iris/invoke.ccp

#pypp 0
#include "kernel.hh"

Capability *Memory::find_capability (unsigned code, bool *copy):
	*copy = code & 2 ? true : false
	if code & 1:
		// Cappage capability
		unsigned num = (code & ~PAGE_MASK) >> 1
		if num >= CAPPAGE_SIZE:
			return NULL
		Capability *page = (Capability *)(code & PAGE_MASK)
		for Cappage *p = cappages; p; p = p->next:
			if p->page == page:
				return &page[num]
	else:
		// Normal capability
		for Capability *c = capabilities; c; c = c->next:
			if c == (Capability *)code:
				return c
	return NULL

static Capability *reply
static Receiver *reply_receiver

static void fill_cap (Capability *r, unsigned target, unsigned protected_data):
	Capability **ref
	if target & ~KERNEL_MASK:
		ref = &((Receiver *)target)->capabilities
	else:
		ref = &((Object_base *)protected_data)->refs
	// alloc_capability needs a Memory, but it isn't used if return storage is given.
	top_memory.alloc_capability ((Receiver *)target, NULL, ref, protected_data, r)

static void reply_cap (unsigned target, unsigned protected_data):
	Capability r
	fill_cap (&r, target, protected_data)
	unsigned d[4] = { 0, 0, 0, 0 }
	Capability *caps[4] = { &r, NULL, NULL, NULL }
	bool cops[4] = { true, false, false, false }
	if reply:
		reply->invoke (d, caps, cops)
	else:
		reply_receiver->send_message (~0, d, caps, cops)
	r.invalidate ()

static void reply_cap (Capability *cap, bool copy):
	unsigned d[4] = { 0, 0, 0, 0 }
	Capability *caps[4] = { cap, NULL, NULL, NULL }
	bool cops[4] = { copy, false, false, false }
	if reply:
		reply->invoke (d, caps, cops)
	else:
		reply_receiver->send_message (~0, d, caps, cops)

static void reply_num (unsigned num):
	unsigned d[4] = { num, 0, 0, 0 }
	Capability *caps[4] = { NULL, NULL, NULL, NULL }
	bool cops[4] = { false, false, false, false }
	if reply:
		reply->invoke (d, caps, cops)
	else:
		reply_receiver->send_message (~0, d, caps, cops)

static void receiver_invoke (unsigned target, unsigned protected_data, Capability *cap, unsigned request, unsigned data):
	Receiver *receiver = (Receiver *)protected_data
	switch request:
		case CAP_RECEIVER_SET_OWNER:
			if ((unsigned)cap->target & (CAPTYPE_MASK | ~KERNEL_MASK)) != CAPTYPE_THREAD:
				// FIXME: This makes it impossible to use a fake thread capability.
				return
			receiver->own ((Thread *)cap->protected_data)
			break
		case CAP_RECEIVER_CREATE_CAPABILITY:
			reply_cap ((unsigned)receiver, data)
			break
		case CAP_RECEIVER_CREATE_CALL_CAPABILITY:
			reply_cap (CAPTYPE_RECEIVER | CAP_RECEIVER_CALL, protected_data)
			break
		default:
			break

