[PATCH v3 30/71] ARC: Boot #1: low-level, setup_arch(), /proc/cpuinfo, mem init

From: Vineet Gupta
Date: Thu Jan 24 2013 - 05:56:02 EST


Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/arc/Kconfig | 2 +
arch/arc/include/asm/arcregs.h | 5 +
arch/arc/include/asm/setup.h | 22 +++++
arch/arc/kernel/head.S | 78 +++++++++++++++++
arch/arc/kernel/reset.c | 33 +++++++
arch/arc/kernel/setup.c | 166 ++++++++++++++++++++++++++++++++++++
arch/arc/mm/init.c | 171 ++++++++++++++++++++++++++++++++++++++
arch/arc/plat-arcfpga/platform.c | 29 +++++++
8 files changed, 506 insertions(+), 0 deletions(-)
create mode 100644 arch/arc/include/asm/setup.h
create mode 100644 arch/arc/kernel/head.S
create mode 100644 arch/arc/kernel/reset.c
create mode 100644 arch/arc/kernel/setup.c
create mode 100644 arch/arc/mm/init.c
create mode 100644 arch/arc/plat-arcfpga/platform.c

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 756beff..a353849 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -23,7 +23,9 @@ config ARC
select GENERIC_SIGALTSTACK
select GENERIC_SMP_IDLE_THREAD
select HAVE_GENERIC_HARDIRQS
+ select HAVE_MEMBLOCK
select MODULES_USE_ELF_RELA
+ select NO_BOOTMEM

config SCHED_OMIT_FRAME_POINTER
def_bool y
diff --git a/arch/arc/include/asm/arcregs.h b/arch/arc/include/asm/arcregs.h
index 1c24485..9e42611 100644
--- a/arch/arc/include/asm/arcregs.h
+++ b/arch/arc/include/asm/arcregs.h
@@ -258,6 +258,11 @@
} \
}

+/* Helpers */
+#define TO_KB(bytes) ((bytes) >> 10)
+#define TO_MB(bytes) (TO_KB(bytes) >> 10)
+#define PAGES_TO_KB(n_pages) ((n_pages) << (PAGE_SHIFT - 10))
+#define PAGES_TO_MB(n_pages) (PAGES_TO_KB(n_pages) >> 10)

