[deliverable/linux.git] / arch / powerpc / kernel / softemu8xx.c

/*
 * Software emulation of some PPC instructions for the 8xx core.
 *
 * Copyright (C) 1998 Dan Malek (dmalek@jlc.net)
 *
 * Software floating emuation for the MPC8xx processor.  I did this mostly
 * because it was easier than trying to get the libraries compiled for
 * software floating point.  The goal is still to get the libraries done,
 * but I lost patience and needed some hacks to at least get init and
 * shells running.  The first problem is the setjmp/longjmp that save
 * and restore the floating point registers.
 *
 * For this emulation, our working registers are found on the register
 * save area.
 */

#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/user.h>
#include <linux/interrupt.h>

#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/io.h>

/* Eventually we may need a look-up table, but this works for now.
*/
#define LFS	48
#define LFD	50
#define LFDU	51
#define STFD	54
#define STFDU	55
#define FMR	63

void print_8xx_pte(struct mm_struct *mm, unsigned long addr)
{
	pgd_t *pgd;
	pmd_t *pmd;
	pte_t *pte;

	printk(" pte @ 0x%8lx: ", addr);
	pgd = pgd_offset(mm, addr & PAGE_MASK);
	if (pgd) {
		pmd = pmd_offset(pud_offset(pgd, addr & PAGE_MASK),
		                 addr & PAGE_MASK);
		if (pmd && pmd_present(*pmd)) {
			pte = pte_offset_kernel(pmd, addr & PAGE_MASK);
			if (pte) {
				printk(" (0x%08lx)->(0x%08lx)->0x%08lx\n",
				        (long)pgd, (long)pte, (long)pte_val(*pte));
#define pp ((long)pte_val(*pte))
				printk(" RPN: %05lx PP: %lx SPS: %lx SH: %lx "
				       "CI: %lx v: %lx\n",
				       pp>>12,    /* rpn */
				       (pp>>10)&3, /* pp */
				       (pp>>3)&1, /* small */
				       (pp>>2)&1, /* shared */
				       (pp>>1)&1, /* cache inhibit */
				       pp&1       /* valid */
				       );
#undef pp
			}
			else {
				printk("no pte\n");
			}
		}
		else {
			printk("no pmd\n");
		}
	}
	else {
		printk("no pgd\n");
	}
}

int get_8xx_pte(struct mm_struct *mm, unsigned long addr)
{
	pgd_t *pgd;
	pmd_t *pmd;
	pte_t *pte;
	int retval = 0;

	pgd = pgd_offset(mm, addr & PAGE_MASK);
	if (pgd) {
		pmd = pmd_offset(pud_offset(pgd, addr & PAGE_MASK),
		                 addr & PAGE_MASK);
		if (pmd && pmd_present(*pmd)) {
			pte = pte_offset_kernel(pmd, addr & PAGE_MASK);
			if (pte) {
				retval = (int)pte_val(*pte);
			}
		}
	}
	return retval;
}

/*
 * We return 0 on success, 1 on unimplemented instruction, and EFAULT
 * if a load/store faulted.
 */
int Soft_emulate_8xx(struct pt_regs *regs)
{
	u32 inst, instword;
	u32 flreg, idxreg, disp;
	int retval;
	s16 sdisp;
	u32 *ea, *ip;

	retval = 0;

	instword = *((u32 *)regs->nip);
	inst = instword >> 26;

	flreg = (instword >> 21) & 0x1f;
	idxreg = (instword >> 16) & 0x1f;
	disp = instword & 0xffff;

	ea = (u32 *)(regs->gpr[idxreg] + disp);
	ip = (u32 *)&current->thread.TS_FPR(flreg);

	switch ( inst )
	{
	case LFD:
		/* this is a 16 bit quantity that is sign extended
		 * so use a signed short here -- Cort
		 */
		sdisp = (instword & 0xffff);
		ea = (u32 *)(regs->gpr[idxreg] + sdisp);
		if (copy_from_user(ip, ea, sizeof(double)))
			retval = -EFAULT;
		break;

	case LFDU:
		if (copy_from_user(ip, ea, sizeof(double)))
			retval = -EFAULT;
		else
			regs->gpr[idxreg] = (u32)ea;
		break;
	case LFS:
		sdisp = (instword & 0xffff);
		ea = (u32 *)(regs->gpr[idxreg] + sdisp);
		if (copy_from_user(ip, ea, sizeof(float)))
			retval = -EFAULT;
		break;
	case STFD:
		/* this is a 16 bit quantity that is sign extended
		 * so use a signed short here -- Cort
		 */
		sdisp = (instword & 0xffff);
		ea = (u32 *)(regs->gpr[idxreg] + sdisp);
		if (copy_to_user(ea, ip, sizeof(double)))
			retval = -EFAULT;
		break;