static void memory_invoke (unsigned target, unsigned protected_data, Capability *cap, unsigned request, unsigned data):
	Memory *mem = (Memory *)protected_data
	switch request:
		case CAP_MEMORY_CREATE:
			switch data:
				case CAPTYPE_RECEIVER:
					Receiver *ret = mem->alloc_receiver ()
					if ret:
						reply_cap (data | REQUEST_MASK, (unsigned)ret)
					else:
						reply_num (0)
					break
				case CAPTYPE_MEMORY:
					Memory *ret = mem->alloc_memory ()
					if ret:
						reply_cap (data | REQUEST_MASK, (unsigned)ret)
					else:
						reply_num (0)
					break
				case CAPTYPE_THREAD:
					Thread *ret = mem->alloc_thread ()
					if ret:
						reply_cap (data | REQUEST_MASK, (unsigned)ret)
					else:
						reply_num (0)
					break
				case CAPTYPE_PAGE:
					Page *ret = mem->alloc_page ()
					if ret:
						reply_cap (data | REQUEST_MASK, (unsigned)ret)
					else:
						reply_num (0)
					break
				case CAPTYPE_CAPPAGE:
					Cappage *ret = mem->alloc_cappage ()
					if ret:
						reply_cap (data | REQUEST_MASK, (unsigned)ret)
					else:
						reply_num (0)
					break
				default:
					return
			break
		case CAP_MEMORY_DESTROY:
			if !cap || cap->address_space != mem || (unsigned)cap->target & ~KERNEL_MASK:
				return
			switch (unsigned)cap->target & CAPTYPE_MASK:
				case CAPTYPE_RECEIVER:
					mem->free_receiver ((Receiver *)cap->protected_data)
					return
				case CAPTYPE_MEMORY:
					mem->free_memory ((Memory *)cap->protected_data)
					return
				case CAPTYPE_THREAD:
					mem->free_thread ((Thread *)cap->protected_data)
					return
				case CAPTYPE_PAGE:
					mem->free_page ((Page *)cap->protected_data)
					return
				case CAPTYPE_CAPABILITY:
					mem->free_capability ((Capability *)cap->protected_data)
					return
				case CAPTYPE_CAPPAGE:
					mem->free_cappage ((Cappage *)cap->protected_data)
					return
				default:
					panic (0x55228930, "invalid case")
			break
		case CAP_MEMORY_LIST:
			// TODO
			break
		case CAP_MEMORY_MAPPING:
			bool write
			Page *page = mem->get_mapping (data, &write)
			unsigned t = CAPTYPE_PAGE | REQUEST_MASK
			if !write:
				t &= ~CAP_PAGE_WRITE
			reply_cap (t, (unsigned)page)
			break
		case CAP_MEMORY_SET_LIMIT:
			mem->limit = data
			break
		case CAP_MEMORY_GET_LIMIT:
			reply_num (mem->limit)
			break
		case CAP_MEMORY_DROP:
			if cap->address_space != mem:
				break
			mem->free_capability (cap)
			break
		default:
			break

static void thread_invoke (unsigned target, unsigned protected_data, Capability *cap, unsigned data[4]):
	Thread *thread = (Thread *)protected_data
	switch data[0]:
		case CAP_THREAD_GET_INFO:
			switch data[1]:
				case CAP_THREAD_INFO_PC:
					reply_num (thread->pc)
					break
				case CAP_THREAD_INFO_SP:
					reply_num (thread->sp)
					break
				case CAP_THREAD_INFO_FLAGS:
					reply_num (thread->flags)
					break
				default:
					unsigned *n = Thread_arch_info (thread, data[1])
					if n:
						reply_num (*n)
					break
			break
		case CAP_THREAD_SET_INFO:
			unsigned *value
			switch data[1]:
				case CAP_THREAD_INFO_PC:
					value = &thread->pc
					break
				case CAP_THREAD_INFO_SP:
					value = &thread->sp
					break
				case CAP_THREAD_INFO_FLAGS:
					// It is not possible to set the PRIV flag, but it can be reset.
					data[2] &= ~THREAD_FLAG_PRIV
					value = &thread->flags
					if data[3] & ~THREAD_FLAG_USER:
						unsigned v = (*value & data[3]) | (data[2] & data[3])
						if (v & THREAD_FLAG_WAITING) != (*value & THREAD_FLAG_WAITING):
							if v & THREAD_FLAG_WAITING:
								thread->wait ()
							else
								thread->unwait ()
						if (v & THREAD_FLAG_RUNNING) != (*value & THREAD_FLAG_RUNNING):
							if v & THREAD_FLAG_RUNNING:
								thread->run ()
							else
								thread->unrun ()
					break
				default:
					value = Thread_arch_info (thread, data[1])
					break
			if value:
				*value &= ~data[3]
				*value |= data[2] & data[3]
			break
		case CAP_THREAD_SCHEDULE:
			schedule ()
			break
		case CAP_THREAD_REGISTER_INTERRUPT:
			arch_register_interrupt (data[1], (Receiver *)cap->protected_data)
			break
		default:
			break

static void page_invoke (unsigned target, unsigned protected_data, Capability *cap, bool copy, unsigned request, unsigned data):
	Page *page
	Cappage *cappage
	if (target & CAPTYPE_MASK) == CAPTYPE_PAGE:
		page = (Page *)protected_data
		cappage = NULL
	else:
		page = NULL
		cappage = (Cappage *)protected_data
	switch request:
		case CAP_PAGE_MAP:
			if !page:
				return
			page->address_space->map (page, data, target & CAP_PAGE_WRITE)
			break
		case CAP_PAGE_SHARE:
			// TODO
		case CAP_PAGE_SHARE_COW:
			// TODO
		case CAP_PAGE_FORGET:
			// TODO
		case CAP_CAPPAGE_SET:
			if !cappage || data >= CAPPAGE_SIZE || !(target & CAP_PAGE_WRITE):
				return
			Capability *c = &cappage->page[data]
			c->invalidate ()
			// clone_capability needs a Memory, but doesn't use it when storage is provided.
			top_memory.clone_capability (cap, copy, c)
			break
		default:
			break

