arch/mips/mti-malta/malta-dtshim.c - linux - Git at Google

 /*
  * Copyright (C) 2015 Imagination Technologies
  * Author: Paul Burton <paul.burton@imgtec.com>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the
  * Free Software Foundation; either version 2 of the License, or (at your
  * option) any later version.
  */

 #include <linux/bug.h>
 #include <linux/kernel.h>
 #include <linux/libfdt.h>
 #include <linux/of_fdt.h>
 #include <linux/sizes.h>
 #include <asm/addrspace.h>
 #include <asm/bootinfo.h>
 #include <asm/fw/fw.h>
 #include <asm/mips-boards/generic.h>
 #include <asm/mips-boards/malta.h>
 #include <asm/mips-cm.h>
 #include <asm/page.h>

 #define ROCIT_REG_BASE			0x1f403000
 #define ROCIT_CONFIG_GEN1		(ROCIT_REG_BASE + 0x04)
 #define  ROCIT_CONFIG_GEN1_MEMMAP_SHIFT	8
 #define  ROCIT_CONFIG_GEN1_MEMMAP_MASK	(0xf << 8)

 static unsigned char fdt_buf[16 << 10] __initdata;

 /* determined physical memory size, not overridden by command line args	 */
 extern unsigned long physical_memsize;

 enum mem_map {
 	MEM_MAP_V1 = 0,
 	MEM_MAP_V2,
 };

 #define MAX_MEM_ARRAY_ENTRIES 2

 static __init int malta_scon(void)
 {
 	int scon = MIPS_REVISION_SCONID;

 	if (scon != MIPS_REVISION_SCON_OTHER)
 		return scon;

 	switch (MIPS_REVISION_CORID) {
 	case MIPS_REVISION_CORID_QED_RM5261:
 	case MIPS_REVISION_CORID_CORE_LV:
 	case MIPS_REVISION_CORID_CORE_FPGA:
 	case MIPS_REVISION_CORID_CORE_FPGAR2:
 		return MIPS_REVISION_SCON_GT64120;

 	case MIPS_REVISION_CORID_CORE_EMUL_BON:
 	case MIPS_REVISION_CORID_BONITO64:
 	case MIPS_REVISION_CORID_CORE_20K:
 		return MIPS_REVISION_SCON_BONITO;

 	case MIPS_REVISION_CORID_CORE_MSC:
 	case MIPS_REVISION_CORID_CORE_FPGA2:
 	case MIPS_REVISION_CORID_CORE_24K:
 		return MIPS_REVISION_SCON_SOCIT;

 	case MIPS_REVISION_CORID_CORE_FPGA3:
 	case MIPS_REVISION_CORID_CORE_FPGA4:
 	case MIPS_REVISION_CORID_CORE_FPGA5:
 	case MIPS_REVISION_CORID_CORE_EMUL_MSC:
 	default:
 		return MIPS_REVISION_SCON_ROCIT;
 	}
 }

 static unsigned __init gen_fdt_mem_array(__be32 *mem_array, unsigned long size,
 					 enum mem_map map)
 {
 	unsigned long size_preio;
 	unsigned entries;

 	entries = 1;
 	mem_array[0] = cpu_to_be32(PHYS_OFFSET);
 	if (IS_ENABLED(CONFIG_EVA)) {
 		/*
 		 * The current Malta EVA configuration is "special" in that it
 		 * always makes use of addresses in the upper half of the 32 bit
 		 * physical address map, which gives it a contiguous region of
 		 * DDR but limits it to 2GB.
 		 */
 		mem_array[1] = cpu_to_be32(size);
 		goto done;
 	}

 	size_preio = min_t(unsigned long, size, SZ_256M);
 	mem_array[1] = cpu_to_be32(size_preio);
 	size -= size_preio;
 	if (!size)
 		goto done;

 	if (map == MEM_MAP_V2) {
 		/*
 		 * We have a flat 32 bit physical memory map with DDR filling
 		 * all 4GB of the memory map, apart from the I/O region which
 		 * obscures 256MB from 0x10000000-0x1fffffff.
 		 *
 		 * Therefore we discard the 256MB behind the I/O region.
 		 */
 		if (size <= SZ_256M)
 			goto done;
 		size -= SZ_256M;

