nds32: Kernel booting and initialization

This patch includes the kernel startup code. It can get dtb pointer
passed from bootloader. It will create a temp mapping by tlb
instructions at beginning and goto start_kernel.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 363 insertions, 0 deletions

diff --git a/arch/nds32/kernel/setup.c b/arch/nds32/kernel/setup.c
new file mode 100644
index 000000000000..ba910e9e4ecb
--- /dev/null
+++ b/arch/nds32/kernel/setup.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2005-2017 Andes Technology Corporation
+
+#include <linux/cpu.h>
+#include <linux/bootmem.h>
+#include <linux/seq_file.h>
+#include <linux/memblock.h>
+#include <linux/console.h>
+#include <linux/screen_info.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
+#include <asm/setup.h>
+#include <asm/sections.h>
+#include <asm/proc-fns.h>
+#include <asm/cache_info.h>
+#include <asm/elf.h>
+#include <nds32_intrinsic.h>
+
+#define HWCAP_MFUSR_PC		0x000001
+#define HWCAP_EXT		0x000002
+#define HWCAP_EXT2		0x000004
+#define HWCAP_FPU		0x000008
+#define HWCAP_AUDIO		0x000010
+#define HWCAP_BASE16		0x000020
+#define HWCAP_STRING		0x000040
+#define HWCAP_REDUCED_REGS	0x000080
+#define HWCAP_VIDEO		0x000100
+#define HWCAP_ENCRYPT		0x000200
+#define HWCAP_EDM		0x000400
+#define HWCAP_LMDMA		0x000800
+#define HWCAP_PFM		0x001000
+#define HWCAP_HSMP		0x002000
+#define HWCAP_TRACE		0x004000
+#define HWCAP_DIV		0x008000
+#define HWCAP_MAC		0x010000
+#define HWCAP_L2C		0x020000
+#define HWCAP_FPU_DP		0x040000
+#define HWCAP_V2		0x080000
+#define HWCAP_DX_REGS		0x100000
+
+unsigned long cpu_id, cpu_rev, cpu_cfgid;
+char cpu_series;
+char *endianness = NULL;
+
+unsigned int __atags_pointer __initdata;
+unsigned int elf_hwcap;
+EXPORT_SYMBOL(elf_hwcap);
+
+/*
+ * The following string table, must sync with HWCAP_xx bitmask,
+ * which is defined in <asm/procinfo.h>
+ */
+static const char *hwcap_str[] = {
+	"mfusr_pc",
+	"perf1",
+	"perf2",
+	"fpu",
+	"audio",
+	"16b",
+	"string",
+	"reduced_regs",
+	"video",
+	"encrypt",
+	"edm",
+	"lmdma",
+	"pfm",
+	"hsmp",
+	"trace",
+	"div",
+	"mac",
+	"l2c",
+	"dx_regs",
+	"v2",
+	NULL,
+};
+
+#ifdef CONFIG_CPU_DCACHE_WRITETHROUGH
+#define WRITE_METHOD "write through"
+#else
+#define WRITE_METHOD "write back"
+#endif
+
+struct cache_info L1_cache_info[2];
+static void __init dump_cpu_info(int cpu)
+{
+	int i, p = 0;
+	char str[sizeof(hwcap_str) + 16];
+
+	for (i = 0; hwcap_str[i]; i++) {
+		if (elf_hwcap & (1 << i)) {
+			sprintf(str + p, "%s ", hwcap_str[i]);
+			p += strlen(hwcap_str[i]) + 1;
+		}
+	}
+
+	pr_info("CPU%d Features: %s\n", cpu, str);
+
