122 lines
2.8 KiB
C
122 lines
2.8 KiB
C
|
// SPDX-License-Identifier: GPL-2.0-only
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/export.h>
|
||
|
|
#include <linux/spinlock_types.h>
|
||
|
|
#include <linux/init.h>
|
||
|
|
#include <linux/pgtable.h>
|
||
|
|
#include <asm/page.h>
|
||
|
|
#include <asm/setup.h>
|
||
|
|
#include <asm/io.h>
|
||
|
|
#include <asm/cpufeature.h>
|
||
|
|
#include <asm/special_insns.h>
|
||
|
|
#include <asm/olpc_ofw.h>
|
||
|
|
|
||
|
|
/* address of OFW callback interface; will be NULL if OFW isn't found */
|
||
|
|
static int (*olpc_ofw_cif)(int *);
|
||
|
|
|
||
|
|
/* page dir entry containing OFW's pgdir table; filled in by head_32.S */
|
||
|
|
u32 olpc_ofw_pgd __initdata;
|
||
|
|
|
||
|
|
static DEFINE_SPINLOCK(ofw_lock);
|
||
|
|
|
||
|
|
#define MAXARGS 10
|
||
|
|
|
||
|
|
void __init setup_olpc_ofw_pgd(void)
|
||
|
|
{
|
||
|
|
pgd_t *base, *ofw_pde;
|
||
|
|
|
||
|
|
if (!olpc_ofw_cif)
|
||
|
|
return;
|
||
|
|
|
||
|
|
/* fetch OFW's PDE */
|
||
|
|
base = early_ioremap(olpc_ofw_pgd, sizeof(olpc_ofw_pgd) * PTRS_PER_PGD);
|
||
|
|
if (!base) {
|
||
|
|
printk(KERN_ERR "failed to remap OFW's pgd - disabling OFW!\n");
|
||
|
|
olpc_ofw_cif = NULL;
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
ofw_pde = &base[OLPC_OFW_PDE_NR];
|
||
|
|
|
||
|
|
/* install OFW's PDE permanently into the kernel's pgtable */
|
||
|
|
set_pgd(&swapper_pg_dir[OLPC_OFW_PDE_NR], *ofw_pde);
|
||
|
|
/* implicit optimization barrier here due to uninline function return */
|
||
|
|
|
||
|
|
early_iounmap(base, sizeof(olpc_ofw_pgd) * PTRS_PER_PGD);
|
||
|
|
}
|
||
|
|
|
||
|
|
int __olpc_ofw(const char *name, int nr_args, const void **args, int nr_res,
|
||
|
|
void **res)
|
||
|
|
{
|
||
|
|
int ofw_args[MAXARGS + 3];
|
||
|
|
unsigned long flags;
|
||
|
|
int ret, i, *p;
|
||
|
|
|
||
|
|
BUG_ON(nr_args + nr_res > MAXARGS);
|
||
|
|
|
||
|
|
if (!olpc_ofw_cif)
|
||
|
|
return -EIO;
|
||
|
|
|
||
|
|
ofw_args[0] = (int)name;
|
||
|
|
ofw_args[1] = nr_args;
|
||
|
|
ofw_args[2] = nr_res;
|
||
|
|
|
||
|
|
p = &ofw_args[3];
|
||
|
|
for (i = 0; i < nr_args; i++, p++)
|
||
|
|
*p = (int)args[i];
|
||
|
|
|
||
|
|
/* call into ofw */
|
||
|
|
spin_lock_irqsave(&ofw_lock, flags);
|
||
|
|
ret = olpc_ofw_cif(ofw_args);
|
||
|
|
spin_unlock_irqrestore(&ofw_lock, flags);
|
||
|
|
|
||
|
|
if (!ret) {
|
||
|
|
for (i = 0; i < nr_res; i++, p++)
|
||
|
|
*((int *)res[i]) = *p;
|
||
|
|
}
|
||
|
|
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(__olpc_ofw);
|
||
|
|
|
||
|
|
bool olpc_ofw_present(void)
|
||
|
|
{
|
||
|
|
return olpc_ofw_cif != NULL;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(olpc_ofw_present);
|
||
|
|
|
||
|
|
/* OFW cif _should_ be above this address */
|
||
|
|
#define OFW_MIN 0xff000000
|
||
|
|
|
||
|
|
/* OFW starts on a 1MB boundary */
|
||
|
|
#define OFW_BOUND (1<<20)
|
||
|
|
|
||
|
|
void __init olpc_ofw_detect(void)
|
||
|
|
{
|
||
|
|
struct olpc_ofw_header *hdr = &boot_params.olpc_ofw_header;
|
||
|
|
unsigned long start;
|
||
|
|
|
||
|
|
/* ensure OFW booted us by checking for "OFW " string */
|
||
|
|
if (hdr->ofw_magic != OLPC_OFW_SIG)
|
||
|
|
return;
|
||
|
|
|
||
|
|
olpc_ofw_cif = (int (*)(int *))hdr->cif_handler;
|
||
|
|
|
||
|
|
if ((unsigned long)olpc_ofw_cif < OFW_MIN) {
|
||
|
|
printk(KERN_ERR "OFW detected, but cif has invalid address 0x%lx - disabling.\n",
|
||
|
|
(unsigned long)olpc_ofw_cif);
|
||
|
|
olpc_ofw_cif = NULL;
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* determine where OFW starts in memory */
|
||
|
|
start = round_down((unsigned long)olpc_ofw_cif, OFW_BOUND);
|
||
|
|
printk(KERN_INFO "OFW detected in memory, cif @ 0x%lx (reserving top %ldMB)\n",
|
||
|
|
(unsigned long)olpc_ofw_cif, (-start) >> 20);
|
||
|
|
reserve_top_address(-start);
|
||
|
|
}
|
||
|
|
|
||
|
|
bool __init olpc_ofw_is_installed(void)
|
||
|
|
{
|
||
|
|
return olpc_ofw_cif != NULL;
|
||
|
|
}
|