#ifdef CONFIG_ARC_FPU_SAVE_RESTORE
/* These DPFP regs need to be saved/restored across ctx-sw */
diff --git a/arch/arc/include/asm/setup.h b/arch/arc/include/asm/setup.h
new file mode 100644
index 0000000..ab427e6
--- /dev/null
+++ b/arch/arc/include/asm/setup.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASMARC_SETUP_H
+#define __ASMARC_SETUP_H
+
+#include <linux/types.h>
+
+#define COMMAND_LINE_SIZE 256
+
+extern int root_mountflags, end_mem;
+extern int running_on_hw;
+
+void __init setup_processor(void);
+void __init setup_arch_memory(void);
+
+#endif /* __ASMARC_SETUP_H */
diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
new file mode 100644
index 0000000..e63f6a4
--- /dev/null
+++ b/arch/arc/kernel/head.S
@@ -0,0 +1,78 @@
+/*
+ * ARC CPU startup Code
+ *
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Vineetg: Dec 2007
+ * -Check if we are running on Simulator or on real hardware
+ * to skip certain things during boot on simulator
+ */
+
+#include <asm/asm-offsets.h>
+#include <asm/entry.h>
+#include <linux/linkage.h>
+#include <asm/arcregs.h>
+
+ .cpu A7
+
+ .section .init.text, "ax",@progbits
+ .type stext, @function
+ .globl stext
+stext:
+ ;-------------------------------------------------------------------
+ ; Don't clobber r0-r4 yet. It might have bootloader provided info
+ ;-------------------------------------------------------------------
+
+ ; Clear BSS before updating any globals
+ ; XXX: use ZOL here
+ mov r5, __bss_start
+ mov r6, __bss_stop
+1:
+ st.ab 0, [r5,4]
+ brlt r5, r6, 1b
+
+#ifdef CONFIG_CMDLINE_UBOOT
+ ; support for bootloader provided cmdline
+ ; If cmdline passed by u-boot, then
+ ; r0 = 1 (because ATAGS parsing, now retired, used to use 0)
+ ; r1 = magic number (board identity)
+ ; r2 = addr of cmdline string (somewhere in memory/flash)
+
+ brne r0, 1, .Lother_bootup_chores ; u-boot didn't pass cmdline
+ breq r2, 0, .Lother_bootup_chores ; or cmdline is NULL
+
+ mov r5, @command_line
+1:
+ ldb.ab r6, [r2, 1]
+ breq r6, 0, .Lother_bootup_chores
+ b.d 1b
+ stb.ab r6, [r5, 1]
+#endif
+
+.Lother_bootup_chores:
+
+ ; Identify if running on ISS vs Silicon
+ ; IDENTITY Reg [ 3 2 1 0 ]
+ ; (chip-id) ^^^^^ ==> 0xffff for ISS
+ lr r0, [identity]
+ lsr r3, r0, 16
+ cmp r3, 0xffff
+ mov.z r4, 0
+ mov.nz r4, 1
+ st r4, [@running_on_hw]
+
+ ; setup "current" tsk and optionally cache it in dedicated r25
+ mov r9, @init_task
+ SET_CURR_TASK_ON_CPU r9, r0 ; r9 = tsk, r0 = scratch
+
+ ; setup stack (fp, sp)
+ mov fp, 0
+
+ ; tsk->thread_info is really a PAGE, whose bottom hoists stack
+ GET_TSK_STACK_BASE r9, sp ; r9 = tsk, sp = stack base(output)
+
+ j start_kernel ; "C" entry point
diff --git a/arch/arc/kernel/reset.c b/arch/arc/kernel/reset.c
new file mode 100644
index 0000000..e227a2b
--- /dev/null
+++ b/arch/arc/kernel/reset.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright (C) 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/reboot.h>
+#include <linux/pm.h>
+
+void machine_halt(void)
+{
+ /* Halt the processor */
+ __asm__ __volatile__("flag 1\n");
+}
+
+void machine_restart(char *__unused)
+{
+ /* Soft reset : jump to reset vector */
+ pr_info("Put your restart handler here\n");
+ machine_halt();
+}
+
+void machine_power_off(void)
+{
+ /* FIXME :: power off ??? */
+ machine_halt();
+}
+
+void (*pm_power_off) (void) = NULL;
diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c
new file mode 100644
index 0000000..82ac206
--- /dev/null
+++ b/arch/arc/kernel/setup.c
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/seq_file.h>
+#include <linux/fs.h>
+#include <linux/delay.h>
+#include <linux/root_dev.h>
+#include <linux/console.h>
+#include <linux/module.h>
+#include <linux/cpu.h>
+#include <asm/arcregs.h>
+#include <asm/tlb.h>
+#include <asm/cache.h>
+#include <asm/setup.h>
+#include <asm/page.h>
+#include <asm/irq.h>
+#include <asm/arcregs.h>
+
+#define FIX_PTR(x) __asm__ __volatile__(";" : "+r"(x))
+
+int running_on_hw = 1; /* vs. on ISS */
+
+char __initdata command_line[COMMAND_LINE_SIZE];
+
+struct task_struct *_current_task[NR_CPUS]; /* For stack switching */
+
+struct cpuinfo_arc cpuinfo_arc700[NR_CPUS];
+
+void __init read_arc_build_cfg_regs(void)
+{
+ read_decode_mmu_bcr();
+ read_decode_cache_bcr();