+	L1_cache_info[ICACHE].ways = CACHE_WAY(ICACHE);
+	L1_cache_info[ICACHE].line_size = CACHE_LINE_SIZE(ICACHE);
+	L1_cache_info[ICACHE].sets = CACHE_SET(ICACHE);
+	L1_cache_info[ICACHE].size =
+	    L1_cache_info[ICACHE].ways * L1_cache_info[ICACHE].line_size *
+	    L1_cache_info[ICACHE].sets / 1024;
+	pr_info("L1I:%dKB/%dS/%dW/%dB\n", L1_cache_info[ICACHE].size,
+		L1_cache_info[ICACHE].sets, L1_cache_info[ICACHE].ways,
+		L1_cache_info[ICACHE].line_size);
+	L1_cache_info[DCACHE].ways = CACHE_WAY(DCACHE);
+	L1_cache_info[DCACHE].line_size = CACHE_LINE_SIZE(DCACHE);
+	L1_cache_info[DCACHE].sets = CACHE_SET(DCACHE);
+	L1_cache_info[DCACHE].size =
+	    L1_cache_info[DCACHE].ways * L1_cache_info[DCACHE].line_size *
+	    L1_cache_info[DCACHE].sets / 1024;
+	pr_info("L1D:%dKB/%dS/%dW/%dB\n", L1_cache_info[DCACHE].size,
+		L1_cache_info[DCACHE].sets, L1_cache_info[DCACHE].ways,
+		L1_cache_info[DCACHE].line_size);
+	pr_info("L1 D-Cache is %s\n", WRITE_METHOD);
+	if (L1_cache_info[DCACHE].size != L1_CACHE_BYTES)
+		pr_crit
+		    ("The cache line size(%d) of this processor is not the same as L1_CACHE_BYTES(%d).\n",
+		     L1_cache_info[DCACHE].size, L1_CACHE_BYTES);
+#ifdef CONFIG_CPU_CACHE_ALIASING
+	{
+		int aliasing_num;
+		aliasing_num =
+		    L1_cache_info[ICACHE].size * 1024 / PAGE_SIZE /
+		    L1_cache_info[ICACHE].ways;
+		L1_cache_info[ICACHE].aliasing_num = aliasing_num;
+		L1_cache_info[ICACHE].aliasing_mask =
+		    (aliasing_num - 1) << PAGE_SHIFT;
+		aliasing_num =
+		    L1_cache_info[DCACHE].size * 1024 / PAGE_SIZE /
+		    L1_cache_info[DCACHE].ways;
+		L1_cache_info[DCACHE].aliasing_num = aliasing_num;
+		L1_cache_info[DCACHE].aliasing_mask =
+		    (aliasing_num - 1) << PAGE_SHIFT;
+	}
+#endif
+}
+
+static void __init setup_cpuinfo(void)
+{
+	unsigned long tmp = 0, cpu_name;
+
+	cpu_dcache_inval_all();
+	cpu_icache_inval_all();
+	__nds32__isb();
+
+	cpu_id = (__nds32__mfsr(NDS32_SR_CPU_VER) & CPU_VER_mskCPUID) >> CPU_VER_offCPUID;
+	cpu_name = ((cpu_id) & 0xf0) >> 4;
+	cpu_series = cpu_name ? cpu_name - 10 + 'A' : 'N';
+	cpu_id = cpu_id & 0xf;
+	cpu_rev = (__nds32__mfsr(NDS32_SR_CPU_VER) & CPU_VER_mskREV) >> CPU_VER_offREV;
+	cpu_cfgid = (__nds32__mfsr(NDS32_SR_CPU_VER) & CPU_VER_mskCFGID) >> CPU_VER_offCFGID;
+
+	pr_info("CPU:%c%ld, CPU_VER 0x%08x(id %lu, rev %lu, cfg %lu)\n",
+		cpu_series, cpu_id, __nds32__mfsr(NDS32_SR_CPU_VER), cpu_id, cpu_rev, cpu_cfgid);
+
+	elf_hwcap |= HWCAP_MFUSR_PC;
+
+	if (((__nds32__mfsr(NDS32_SR_MSC_CFG) & MSC_CFG_mskBASEV) >> MSC_CFG_offBASEV) == 0) {
+		if (__nds32__mfsr(NDS32_SR_MSC_CFG) & MSC_CFG_mskDIV)
+			elf_hwcap |= HWCAP_DIV;
+