 		/* Make use of the memory following the I/O region */
 		entries++;
 		mem_array[2] = cpu_to_be32(PHYS_OFFSET + SZ_512M);
 		mem_array[3] = cpu_to_be32(size);
 	} else {
 		/*
 		 * We have a 32 bit physical memory map with a 2GB DDR region
 		 * aliased in the upper & lower halves of it. The I/O region
 		 * obscures 256MB from 0x10000000-0x1fffffff in the low alias
 		 * but the DDR it obscures is accessible via the high alias.
 		 *
 		 * Simply access everything beyond the lowest 256MB of DDR using
 		 * the high alias.
 		 */
 		entries++;
 		mem_array[2] = cpu_to_be32(PHYS_OFFSET + SZ_2G + SZ_256M);
 		mem_array[3] = cpu_to_be32(size);
 	}

 done:
 	BUG_ON(entries > MAX_MEM_ARRAY_ENTRIES);
 	return entries;
 }

 static void __init append_memory(void *fdt, int root_off)
 {
 	__be32 mem_array[2 * MAX_MEM_ARRAY_ENTRIES];
 	unsigned long memsize;
 	unsigned mem_entries;
 	int i, err, mem_off;
 	enum mem_map mem_map;
 	u32 config;
 	char *var, param_name[10], *var_names[] = {
 		"ememsize", "memsize",
 	};

 	/* if a memory node already exists, leave it alone */
 	mem_off = fdt_path_offset(fdt, "/memory");
 	if (mem_off >= 0)
 		return;

 	/* find memory size from the bootloader environment */
 	for (i = 0; i < ARRAY_SIZE(var_names); i++) {
 		var = fw_getenv(var_names[i]);
 		if (!var)
 			continue;

 		err = kstrtoul(var, 0, &physical_memsize);
 		if (!err)
 			break;

 		pr_warn("Failed to read the '%s' env variable '%s'\n",
 			var_names[i], var);
 	}

 	if (!physical_memsize) {
 		pr_warn("The bootloader didn't provide memsize: defaulting to 32MB\n");
 		physical_memsize = 32 << 20;
 	}

 	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
 		/*
 		 * SOC-it swaps, or perhaps doesn't swap, when DMA'ing
 		 * the last word of physical memory.
 		 */
 		physical_memsize -= PAGE_SIZE;
 	}

 	/* default to using all available RAM */
 	memsize = physical_memsize;

 	/* allow the user to override the usable memory */
 	for (i = 0; i < ARRAY_SIZE(var_names); i++) {
 		snprintf(param_name, sizeof(param_name), "%s=", var_names[i]);
 		var = strstr(arcs_cmdline, param_name);
 		if (!var)
 			continue;

 		memsize = memparse(var + strlen(param_name), NULL);
 	}

 	/* if the user says there's more RAM than we thought, believe them */
 	physical_memsize = max_t(unsigned long, physical_memsize, memsize);

 	/* detect the memory map in use */
 	if (malta_scon() == MIPS_REVISION_SCON_ROCIT) {
 		/* ROCit has a register indicating the memory map in use */
 		config = readl((void __iomem *)CKSEG1ADDR(ROCIT_CONFIG_GEN1));
 		mem_map = config & ROCIT_CONFIG_GEN1_MEMMAP_MASK;
 		mem_map >>= ROCIT_CONFIG_GEN1_MEMMAP_SHIFT;
 	} else {
 		/* if not using ROCit, presume the v1 memory map */
 		mem_map = MEM_MAP_V1;
 	}
 	if (mem_map > MEM_MAP_V2)
 		panic("Unsupported physical memory map v%u detected",
 		      (unsigned int)mem_map);

