linux/arch/xtensa/kernel/setup.c
Marc Gauthier 2d1c645cc5 xtensa: dispatch medium-priority interrupts
Add support for dispatching medium-priority interrupts, that is,
interrupts of priority levels 2 to EXCM_LEVEL. IRQ handling may be
preempted by higher priority IRQ.

Signed-off-by: Marc Gauthier <marc@tensilica.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
2013-02-23 19:12:52 -08:00

726 lines
16 KiB
C

/*
* arch/xtensa/kernel/setup.c
*
* 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.
*
* Copyright (C) 1995 Linus Torvalds
* Copyright (C) 2001 - 2005 Tensilica Inc.
*
* Chris Zankel <chris@zankel.net>
* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
* Kevin Chea
* Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca>
*/
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/proc_fs.h>
#include <linux/screen_info.h>
#include <linux/bootmem.h>
#include <linux/kernel.h>
#ifdef CONFIG_OF
#include <linux/of_fdt.h>
#include <linux/of_platform.h>
#endif
#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE)
# include <linux/console.h>
#endif
#ifdef CONFIG_RTC
# include <linux/timex.h>
#endif
#ifdef CONFIG_PROC_FS
# include <linux/seq_file.h>
#endif
#include <asm/bootparam.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/timex.h>
#include <asm/platform.h>
#include <asm/page.h>
#include <asm/setup.h>
#include <asm/param.h>
#include <asm/traps.h>
#include <platform/hardware.h>
#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE)
struct screen_info screen_info = { 0, 24, 0, 0, 0, 80, 0, 0, 0, 24, 1, 16};
#endif
#ifdef CONFIG_BLK_DEV_FD
extern struct fd_ops no_fd_ops;
struct fd_ops *fd_ops;
#endif
extern struct rtc_ops no_rtc_ops;
struct rtc_ops *rtc_ops;
#ifdef CONFIG_BLK_DEV_INITRD
extern void *initrd_start;
extern void *initrd_end;
int initrd_is_mapped = 0;
extern int initrd_below_start_ok;
#endif
#ifdef CONFIG_OF
extern u32 __dtb_start[];
void *dtb_start = __dtb_start;
#endif
unsigned char aux_device_present;
extern unsigned long loops_per_jiffy;
/* Command line specified as configuration option. */
static char __initdata command_line[COMMAND_LINE_SIZE];
#ifdef CONFIG_CMDLINE_BOOL
static char default_command_line[COMMAND_LINE_SIZE] __initdata = CONFIG_CMDLINE;
#endif
sysmem_info_t __initdata sysmem;
#ifdef CONFIG_MMU
extern void init_mmu(void);
#else
static inline void init_mmu(void) { }
#endif
extern int mem_reserve(unsigned long, unsigned long, int);
extern void bootmem_init(void);
extern void zones_init(void);
/*
* Boot parameter parsing.
*
* The Xtensa port uses a list of variable-sized tags to pass data to
* the kernel. The first tag must be a BP_TAG_FIRST tag for the list
* to be recognised. The list is terminated with a zero-sized
* BP_TAG_LAST tag.
