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linux/arch/sparc64/kernel/setup.c
David S. Miller 56fb4df6da [SPARC64]: Elminate all usage of hard-coded trap globals. 
UltraSPARC has special sets of global registers which are switched to
for certain trap types.  There is one set for MMU related traps, one
set of Interrupt Vector processing, and another set (called the
Alternate globals) for all other trap types.

For what seems like forever we've hard coded the values in some of
these trap registers.  Some examples include:

1) Interrupt Vector global %g6 holds current processors interrupt
   work struct where received interrupts are managed for IRQ handler
   dispatch.

2) MMU global %g7 holds the base of the page tables of the currently
   active address space.

3) Alternate global %g6 held the current_thread_info() value.

Such hardcoding has resulted in some serious issues in many areas.
There are some code sequences where having another register available
would help clean up the implementation.  Taking traps such as
cross-calls from the OBP firmware requires some trick code sequences
wherein we have to save away and restore all of the special sets of
global registers when we enter/exit OBP.

We were also using the IMMU TSB register on SMP to hold the per-cpu
area base address, which doesn't work any longer now that we actually
use the TSB facility of the cpu.

The implementation is pretty straight forward.  One tricky bit is
getting the current processor ID as that is different on different cpu
variants.  We use a stub with a fancy calling convention which we
patch at boot time.  The calling convention is that the stub is
branched to and the (PC - 4) to return to is in register %g1.  The cpu
number is left in %g6.  This stub can be invoked by using the
__GET_CPUID macro.

We use an array of per-cpu trap state to store the current thread and
physical address of the current address space's page tables.  The
TRAP_LOAD_THREAD_REG loads %g6 with the current thread from this
table, it uses __GET_CPUID and also clobbers %g1.

TRAP_LOAD_IRQ_WORK is used by the interrupt vector processing to load
the current processor's IRQ software state into %g6.  It also uses
__GET_CPUID and clobbers %g1.

Finally, TRAP_LOAD_PGD_PHYS loads the physical address base of the
current address space's page tables into %g7, it clobbers %g1 and uses
__GET_CPUID.

Many refinements are possible, as well as some tuning, with this stuff
in place.

