@ -55,6 +55,94 @@ void print_test_number(int i)
putchar(':');
}
static inline void do_tlbie(unsigned long rb, unsigned long rs)
{
__asm__ volatile("tlbie %0,%1" : : "r" (rb), "r" (rs) : "memory");
}
static inline void store_pte(unsigned long *p, unsigned long pte)
{
__asm__ volatile("stdbrx %1,0,%0" : : "r" (p), "r" (pte) : "memory");
}
#define CACHE_LINE_SIZE 64
void zero_memory(void *ptr, unsigned long nbytes)
{
unsigned long nb, i, nl;
void *p;
for (; nbytes != 0; nbytes -= nb, ptr += nb) {
nb = -((unsigned long)ptr) & (CACHE_LINE_SIZE - 1);
if (nb == 0 && nbytes >= CACHE_LINE_SIZE) {
nl = nbytes / CACHE_LINE_SIZE;
p = ptr;
for (i = 0; i < nl; ++i) {
__asm__ volatile("dcbz 0,%0" : : "r" (p) : "memory");
p += CACHE_LINE_SIZE;
}
nb = nl * CACHE_LINE_SIZE;
} else {
if (nb > nbytes)
nb = nbytes;
for (i = 0; i < nb; ++i)
((unsigned char *)ptr)[i] = 0;
}
}
}
#define PERM_EX 0x001
#define PERM_WR 0x002
#define PERM_RD 0x004
#define PERM_PRIV 0x008
#define ATTR_NC 0x020
#define CHG 0x080
#define REF 0x100
#define DFLT_PERM (PERM_WR | PERM_RD | REF | CHG)
/*
* Set up an MMU translation tree using memory starting at the 64k point.
* We use 2 levels, mapping 2GB (the minimum size possible), with a
* 8kB PGD level pointing to 4kB PTE pages.
*/
unsigned long *pgdir = (unsigned long *) 0x10000;
unsigned long free_ptr = 0x12000;
void init_mmu(void)
{
zero_memory(pgdir, 1024 * sizeof(unsigned long));
/* RTS = 0 (2GB address space), RPDS = 10 (1024-entry top level) */
mtspr(720, (unsigned long) pgdir | 10);
do_tlbie(0xc00, 0); /* invalidate all TLB entries */
}
static unsigned long *read_pgd(unsigned long i)
{
unsigned long ret;
__asm__ volatile("ldbrx %0,%1,%2" : "=r" (ret) : "b" (pgdir),
"r" (i * sizeof(unsigned long)));
return (unsigned long *) (ret & 0x00ffffffffffff00);
}
void map(unsigned long ea, unsigned long pa, unsigned long perm_attr)
{
unsigned long epn = ea >> 12;
unsigned long i, j;
unsigned long *ptep;
i = (epn >> 9) & 0x3ff;
j = epn & 0x1ff;
if (pgdir[i] == 0) {
zero_memory((void *)free_ptr, 512 * sizeof(unsigned long));
store_pte(&pgdir[i], 0x8000000000000000 | free_ptr | 9);
free_ptr += 512 * sizeof(unsigned long);
}
ptep = read_pgd(i);
store_pte(&ptep[j], 0xc000000000000000 | (pa & 0x00fffffffffff000) | perm_attr);
}
int priv_fn_1(unsigned long x)
{
__asm__ volatile("attn");
@ -140,6 +228,9 @@ void do_test(int num, int (*fn)(unsigned long))
int main(void)
{
potato_uart_init();
init_mmu();
map(0x2000, 0x2000, REF | CHG | PERM_RD | PERM_EX); /* map code page */
map(0x7000, 0x7000, REF | CHG | PERM_RD | PERM_WR); /* map stack page */
do_test(1, priv_fn_1);
do_test(2, priv_fn_2);