump(int cpu, void *jump_addr)
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{
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	cpu = cpu_logical_map(cpu);
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	writel_relaxed(virt_to_phys(jump_addr),
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		       src_base + SRC_GPR1 + cpu * 8);
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}
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void imx_src_prepare_restart(void)
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{
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	u32 val;
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	/* clear enable bits of secondary cores */
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	val = readl_relaxed(src_base + SRC_SCR);
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	val &= ~(0x7 << BP_SRC_SCR_CORE1_ENABLE);
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	writel_relaxed(val, src_base + SRC_SCR);
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	/* clear persistent entry register of primary core */
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	writel_relaxed(0, src_base + SRC_GPR1);
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}
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void __init imx_src_init(void)
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{
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	struct device_node *np;
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	u32 val;
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	np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-src");
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	src_base = of_iomap(np, 0);
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	WARN_ON(!src_base);
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	/*
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	 * force warm reset sources to generate cold reset
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	 * for a more reliable restart
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	 */
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	val = readl_relaxed(src_base + SRC_SCR);
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	val &= ~(1 << BP_SRC_SCR_WARM_RESET_ENABLE);
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	writel_relaxed(val, src_base + SRC_SCR);
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}
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