[mirror_ubuntu-bionic-kernel.git] / arch / metag / kernel / process.c

/*
 * Copyright (C) 2005,2006,2007,2008,2009,2010,2011 Imagination Technologies
 *
 * This file contains the architecture-dependent parts of process handling.
 *
 */

#include <linux/errno.h>
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/reboot.h>
#include <linux/elfcore.h>
#include <linux/fs.h>
#include <linux/tick.h>
#include <linux/slab.h>
#include <linux/mman.h>
#include <linux/pm.h>
#include <linux/syscalls.h>
#include <linux/uaccess.h>
#include <linux/smp.h>
#include <asm/core_reg.h>
#include <asm/user_gateway.h>
#include <asm/tcm.h>
#include <asm/traps.h>
#include <asm/switch_to.h>

/*
 * Wait for the next interrupt and enable local interrupts
 */
void arch_cpu_idle(void)
{
	int tmp;

	/*
	 * Quickly jump straight into the interrupt entry point without actually
	 * triggering an interrupt. When TXSTATI gets read the processor will
	 * block until an interrupt is triggered.
	 */
	asm volatile (/* Switch into ISTAT mode */
		      "RTH\n\t"
		      /* Enable local interrupts */
		      "MOV	TXMASKI, %1\n\t"
		      /*
		       * We can't directly "SWAP PC, PCX", so we swap via a
		       * temporary. Essentially we do:
		       *  PCX_new = 1f (the place to continue execution)
		       *  PC = PCX_old
		       */
		      "ADD	%0, CPC0, #(1f-.)\n\t"
		      "SWAP	PCX, %0\n\t"
		      "MOV	PC, %0\n"
		      /* Continue execution here with interrupts enabled */
		      "1:"
		      : "=a" (tmp)
		      : "r" (get_trigger_mask()));
}

#ifdef CONFIG_HOTPLUG_CPU
void arch_cpu_idle_dead(void)
{
	cpu_die();
}
#endif

void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);

void (*soc_restart)(char *cmd);
void (*soc_halt)(void);

void machine_restart(char *cmd)
{
	if (soc_restart)
		soc_restart(cmd);
	hard_processor_halt(HALT_OK);
}

void machine_halt(void)
{
	if (soc_halt)
		soc_halt();
	smp_send_stop();
	hard_processor_halt(HALT_OK);
}

void machine_power_off(void)
{
	if (pm_power_off)
		pm_power_off();
	smp_send_stop();
	hard_processor_halt(HALT_OK);
}

#define FLAG_Z 0x8
#define FLAG_N 0x4
#define FLAG_O 0x2
#define FLAG_C 0x1

void show_regs(struct pt_regs *regs)
{
	int i;
	const char *AX0_names[] = {"A0StP", "A0FrP"};
	const char *AX1_names[] = {"A1GbP", "A1LbP"};

	const char *DX0_names[] = {
		"D0Re0",
		"D0Ar6",
		"D0Ar4",
		"D0Ar2",
		"D0FrT",
		"D0.5 ",
		"D0.6 ",
		"D0.7 "
	};

	const char *DX1_names[] = {
		"D1Re0",
		"D1Ar5",
		"D1Ar3",
		"D1Ar1",
		"D1RtP",
		"D1.5 ",
		"D1.6 ",
		"D1.7 "
	};

	show_regs_print_info(KERN_INFO);

	pr_info(" pt_regs @ %p\n", regs);
	pr_info(" SaveMask = 0x%04hx\n", regs->ctx.SaveMask);
	pr_info(" Flags = 0x%04hx (%c%c%c%c)\n", regs->ctx.Flags,
		regs->ctx.Flags & FLAG_Z ? 'Z' : 'z',
		regs->ctx.Flags & FLAG_N ? 'N' : 'n',
		regs->ctx.Flags & FLAG_O ? 'O' : 'o',
		regs->ctx.Flags & FLAG_C ? 'C' : 'c');
	pr_info(" TXRPT = 0x%08x\n", regs->ctx.CurrRPT);
	pr_info(" PC = 0x%08x\n", regs->ctx.CurrPC);