	case STFDU:
		if (copy_to_user(ea, ip, sizeof(double)))
			retval = -EFAULT;
		else
			regs->gpr[idxreg] = (u32)ea;
		break;
	case FMR:
		/* assume this is a fp move -- Cort */
		memcpy(ip, &current->thread.TS_FPR((instword>>11)&0x1f),
		       sizeof(double));
		break;
	default:
		retval = 1;
		printk("Bad emulation %s/%d\n"
		       " NIP: %08lx instruction: %08x opcode: %x "
		       "A: %x B: %x C: %x code: %x rc: %x\n",
		       current->comm,current->pid,
		       regs->nip,
		       instword,inst,
		       (instword>>16)&0x1f,
		       (instword>>11)&0x1f,
		       (instword>>6)&0x1f,
		       (instword>>1)&0x3ff,
		       instword&1);
		{
			int pa;
			print_8xx_pte(current->mm,regs->nip);
			pa = get_8xx_pte(current->mm,regs->nip) & PAGE_MASK;
			pa |= (regs->nip & ~PAGE_MASK);
			pa = (unsigned long)__va(pa);
			printk("Kernel VA for NIP %x ", pa);
			print_8xx_pte(current->mm,pa);
		}
	}

	if (retval == 0)
		regs->nip += 4;

