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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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6edde02476
Assume that the boot loader knows the physical memory of the system and deduce that information from the contents of the SDRAM control register. It is still possible to override with with the "mem=" parameter, but we have a sensible default now. Signed-off-by: Maarten ter Huurne <maarten@treewalker.org> Acked-by: Lars-Peter Clausen <lars@metafoo.de> Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/2319/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
62 lines
1.5 KiB
C
62 lines
1.5 KiB
C
/*
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* Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
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* Copyright (C) 2011, Maarten ter Huurne <maarten@treewalker.org>
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* JZ4740 setup code
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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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/kernel.h>
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#include <asm/bootinfo.h>
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#include <asm/mach-jz4740/base.h>
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#include "reset.h"
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#define JZ4740_EMC_SDRAM_CTRL 0x80
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static void __init jz4740_detect_mem(void)
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{
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void __iomem *jz_emc_base;
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u32 ctrl, bus, bank, rows, cols;
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phys_t size;
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jz_emc_base = ioremap(JZ4740_EMC_BASE_ADDR, 0x100);
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ctrl = readl(jz_emc_base + JZ4740_EMC_SDRAM_CTRL);
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bus = 2 - ((ctrl >> 31) & 1);
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bank = 1 + ((ctrl >> 19) & 1);
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cols = 8 + ((ctrl >> 26) & 7);
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rows = 11 + ((ctrl >> 20) & 3);
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printk(KERN_DEBUG
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"SDRAM preconfigured: bus:%u bank:%u rows:%u cols:%u\n",
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bus, bank, rows, cols);
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iounmap(jz_emc_base);
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size = 1 << (bus + bank + cols + rows);
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add_memory_region(0, size, BOOT_MEM_RAM);
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}
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void __init plat_mem_setup(void)
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{
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jz4740_reset_init();
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jz4740_detect_mem();
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}
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const char *get_system_type(void)
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{
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return "JZ4740";
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}
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