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linux/arch/microblaze/kernel/setup.c
Michal Simek bf2d809668 microblaze: Lockdep support 
Microblaze needs to do lock_init very soon because MMU init calls lock functions.

Here is the explanation from Peter Zijlstra why we have to enable
__ARCH_WANTS_INTERRUPTS_ON_CTSW.

"So we schedule while holding rq->lock (for obvious reasons), but since
lockdep tracks held locks per tasks, we need to transfer the held state
from the prev to the next task. We do this by explicity calling
spin_release(&rq->lock) in context_switch() right before switch_to(),
and calling spin_acquire(&rq->lock) in
finish_task_switch()->finish_lock_switch().

Now, for some reason lockdep thinks that interrupts got enabled over the
context switch (git grep __ARCH_WANTS_INTERRUPTS_ON_CTSW arch/microblaze
doesn't seem to turn up anything).

Clearly trying to acquire the rq->lock with interrupts enabled is a bad
idea and lockdep warns you about this."

Signed-off-by: Michal Simek <monstr@monstr.eu>
2009-12-14 08:40:09 +01:00

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/*
* Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2007-2009 PetaLogix
* Copyright (C) 2006 Atmark Techno, Inc.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/init.h>
#include <linux/string.h>
#include <linux/seq_file.h>
#include <linux/cpu.h>
#include <linux/initrd.h>
#include <linux/console.h>
#include <linux/debugfs.h>
#include <asm/setup.h>
#include <asm/sections.h>
#include <asm/page.h>
#include <linux/io.h>
#include <linux/bug.h>
#include <linux/param.h>
#include <linux/cache.h>
#include <asm/cacheflush.h>
#include <asm/entry.h>
#include <asm/cpuinfo.h>
#include <asm/system.h>
#include <asm/prom.h>
#include <asm/pgtable.h>
DEFINE_PER_CPU(unsigned int, KSP); /* Saved kernel stack pointer */
DEFINE_PER_CPU(unsigned int, KM); /* Kernel/user mode */
DEFINE_PER_CPU(unsigned int, ENTRY_SP); /* Saved SP on kernel entry */
DEFINE_PER_CPU(unsigned int, R11_SAVE); /* Temp variable for entry */
DEFINE_PER_CPU(unsigned int, CURRENT_SAVE); /* Saved current pointer */
unsigned int boot_cpuid;
char cmd_line[COMMAND_LINE_SIZE];
void __init setup_arch(char **cmdline_p)
{
*cmdline_p = cmd_line;
console_verbose();
unflatten_device_tree();
/* NOTE I think that this function is not necessary to call */
/* irq_early_init(); */
setup_cpuinfo();
__invalidate_icache_all();
__enable_icache();
__invalidate_dcache_all();
__enable_dcache();
panic_timeout = 120;
setup_memory();
#if defined(CONFIG_SELFMOD_INTC) || defined(CONFIG_SELFMOD_TIMER)
printk(KERN_NOTICE "Self modified code enable\n");
#endif
#ifdef CONFIG_VT
#if defined(CONFIG_XILINX_CONSOLE)
conswitchp = &xil_con;
#elif defined(CONFIG_DUMMY_CONSOLE)
conswitchp = &dummy_con;
#endif
#endif
}
#ifdef CONFIG_MTD_UCLINUX
/* Handle both romfs and cramfs types, without generating unnecessary
code (ie no point checking for CRAMFS if it's not even enabled) */
inline unsigned get_romfs_len(unsigned *addr)
{
#ifdef CONFIG_ROMFS_FS
if (memcmp(&addr[0], "-rom1fs-", 8) == 0) /* romfs */
return be32_to_cpu(addr[2]);
#endif
#ifdef CONFIG_CRAMFS
if (addr[0] == le32_to_cpu(0x28cd3d45)) /* cramfs */
return le32_to_cpu(addr[1]);
#endif
return 0;
}
#endif /* CONFIG_MTD_UCLINUX_EBSS */
void __init machine_early_init(const char *cmdline, unsigned int ram,
unsigned int fdt, unsigned int msr)
{
unsigned long *src, *dst = (unsigned long *)0x0;
/* If CONFIG_MTD_UCLINUX is defined, assume ROMFS is at the
* end of kernel. There are two position which we want to check.
* The first is __init_end and the second __bss_start.
*/
#ifdef CONFIG_MTD_UCLINUX
int romfs_size;
unsigned int romfs_base;
char *old_klimit = klimit;
romfs_base = (ram ? ram : (unsigned int)&__init_end);
romfs_size = PAGE_ALIGN(get_romfs_len((unsigned *)romfs_base));
if (!romfs_size) {
romfs_base = (unsigned int)&__bss_start;
romfs_size = PAGE_ALIGN(get_romfs_len((unsigned *)romfs_base));
}
/* Move ROMFS out of BSS before clearing it */
if (romfs_size > 0) {
memmove(&_ebss, (int *)romfs_base, romfs_size);
klimit += romfs_size;
}
#endif
/* clearing bss section */
memset(__bss_start, 0, __bss_stop-__bss_start);
memset(_ssbss, 0, _esbss-_ssbss);
/* Copy command line passed from bootloader */
#ifndef CONFIG_CMDLINE_BOOL
if (cmdline && cmdline[0] != '\0')
strlcpy(cmd_line, cmdline, COMMAND_LINE_SIZE);
#endif
lockdep_init();
/* initialize device tree for usage in early_printk */
early_init_devtree((void *)_fdt_start);
#ifdef CONFIG_EARLY_PRINTK
setup_early_printk(NULL);
#endif
early_printk("Ramdisk addr 0x%08x, ", ram);
if (fdt)
early_printk("FDT at 0x%08x\n", fdt);
else
early_printk("Compiled-in FDT at 0x%08x\n",
(unsigned int)_fdt_start);
#ifdef CONFIG_MTD_UCLINUX
early_printk("Found romfs @ 0x%08x (0x%08x)\n",
romfs_base, romfs_size);
early_printk("#### klimit %p ####\n", old_klimit);
BUG_ON(romfs_size < 0); /* What else can we do? */
early_printk("Moved 0x%08x bytes from 0x%08x to 0x%08x\n",
romfs_size, romfs_base, (unsigned)&_ebss);
early_printk("New klimit: 0x%08x\n", (unsigned)klimit);
#endif
#if CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR
if (msr)
early_printk("!!!Your kernel has setup MSR instruction but "
"CPU don't have it %d\n", msr);
#else
if (!msr)
early_printk("!!!Your kernel not setup MSR instruction but "
"CPU have it %d\n", msr);
#endif
for (src = __ivt_start; src < __ivt_end; src++, dst++)
*dst = *src;
/* Initialize global data */
per_cpu(KM, 0) = 0x1; /* We start in kernel mode */
per_cpu(CURRENT_SAVE, 0) = (unsigned long)current;
}
#ifdef CONFIG_DEBUG_FS
struct dentry *of_debugfs_root;
static int microblaze_debugfs_init(void)
{
of_debugfs_root = debugfs_create_dir("microblaze", NULL);
return of_debugfs_root == NULL;
}
arch_initcall(microblaze_debugfs_init);
#endif
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