Signed-off-by: David S. Miller <davem@davemloft.net>
2006-03-20 01:11:16 -08:00

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/* $Id: setup.c,v 1.72 2002/02/09 19:49:30 davem Exp $
* linux/arch/sparc64/kernel/setup.c
*
* Copyright (C) 1995,1996 David S. Miller (davem@caip.rutgers.edu)
* Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <asm/smp.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/tty.h>
#include <linux/delay.h>
#include <linux/config.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <linux/syscalls.h>
#include <linux/kdev_t.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/inet.h>
#include <linux/console.h>
#include <linux/root_dev.h>
#include <linux/interrupt.h>
#include <linux/cpu.h>
#include <linux/initrd.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/oplib.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/idprom.h>
#include <asm/head.h>
#include <asm/starfire.h>
#include <asm/mmu_context.h>
#include <asm/timer.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/mmu.h>
#ifdef CONFIG_IP_PNP
#include <net/ipconfig.h>
#endif
struct screen_info screen_info = {
0, 0, /* orig-x, orig-y */
0, /* unused */
0, /* orig-video-page */
0, /* orig-video-mode */
128, /* orig-video-cols */
0, 0, 0, /* unused, ega_bx, unused */
54, /* orig-video-lines */
0, /* orig-video-isVGA */
16 /* orig-video-points */
};
/* Typing sync at the prom prompt calls the function pointed to by
* the sync callback which I set to the following function.
* This should sync all filesystems and return, for now it just
* prints out pretty messages and returns.
*/
void (*prom_palette)(int);
void (*prom_keyboard)(void);
static void
prom_console_write(struct console *con, const char *s, unsigned n)
{
prom_write(s, n);
}
static struct console prom_console = {
.name = "prom",
.write = prom_console_write,
.flags = CON_CONSDEV | CON_ENABLED,
.index = -1,
};
#define PROM_TRUE -1
#define PROM_FALSE 0
/* Pretty sick eh? */
int prom_callback(long *args)
{
struct console *cons, *saved_console = NULL;
unsigned long flags;
char *cmd;
extern spinlock_t prom_entry_lock;
if (!args)
return -1;
if (!(cmd = (char *)args[0]))
return -1;
/*
* The callback can be invoked on the cpu that first dropped
* into prom_cmdline after taking the serial interrupt, or on
* a slave processor that was smp_captured() if the
* administrator has done a switch-cpu inside obp. In either
* case, the cpu is marked as in-interrupt. Drop IRQ locks.
*/
irq_exit();
/* XXX Revisit the locking here someday. This is a debugging
* XXX feature so it isnt all that critical. -DaveM
*/
local_irq_save(flags);
spin_unlock(&prom_entry_lock);
cons = console_drivers;
while (cons) {
unregister_console(cons);
cons->flags &= ~(CON_PRINTBUFFER);
cons->next = saved_console;
saved_console = cons;
cons = console_drivers;
}
register_console(&prom_console);
if (!strcmp(cmd, "sync")) {
prom_printf("PROM `%s' command...\n", cmd);
show_free_areas();
if (current->pid != 0) {
local_irq_enable();
sys_sync();
local_irq_disable();
}
args[2] = 0;
args[args[1] + 3] = -1;
prom_printf("Returning to PROM\n");
} else if (!strcmp(cmd, "va>tte-data")) {
unsigned long ctx, va;
unsigned long tte = 0;
long res = PROM_FALSE;
ctx = args[3];
va = args[4];
if (ctx) {
/*
* Find process owning ctx, lookup mapping.
*/
struct task_struct *p;
struct mm_struct *mm = NULL;
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
pte_t pte;
for_each_process(p) {
mm = p->mm;
if (CTX_NRBITS(mm->context) == ctx)
break;
}
if (!mm ||
CTX_NRBITS(mm->context) != ctx)
goto done;
pgdp = pgd_offset(mm, va);
if (pgd_none(*pgdp))
goto done;
pudp = pud_offset(pgdp, va);