	/* AX regs */
	for (i = 0; i < 2; i++) {
		pr_info(" %s = 0x%08x    ",
			AX0_names[i],
			regs->ctx.AX[i].U0);
		printk(" %s = 0x%08x\n",
			AX1_names[i],
			regs->ctx.AX[i].U1);
	}

	if (regs->ctx.SaveMask & TBICTX_XEXT_BIT)
		pr_warn(" Extended state present - AX2.[01] will be WRONG\n");

	/* Special place with AXx.2 */
	pr_info(" A0.2  = 0x%08x    ",
		regs->ctx.Ext.AX2.U0);
	printk(" A1.2  = 0x%08x\n",
		regs->ctx.Ext.AX2.U1);

	/* 'extended' AX regs (nominally, just AXx.3) */
	for (i = 0; i < (TBICTX_AX_REGS - 3); i++) {
		pr_info(" A0.%d  = 0x%08x    ", i + 3, regs->ctx.AX3[i].U0);
		printk(" A1.%d  = 0x%08x\n", i + 3, regs->ctx.AX3[i].U1);
	}

	for (i = 0; i < 8; i++) {
		pr_info(" %s = 0x%08x    ", DX0_names[i], regs->ctx.DX[i].U0);
		printk(" %s = 0x%08x\n", DX1_names[i], regs->ctx.DX[i].U1);
	}

	show_trace(NULL, (unsigned long *)regs->ctx.AX[0].U0, regs);
}

/*
 * Copy architecture-specific thread state
 */
int copy_thread(unsigned long clone_flags, unsigned long usp,
		unsigned long kthread_arg, struct task_struct *tsk)
{
	struct pt_regs *childregs = task_pt_regs(tsk);
	void *kernel_context = ((void *) childregs +
				sizeof(struct pt_regs));
	unsigned long global_base;

	BUG_ON(((unsigned long)childregs) & 0x7);
	BUG_ON(((unsigned long)kernel_context) & 0x7);

	memset(&tsk->thread.kernel_context, 0,
			sizeof(tsk->thread.kernel_context));

	tsk->thread.kernel_context = __TBISwitchInit(kernel_context,
						     ret_from_fork,
						     0, 0);

	if (unlikely(tsk->flags & PF_KTHREAD)) {
		/*
		 * Make sure we don't leak any kernel data to child's regs
		 * if kernel thread becomes a userspace thread in the future
		 */
		memset(childregs, 0 , sizeof(struct pt_regs));

		global_base = __core_reg_get(A1GbP);
		childregs->ctx.AX[0].U1 = (unsigned long) global_base;
		childregs->ctx.AX[0].U0 = (unsigned long) kernel_context;
		/* Set D1Ar1=kthread_arg and D1RtP=usp (fn) */
		childregs->ctx.DX[4].U1 = usp;
		childregs->ctx.DX[3].U1 = kthread_arg;
		tsk->thread.int_depth = 2;
		return 0;
	}

	/*
	 * Get a pointer to where the new child's register block should have
	 * been pushed.
	 * The Meta's stack grows upwards, and the context is the the first
	 * thing to be pushed by TBX (phew)
	 */
	*childregs = *current_pt_regs();
	/* Set the correct stack for the clone mode */
	if (usp)
		childregs->ctx.AX[0].U0 = ALIGN(usp, 8);
	tsk->thread.int_depth = 1;

	/* set return value for child process */
	childregs->ctx.DX[0].U0 = 0;

	/* The TLS pointer is passed as an argument to sys_clone. */
	if (clone_flags & CLONE_SETTLS)
		tsk->thread.tls_ptr =
				(__force void __user *)childregs->ctx.DX[1].U1;