+		if ((__nds32__mfsr(NDS32_SR_MSC_CFG) & MSC_CFG_mskMAC)
+		    || (cpu_id == 12 && cpu_rev < 4))
+			elf_hwcap |= HWCAP_MAC;
+	} else {
+		elf_hwcap |= HWCAP_V2;
+		elf_hwcap |= HWCAP_DIV;
+		elf_hwcap |= HWCAP_MAC;
+	}
+
+	if (cpu_cfgid & 0x0001)
+		elf_hwcap |= HWCAP_EXT;
+
+	if (cpu_cfgid & 0x0002)
+		elf_hwcap |= HWCAP_BASE16;
+
+	if (cpu_cfgid & 0x0004)
+		elf_hwcap |= HWCAP_EXT2;
+
+	if (cpu_cfgid & 0x0008)
+		elf_hwcap |= HWCAP_FPU;
+
+	if (cpu_cfgid & 0x0010)
+		elf_hwcap |= HWCAP_STRING;
+
+	if (__nds32__mfsr(NDS32_SR_MMU_CFG) & MMU_CFG_mskDE)
+		endianness = "MSB";
+	else
+		endianness = "LSB";
+
+	if (__nds32__mfsr(NDS32_SR_MSC_CFG) & MSC_CFG_mskEDM)
+		elf_hwcap |= HWCAP_EDM;
+
+	if (__nds32__mfsr(NDS32_SR_MSC_CFG) & MSC_CFG_mskLMDMA)
+		elf_hwcap |= HWCAP_LMDMA;
+
+	if (__nds32__mfsr(NDS32_SR_MSC_CFG) & MSC_CFG_mskPFM)
+		elf_hwcap |= HWCAP_PFM;
+
+	if (__nds32__mfsr(NDS32_SR_MSC_CFG) & MSC_CFG_mskHSMP)
+		elf_hwcap |= HWCAP_HSMP;
+
+	if (__nds32__mfsr(NDS32_SR_MSC_CFG) & MSC_CFG_mskTRACE)
+		elf_hwcap |= HWCAP_TRACE;
+
+	if (__nds32__mfsr(NDS32_SR_MSC_CFG) & MSC_CFG_mskAUDIO)
+		elf_hwcap |= HWCAP_AUDIO;
+
+	if (__nds32__mfsr(NDS32_SR_MSC_CFG) & MSC_CFG_mskL2C)
+		elf_hwcap |= HWCAP_L2C;
+
+	tmp = __nds32__mfsr(NDS32_SR_CACHE_CTL);
+	if (!IS_ENABLED(CONFIG_CPU_DCACHE_DISABLE))
+		tmp |= CACHE_CTL_mskDC_EN;
+
+	if (!IS_ENABLED(CONFIG_CPU_ICACHE_DISABLE))
+		tmp |= CACHE_CTL_mskIC_EN;
+	__nds32__mtsr_isb(tmp, NDS32_SR_CACHE_CTL);
+
+	dump_cpu_info(smp_processor_id());
+}
+
+static void __init setup_memory(void)
+{
+	unsigned long ram_start_pfn;
+	unsigned long free_ram_start_pfn;
+	phys_addr_t memory_start, memory_end;
+	struct memblock_region *region;
+
+	memory_end = memory_start = 0;
+
+	/* Find main memory where is the kernel */
+	for_each_memblock(memory, region) {
+		memory_start = region->base;
+		memory_end = region->base + region->size;
+		pr_info("%s: Memory: 0x%x-0x%x\n", __func__,
+			memory_start, memory_end);
+	}
+
+	if (!memory_end) {
+		panic("No memory!");
+	}
+
+	ram_start_pfn = PFN_UP(memblock_start_of_DRAM());
+	/* free_ram_start_pfn is first page after kernel */
+	free_ram_start_pfn = PFN_UP(__pa(&_end));
+	max_pfn = PFN_DOWN(memblock_end_of_DRAM());
+	/* it could update max_pfn */
+	if (max_pfn - ram_start_pfn <= MAXMEM_PFN)
+		max_low_pfn = max_pfn;
+	else {
+		max_low_pfn = MAXMEM_PFN + ram_start_pfn;
+		if (!IS_ENABLED(CONFIG_HIGHMEM))
+			max_pfn = MAXMEM_PFN + ram_start_pfn;
+	}
+	/* high_memory is related with VMALLOC */
+	high_memory = (void *)__va(max_low_pfn * PAGE_SIZE);
+	min_low_pfn = free_ram_start_pfn;
+
+	/*
+	 * initialize the boot-time allocator (with low memory only).