static void capability_invoke (unsigned target, unsigned protected_data, Capability *cap, unsigned request, unsigned data):
	Capability *capability = (Capability *)protected_data
	switch request:
		case CAP_CAPABILITY_GET:
			reply_cap (capability, true)
			break
		case CAP_CAPABILITY_SET_DEATH_NOTIFY:
			// TODO
		default:
			break

static bool kernel_invoke (unsigned target, unsigned protected_data, unsigned d[4], Capability *c[4], bool copy[4]):
	// Kernel calling convention:
	// data[0] is the request.
	// cap[0] is the reply capability
	// other parameters' meanings depend on the operation.
	if !((1 << d[0]) & target & ~REQUEST_MASK):
		// You are not allowed to perform this operation.
		return true
	reply = c[0]
	if d[0] == CAP_DEGRADE:
		reply_cap (target & d[1], protected_data)
		return true
	switch target & CAPTYPE_MASK:
		case CAPTYPE_RECEIVER:
			if target & (1 << CAP_RECEIVER_CALL):
				// This is a call capability.
				Capability r
				Receiver *t = c[0]->target
				unsigned p_d = c[0]->protected_data
				if ~(unsigned)t & ~KERNEL_MASK:
					fill_cap (&r, protected_data, ~0)
					c[0] = &r
					copy[0] = true
					bool ret = kernel_invoke ((unsigned)t, p_d, d, c, copy)
					r.invalidate ()
					return ret
				else:
					// Kernel call: don't create actual capablities.
					reply = NULL
					reply_receiver = (Receiver *)protected_data
					return kernel_invoke ((unsigned)t, p_d, d, c, copy)
			if target & (1 << CAP_RECEIVER_REPLY):
				// This is a reply capability.
				((Receiver *)protected_data)->send_message (~0, d, c, copy)
				return true
			receiver_invoke (target, protected_data, c[1], d[0], d[1])
			break
		case CAPTYPE_MEMORY:
			memory_invoke (target, protected_data, c[1], d[0], d[1])
			break
		case CAPTYPE_THREAD:
			thread_invoke (target, protected_data, c[1], d)
			break
		case CAPTYPE_PAGE:
			page_invoke (target, protected_data, c[1], copy[1], d[0], d[1])
			break
		case CAPTYPE_CAPABILITY:
			capability_invoke (target, protected_data, c[1], d[0], d[1])
			break
		case CAPTYPE_CAPPAGE:
			page_invoke (target, protected_data, c[1], copy[1], d[0], d[1])
			break
		default:
			panic (0x99337744, "invalid capability type invoked")
	return true

bool Receiver::send_message (unsigned protected_data, unsigned data[4], Capability *cap[4], bool copy[4]):
	bool tried_direct = false
	if owner && owner->is_waiting ():
		Capability *c[4]
		for unsigned i = 0; i < 4; ++i:
			if !cap[i]:
				c[i] = NULL
			else:
				c[i] = owner->address_space->clone_capability (cap[i], copy[i])
				if !c[i]:
					for unsigned j = 0; j < i; ++j:
						owner->address_space->free_capability (c[i])
					tried_direct = true
					break
		if !tried_direct:
			Thread_arch_receive (owner, data, c)
			owner->unwait ()
			return true
	// The owner was not waiting, or it was not possible to deliver the message.  Put it in the queue.
	Message *msg = address_space->alloc_message (this, protected_data)
	if !msg:
		return false
	for unsigned i = 0; i < 4; ++i:
		msg->data[i] = data[i]
		if !cap[i]:
			msg->capabilities[i] = NULL
		else:
			msg->capabilities[i] = address_space->clone_capability (cap[i], copy[i])
			if !msg->capabilities[i]:
				for unsigned j = 0; j < i; ++j:
					address_space->free_capability (msg->capabilities[j])
				address_space->free_message (msg)
				return false
	if tried_direct:
		Thread_arch_receive_fail (owner)
		owner->unwait ()
	return true

bool Capability::invoke (unsigned data[4], Capability *cap[4], bool copy[4]):
	if (unsigned)target & ~KERNEL_MASK:
		// This is not a kernel capability: send a message to the receiver.
		return target->send_message (protected_data, data, cap, copy)
	// This is a kernel capability.  Use a function to allow optimized call capabilities.
	return kernel_invoke ((unsigned)target, protected_data, data, cap, copy)