#ifdef CONFIG_METAG_FPU
	if (tsk->thread.fpu_context) {
		struct meta_fpu_context *ctx;

		ctx = kmemdup(tsk->thread.fpu_context,
			      sizeof(struct meta_fpu_context), GFP_ATOMIC);
		tsk->thread.fpu_context = ctx;
	}
#endif

#ifdef CONFIG_METAG_DSP
	if (tsk->thread.dsp_context) {
		struct meta_ext_context *ctx;
		int i;

		ctx = kmemdup(tsk->thread.dsp_context,
			      sizeof(struct meta_ext_context), GFP_ATOMIC);
		for (i = 0; i < 2; i++)
			ctx->ram[i] = kmemdup(ctx->ram[i], ctx->ram_sz[i],
					      GFP_ATOMIC);
		tsk->thread.dsp_context = ctx;
	}
#endif

	return 0;
}

#ifdef CONFIG_METAG_FPU
static void alloc_fpu_context(struct thread_struct *thread)
{
	thread->fpu_context = kzalloc(sizeof(struct meta_fpu_context),
				      GFP_ATOMIC);
}

static void clear_fpu(struct thread_struct *thread)
{
	thread->user_flags &= ~TBICTX_FPAC_BIT;
	kfree(thread->fpu_context);
	thread->fpu_context = NULL;
}
#else
static void clear_fpu(struct thread_struct *thread)
{
}
#endif

#ifdef CONFIG_METAG_DSP
static void clear_dsp(struct thread_struct *thread)
{
	if (thread->dsp_context) {
		kfree(thread->dsp_context->ram[0]);
		kfree(thread->dsp_context->ram[1]);

		kfree(thread->dsp_context);

		thread->dsp_context = NULL;
	}

	__core_reg_set(D0.8, 0);
}
#else
static void clear_dsp(struct thread_struct *thread)
{
}
#endif

struct task_struct *__sched __switch_to(struct task_struct *prev,
					struct task_struct *next)
{
	TBIRES to, from;

	to.Switch.pCtx = next->thread.kernel_context;
	to.Switch.pPara = prev;

#ifdef CONFIG_METAG_FPU
	if (prev->thread.user_flags & TBICTX_FPAC_BIT) {
		struct pt_regs *regs = task_pt_regs(prev);
		TBIRES state;

		state.Sig.SaveMask = prev->thread.user_flags;
		state.Sig.pCtx = &regs->ctx;

		if (!prev->thread.fpu_context)
			alloc_fpu_context(&prev->thread);
		if (prev->thread.fpu_context)
			__TBICtxFPUSave(state, prev->thread.fpu_context);
	}
	/*
	 * Force a restore of the FPU context next time this process is
	 * scheduled.
	 */
	if (prev->thread.fpu_context)
		prev->thread.fpu_context->needs_restore = true;
#endif


	from = __TBISwitch(to, &prev->thread.kernel_context);

	/* Restore TLS pointer for this process. */
	set_gateway_tls(current->thread.tls_ptr);

	return (struct task_struct *) from.Switch.pPara;
}

void flush_thread(void)
{
	clear_fpu(&current->thread);
	clear_dsp(&current->thread);
}

/*
 * Free current thread data structures etc.
 */
void exit_thread(struct task_struct *tsk)
{
	clear_fpu(&tsk->thread);
	clear_dsp(&tsk->thread);
}

/* TODO: figure out how to unwind the kernel stack here to figure out
 * where we went to sleep. */
unsigned long get_wchan(struct task_struct *p)
{
	return 0;
}

int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
{
	/* Returning 0 indicates that the FPU state was not stored (as it was
	 * not in use) */
	return 0;
}

#ifdef CONFIG_METAG_USER_TCM

#define ELF_MIN_ALIGN	PAGE_SIZE

#define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))