+	 *
+	 * This makes the memory from the end of the kernel to the end of
+	 * RAM usable.
+	 */
+	memblock_set_bottom_up(true);
+	memblock_reserve(PFN_PHYS(ram_start_pfn), PFN_PHYS(free_ram_start_pfn - ram_start_pfn));
+
+	early_init_fdt_reserve_self();
+	early_init_fdt_scan_reserved_mem();
+
+	memblock_dump_all();
+}
+
+void __init setup_arch(char **cmdline_p)
+{
+	early_init_devtree( __dtb_start);
+
+	setup_cpuinfo();
+
+	init_mm.start_code = (unsigned long)&_stext;
+	init_mm.end_code = (unsigned long)&_etext;
+	init_mm.end_data = (unsigned long)&_edata;
+	init_mm.brk = (unsigned long)&_end;
+
+	/* setup bootmem allocator */
+	setup_memory();
+
+	/* paging_init() sets up the MMU and marks all pages as reserved */
+	paging_init();
+
+	/* use generic way to parse */
+	parse_early_param();
+
+	unflatten_and_copy_device_tree();
+
+	if(IS_ENABLED(CONFIG_VT)) {
+		if(IS_ENABLED(CONFIG_DUMMY_CONSOLE))
+			conswitchp = &dummy_con;
+	}
+
+	*cmdline_p = boot_command_line;
+	early_trap_init();
+}
+
+static int c_show(struct seq_file *m, void *v)
+{
+	int i;
+
+	seq_printf(m, "Processor\t: %c%ld (id %lu, rev %lu, cfg %lu)\n",
+		   cpu_series, cpu_id, cpu_id, cpu_rev, cpu_cfgid);
+
+	seq_printf(m, "L1I\t\t: %luKB/%luS/%luW/%luB\n",
+		   CACHE_SET(ICACHE) * CACHE_WAY(ICACHE) *
+		   CACHE_LINE_SIZE(ICACHE) / 1024, CACHE_SET(ICACHE),
+		   CACHE_WAY(ICACHE), CACHE_LINE_SIZE(ICACHE));
+
+	seq_printf(m, "L1D\t\t: %luKB/%luS/%luW/%luB\n",
+		   CACHE_SET(DCACHE) * CACHE_WAY(DCACHE) *
+		   CACHE_LINE_SIZE(DCACHE) / 1024, CACHE_SET(DCACHE),
+		   CACHE_WAY(DCACHE), CACHE_LINE_SIZE(DCACHE));
+
+	seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
+		   loops_per_jiffy / (500000 / HZ),
+		   (loops_per_jiffy / (5000 / HZ)) % 100);
+
+	/* dump out the processor features */
+	seq_puts(m, "Features\t: ");
+
+	for (i = 0; hwcap_str[i]; i++)
+		if (elf_hwcap & (1 << i))
+			seq_printf(m, "%s ", hwcap_str[i]);
+
+	seq_puts(m, "\n\n");
+
+	return 0;
+}
+
+static void *c_start(struct seq_file *m, loff_t * pos)
+{
+	return *pos < 1 ? (void *)1 : NULL;
+}
+
+static void *c_next(struct seq_file *m, void *v, loff_t * pos)
+{
+	++*pos;
+	return NULL;
+}
+
+static void c_stop(struct seq_file *m, void *v)
+{
+}
+
+struct seq_operations cpuinfo_op = {
+	.start = c_start,
+	.next = c_next,
+	.stop = c_stop,
+	.show = c_show
+};