#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>

#include "console.h"

#define MSR_LE	0x1
#define MSR_DR	0x10
#define MSR_IR	0x20
#define MSR_SF	0x8000000000000000ul

extern unsigned long callit(unsigned long arg1, unsigned long arg2,
			    unsigned long fn, unsigned long msr);

static inline void do_tlbie(unsigned long rb, unsigned long rs)
{
	__asm__ volatile("tlbie %0,%1" : : "r" (rb), "r" (rs) : "memory");
}

#define SRR0	26
#define SRR1	27
#define PID	48
#define SPRG0	272
#define SPRG1	273
#define PTCR	464

static inline unsigned long mfspr(int sprnum)
{
	long val;

	__asm__ volatile("mfspr %0,%1" : "=r" (val) : "i" (sprnum));
	return val;
}

static inline void mtspr(int sprnum, unsigned long val)
{
	__asm__ volatile("mtspr %0,%1" : : "i" (sprnum), "r" (val));
}

static inline void store_pte(unsigned long *p, unsigned long pte)
{
	__asm__ volatile("stdbrx %1,0,%0" : : "r" (p), "r" (pte) : "memory");
}

void print_string(const char *str)
{
	for (; *str; ++str)
		putchar(*str);
}

void print_hex(unsigned long val, int ndigit)
{
	int i, x;

	for (i = (ndigit - 1) * 4; i >= 0; i -= 4) {
		x = (val >> i) & 0xf;
		if (x >= 10)
			putchar(x + 'a' - 10);
		else
			putchar(x + '0');
	}
}

// i < 100
void print_test_number(int i)
{
	print_string("test ");
	putchar(48 + i/10);
	putchar(48 + i%10);
	putchar(':');
}

#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_EX | PERM_WR | PERM_RD | REF | CHG)

/*
 * Set up an MMU translation tree using memory starting at the 64k point.
 * We use 3 levels, mapping 512GB, with 4kB PGD/PMD/PTE pages.
 */
unsigned long *part_tbl = (unsigned long *) 0x10000;
unsigned long *proc_tbl = (unsigned long *) 0x11000;
unsigned long *pgdir = (unsigned long *) 0x12000;
unsigned long free_ptr = 0x13000;

void init_mmu(void)
{
	/* set up partition table */
	store_pte(&part_tbl[1], (unsigned long)proc_tbl);
	/* set up process table */
	zero_memory(proc_tbl, 512 * sizeof(unsigned long));
	mtspr(PTCR, (unsigned long)part_tbl);
	mtspr(PID, 1);
	zero_memory(pgdir, 512 * sizeof(unsigned long));
	/* RTS = 8 (512GB address space), RPDS = 9 (512-entry top level) */
	store_pte(&proc_tbl[2 * 1], (unsigned long) pgdir | 0x2000000000000009);
	do_tlbie(0xc00, 0);	/* invalidate all TLB entries */
}

static unsigned long *read_pd(unsigned long *pdp, unsigned long i)
{
	unsigned long ret;

	__asm__ volatile("ldbrx %0,%1,%2" : "=r" (ret) : "b" (pdp),
			 "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 h, i, j;
	unsigned long *ptep;
	unsigned long *pmdp;

	h = (epn >> 18) & 0x1ff;
	i = (epn >> 9) & 0x1ff;
	j = epn & 0x1ff;
	if (pgdir[h] == 0) {
		zero_memory((void *)free_ptr, 512 * sizeof(unsigned long));
		store_pte(&pgdir[h], 0x8000000000000000 | free_ptr | 9);
		free_ptr += 512 * sizeof(unsigned long);
	}
	pmdp = read_pd(pgdir, h);
	if (pmdp[i] == 0) {
		zero_memory((void *)free_ptr, 512 * sizeof(unsigned long));
		store_pte(&pmdp[i], 0x8000000000000000 | free_ptr | 9);
		free_ptr += 512 * sizeof(unsigned long);
	}
	ptep = read_pd(pmdp, i);
	if (ptep[j]) {
		ptep[j] = 0;
		do_tlbie(ea & ~0xfff, 0);
	}
	store_pte(&ptep[j], 0xc000000000000000 | (pa & 0x00fffffffffff000) |
		  perm_attr);
}

void unmap(void *ea)
{
	unsigned long epn = (unsigned long) ea >> 12;
	unsigned long h, i, j;
	unsigned long *ptep, *pmdp;

	h = (epn >> 18) & 0x1ff;
	i = (epn >> 9) & 0x1ff;
	j = epn & 0x1ff;
	if (pgdir[h] == 0)
		return;
	pmdp = read_pd(pgdir, h);
	if (pmdp[i] == 0)
		return;
	ptep = read_pd(pmdp, i);
	ptep[j] = 0;
	do_tlbie(((unsigned long)ea & ~0xfff), 0);
}

extern unsigned long test_code(unsigned long sel, unsigned long addr);

int mode_test_1(void)
{
	unsigned long ret, msr;

	map(0, (unsigned long) &test_code, DFLT_PERM);
	msr = MSR_SF | MSR_IR | MSR_DR | MSR_LE;
	ret = callit(2, 0, 0x0, msr);

	return ret;
}

int fail = 0;

void do_test(int num, int (*test)(void))
{
	int ret;

	print_test_number(num);
	ret = test();
	if (ret == 0) {
		print_string("PASS\r\n");
	} else {
		fail = 1;
		print_string("FAIL ");
		print_hex(ret, 16);
		if (ret != 0 && (ret & ~0xfe0ul) == 0) {
			print_string(" SRR0=");
			print_hex(mfspr(SPRG0), 16);
			print_string(" SRR1=");
			print_hex(mfspr(SPRG1), 16);
		}
		print_string("\r\n");
	}
}

int main(void)
{
	console_init();
	init_mmu();

	// Prime the branch caches
	__asm__ __volatile__("sc");

	do_test(1, mode_test_1);

	return fail;
}