#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)

unsigned long __metag_elf_map(struct file *filep, unsigned long addr,
			      struct elf_phdr *eppnt, int prot, int type,
			      unsigned long total_size)
{
	unsigned long map_addr, size;
	unsigned long page_off = ELF_PAGEOFFSET(eppnt->p_vaddr);
	unsigned long raw_size = eppnt->p_filesz + page_off;
	unsigned long off = eppnt->p_offset - page_off;
	unsigned int tcm_tag;
	addr = ELF_PAGESTART(addr);
	size = ELF_PAGEALIGN(raw_size);

	/* mmap() will return -EINVAL if given a zero size, but a
	 * segment with zero filesize is perfectly valid */
	if (!size)
		return addr;

	tcm_tag = tcm_lookup_tag(addr);

	if (tcm_tag != TCM_INVALID_TAG)
		type &= ~MAP_FIXED;

	/*
	* total_size is the size of the ELF (interpreter) image.
	* The _first_ mmap needs to know the full size, otherwise
	* randomization might put this image into an overlapping
	* position with the ELF binary image. (since size < total_size)
	* So we first map the 'big' image - and unmap the remainder at
	* the end. (which unmap is needed for ELF images with holes.)
	*/
	if (total_size) {
		total_size = ELF_PAGEALIGN(total_size);
		map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
		if (!BAD_ADDR(map_addr))
			vm_munmap(map_addr+size, total_size-size);
	} else
		map_addr = vm_mmap(filep, addr, size, prot, type, off);

	if (!BAD_ADDR(map_addr) && tcm_tag != TCM_INVALID_TAG) {
		struct tcm_allocation *tcm;
		unsigned long tcm_addr;

		tcm = kmalloc(sizeof(*tcm), GFP_KERNEL);
		if (!tcm)
			return -ENOMEM;

		tcm_addr = tcm_alloc(tcm_tag, raw_size);
		if (tcm_addr != addr) {
			kfree(tcm);
			return -ENOMEM;
		}

		tcm->tag = tcm_tag;
		tcm->addr = tcm_addr;
		tcm->size = raw_size;

		list_add(&tcm->list, &current->mm->context.tcm);

		eppnt->p_vaddr = map_addr;
		if (copy_from_user((void *) addr, (void __user *) map_addr,
				   raw_size))
			return -EFAULT;
	}