	return retval;
}
Commit	Line	Data
5dd57a13 SW	1	/*
	2	* Software emulation of some PPC instructions for the 8xx core.
	3	*
	4	* Copyright (C) 1998 Dan Malek (dmalek@jlc.net)
	5	*
	6	* Software floating emuation for the MPC8xx processor. I did this mostly
	7	* because it was easier than trying to get the libraries compiled for
	8	* software floating point. The goal is still to get the libraries done,
	9	* but I lost patience and needed some hacks to at least get init and
	10	* shells running. The first problem is the setjmp/longjmp that save
	11	* and restore the floating point registers.
	12	*
	13	* For this emulation, our working registers are found on the register
	14	* save area.
	15	*/
	16
	17	#include <linux/errno.h>
	18	#include <linux/sched.h>
	19	#include <linux/kernel.h>
	20	#include <linux/mm.h>
	21	#include <linux/stddef.h>
	22	#include <linux/unistd.h>
	23	#include <linux/ptrace.h>
5dd57a13	24	#include <linux/user.h>
5dd57a13 SW	25	#include <linux/interrupt.h>
	26
	27	#include <asm/pgtable.h>
	28	#include <asm/uaccess.h>
5dd57a13 SW	29	#include <asm/io.h>
	30
	31	/* Eventually we may need a look-up table, but this works for now.
	32	*/
	33	#define LFS 48
	34	#define LFD 50
	35	#define LFDU 51
	36	#define STFD 54
	37	#define STFDU 55
	38	#define FMR 63
	39
	40	void print_8xx_pte(struct mm_struct *mm, unsigned long addr)
	41	{
	42	pgd_t *pgd;
	43	pmd_t *pmd;
	44	pte_t *pte;
	45
	46	printk(" pte @ 0x%8lx: ", addr);
	47	pgd = pgd_offset(mm, addr & PAGE_MASK);
	48	if (pgd) {
	49	pmd = pmd_offset(pud_offset(pgd, addr & PAGE_MASK),
	50	addr & PAGE_MASK);
	51	if (pmd && pmd_present(*pmd)) {
	52	pte = pte_offset_kernel(pmd, addr & PAGE_MASK);
	53	if (pte) {
	54	printk(" (0x%08lx)->(0x%08lx)->0x%08lx\n",
	55	(long)pgd, (long)pte, (long)pte_val(*pte));
	56	#define pp ((long)pte_val(*pte))
	57	printk(" RPN: %05lx PP: %lx SPS: %lx SH: %lx "
	58	"CI: %lx v: %lx\n",
	59	pp>>12, /* rpn */
	60	(pp>>10)&3, /* pp */
	61	(pp>>3)&1, /* small */
	62	(pp>>2)&1, /* shared */
	63	(pp>>1)&1, /* cache inhibit */
	64	pp&1 /* valid */
	65	);
	66	#undef pp
	67	}
	68	else {
	69	printk("no pte\n");
	70	}
	71	}
	72	else {
	73	printk("no pmd\n");
	74	}
	75	}
	76	else {
	77	printk("no pgd\n");
	78	}
	79	}
	80
	81	int get_8xx_pte(struct mm_struct *mm, unsigned long addr)
	82	{
	83	pgd_t *pgd;
	84	pmd_t *pmd;
	85	pte_t *pte;
	86	int retval = 0;
	87
	88	pgd = pgd_offset(mm, addr & PAGE_MASK);
	89	if (pgd) {
	90	pmd = pmd_offset(pud_offset(pgd, addr & PAGE_MASK),
	91	addr & PAGE_MASK);
	92	if (pmd && pmd_present(*pmd)) {
93	pte = pte_offset_kernel(pmd, addr & PAGE_MASK);
94	if (pte) {
95	retval = (int)pte_val(*pte);
96	}
97	}
98	}
99	return retval;
100	}
101
102	/*
103	* We return 0 on success, 1 on unimplemented instruction, and EFAULT
104	* if a load/store faulted.
105	*/
106	int Soft_emulate_8xx(struct pt_regs *regs)
107	{
108	u32 inst, instword;
109	u32 flreg, idxreg, disp;
110	int retval;
111	s16 sdisp;
112	u32 ea, ip;
113
114	retval = 0;
115
116	instword = ((u32 )regs->nip);
117	inst = instword >> 26;
118
119	flreg = (instword >> 21) & 0x1f;
120	idxreg = (instword >> 16) & 0x1f;
121	disp = instword & 0xffff;
122
123	ea = (u32 *)(regs->gpr[idxreg] + disp);
9c75a31c	124	ip = (u32 *)&current->thread.TS_FPR(flreg);
5dd57a13 SW	125
	126	switch ( inst )
	127	{
	128	case LFD:
	129	/* this is a 16 bit quantity that is sign extended
	130	* so use a signed short here -- Cort
	131	*/
	132	sdisp = (instword & 0xffff);
	133	ea = (u32 *)(regs->gpr[idxreg] + sdisp);
	134	if (copy_from_user(ip, ea, sizeof(double)))
	135	retval = -EFAULT;
	136	break;
	137
	138	case LFDU:
	139	if (copy_from_user(ip, ea, sizeof(double)))
	140	retval = -EFAULT;
	141	else
	142	regs->gpr[idxreg] = (u32)ea;
	143	break;
	144	case LFS:
	145	sdisp = (instword & 0xffff);
	146	ea = (u32 *)(regs->gpr[idxreg] + sdisp);
	147	if (copy_from_user(ip, ea, sizeof(float)))
	148	retval = -EFAULT;
	149	break;
	150	case STFD:
	151	/* this is a 16 bit quantity that is sign extended
	152	* so use a signed short here -- Cort
	153	*/
	154	sdisp = (instword & 0xffff);
	155	ea = (u32 *)(regs->gpr[idxreg] + sdisp);
	156	if (copy_to_user(ea, ip, sizeof(double)))
	157	retval = -EFAULT;
	158	break;
	159
	160	case STFDU:
	161	if (copy_to_user(ea, ip, sizeof(double)))
	162	retval = -EFAULT;
	163	else
	164	regs->gpr[idxreg] = (u32)ea;
	165	break;
	166	case FMR:
	167	/* assume this is a fp move -- Cort */
9c75a31c	168	memcpy(ip, &current->thread.TS_FPR((instword>>11)&0x1f),
5dd57a13 SW	169	sizeof(double));
	170	break;
	171	default:
	172	retval = 1;
	173	printk("Bad emulation %s/%d\n"
	174	" NIP: %08lx instruction: %08x opcode: %x "
	175	"A: %x B: %x C: %x code: %x rc: %x\n",
	176	current->comm,current->pid,
	177	regs->nip,
	178	instword,inst,
	179	(instword>>16)&0x1f,
	180	(instword>>11)&0x1f,
	181	(instword>>6)&0x1f,
	182	(instword>>1)&0x3ff,
	183	instword&1);
	184	{
	185	int pa;
	186	print_8xx_pte(current->mm,regs->nip);
	187	pa = get_8xx_pte(current->mm,regs->nip) & PAGE_MASK;
	188	pa \|= (regs->nip & ~PAGE_MASK);
	189	pa = (unsigned long)__va(pa);
	190	printk("Kernel VA for NIP %x ", pa);
	191	print_8xx_pte(current->mm,pa);
	192	}
	193	}
	194
	195	if (retval == 0)
	196	regs->nip += 4;
	197
	198	return retval;
	199	}