*/
typedef struct tagtable {
u32 tag;
int (*parse)(const bp_tag_t*);
} tagtable_t;
#define __tagtable(tag, fn) static tagtable_t __tagtable_##fn \
__attribute__((used, section(".taglist"))) = { tag, fn }
/* parse current tag */
static int __init add_sysmem_bank(unsigned long type, unsigned long start,
unsigned long end)
{
if (sysmem.nr_banks >= SYSMEM_BANKS_MAX) {
printk(KERN_WARNING
"Ignoring memory bank 0x%08lx size %ldKB\n",
start, end - start);
return -EINVAL;
}
sysmem.bank[sysmem.nr_banks].type = type;
sysmem.bank[sysmem.nr_banks].start = PAGE_ALIGN(start);
sysmem.bank[sysmem.nr_banks].end = end & PAGE_MASK;
sysmem.nr_banks++;
return 0;
}
static int __init parse_tag_mem(const bp_tag_t *tag)
{
meminfo_t *mi = (meminfo_t *)(tag->data);
if (mi->type != MEMORY_TYPE_CONVENTIONAL)
return -1;
return add_sysmem_bank(mi->type, mi->start, mi->end);
}
__tagtable(BP_TAG_MEMORY, parse_tag_mem);
#ifdef CONFIG_BLK_DEV_INITRD
static int __init parse_tag_initrd(const bp_tag_t* tag)
{
meminfo_t* mi;
mi = (meminfo_t*)(tag->data);
initrd_start = (void*)(mi->start);
initrd_end = (void*)(mi->end);
return 0;
}
__tagtable(BP_TAG_INITRD, parse_tag_initrd);
#ifdef CONFIG_OF
static int __init parse_tag_fdt(const bp_tag_t *tag)
{
dtb_start = (void *)(tag->data[0]);
return 0;
}
__tagtable(BP_TAG_FDT, parse_tag_fdt);
void __init early_init_dt_setup_initrd_arch(unsigned long start,
unsigned long end)
{
initrd_start = (void *)__va(start);
initrd_end = (void *)__va(end);
initrd_below_start_ok = 1;
}
#endif /* CONFIG_OF */
#endif /* CONFIG_BLK_DEV_INITRD */
static int __init parse_tag_cmdline(const bp_tag_t* tag)
{
strlcpy(command_line, (char *)(tag->data), COMMAND_LINE_SIZE);
return 0;
}
__tagtable(BP_TAG_COMMAND_LINE, parse_tag_cmdline);
static int __init parse_bootparam(const bp_tag_t* tag)
{
extern tagtable_t __tagtable_begin, __tagtable_end;
tagtable_t *t;
/* Boot parameters must start with a BP_TAG_FIRST tag. */
if (tag->id != BP_TAG_FIRST) {
printk(KERN_WARNING "Invalid boot parameters!\n");
return 0;
}
tag = (bp_tag_t*)((unsigned long)tag + sizeof(bp_tag_t) + tag->size);
/* Parse all tags. */
while (tag != NULL && tag->id != BP_TAG_LAST) {
for (t = &__tagtable_begin; t < &__tagtable_end; t++) {
if (tag->id == t->tag) {
t->parse(tag);
break;
}
}
if (t == &__tagtable_end)
printk(KERN_WARNING "Ignoring tag "
"0x%08x\n", tag->id);
tag = (bp_tag_t*)((unsigned long)(tag + 1) + tag->size);
}
return 0;
}
#ifdef CONFIG_OF
void __init early_init_dt_add_memory_arch(u64 base, u64 size)
{
size &= PAGE_MASK;
add_sysmem_bank(MEMORY_TYPE_CONVENTIONAL, base, base + size);
}
void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
{
return __alloc_bootmem(size, align, 0);
}
void __init early_init_devtree(void *params)
{
/* Setup flat device-tree pointer */
initial_boot_params = params;
/* Retrieve various informations from the /chosen node of the
* device-tree, including the platform type, initrd location and
* size, TCE reserve, and more ...
*/
if (!command_line[0])
of_scan_flat_dt(early_init_dt_scan_chosen, command_line);
/* Scan memory nodes and rebuild MEMBLOCKs */
of_scan_flat_dt(early_init_dt_scan_root, NULL);
if (sysmem.nr_banks == 0)
of_scan_flat_dt(early_init_dt_scan_memory, NULL);
}
static void __init copy_devtree(void)
{
void *alloc = early_init_dt_alloc_memory_arch(
be32_to_cpu(initial_boot_params->totalsize), 0);
if (alloc) {
memcpy(alloc, initial_boot_params,
be32_to_cpu(initial_boot_params->totalsize));
initial_boot_params = alloc;
}
}
static int __init xtensa_device_probe(void)
{
of_platform_populate(NULL, NULL, NULL, NULL);
return 0;
}
device_initcall(xtensa_device_probe);
#endif /* CONFIG_OF */
/*
* Initialize architecture. (Early stage)
*/
void __init init_arch(bp_tag_t *bp_start)
{
sysmem.nr_banks = 0;
/* Parse boot parameters */
if (bp_start)
parse_bootparam(bp_start);
#ifdef CONFIG_OF
early_init_devtree(dtb_start);
#endif
if (sysmem.nr_banks == 0) {
sysmem.nr_banks = 1;
sysmem.bank[0].start = PLATFORM_DEFAULT_MEM_START;
sysmem.bank[0].end = PLATFORM_DEFAULT_MEM_START
+ PLATFORM_DEFAULT_MEM_SIZE;
}
#ifdef CONFIG_CMDLINE_BOOL
if (!command_line[0])
strlcpy(command_line, default_command_line, COMMAND_LINE_SIZE);
#endif
/* Early hook for platforms */
platform_init(bp_start);
/* Initialize MMU. */
init_mmu();
}
/*
* Initialize system. Setup memory and reserve regions.