	return map_addr;
}
#endif
Commit	Line	Data
44dea393 JH	1	/*
	2	* Copyright (C) 2005,2006,2007,2008,2009,2010,2011 Imagination Technologies
	3	*
	4	* This file contains the architecture-dependent parts of process handling.
	5	*
	6	*/
	7
	8	#include <linux/errno.h>
	9	#include <linux/export.h>
	10	#include <linux/sched.h>
b17b0153	11	#include <linux/sched/debug.h>
29930025	12	#include <linux/sched/task.h>
44dea393 JH	13	#include <linux/kernel.h>
	14	#include <linux/mm.h>
	15	#include <linux/unistd.h>
	16	#include <linux/ptrace.h>
	17	#include <linux/user.h>
	18	#include <linux/reboot.h>
	19	#include <linux/elfcore.h>
	20	#include <linux/fs.h>
	21	#include <linux/tick.h>
	22	#include <linux/slab.h>
	23	#include <linux/mman.h>
	24	#include <linux/pm.h>
	25	#include <linux/syscalls.h>
	26	#include <linux/uaccess.h>
d1dba0fc	27	#include <linux/smp.h>
44dea393 JH	28	#include <asm/core_reg.h>
	29	#include <asm/user_gateway.h>
	30	#include <asm/tcm.h>
	31	#include <asm/traps.h>
	32	#include <asm/switch_to.h>
	33
	34	/*
	35	* Wait for the next interrupt and enable local interrupts
	36	*/
d1dba0fc	37	void arch_cpu_idle(void)
44dea393 JH	38	{
	39	int tmp;
	40
	41	/*
	42	* Quickly jump straight into the interrupt entry point without actually
	43	* triggering an interrupt. When TXSTATI gets read the processor will
	44	* block until an interrupt is triggered.
	45	*/
	46	asm volatile (/* Switch into ISTAT mode */
	47	"RTH\n\t"
	48	/* Enable local interrupts */
	49	"MOV TXMASKI, %1\n\t"
	50	/*
	51	* We can't directly "SWAP PC, PCX", so we swap via a
	52	* temporary. Essentially we do:
	53	* PCX_new = 1f (the place to continue execution)
	54	* PC = PCX_old
	55	*/
	56	"ADD %0, CPC0, #(1f-.)\n\t"
	57	"SWAP PCX, %0\n\t"
	58	"MOV PC, %0\n"
	59	/* Continue execution here with interrupts enabled */
	60	"1:"
	61	: "=a" (tmp)
	62	: "r" (get_trigger_mask()));
	63	}
	64
44dea393	65	#ifdef CONFIG_HOTPLUG_CPU
d1dba0fc TG	66	void arch_cpu_idle_dead(void)
	67	{
	68	cpu_die();
44dea393	69	}
d1dba0fc	70	#endif
44dea393 JH	71
	72	void (*pm_power_off)(void);
	73	EXPORT_SYMBOL(pm_power_off);
	74
	75	void (soc_restart)(char cmd);
	76	void (*soc_halt)(void);
	77
	78	void machine_restart(char *cmd)
	79	{
	80	if (soc_restart)
	81	soc_restart(cmd);
	82	hard_processor_halt(HALT_OK);
	83	}
	84
	85	void machine_halt(void)
	86	{
	87	if (soc_halt)
	88	soc_halt();
	89	smp_send_stop();
	90	hard_processor_halt(HALT_OK);
	91	}
	92
	93	void machine_power_off(void)
	94	{
	95	if (pm_power_off)
	96	pm_power_off();
	97	smp_send_stop();
	98	hard_processor_halt(HALT_OK);
	99	}
	100
	101	#define FLAG_Z 0x8
	102	#define FLAG_N 0x4
	103	#define FLAG_O 0x2
	104	#define FLAG_C 0x1
	105
	106	void show_regs(struct pt_regs *regs)
	107	{
	108	int i;
	109	const char *AX0_names[] = {"A0StP", "A0FrP"};
	110	const char *AX1_names[] = {"A1GbP", "A1LbP"};
	111
	112	const char *DX0_names[] = {
	113	"D0Re0",
	114	"D0Ar6",
	115	"D0Ar4",
	116	"D0Ar2",
	117	"D0FrT",
	118	"D0.5 ",
	119	"D0.6 ",
	120	"D0.7 "
	121	};
	122
	123	const char *DX1_names[] = {
	124	"D1Re0",
	125	"D1Ar5",
	126	"D1Ar3",
	127	"D1Ar1",
	128	"D1RtP",
	129	"D1.5 ",