+}
+
+/*
+ * Initialize and setup the processor core
+ * This is called by all the CPUs thus should not do special case stuff
+ * such as only for boot CPU etc
+ */
+
+void __init setup_processor(void)
+{
+ read_arc_build_cfg_regs();
+ arc_init_IRQ();
+ arc_mmu_init();
+ arc_cache_init();
+}
+
+void __init __attribute__((weak)) arc_platform_early_init(void)
+{
+}
+
+void __init setup_arch(char **cmdline_p)
+{
+#ifdef CONFIG_CMDLINE_UBOOT
+ /* Make sure that a whitespace is inserted before */
+ strlcat(command_line, " ", sizeof(command_line));
+#endif
+ /*
+ * Append .config cmdline to base command line, which might already
+ * contain u-boot "bootargs" (handled by head.S, if so configured)
+ */
+ strlcat(command_line, CONFIG_CMDLINE, sizeof(command_line));
+
+ /* Save unparsed command line copy for /proc/cmdline */
+ strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
+ *cmdline_p = command_line;
+
+ /* To force early parsing of things like mem=xxx */
+ parse_early_param();
+
+ /* Platform/board specific: e.g. early console registration */
+ arc_platform_early_init();
+
+ setup_processor();
+
+ setup_arch_memory();
+
+ /* Can be issue if someone passes cmd line arg "ro"
+ * But that is unlikely so keeping it as it is
+ */
+ root_mountflags &= ~MS_RDONLY;
+
+ console_verbose();
+
+#if defined(CONFIG_VT) && defined(CONFIG_DUMMY_CONSOLE)
+ conswitchp = &dummy_con;
+#endif
+
+}
+
+/*
+ * Get CPU information for use by the procfs.
+ */
+
+#define cpu_to_ptr(c) ((void *)(0xFFFF0000 | (unsigned int)(c)))
+#define ptr_to_cpu(p) (~0xFFFF0000UL & (unsigned int)(p))
+
+static int show_cpuinfo(struct seq_file *m, void *v)
+{
+ char *str;
+ int cpu_id = ptr_to_cpu(v);
+
+ str = (char *)__get_free_page(GFP_TEMPORARY);
+ if (!str)
+ goto done;
+
+ seq_printf(m, "ARC700 #%d\n", cpu_id);
+
+ seq_printf(m, "Bogo MIPS : \t%lu.%02lu\n",
+ loops_per_jiffy / (500000 / HZ),
+ (loops_per_jiffy / (5000 / HZ)) % 100);
+
+ free_page((unsigned long)str);
+done:
+ seq_printf(m, "\n\n");
+
+ return 0;
+}
+
+static void *c_start(struct seq_file *m, loff_t *pos)
+{
+ /*
+ * Callback returns cpu-id to iterator for show routine, NULL to stop.
+ * However since NULL is also a valid cpu-id (0), we use a round-about
+ * way to pass it w/o having to kmalloc/free a 2 byte string.
+ * Encode cpu-id as 0xFFcccc, which is decoded by show routine.
+ */
+ return *pos < num_possible_cpus() ? cpu_to_ptr(*pos) : NULL;
+}
+
+static void *c_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ ++*pos;
+ return c_start(m, pos);
+}
+
+static void c_stop(struct seq_file *m, void *v)
+{
+}
+
+const struct seq_operations cpuinfo_op = {
+ .start = c_start,
+ .next = c_next,
+ .stop = c_stop,
+ .show = show_cpuinfo
+};
+
+static DEFINE_PER_CPU(struct cpu, cpu_topology);
+
+static int __init topology_init(void)
+{
+ int cpu;
+
+ for_each_present_cpu(cpu)
+ register_cpu(&per_cpu(cpu_topology, cpu), cpu);
+
+ return 0;
+}
+
+subsys_initcall(topology_init);
diff --git a/arch/arc/mm/init.c b/arch/arc/mm/init.c
new file mode 100644
index 0000000..63da347
--- /dev/null
+++ b/arch/arc/mm/init.c
@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#ifdef CONFIG_BLOCK_DEV_RAM
+#include <linux/blk.h>
+#endif
+#include <linux/swap.h>
+#include <linux/module.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/sections.h>
+#include <asm/arcregs.h>
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD] __aligned(PAGE_SIZE);
+char empty_zero_page[PAGE_SIZE] __aligned(PAGE_SIZE);
+EXPORT_SYMBOL(empty_zero_page);
+
+/* Default tot mem from .config */
+static unsigned long arc_mem_sz = CONFIG_ARC_PLAT_SDRAM_SIZE;
+
+/* User can over-ride above with "mem=nnn[KkMm]" in cmdline */
+static int __init setup_mem_sz(char *str)
+{
+ arc_mem_sz = memparse(str, NULL) & PAGE_MASK;
+
+ /* early console might not be setup yet - it will show up later */
+ pr_info("\"mem=%s\": mem sz set to %ldM\n", str, TO_MB(arc_mem_sz));
+
+ return 0;
+}
+early_param("mem", setup_mem_sz);
+
+/*
+ * First memory setup routine called from setup_arch()
+ * 1. setup swapper's mm @init_mm
+ * 2. Count the pages we have and setup bootmem allocator
+ * 3. zone setup
+ */
+void __init setup_arch_memory(void)
+{
+ unsigned long zones_size[MAX_NR_ZONES] = { 0, 0 };
