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	The previous IPI code initialized the device whenever the first call was made to a riscv_*_ipi function. This made it difficult to determine when the IPI device was initialized. This patch introduces a new function riscv_init_ipi. It is called once during arch_cpu_init_dm. In SPL, it is called in spl_invoke_opensbi. Before this point, no riscv_*_ipi functions should be called. Signed-off-by: Sean Anderson <seanga2@gmail.com> Reviewed-by: Rick Chen <rick@andestech.com>
		
			
				
	
	
		
			133 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			133 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0+
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| /*
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|  * Copyright (C) 2019, Rick Chen <rick@andestech.com>
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|  *
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|  * U-Boot syscon driver for Andes's Platform Level Interrupt Controller (PLIC).
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|  * The PLIC block holds memory-mapped claim and pending registers
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|  * associated with software interrupt.
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|  */
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| 
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| #include <common.h>
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| #include <dm.h>
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| #include <dm/device-internal.h>
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| #include <dm/lists.h>
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| #include <dm/uclass-internal.h>
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| #include <regmap.h>
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| #include <syscon.h>
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| #include <asm/io.h>
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| #include <asm/syscon.h>
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| #include <cpu.h>
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| #include <linux/err.h>
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| 
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| /* pending register */
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| #define PENDING_REG(base, hart)	((ulong)(base) + 0x1000 + ((hart) / 4) * 4)
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| /* enable register */
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| #define ENABLE_REG(base, hart)	((ulong)(base) + 0x2000 + (hart) * 0x80)
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| /* claim register */
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| #define CLAIM_REG(base, hart)	((ulong)(base) + 0x200004 + (hart) * 0x1000)
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| 
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| #define ENABLE_HART_IPI         (0x80808080)
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| #define SEND_IPI_TO_HART(hart)  (0x80 >> (hart))
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| 
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| DECLARE_GLOBAL_DATA_PTR;
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| 
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| static int enable_ipi(int hart)
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| {
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| 	unsigned int en;
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| 
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| 	en = ENABLE_HART_IPI >> hart;
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| 	writel(en, (void __iomem *)ENABLE_REG(gd->arch.plic, hart));
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| 
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| 	return 0;
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| }
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| 
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| static int init_plic(void)
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| {
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| 	struct udevice *dev;
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| 	ofnode node;
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| 	int ret;
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| 	u32 reg;
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| 
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| 	ret = uclass_find_first_device(UCLASS_CPU, &dev);
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| 	if (ret)
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| 		return ret;
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| 
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| 	if (ret == 0 && dev) {
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| 		ofnode_for_each_subnode(node, dev_ofnode(dev->parent)) {
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| 			const char *device_type;
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| 
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| 			device_type = ofnode_read_string(node, "device_type");
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| 			if (!device_type)
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| 				continue;
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| 
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| 			if (strcmp(device_type, "cpu"))
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| 				continue;
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| 
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| 			/* skip if hart is marked as not available */
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| 			if (!ofnode_is_available(node))
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| 				continue;
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| 
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| 			/* read hart ID of CPU */
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| 			ret = ofnode_read_u32(node, "reg", ®);
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| 			if (ret == 0)
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| 				enable_ipi(reg);
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| 		}
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| 
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| 		return 0;
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| 	}
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| 
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| 	return -ENODEV;
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| }
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| 
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| int riscv_init_ipi(void)
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| {
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| 	long *ret = syscon_get_first_range(RISCV_SYSCON_PLIC);
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| 
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| 	if (IS_ERR(ret))
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| 		return PTR_ERR(ret);
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| 	gd->arch.plic = ret;
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| 
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| 	return init_plic();
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| }
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| 
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| int riscv_send_ipi(int hart)
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| {
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| 	unsigned int ipi = (SEND_IPI_TO_HART(hart) << (8 * gd->arch.boot_hart));
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| 
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| 	writel(ipi, (void __iomem *)PENDING_REG(gd->arch.plic,
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| 				gd->arch.boot_hart));
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| 
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| 	return 0;
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| }
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| 
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| int riscv_clear_ipi(int hart)
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| {
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| 	u32 source_id;
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| 
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| 	source_id = readl((void __iomem *)CLAIM_REG(gd->arch.plic, hart));
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| 	writel(source_id, (void __iomem *)CLAIM_REG(gd->arch.plic, hart));
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| 
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| 	return 0;
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| }
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| 
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| int riscv_get_ipi(int hart, int *pending)
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| {
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| 	*pending = readl((void __iomem *)PENDING_REG(gd->arch.plic,
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| 						     gd->arch.boot_hart));
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| 	*pending = !!(*pending & SEND_IPI_TO_HART(hart));
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| 
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| 	return 0;
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| }
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| 
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| static const struct udevice_id andes_plic_ids[] = {
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| 	{ .compatible = "riscv,plic1", .data = RISCV_SYSCON_PLIC },
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| 	{ }
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| };
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| 
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| U_BOOT_DRIVER(andes_plic) = {
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| 	.name		= "andes_plic",
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| 	.id		= UCLASS_SYSCON,
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| 	.of_match	= andes_plic_ids,
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| 	.flags		= DM_FLAG_PRE_RELOC,
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| };
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