kernel-fxtec-pro1x/arch/microblaze/kernel/setup.c
Michal Simek e02db0aa3e microblaze: Handle TLB skip size dynamically
This patch fix the problem with rootfs on JFFS2 with early printk
console turned on.

The origin version used TLB63 for temporary early printk mapping.
The code expect that kernel is not able to use all 64 TLB entries
till early printk console is remapped by ioremap. After that
temporary mapping on TLB63 is silently lost.
This expectation give the opportunity to have early console pretty
early.

Microblaze systems with JFFS2 rootfs with early printk console turned on
used more than 64 TLB entries before kernel can remap early console.
Based on that kernel does access to bad area because early printk mapping
is rewritten.

This patch introduces tlb_skip variable which dynamically stores number
of skipped TLB entries from the TLB0. skip_tlb=2 means that TLB0 and TLB1
should be skipped.

MICROBLAZE_TLB_SKIP defines how many TLB is skipped at the kernel start.
They can be used for user purpose.

TLB 63 is used for temporary LMB mapping (MICROBLAZE_LMB_TLB_ID).

Also clean TLBLO when kernel starts.

For specific kernel sizes kernel can use just one TLB. Detect this case
and use the second TLB for general purpose.

Change _tlbia function to flush TLB entries from tlb_skip to TLB_SIZE.

Export tlb_skip size through debugfs.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2012-03-23 09:28:19 +01:00

252 lines
6.2 KiB
C

/*
* 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/pci.h>
#include <linux/cache.h>
#include <linux/of_platform.h>
#include <linux/dma-mapping.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();
microblaze_cache_init();
setup_memory();
#ifdef CONFIG_EARLY_PRINTK
/* remap early console to virtual address */
remap_early_printk();
#endif
xilinx_pci_init();
#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 */
unsigned long kernel_tlb;
void __init machine_early_init(const char *cmdline, unsigned int ram,
unsigned int fdt, unsigned int msr, unsigned int tlb0,
unsigned int tlb1)
{
unsigned long *src, *dst;
unsigned int offset = 0;
/* 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
/* setup kernel_tlb after BSS cleaning
* Maybe worth to move to asm code */
kernel_tlb = tlb0 + tlb1;
/* printk("TLB1 0x%08x, TLB0 0x%08x, tlb 0x%x\n", tlb0,
tlb1, kernel_tlb); */
printk("Ramdisk addr 0x%08x, ", ram);
if (fdt)
printk("FDT at 0x%08x\n", fdt);
else
printk("Compiled-in FDT at 0x%08x\n",
(unsigned int)_fdt_start);
#ifdef CONFIG_MTD_UCLINUX
printk("Found romfs @ 0x%08x (0x%08x)\n",
romfs_base, romfs_size);
printk("#### klimit %p ####\n", old_klimit);
BUG_ON(romfs_size < 0); /* What else can we do? */
printk("Moved 0x%08x bytes from 0x%08x to 0x%08x\n",
romfs_size, romfs_base, (unsigned)&_ebss);
printk("New klimit: 0x%08x\n", (unsigned)klimit);
#endif
#if CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR
if (msr)
printk("!!!Your kernel has setup MSR instruction but "
"CPU don't have it %x\n", msr);
#else
if (!msr)
printk("!!!Your kernel not setup MSR instruction but "
"CPU have it %x\n", msr);
#endif
/* Do not copy reset vectors. offset = 0x2 means skip the first
* two instructions. dst is pointer to MB vectors which are placed
* in block ram. If you want to copy reset vector setup offset to 0x0 */
#if !CONFIG_MANUAL_RESET_VECTOR
offset = 0x2;
#endif
dst = (unsigned long *) (offset * sizeof(u32));
for (src = __ivt_start + offset; 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);
static int __init debugfs_tlb(void)
{
struct dentry *d;
if (!of_debugfs_root)
return -ENODEV;
d = debugfs_create_u32("tlb_skip", S_IRUGO, of_debugfs_root, &tlb_skip);
if (!d)
return -ENOMEM;
}
device_initcall(debugfs_tlb);
#endif
static int dflt_bus_notify(struct notifier_block *nb,
unsigned long action, void *data)
{
struct device *dev = data;
/* We are only intereted in device addition */
if (action != BUS_NOTIFY_ADD_DEVICE)
return 0;
set_dma_ops(dev, &dma_direct_ops);
return NOTIFY_DONE;
}
static struct notifier_block dflt_plat_bus_notifier = {
.notifier_call = dflt_bus_notify,
.priority = INT_MAX,
};
static int __init setup_bus_notifier(void)
{
bus_register_notifier(&platform_bus_type, &dflt_plat_bus_notifier);
return 0;
}
arch_initcall(setup_bus_notifier);