 	/* append memory to the DT */
 	mem_off = fdt_add_subnode(fdt, root_off, "memory");
 	if (mem_off < 0)
 		panic("Unable to add memory node to DT: %d", mem_off);

 	err = fdt_setprop_string(fdt, mem_off, "device_type", "memory");
 	if (err)
 		panic("Unable to set memory node device_type: %d", err);

 	mem_entries = gen_fdt_mem_array(mem_array, physical_memsize, mem_map);
 	err = fdt_setprop(fdt, mem_off, "reg", mem_array,
 			  mem_entries * 2 * sizeof(mem_array[0]));
 	if (err)
 		panic("Unable to set memory regs property: %d", err);

 	mem_entries = gen_fdt_mem_array(mem_array, memsize, mem_map);
 	err = fdt_setprop(fdt, mem_off, "linux,usable-memory", mem_array,
 			  mem_entries * 2 * sizeof(mem_array[0]));
 	if (err)
 		panic("Unable to set linux,usable-memory property: %d", err);
 }

 static void __init remove_gic(void *fdt)
 {
 	int err, gic_off, i8259_off, cpu_off;
 	void __iomem *biu_base;
 	uint32_t cpu_phandle, sc_cfg;

 	/* if we have a CM which reports a GIC is present, leave the DT alone */
 	err = mips_cm_probe();
 	if (!err && (read_gcr_gic_status() & CM_GCR_GIC_STATUS_GICEX_MSK))
 		return;

 	if (malta_scon() == MIPS_REVISION_SCON_ROCIT) {
 		/*
 		 * On systems using the RocIT system controller a GIC may be
 		 * present without a CM. Detect whether that is the case.
 		 */
 		biu_base = ioremap_nocache(MSC01_BIU_REG_BASE,
 				MSC01_BIU_ADDRSPACE_SZ);
 		sc_cfg = __raw_readl(biu_base + MSC01_SC_CFG_OFS);
 		if (sc_cfg & MSC01_SC_CFG_GICPRES_MSK) {
 			/* enable the GIC at the system controller level */
 			sc_cfg |= BIT(MSC01_SC_CFG_GICENA_SHF);
 			__raw_writel(sc_cfg, biu_base + MSC01_SC_CFG_OFS);
 			return;
 		}
 	}

 	gic_off = fdt_node_offset_by_compatible(fdt, -1, "mti,gic");
 	if (gic_off < 0) {
 		pr_warn("malta-dtshim: unable to find DT GIC node: %d\n",
 			gic_off);
 		return;
 	}

 	err = fdt_nop_node(fdt, gic_off);
 	if (err)
 		pr_warn("malta-dtshim: unable to nop GIC node\n");

 	i8259_off = fdt_node_offset_by_compatible(fdt, -1, "intel,i8259");
 	if (i8259_off < 0) {
 		pr_warn("malta-dtshim: unable to find DT i8259 node: %d\n",
 			i8259_off);
 		return;
 	}

 	cpu_off = fdt_node_offset_by_compatible(fdt, -1,
 			"mti,cpu-interrupt-controller");
 	if (cpu_off < 0) {
 		pr_warn("malta-dtshim: unable to find CPU intc node: %d\n",
 			cpu_off);
 		return;
 	}

 	cpu_phandle = fdt_get_phandle(fdt, cpu_off);
 	if (!cpu_phandle) {
 		pr_warn("malta-dtshim: unable to get CPU intc phandle\n");
 		return;
 	}

 	err = fdt_setprop_u32(fdt, i8259_off, "interrupt-parent", cpu_phandle);
 	if (err) {
 		pr_warn("malta-dtshim: unable to set i8259 interrupt-parent: %d\n",
 			err);
 		return;
 	}

 	err = fdt_setprop_u32(fdt, i8259_off, "interrupts", 2);
 	if (err) {
 		pr_warn("malta-dtshim: unable to set i8259 interrupts: %d\n",
 			err);
 		return;
 	}
 }

 void __init *malta_dt_shim(void *fdt)
 {
 	int root_off, len, err;
 	const char *compat;

 	if (fdt_check_header(fdt))
 		panic("Corrupt DT");

 	err = fdt_open_into(fdt, fdt_buf, sizeof(fdt_buf));
 	if (err)
 		panic("Unable to open FDT: %d", err);

 	root_off = fdt_path_offset(fdt_buf, "/");
 	if (root_off < 0)
 		panic("No / node in DT");

 	compat = fdt_getprop(fdt_buf, root_off, "compatible", &len);
 	if (!compat)
 		panic("No root compatible property in DT: %d", len);