if (pud_none(*pudp))
goto done;
pmdp = pmd_offset(pudp, va);
if (pmd_none(*pmdp))
goto done;
/* Preemption implicitly disabled by virtue of
* being called from inside OBP.
*/
ptep = pte_offset_map(pmdp, va);
pte = *ptep;
if (pte_present(pte)) {
tte = pte_val(pte);
res = PROM_TRUE;
}
pte_unmap(ptep);
goto done;
}
if ((va >= KERNBASE) && (va < (KERNBASE + (4 * 1024 * 1024)))) {
extern unsigned long sparc64_kern_pri_context;
/* Spitfire Errata #32 workaround */
__asm__ __volatile__("stxa %0, [%1] %2\n\t"
"flush %%g6"
: /* No outputs */
: "r" (sparc64_kern_pri_context),
"r" (PRIMARY_CONTEXT),
"i" (ASI_DMMU));
/*
* Locked down tlb entry.
*/
if (tlb_type == spitfire)
tte = spitfire_get_dtlb_data(SPITFIRE_HIGHEST_LOCKED_TLBENT);
else if (tlb_type == cheetah || tlb_type == cheetah_plus)
tte = cheetah_get_ldtlb_data(CHEETAH_HIGHEST_LOCKED_TLBENT);
res = PROM_TRUE;
goto done;
}
if (va < PGDIR_SIZE) {
/*
* vmalloc or prom_inherited mapping.
*/
pgd_t *pgdp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
pte_t pte;
int error;
if ((va >= LOW_OBP_ADDRESS) && (va < HI_OBP_ADDRESS)) {
tte = prom_virt_to_phys(va, &error);
if (!error)
res = PROM_TRUE;
goto done;
}
pgdp = pgd_offset_k(va);
if (pgd_none(*pgdp))
goto done;
pudp = pud_offset(pgdp, va);
if (pud_none(*pudp))
goto done;
pmdp = pmd_offset(pudp, va);
if (pmd_none(*pmdp))
goto done;
/* Preemption implicitly disabled by virtue of
* being called from inside OBP.
*/
ptep = pte_offset_kernel(pmdp, va);
pte = *ptep;
if (pte_present(pte)) {
tte = pte_val(pte);
res = PROM_TRUE;
}
goto done;
}
if (va < PAGE_OFFSET) {
/*
* No mappings here.
*/
goto done;
}
if (va & (1UL << 40)) {
/*
* I/O page.
*/
tte = (__pa(va) & _PAGE_PADDR) |
_PAGE_VALID | _PAGE_SZ4MB |
_PAGE_E | _PAGE_P | _PAGE_W;
res = PROM_TRUE;
goto done;
}
/*
* Normal page.
*/
tte = (__pa(va) & _PAGE_PADDR) |
_PAGE_VALID | _PAGE_SZ4MB |
_PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_W;
res = PROM_TRUE;
done:
if (res == PROM_TRUE) {
args[2] = 3;
args[args[1] + 3] = 0;
args[args[1] + 4] = res;
args[args[1] + 5] = tte;
} else {
args[2] = 2;
args[args[1] + 3] = 0;
args[args[1] + 4] = res;
}
} else if (!strcmp(cmd, ".soft1")) {
unsigned long tte;
tte = args[3];
prom_printf("%lx:\"%s%s%s%s%s\" ",
(tte & _PAGE_SOFT) >> 7,
tte & _PAGE_MODIFIED ? "M" : "-",
tte & _PAGE_ACCESSED ? "A" : "-",
tte & _PAGE_READ ? "W" : "-",
tte & _PAGE_WRITE ? "R" : "-",
tte & _PAGE_PRESENT ? "P" : "-");
args[2] = 2;
args[args[1] + 3] = 0;
args[args[1] + 4] = PROM_TRUE;
} else if (!strcmp(cmd, ".soft2")) {
unsigned long tte;
tte = args[3];
prom_printf("%lx ", (tte & 0x07FC000000000000UL) >> 50);
args[2] = 2;
args[args[1] + 3] = 0;
args[args[1] + 4] = PROM_TRUE;
} else {
prom_printf("unknown PROM `%s' command...\n", cmd);
}
unregister_console(&prom_console);
while (saved_console) {
cons = saved_console;
saved_console = cons->next;
register_console(cons);
}
spin_lock(&prom_entry_lock);
local_irq_restore(flags);
/*
* Restore in-interrupt status for a resume from obp.
*/
irq_enter();
return 0;
}
unsigned int boot_flags = 0;
#define BOOTME_DEBUG 0x1
#define BOOTME_SINGLE 0x2
/* Exported for mm/init.c:paging_init. */
unsigned long cmdline_memory_size = 0;
static struct console prom_debug_console = {
.name = "debug",
.write = prom_console_write,
.flags = CON_PRINTBUFFER,
.index = -1,
};
/* XXX Implement this at some point... */
void kernel_enter_debugger(void)
{
}
int obp_system_intr(void)
{
if (boot_flags & BOOTME_DEBUG) {
printk("OBP: system interrupted\n");
prom_halt();
return 1;
}
return 0;
}
/*
* Process kernel command line switches that are specific to the
* SPARC or that require special low-level processing.