	130	"D1.6 ",
	131	"D1.7 "
	132	};
	133
a43cb95d TH	134	show_regs_print_info(KERN_INFO);
a43cb95d TH	135
44dea393 JH	136	pr_info(" pt_regs @ %p\n", regs);
	137	pr_info(" SaveMask = 0x%04hx\n", regs->ctx.SaveMask);
	138	pr_info(" Flags = 0x%04hx (%c%c%c%c)\n", regs->ctx.Flags,
	139	regs->ctx.Flags & FLAG_Z ? 'Z' : 'z',
	140	regs->ctx.Flags & FLAG_N ? 'N' : 'n',
	141	regs->ctx.Flags & FLAG_O ? 'O' : 'o',
	142	regs->ctx.Flags & FLAG_C ? 'C' : 'c');
	143	pr_info(" TXRPT = 0x%08x\n", regs->ctx.CurrRPT);
	144	pr_info(" PC = 0x%08x\n", regs->ctx.CurrPC);
	145
	146	/* AX regs */
	147	for (i = 0; i < 2; i++) {
	148	pr_info(" %s = 0x%08x ",
	149	AX0_names[i],
	150	regs->ctx.AX[i].U0);
	151	printk(" %s = 0x%08x\n",
	152	AX1_names[i],
	153	regs->ctx.AX[i].U1);
	154	}
	155
	156	if (regs->ctx.SaveMask & TBICTX_XEXT_BIT)
	157	pr_warn(" Extended state present - AX2.[01] will be WRONG\n");
	158
	159	/* Special place with AXx.2 */
	160	pr_info(" A0.2 = 0x%08x ",
	161	regs->ctx.Ext.AX2.U0);
	162	printk(" A1.2 = 0x%08x\n",
	163	regs->ctx.Ext.AX2.U1);
	164
	165	/* 'extended' AX regs (nominally, just AXx.3) */
	166	for (i = 0; i < (TBICTX_AX_REGS - 3); i++) {
	167	pr_info(" A0.%d = 0x%08x ", i + 3, regs->ctx.AX3[i].U0);
	168	printk(" A1.%d = 0x%08x\n", i + 3, regs->ctx.AX3[i].U1);
	169	}
	170
	171	for (i = 0; i < 8; i++) {
	172	pr_info(" %s = 0x%08x ", DX0_names[i], regs->ctx.DX[i].U0);
	173	printk(" %s = 0x%08x\n", DX1_names[i], regs->ctx.DX[i].U1);
	174	}
	175
	176	show_trace(NULL, (unsigned long *)regs->ctx.AX[0].U0, regs);
	177	}
	178
40346a03 AD	179	/*
	180	* Copy architecture-specific thread state
	181	*/
44dea393	182	int copy_thread(unsigned long clone_flags, unsigned long usp,
40346a03	183	unsigned long kthread_arg, struct task_struct *tsk)
44dea393 JH	184	{
	185	struct pt_regs *childregs = task_pt_regs(tsk);
	186	void kernel_context = ((void ) childregs +
	187	sizeof(struct pt_regs));
	188	unsigned long global_base;
	189
	190	BUG_ON(((unsigned long)childregs) & 0x7);
	191	BUG_ON(((unsigned long)kernel_context) & 0x7);
	192
	193	memset(&tsk->thread.kernel_context, 0,
	194	sizeof(tsk->thread.kernel_context));
	195
	196	tsk->thread.kernel_context = __TBISwitchInit(kernel_context,
	197	ret_from_fork,
	198	0, 0);
	199
	200	if (unlikely(tsk->flags & PF_KTHREAD)) {
	201	/*
	202	* Make sure we don't leak any kernel data to child's regs
	203	* if kernel thread becomes a userspace thread in the future
	204	*/
	205	memset(childregs, 0 , sizeof(struct pt_regs));
	206
	207	global_base = __core_reg_get(A1GbP);
	208	childregs->ctx.AX[0].U1 = (unsigned long) global_base;
	209	childregs->ctx.AX[0].U0 = (unsigned long) kernel_context;
40346a03	210	/* Set D1Ar1=kthread_arg and D1RtP=usp (fn) */
44dea393	211	childregs->ctx.DX[4].U1 = usp;
40346a03	212	childregs->ctx.DX[3].U1 = kthread_arg;
44dea393 JH	213	tsk->thread.int_depth = 2;
	214	return 0;
	215	}
40346a03	216
44dea393 JH	217	/*
	218	* Get a pointer to where the new child's register block should have
	219	* been pushed.
	220	* The Meta's stack grows upwards, and the context is the the first
	221	* thing to be pushed by TBX (phew)