 	/* if this isn't Malta, leave the DT alone */
 	if (strncmp(compat, "mti,malta", len))
 		return fdt;

 	append_memory(fdt_buf, root_off);
 	remove_gic(fdt_buf);

 	err = fdt_pack(fdt_buf);
 	if (err)
 		panic("Unable to pack FDT: %d\n", err);

 	return fdt_buf;
 }
	/*
	* Copyright (C) 2015 Imagination Technologies
	* Author: Paul Burton <paul.burton@imgtec.com>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the
	* Free Software Foundation; either version 2 of the License, or (at your
	* option) any later version.
	*/

	#include <linux/bug.h>
	#include <linux/kernel.h>
	#include <linux/libfdt.h>
	#include <linux/of_fdt.h>
	#include <linux/sizes.h>
	#include <asm/addrspace.h>
	#include <asm/bootinfo.h>
	#include <asm/fw/fw.h>
	#include <asm/mips-boards/generic.h>
	#include <asm/mips-boards/malta.h>
	#include <asm/mips-cm.h>
	#include <asm/page.h>

	#define ROCIT_REG_BASE 0x1f403000
	#define ROCIT_CONFIG_GEN1 (ROCIT_REG_BASE + 0x04)
	#define ROCIT_CONFIG_GEN1_MEMMAP_SHIFT 8
	#define ROCIT_CONFIG_GEN1_MEMMAP_MASK (0xf << 8)

	static unsigned char fdt_buf[16 << 10] __initdata;

	/* determined physical memory size, not overridden by command line args */
	extern unsigned long physical_memsize;

	enum mem_map {
	MEM_MAP_V1 = 0,
	MEM_MAP_V2,
	};

	#define MAX_MEM_ARRAY_ENTRIES 2

	static __init int malta_scon(void)
	{
	int scon = MIPS_REVISION_SCONID;

	if (scon != MIPS_REVISION_SCON_OTHER)
	return scon;

	switch (MIPS_REVISION_CORID) {
	case MIPS_REVISION_CORID_QED_RM5261:
	case MIPS_REVISION_CORID_CORE_LV:
	case MIPS_REVISION_CORID_CORE_FPGA:
	case MIPS_REVISION_CORID_CORE_FPGAR2:
	return MIPS_REVISION_SCON_GT64120;

	case MIPS_REVISION_CORID_CORE_EMUL_BON:
	case MIPS_REVISION_CORID_BONITO64:
	case MIPS_REVISION_CORID_CORE_20K:
	return MIPS_REVISION_SCON_BONITO;

	case MIPS_REVISION_CORID_CORE_MSC:
	case MIPS_REVISION_CORID_CORE_FPGA2:
	case MIPS_REVISION_CORID_CORE_24K:
	return MIPS_REVISION_SCON_SOCIT;

	case MIPS_REVISION_CORID_CORE_FPGA3:
	case MIPS_REVISION_CORID_CORE_FPGA4:
	case MIPS_REVISION_CORID_CORE_FPGA5:
	case MIPS_REVISION_CORID_CORE_EMUL_MSC:
	default:
	return MIPS_REVISION_SCON_ROCIT;
	}
	}

	static unsigned __init gen_fdt_mem_array(__be32 *mem_array, unsigned long size,
	enum mem_map map)
	{
	unsigned long size_preio;
	unsigned entries;

	entries = 1;
	mem_array[0] = cpu_to_be32(PHYS_OFFSET);
	if (IS_ENABLED(CONFIG_EVA)) {
	/*
	* The current Malta EVA configuration is "special" in that it
	* always makes use of addresses in the upper half of the 32 bit
	* physical address map, which gives it a contiguous region of
	* DDR but limits it to 2GB.
	*/
	mem_array[1] = cpu_to_be32(size);
	goto done;
	}

	size_preio = min_t(unsigned long, size, SZ_256M);
	mem_array[1] = cpu_to_be32(size_preio);
	size -= size_preio;
	if (!size)
	goto done;

	if (map == MEM_MAP_V2) {
	/*
	* We have a flat 32 bit physical memory map with DDR filling
	* all 4GB of the memory map, apart from the I/O region which
	* obscures 256MB from 0x10000000-0x1fffffff.
	*
	* Therefore we discard the 256MB behind the I/O region.
	*/
	if (size <= SZ_256M)
	goto done;
	size -= SZ_256M;