*/
static void __init process_switch(char c)
{
switch (c) {
case 'd':
boot_flags |= BOOTME_DEBUG;
break;
case 's':
boot_flags |= BOOTME_SINGLE;
break;
case 'h':
prom_printf("boot_flags_init: Halt!\n");
prom_halt();
break;
case 'p':
/* Use PROM debug console. */
register_console(&prom_debug_console);
break;
case 'P':
/* Force UltraSPARC-III P-Cache on. */
if (tlb_type != cheetah) {
printk("BOOT: Ignoring P-Cache force option.\n");
break;
}
cheetah_pcache_forced_on = 1;
add_taint(TAINT_MACHINE_CHECK);
cheetah_enable_pcache();
break;
default:
printk("Unknown boot switch (-%c)\n", c);
break;
}
}
static void __init process_console(char *commands)
{
serial_console = 0;
commands += 8;
/* Linux-style serial */
if (!strncmp(commands, "ttyS", 4))
serial_console = simple_strtoul(commands + 4, NULL, 10) + 1;
else if (!strncmp(commands, "tty", 3)) {
char c = *(commands + 3);
/* Solaris-style serial */
if (c == 'a' || c == 'b') {
serial_console = c - 'a' + 1;
prom_printf ("Using /dev/tty%c as console.\n", c);
}
/* else Linux-style fbcon, not serial */
}
#if defined(CONFIG_PROM_CONSOLE)
if (!strncmp(commands, "prom", 4)) {
char *p;
for (p = commands - 8; *p && *p != ' '; p++)
*p = ' ';
conswitchp = &prom_con;
}
#endif
}
static void __init boot_flags_init(char *commands)
{
while (*commands) {
/* Move to the start of the next "argument". */
while (*commands && *commands == ' ')
commands++;
/* Process any command switches, otherwise skip it. */
if (*commands == '\0')
break;
if (*commands == '-') {
commands++;
while (*commands && *commands != ' ')
process_switch(*commands++);
continue;
}
if (!strncmp(commands, "console=", 8)) {
process_console(commands);
} else if (!strncmp(commands, "mem=", 4)) {
/*
* "mem=XXX[kKmM]" overrides the PROM-reported
* memory size.
*/
cmdline_memory_size = simple_strtoul(commands + 4,
&commands, 0);
if (*commands == 'K' || *commands == 'k') {
cmdline_memory_size <<= 10;
commands++;
} else if (*commands=='M' || *commands=='m') {
cmdline_memory_size <<= 20;
commands++;
}
}
while (*commands && *commands != ' ')
commands++;
}
}
extern void panic_setup(char *, int *);
extern unsigned short root_flags;
extern unsigned short root_dev;
extern unsigned short ram_flags;
#define RAMDISK_IMAGE_START_MASK 0x07FF
#define RAMDISK_PROMPT_FLAG 0x8000
#define RAMDISK_LOAD_FLAG 0x4000
extern int root_mountflags;
char reboot_command[COMMAND_LINE_SIZE];
static struct pt_regs fake_swapper_regs = { { 0, }, 0, 0, 0, 0 };
void register_prom_callbacks(void)
{
prom_setcallback(prom_callback);
prom_feval(": linux-va>tte-data 2 \" va>tte-data\" $callback drop ; "
"' linux-va>tte-data to va>tte-data");
prom_feval(": linux-.soft1 1 \" .soft1\" $callback 2drop ; "
"' linux-.soft1 to .soft1");
prom_feval(": linux-.soft2 1 \" .soft2\" $callback 2drop ; "
"' linux-.soft2 to .soft2");
}
void __init setup_arch(char **cmdline_p)
{
/* Initialize PROM console and command line. */
*cmdline_p = prom_getbootargs();
strcpy(saved_command_line, *cmdline_p);
printk("ARCH: SUN4U\n");
#ifdef CONFIG_DUMMY_CONSOLE
conswitchp = &dummy_con;
#elif defined(CONFIG_PROM_CONSOLE)
conswitchp = &prom_con;
#endif
/* Work out if we are starfire early on */
check_if_starfire();
/* Now we know enough to patch the __get_cpu_id()
* trampoline used by trap code.
*/
per_cpu_patch();
boot_flags_init(*cmdline_p);
idprom_init();
if (!root_flags)
root_mountflags &= ~MS_RDONLY;
ROOT_DEV = old_decode_dev(root_dev);
#ifdef CONFIG_BLK_DEV_INITRD
rd_image_start = ram_flags & RAMDISK_IMAGE_START_MASK;
rd_prompt = ((ram_flags & RAMDISK_PROMPT_FLAG) != 0);
rd_doload = ((ram_flags & RAMDISK_LOAD_FLAG) != 0);
#endif