+ unsigned long end_mem = CONFIG_LINUX_LINK_BASE + arc_mem_sz;
+
+ init_mm.start_code = (unsigned long)_text;
+ init_mm.end_code = (unsigned long)_etext;
+ init_mm.end_data = (unsigned long)_edata;
+ init_mm.brk = (unsigned long)_end;
+
+ /*
+ * We do it here, so that memory is correctly instantiated
+ * even if "mem=xxx" cmline over-ride is not given
+ */
+ memblock_add(CONFIG_LINUX_LINK_BASE, arc_mem_sz);
+
+ /*------------- externs in mm need setting up ---------------*/
+
+ /* first page of system - kernel .vector starts here */
+ min_low_pfn = PFN_DOWN(CONFIG_LINUX_LINK_BASE);
+
+ /* Last usable page of low mem (no HIGHMEM yet for ARC port) */
+ max_low_pfn = max_pfn = PFN_DOWN(end_mem);
+
+ max_mapnr = num_physpages = max_low_pfn - min_low_pfn;
+
+ /*------------- reserve kernel image -----------------------*/
+ memblock_reserve(CONFIG_LINUX_LINK_BASE,
+ __pa(_end) - CONFIG_LINUX_LINK_BASE);
+
+ memblock_dump_all();
+
+ /*-------------- node setup --------------------------------*/
+ memset(zones_size, 0, sizeof(zones_size));
+ zones_size[ZONE_NORMAL] = num_physpages;
+
+ /*
+ * We can't use the helper free_area_init(zones[]) because it uses
+ * PAGE_OFFSET to compute the @min_low_pfn which would be wrong
+ * when our kernel doesn't start at PAGE_OFFSET, i.e.
+ * PAGE_OFFSET != CONFIG_LINUX_LINK_BASE
+ */
+ free_area_init_node(0, /* node-id */
+ zones_size, /* num pages per zone */
+ min_low_pfn, /* first pfn of node */
+ NULL); /* NO holes */
+}
+
+/*
+ * mem_init - initializes memory
+ *
+ * Frees up bootmem
+ * Calculates and displays memory available/used
+ */
+void __init mem_init(void)
+{
+ int codesize, datasize, initsize, reserved_pages, free_pages;
+ int tmp;
+
+ high_memory = (void *)(CONFIG_LINUX_LINK_BASE + arc_mem_sz);
+
+ totalram_pages = free_all_bootmem();
+
+ /* count all reserved pages [kernel code/data/mem_map..] */
+ reserved_pages = 0;
+ for (tmp = 0; tmp < max_mapnr; tmp++)
+ if (PageReserved(mem_map + tmp))
+ reserved_pages++;
+
+ /* XXX: nr_free_pages() is equivalent */
+ free_pages = max_mapnr - reserved_pages;
+
+ /*
+ * For the purpose of display below, split the "reserve mem"
+ * kernel code/data is already shown explicitly,
+ * Show any other reservations (mem_map[ ] et al)
+ */
+ reserved_pages -= (((unsigned int)_end - CONFIG_LINUX_LINK_BASE) >>
+ PAGE_SHIFT);
+
+ codesize = _etext - _text;
+ datasize = _end - _etext;
+ initsize = __init_end - __init_begin;
+
+ pr_info("Memory Available: %dM / %ldM (%dK code, %dK data, %dK init, %dK reserv)\n",
+ PAGES_TO_MB(free_pages),
+ TO_MB(arc_mem_sz),
+ TO_KB(codesize), TO_KB(datasize), TO_KB(initsize),
+ PAGES_TO_KB(reserved_pages));
+}
+
+static void __init free_init_pages(const char *what, unsigned long begin,
+ unsigned long end)
+{
+ unsigned long addr;
+
+ pr_info("Freeing %s: %ldk [%lx] to [%lx]\n",
+ what, TO_KB(end - begin), begin, end);
+
+ /* need to check that the page we free is not a partial page */
+ for (addr = begin; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) {
+ ClearPageReserved(virt_to_page(addr));
+ init_page_count(virt_to_page(addr));
+ free_page(addr);
+ totalram_pages++;
+ }
+}
+
+/*
+ * free_initmem: Free all the __init memory.
+ */
+void __init_refok free_initmem(void)
+{
+ free_init_pages("unused kernel memory",
+ (unsigned long)__init_begin,
+ (unsigned long)__init_end);
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init free_initrd_mem(unsigned long start, unsigned long end)
+{
+ free_init_pages("initrd memory", start, end);
+}
+#endif
diff --git a/arch/arc/plat-arcfpga/platform.c b/arch/arc/plat-arcfpga/platform.c
new file mode 100644
index 0000000..7b5dcab
--- /dev/null
+++ b/arch/arc/plat-arcfpga/platform.c
@@ -0,0 +1,29 @@
+/*
+ * ARC FPGA Platform support code
+ *
+ * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+
+/*
+ * Early Platform Initialization called from setup_arch()
+ */
+void __init arc_platform_early_init(void)
+{
+ pr_info("[plat-arcfpga]: registering early dev resources\n");
+}
+
+int __init fpga_plat_init(void)
+{
+ pr_info("[plat-arcfpga]: registering device resources\n");
+
+ return 0;
+}
+arch_initcall(fpga_plat_init);
--
1.7.4.1

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