	/* Make use of the memory following the I/O region */
	entries++;
	mem_array[2] = cpu_to_be32(PHYS_OFFSET + SZ_512M);
	mem_array[3] = cpu_to_be32(size);
	} else {
	/*
	* We have a 32 bit physical memory map with a 2GB DDR region
	* aliased in the upper & lower halves of it. The I/O region
	* obscures 256MB from 0x10000000-0x1fffffff in the low alias
	* but the DDR it obscures is accessible via the high alias.
	*
	* Simply access everything beyond the lowest 256MB of DDR using
	* the high alias.
	*/
	entries++;
	mem_array[2] = cpu_to_be32(PHYS_OFFSET + SZ_2G + SZ_256M);
	mem_array[3] = cpu_to_be32(size);
	}

	done:
	BUG_ON(entries > MAX_MEM_ARRAY_ENTRIES);
	return entries;
	}

	static void __init append_memory(void *fdt, int root_off)
	{
	__be32 mem_array[2 * MAX_MEM_ARRAY_ENTRIES];
	unsigned long memsize;
	unsigned mem_entries;
	int i, err, mem_off;
	enum mem_map mem_map;
	u32 config;
	char var, param_name[10], var_names[] = {
	"ememsize", "memsize",
	};

	/* if a memory node already exists, leave it alone */
	mem_off = fdt_path_offset(fdt, "/memory");
	if (mem_off >= 0)
	return;

	/* find memory size from the bootloader environment */
	for (i = 0; i < ARRAY_SIZE(var_names); i++) {
	var = fw_getenv(var_names[i]);
	if (!var)
	continue;

	err = kstrtoul(var, 0, &physical_memsize);
	if (!err)
	break;

	pr_warn("Failed to read the '%s' env variable '%s'\n",
	var_names[i], var);
	}

	if (!physical_memsize) {
	pr_warn("The bootloader didn't provide memsize: defaulting to 32MB\n");
	physical_memsize = 32 << 20;
	}

	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN)) {
	/*
	* SOC-it swaps, or perhaps doesn't swap, when DMA'ing
	* the last word of physical memory.
	*/
	physical_memsize -= PAGE_SIZE;
	}

	/* default to using all available RAM */
	memsize = physical_memsize;

	/* allow the user to override the usable memory */
	for (i = 0; i < ARRAY_SIZE(var_names); i++) {
	snprintf(param_name, sizeof(param_name), "%s=", var_names[i]);
	var = strstr(arcs_cmdline, param_name);
	if (!var)
	continue;

	memsize = memparse(var + strlen(param_name), NULL);
	}

	/* if the user says there's more RAM than we thought, believe them */
	physical_memsize = max_t(unsigned long, physical_memsize, memsize);

	/* detect the memory map in use */
	if (malta_scon() == MIPS_REVISION_SCON_ROCIT) {
	/* ROCit has a register indicating the memory map in use */
	config = readl((void __iomem *)CKSEG1ADDR(ROCIT_CONFIG_GEN1));
	mem_map = config & ROCIT_CONFIG_GEN1_MEMMAP_MASK;
	mem_map >>= ROCIT_CONFIG_GEN1_MEMMAP_SHIFT;
	} else {
	/* if not using ROCit, presume the v1 memory map */
	mem_map = MEM_MAP_V1;
	}
	if (mem_map > MEM_MAP_V2)
	panic("Unsupported physical memory map v%u detected",
	(unsigned int)mem_map);