	222	*/
	223	childregs = current_pt_regs();
	224	/* Set the correct stack for the clone mode */
	225	if (usp)
	226	childregs->ctx.AX[0].U0 = ALIGN(usp, 8);
	227	tsk->thread.int_depth = 1;
	228
	229	/* set return value for child process */
	230	childregs->ctx.DX[0].U0 = 0;
	231
	232	/* The TLS pointer is passed as an argument to sys_clone. */
	233	if (clone_flags & CLONE_SETTLS)
	234	tsk->thread.tls_ptr =
	235	(__force void __user *)childregs->ctx.DX[1].U1;
	236
	237	#ifdef CONFIG_METAG_FPU
	238	if (tsk->thread.fpu_context) {
	239	struct meta_fpu_context *ctx;
	240
	241	ctx = kmemdup(tsk->thread.fpu_context,
	242	sizeof(struct meta_fpu_context), GFP_ATOMIC);
	243	tsk->thread.fpu_context = ctx;
	244	}
	245	#endif
	246
	247	#ifdef CONFIG_METAG_DSP
	248	if (tsk->thread.dsp_context) {
	249	struct meta_ext_context *ctx;
	250	int i;
	251
	252	ctx = kmemdup(tsk->thread.dsp_context,
	253	sizeof(struct meta_ext_context), GFP_ATOMIC);
	254	for (i = 0; i < 2; i++)
	255	ctx->ram[i] = kmemdup(ctx->ram[i], ctx->ram_sz[i],
	256	GFP_ATOMIC);
	257	tsk->thread.dsp_context = ctx;
	258	}
	259	#endif
	260
	261	return 0;
	262	}
	263
	264	#ifdef CONFIG_METAG_FPU
	265	static void alloc_fpu_context(struct thread_struct *thread)
	266	{
	267	thread->fpu_context = kzalloc(sizeof(struct meta_fpu_context),
	268	GFP_ATOMIC);
	269	}
	270
	271	static void clear_fpu(struct thread_struct *thread)
	272	{
	273	thread->user_flags &= ~TBICTX_FPAC_BIT;
	274	kfree(thread->fpu_context);
	275	thread->fpu_context = NULL;
	276	}
	277	#else
	278	static void clear_fpu(struct thread_struct *thread)
	279	{
	280	}
281	#endif
282
283	#ifdef CONFIG_METAG_DSP
284	static void clear_dsp(struct thread_struct *thread)
285	{
286	if (thread->dsp_context) {
287	kfree(thread->dsp_context->ram[0]);
288	kfree(thread->dsp_context->ram[1]);
289
290	kfree(thread->dsp_context);
291
292	thread->dsp_context = NULL;
293	}
294
295	__core_reg_set(D0.8, 0);
296	}
297	#else
298	static void clear_dsp(struct thread_struct *thread)
299	{
300	}
301	#endif
302
303	struct task_struct __sched __switch_to(struct task_struct prev,
304	struct task_struct *next)
305	{
306	TBIRES to, from;
307
308	to.Switch.pCtx = next->thread.kernel_context;
309	to.Switch.pPara = prev;
310
311	#ifdef CONFIG_METAG_FPU
312	if (prev->thread.user_flags & TBICTX_FPAC_BIT) {
313	struct pt_regs *regs = task_pt_regs(prev);
314	TBIRES state;
315
316	state.Sig.SaveMask = prev->thread.user_flags;
317	state.Sig.pCtx = &regs->ctx;
318
319	if (!prev->thread.fpu_context)
320	alloc_fpu_context(&prev->thread);
321	if (prev->thread.fpu_context)
322	__TBICtxFPUSave(state, prev->thread.fpu_context);
323	}
324	/*
325	* Force a restore of the FPU context next time this process is
326	* scheduled.
327	*/
328	if (prev->thread.fpu_context)
329	prev->thread.fpu_context->needs_restore = true;
330	#endif
331
332
333	from = __TBISwitch(to, &prev->thread.kernel_context);
334
335	/* Restore TLS pointer for this process. */
336	set_gateway_tls(current->thread.tls_ptr);
337
338	return (struct task_struct *) from.Switch.pPara;
339	}
340
341	void flush_thread(void)
342	{