task_thread_info(&init_task)->kregs = &fake_swapper_regs;
#ifdef CONFIG_IP_PNP
if (!ic_set_manually) {
int chosen = prom_finddevice ("/chosen");
u32 cl, sv, gw;
cl = prom_getintdefault (chosen, "client-ip", 0);
sv = prom_getintdefault (chosen, "server-ip", 0);
gw = prom_getintdefault (chosen, "gateway-ip", 0);
if (cl && sv) {
ic_myaddr = cl;
ic_servaddr = sv;
if (gw)
ic_gateway = gw;
#if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_RARP)
ic_proto_enabled = 0;
#endif
}
}
#endif
smp_setup_cpu_possible_map();
paging_init();
/* Get boot processor trap_block[] setup. */
init_cur_cpu_trap();
}
static int __init set_preferred_console(void)
{
int idev, odev;
/* The user has requested a console so this is already set up. */
if (serial_console >= 0)
return -EBUSY;
idev = prom_query_input_device();
odev = prom_query_output_device();
if (idev == PROMDEV_IKBD && odev == PROMDEV_OSCREEN) {
serial_console = 0;
} else if (idev == PROMDEV_ITTYA && odev == PROMDEV_OTTYA) {
serial_console = 1;
} else if (idev == PROMDEV_ITTYB && odev == PROMDEV_OTTYB) {
serial_console = 2;
} else if (idev == PROMDEV_IRSC && odev == PROMDEV_ORSC) {
serial_console = 3;
} else {
prom_printf("Inconsistent console: "
"input %d, output %d\n",
idev, odev);
prom_halt();
}
if (serial_console)
return add_preferred_console("ttyS", serial_console - 1, NULL);
return -ENODEV;
}
console_initcall(set_preferred_console);
/* BUFFER is PAGE_SIZE bytes long. */
extern char *sparc_cpu_type;
extern char *sparc_fpu_type;
extern void smp_info(struct seq_file *);
extern void smp_bogo(struct seq_file *);
extern void mmu_info(struct seq_file *);
unsigned int dcache_parity_tl1_occurred;
unsigned int icache_parity_tl1_occurred;
static int ncpus_probed;
static int show_cpuinfo(struct seq_file *m, void *__unused)
{
seq_printf(m,
"cpu\t\t: %s\n"
"fpu\t\t: %s\n"
"promlib\t\t: Version 3 Revision %d\n"
"prom\t\t: %d.%d.%d\n"
"type\t\t: sun4u\n"
"ncpus probed\t: %d\n"
"ncpus active\t: %d\n"
"D$ parity tl1\t: %u\n"
"I$ parity tl1\t: %u\n"
#ifndef CONFIG_SMP
"Cpu0Bogo\t: %lu.%02lu\n"
"Cpu0ClkTck\t: %016lx\n"
#endif
,
sparc_cpu_type,
sparc_fpu_type,
prom_rev,
prom_prev >> 16,
(prom_prev >> 8) & 0xff,
prom_prev & 0xff,
ncpus_probed,
num_online_cpus(),
dcache_parity_tl1_occurred,
icache_parity_tl1_occurred
#ifndef CONFIG_SMP
, cpu_data(0).udelay_val/(500000/HZ),
(cpu_data(0).udelay_val/(5000/HZ)) % 100,
cpu_data(0).clock_tick
#endif
);
#ifdef CONFIG_SMP
smp_bogo(m);
#endif
mmu_info(m);
#ifdef CONFIG_SMP
smp_info(m);
#endif
return 0;
}
static void *c_start(struct seq_file *m, loff_t *pos)
{
/* The pointer we are returning is arbitrary,
* it just has to be non-NULL and not IS_ERR
* in the success case.
*/
return *pos == 0 ? &c_start : 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)
{
}
struct seq_operations cpuinfo_op = {
.start =c_start,
.next = c_next,
.stop = c_stop,
.show = show_cpuinfo,
};
extern int stop_a_enabled;
void sun_do_break(void)
{
if (!stop_a_enabled)
return;
prom_printf("\n");
flush_user_windows();
prom_cmdline();
}
int serial_console = -1;
int stop_a_enabled = 1;
static int __init topology_init(void)
{
int i, err;
err = -ENOMEM;
/* Count the number of physically present processors in
* the machine, even on uniprocessor, so that /proc/cpuinfo
* output is consistent with 2.4.x
*/
ncpus_probed = 0;
while (!cpu_find_by_instance(ncpus_probed, NULL, NULL))
ncpus_probed++;
for (i = 0; i < NR_CPUS; i++) {
if (cpu_possible(i)) {
struct cpu *p = kmalloc(sizeof(*p), GFP_KERNEL);
if (p) {
memset(p, 0, sizeof(*p));
register_cpu(p, i, NULL);
err = 0;
}
}
}
return err;
}
subsys_initcall(topology_init);
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