	/* append memory to the DT */
	mem_off = fdt_add_subnode(fdt, root_off, "memory");
	if (mem_off < 0)
	panic("Unable to add memory node to DT: %d", mem_off);

	err = fdt_setprop_string(fdt, mem_off, "device_type", "memory");
	if (err)
	panic("Unable to set memory node device_type: %d", err);

	mem_entries = gen_fdt_mem_array(mem_array, physical_memsize, mem_map);
	err = fdt_setprop(fdt, mem_off, "reg", mem_array,
	mem_entries * 2 * sizeof(mem_array[0]));
	if (err)
	panic("Unable to set memory regs property: %d", err);

	mem_entries = gen_fdt_mem_array(mem_array, memsize, mem_map);
	err = fdt_setprop(fdt, mem_off, "linux,usable-memory", mem_array,
	mem_entries * 2 * sizeof(mem_array[0]));
	if (err)
	panic("Unable to set linux,usable-memory property: %d", err);
	}

	static void __init remove_gic(void *fdt)
	{
	int err, gic_off, i8259_off, cpu_off;
	void __iomem *biu_base;
	uint32_t cpu_phandle, sc_cfg;

	/* if we have a CM which reports a GIC is present, leave the DT alone */
	err = mips_cm_probe();
	if (!err && (read_gcr_gic_status() & CM_GCR_GIC_STATUS_GICEX_MSK))
	return;

	if (malta_scon() == MIPS_REVISION_SCON_ROCIT) {
	/*
	* On systems using the RocIT system controller a GIC may be
	* present without a CM. Detect whether that is the case.
	*/
	biu_base = ioremap_nocache(MSC01_BIU_REG_BASE,
	MSC01_BIU_ADDRSPACE_SZ);
	sc_cfg = __raw_readl(biu_base + MSC01_SC_CFG_OFS);
	if (sc_cfg & MSC01_SC_CFG_GICPRES_MSK) {
	/* enable the GIC at the system controller level */
	sc_cfg \|= BIT(MSC01_SC_CFG_GICENA_SHF);
	__raw_writel(sc_cfg, biu_base + MSC01_SC_CFG_OFS);
	return;
	}
	}

	gic_off = fdt_node_offset_by_compatible(fdt, -1, "mti,gic");
	if (gic_off < 0) {
	pr_warn("malta-dtshim: unable to find DT GIC node: %d\n",
	gic_off);
	return;
	}

	err = fdt_nop_node(fdt, gic_off);
	if (err)
	pr_warn("malta-dtshim: unable to nop GIC node\n");

	i8259_off = fdt_node_offset_by_compatible(fdt, -1, "intel,i8259");
	if (i8259_off < 0) {
	pr_warn("malta-dtshim: unable to find DT i8259 node: %d\n",
	i8259_off);
	return;
	}

	cpu_off = fdt_node_offset_by_compatible(fdt, -1,
	"mti,cpu-interrupt-controller");
	if (cpu_off < 0) {
	pr_warn("malta-dtshim: unable to find CPU intc node: %d\n",
	cpu_off);
	return;
	}

	cpu_phandle = fdt_get_phandle(fdt, cpu_off);
	if (!cpu_phandle) {
	pr_warn("malta-dtshim: unable to get CPU intc phandle\n");
	return;
	}

	err = fdt_setprop_u32(fdt, i8259_off, "interrupt-parent", cpu_phandle);
	if (err) {
	pr_warn("malta-dtshim: unable to set i8259 interrupt-parent: %d\n",
	err);
	return;
	}

	err = fdt_setprop_u32(fdt, i8259_off, "interrupts", 2);
	if (err) {
	pr_warn("malta-dtshim: unable to set i8259 interrupts: %d\n",
	err);
	return;
	}
	}

	void __init malta_dt_shim(void fdt)
	{
	int root_off, len, err;
	const char *compat;

	if (fdt_check_header(fdt))
	panic("Corrupt DT");

	err = fdt_open_into(fdt, fdt_buf, sizeof(fdt_buf));
	if (err)
	panic("Unable to open FDT: %d", err);

	root_off = fdt_path_offset(fdt_buf, "/");
	if (root_off < 0)
	panic("No / node in DT");

	compat = fdt_getprop(fdt_buf, root_off, "compatible", &len);
	if (!compat)
	panic("No root compatible property in DT: %d", len);

	/* if this isn't Malta, leave the DT alone */
	if (strncmp(compat, "mti,malta", len))
	return fdt;

	append_memory(fdt_buf, root_off);
	remove_gic(fdt_buf);

	err = fdt_pack(fdt_buf);
	if (err)
	panic("Unable to pack FDT: %d\n", err);

	return fdt_buf;
	}