*/
extern char _end;
extern char _stext;
extern char _WindowVectors_text_start;
extern char _WindowVectors_text_end;
extern char _DebugInterruptVector_literal_start;
extern char _DebugInterruptVector_text_end;
extern char _KernelExceptionVector_literal_start;
extern char _KernelExceptionVector_text_end;
extern char _UserExceptionVector_literal_start;
extern char _UserExceptionVector_text_end;
extern char _DoubleExceptionVector_literal_start;
extern char _DoubleExceptionVector_text_end;
#if XCHAL_EXCM_LEVEL >= 2
extern char _Level2InterruptVector_text_start;
extern char _Level2InterruptVector_text_end;
#endif
#if XCHAL_EXCM_LEVEL >= 3
extern char _Level3InterruptVector_text_start;
extern char _Level3InterruptVector_text_end;
#endif
#if XCHAL_EXCM_LEVEL >= 4
extern char _Level4InterruptVector_text_start;
extern char _Level4InterruptVector_text_end;
#endif
#if XCHAL_EXCM_LEVEL >= 5
extern char _Level5InterruptVector_text_start;
extern char _Level5InterruptVector_text_end;
#endif
#if XCHAL_EXCM_LEVEL >= 6
extern char _Level6InterruptVector_text_start;
extern char _Level6InterruptVector_text_end;
#endif
#ifdef CONFIG_S32C1I_SELFTEST
#if XCHAL_HAVE_S32C1I
static int __initdata rcw_word, rcw_probe_pc, rcw_exc;
/*
* Basic atomic compare-and-swap, that records PC of S32C1I for probing.
*
* If *v == cmp, set *v = set. Return previous *v.
*/
static inline int probed_compare_swap(int *v, int cmp, int set)
{
int tmp;
__asm__ __volatile__(
" movi %1, 1f\n"
" s32i %1, %4, 0\n"
" wsr %2, scompare1\n"
"1: s32c1i %0, %3, 0\n"
: "=a" (set), "=&a" (tmp)
: "a" (cmp), "a" (v), "a" (&rcw_probe_pc), "0" (set)
: "memory"
);
return set;
}
/* Handle probed exception */
void __init do_probed_exception(struct pt_regs *regs, unsigned long exccause)
{
if (regs->pc == rcw_probe_pc) { /* exception on s32c1i ? */
regs->pc += 3; /* skip the s32c1i instruction */
rcw_exc = exccause;
} else {
do_unhandled(regs, exccause);
}
}
/* Simple test of S32C1I (soc bringup assist) */
void __init check_s32c1i(void)
{
int n, cause1, cause2;
void *handbus, *handdata, *handaddr; /* temporarily saved handlers */
rcw_probe_pc = 0;
handbus = trap_set_handler(EXCCAUSE_LOAD_STORE_ERROR,
do_probed_exception);
handdata = trap_set_handler(EXCCAUSE_LOAD_STORE_DATA_ERROR,
do_probed_exception);
handaddr = trap_set_handler(EXCCAUSE_LOAD_STORE_ADDR_ERROR,
do_probed_exception);
/* First try an S32C1I that does not store: */
rcw_exc = 0;
rcw_word = 1;
n = probed_compare_swap(&rcw_word, 0, 2);
cause1 = rcw_exc;
/* took exception? */
if (cause1 != 0) {
/* unclean exception? */
if (n != 2 || rcw_word != 1)
panic("S32C1I exception error");
} else if (rcw_word != 1 || n != 1) {
panic("S32C1I compare error");
}
/* Then an S32C1I that stores: */
rcw_exc = 0;
rcw_word = 0x1234567;
n = probed_compare_swap(&rcw_word, 0x1234567, 0xabcde);
cause2 = rcw_exc;
if (cause2 != 0) {
/* unclean exception? */
if (n != 0xabcde || rcw_word != 0x1234567)
panic("S32C1I exception error (b)");
} else if (rcw_word != 0xabcde || n != 0x1234567) {
panic("S32C1I store error");
}
/* Verify consistency of exceptions: */
if (cause1 || cause2) {
pr_warn("S32C1I took exception %d, %d\n", cause1, cause2);
/* If emulation of S32C1I upon bus error gets implemented,
we can get rid of this panic for single core (not SMP) */
panic("S32C1I exceptions not currently supported");
}
if (cause1 != cause2)
panic("inconsistent S32C1I exceptions");
trap_set_handler(EXCCAUSE_LOAD_STORE_ERROR, handbus);
trap_set_handler(EXCCAUSE_LOAD_STORE_DATA_ERROR, handdata);
trap_set_handler(EXCCAUSE_LOAD_STORE_ADDR_ERROR, handaddr);
}
#else /* XCHAL_HAVE_S32C1I */
/* This condition should not occur with a commercially deployed processor.