343	clear_fpu(&current->thread);
344	clear_dsp(&current->thread);
345	}
346
347	/*
348	* Free current thread data structures etc.
349	*/
e6464694	350	void exit_thread(struct task_struct *tsk)
44dea393	351	{
e6464694 JS	352	clear_fpu(&tsk->thread);
e6464694 JS	353	clear_dsp(&tsk->thread);
44dea393 JH	354	}
	355
	356	/* TODO: figure out how to unwind the kernel stack here to figure out
	357	* where we went to sleep. */
	358	unsigned long get_wchan(struct task_struct *p)
	359	{
	360	return 0;
	361	}
	362
	363	int dump_fpu(struct pt_regs regs, elf_fpregset_t fpu)
	364	{
	365	/* Returning 0 indicates that the FPU state was not stored (as it was
	366	* not in use) */
	367	return 0;
	368	}
	369
	370	#ifdef CONFIG_METAG_USER_TCM
	371
	372	#define ELF_MIN_ALIGN PAGE_SIZE
	373
	374	#define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
	375	#define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
	376	#define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
	377
	378	#define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
	379
	380	unsigned long __metag_elf_map(struct file *filep, unsigned long addr,
	381	struct elf_phdr *eppnt, int prot, int type,
	382	unsigned long total_size)
	383	{
	384	unsigned long map_addr, size;
	385	unsigned long page_off = ELF_PAGEOFFSET(eppnt->p_vaddr);
	386	unsigned long raw_size = eppnt->p_filesz + page_off;
	387	unsigned long off = eppnt->p_offset - page_off;
	388	unsigned int tcm_tag;
	389	addr = ELF_PAGESTART(addr);
	390	size = ELF_PAGEALIGN(raw_size);
	391
	392	/* mmap() will return -EINVAL if given a zero size, but a
	393	* segment with zero filesize is perfectly valid */
	394	if (!size)
	395	return addr;
	396
	397	tcm_tag = tcm_lookup_tag(addr);
	398
	399	if (tcm_tag != TCM_INVALID_TAG)
	400	type &= ~MAP_FIXED;
	401
	402	/*
	403	* total_size is the size of the ELF (interpreter) image.
	404	* The _first_ mmap needs to know the full size, otherwise
	405	* randomization might put this image into an overlapping
	406	* position with the ELF binary image. (since size < total_size)
	407	* So we first map the 'big' image - and unmap the remainder at
	408	* the end. (which unmap is needed for ELF images with holes.)
	409	*/
	410	if (total_size) {
	411	total_size = ELF_PAGEALIGN(total_size);
	412	map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
	413	if (!BAD_ADDR(map_addr))
	414	vm_munmap(map_addr+size, total_size-size);
	415	} else
	416	map_addr = vm_mmap(filep, addr, size, prot, type, off);
	417
418	if (!BAD_ADDR(map_addr) && tcm_tag != TCM_INVALID_TAG) {
419	struct tcm_allocation *tcm;
420	unsigned long tcm_addr;
421
422	tcm = kmalloc(sizeof(*tcm), GFP_KERNEL);
423	if (!tcm)
424	return -ENOMEM;
425
426	tcm_addr = tcm_alloc(tcm_tag, raw_size);
427	if (tcm_addr != addr) {
428	kfree(tcm);
429	return -ENOMEM;
430	}
431
432	tcm->tag = tcm_tag;
433	tcm->addr = tcm_addr;
434	tcm->size = raw_size;
435
436	list_add(&tcm->list, &current->mm->context.tcm);
437
438	eppnt->p_vaddr = map_addr;
439	if (copy_from_user((void ) addr, (void __user ) map_addr,
440	raw_size))
441	return -EFAULT;
442	}
443
444	return map_addr;
445	}
446	#endif