Display reminder for early engr test or demo chips / FPGA bitstreams */
void __init check_s32c1i(void)
{
pr_warn("Processor configuration lacks atomic compare-and-swap support!\n");
}
#endif /* XCHAL_HAVE_S32C1I */
#else /* CONFIG_S32C1I_SELFTEST */
void __init check_s32c1i(void)
{
}
#endif /* CONFIG_S32C1I_SELFTEST */
void __init setup_arch(char **cmdline_p)
{
strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;
check_s32c1i();
/* Reserve some memory regions */
#ifdef CONFIG_BLK_DEV_INITRD
if (initrd_start < initrd_end) {
initrd_is_mapped = mem_reserve(__pa(initrd_start),
__pa(initrd_end), 0);
initrd_below_start_ok = 1;
} else {
initrd_start = 0;
}
#endif
mem_reserve(__pa(&_stext),__pa(&_end), 1);
mem_reserve(__pa(&_WindowVectors_text_start),
__pa(&_WindowVectors_text_end), 0);
mem_reserve(__pa(&_DebugInterruptVector_literal_start),
__pa(&_DebugInterruptVector_text_end), 0);
mem_reserve(__pa(&_KernelExceptionVector_literal_start),
__pa(&_KernelExceptionVector_text_end), 0);
mem_reserve(__pa(&_UserExceptionVector_literal_start),
__pa(&_UserExceptionVector_text_end), 0);
mem_reserve(__pa(&_DoubleExceptionVector_literal_start),
__pa(&_DoubleExceptionVector_text_end), 0);
#if XCHAL_EXCM_LEVEL >= 2
mem_reserve(__pa(&_Level2InterruptVector_text_start),
__pa(&_Level2InterruptVector_text_end), 0);
#endif
#if XCHAL_EXCM_LEVEL >= 3
mem_reserve(__pa(&_Level3InterruptVector_text_start),
__pa(&_Level3InterruptVector_text_end), 0);
#endif
#if XCHAL_EXCM_LEVEL >= 4
mem_reserve(__pa(&_Level4InterruptVector_text_start),
__pa(&_Level4InterruptVector_text_end), 0);
#endif
#if XCHAL_EXCM_LEVEL >= 5
mem_reserve(__pa(&_Level5InterruptVector_text_start),
__pa(&_Level5InterruptVector_text_end), 0);
#endif
#if XCHAL_EXCM_LEVEL >= 6
mem_reserve(__pa(&_Level6InterruptVector_text_start),
__pa(&_Level6InterruptVector_text_end), 0);
#endif
bootmem_init();
#ifdef CONFIG_OF
copy_devtree();
unflatten_device_tree();
#endif
platform_setup(cmdline_p);
paging_init();
zones_init();
#ifdef CONFIG_VT
# if defined(CONFIG_VGA_CONSOLE)
conswitchp = &vga_con;
# elif defined(CONFIG_DUMMY_CONSOLE)
conswitchp = &dummy_con;
# endif
#endif
#ifdef CONFIG_PCI
platform_pcibios_init();
#endif
}
void machine_restart(char * cmd)
{
platform_restart();
}
void machine_halt(void)
{
platform_halt();
while (1);
}
void machine_power_off(void)
{
platform_power_off();
while (1);
}
#ifdef CONFIG_PROC_FS
/*
* Display some core information through /proc/cpuinfo.
*/
static int
c_show(struct seq_file *f, void *slot)
{
/* high-level stuff */
seq_printf(f,"processor\t: 0\n"
"vendor_id\t: Tensilica\n"
"model\t\t: Xtensa " XCHAL_HW_VERSION_NAME "\n"
"core ID\t\t: " XCHAL_CORE_ID "\n"
"build ID\t: 0x%x\n"
"byte order\t: %s\n"
"cpu MHz\t\t: %lu.%02lu\n"
"bogomips\t: %lu.%02lu\n",
XCHAL_BUILD_UNIQUE_ID,
XCHAL_HAVE_BE ? "big" : "little",
CCOUNT_PER_JIFFY/(1000000/HZ),
(CCOUNT_PER_JIFFY/(10000/HZ)) % 100,
loops_per_jiffy/(500000/HZ),
(loops_per_jiffy/(5000/HZ)) % 100);
seq_printf(f,"flags\t\t: "
#if XCHAL_HAVE_NMI
"nmi "
#endif
#if XCHAL_HAVE_DEBUG
"debug "
# if XCHAL_HAVE_OCD
"ocd "
# endif
#endif
#if XCHAL_HAVE_DENSITY
"density "
#endif
#if XCHAL_HAVE_BOOLEANS
"boolean "
#endif
#if XCHAL_HAVE_LOOPS
"loop "
#endif
#if XCHAL_HAVE_NSA
"nsa "
#endif
#if XCHAL_HAVE_MINMAX
"minmax "
#endif
#if XCHAL_HAVE_SEXT
"sext "
#endif
#if XCHAL_HAVE_CLAMPS
"clamps "
#endif
#if XCHAL_HAVE_MAC16
"mac16 "
#endif
#if XCHAL_HAVE_MUL16
"mul16 "
#endif
#if XCHAL_HAVE_MUL32
"mul32 "
#endif
#if XCHAL_HAVE_MUL32_HIGH
"mul32h "
#endif
#if XCHAL_HAVE_FP
"fpu "
#endif
#if XCHAL_HAVE_S32C1I
"s32c1i "
#endif
"\n");
/* Registers. */
seq_printf(f,"physical aregs\t: %d\n"
"misc regs\t: %d\n"
"ibreak\t\t: %d\n"
"dbreak\t\t: %d\n",
XCHAL_NUM_AREGS,
XCHAL_NUM_MISC_REGS,
XCHAL_NUM_IBREAK,
XCHAL_NUM_DBREAK);
/* Interrupt. */
seq_printf(f,"num ints\t: %d\n"
"ext ints\t: %d\n"
"int levels\t: %d\n"
"timers\t\t: %d\n"
"debug level\t: %d\n",
XCHAL_NUM_INTERRUPTS,
XCHAL_NUM_EXTINTERRUPTS,
XCHAL_NUM_INTLEVELS,
XCHAL_NUM_TIMERS,
XCHAL_DEBUGLEVEL);
/* Cache */
seq_printf(f,"icache line size: %d\n"
"icache ways\t: %d\n"
"icache size\t: %d\n"
"icache flags\t: "
#if XCHAL_ICACHE_LINE_LOCKABLE
"lock "
#endif
"\n"
"dcache line size: %d\n"
"dcache ways\t: %d\n"
"dcache size\t: %d\n"
"dcache flags\t: "
#if XCHAL_DCACHE_IS_WRITEBACK
"writeback "
#endif
#if XCHAL_DCACHE_LINE_LOCKABLE
"lock "
#endif
"\n",
XCHAL_ICACHE_LINESIZE,
XCHAL_ICACHE_WAYS,
XCHAL_ICACHE_SIZE,
XCHAL_DCACHE_LINESIZE,
XCHAL_DCACHE_WAYS,
XCHAL_DCACHE_SIZE);
return 0;
}
/*
* We show only CPU #0 info.
*/
static void *
c_start(struct seq_file *f, loff_t *pos)
{
return (void *) ((*pos == 0) ? (void *)1 : NULL);
}
static void *
c_next(struct seq_file *f, void *v, loff_t *pos)
{
return NULL;
}
static void
c_stop(struct seq_file *f, void *v)
{
}
const struct seq_operations cpuinfo_op =
{
start: c_start,
next: c_next,
stop: c_stop,
show: c_show
};
#endif /* CONFIG_PROC_FS */