#pypp 0
// Iris: micro-kernel for a capability-based operating system.
// mips/arch.ccp: Most mips-specific parts.
// Copyright 2009 Bas Wijnen <wijnen@debian.org>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#define ARCH
#include "kernel.hh"

void kThread_arch_init (kThread *thread):
	thread->arch.at = 0
	for unsigned i = 0; i < 2; ++i:
		thread->arch.v[i] = 0
		thread->arch.k[i] = 0
	for unsigned i = 0; i < 4; ++i:
		thread->arch.a[i] = 0
	for unsigned i = 0; i < 10; ++i:
		thread->arch.t[i] = 0
	thread->arch.gp = 0
	thread->arch.fp = 0
	thread->arch.ra = 0
	thread->arch.hi = 0
	thread->arch.lo = 0

void kPage_arch_init (kPage *page):
	page->arch.prev_mapped = NULL
	page->arch.next_mapped = NULL

void kThread_arch_receive (kThread *thread, Kernel::Num protected_data, Kernel::Num *data):
	thread->arch.a[0] = data[0].l
	thread->arch.a[1] = data[0].h
	thread->arch.a[2] = data[1].l
	thread->arch.a[3] = data[1].h
	thread->arch.t[0] = protected_data.l
	thread->arch.t[1] = protected_data.h

unsigned *kThread_arch_info (kThread *thread, unsigned num):
	switch num:
		case 1:
			return &thread->arch.at
		case 2:
			return &thread->arch.v[0]
		case 3:
			return &thread->arch.v[1]
		case 4:
			return &thread->arch.a[0]
		case 5:
			return &thread->arch.a[1]
		case 6:
			return &thread->arch.a[2]
		case 7:
			return &thread->arch.a[3]
		case 8:
			return &thread->arch.t[0]
		case 9:
			return &thread->arch.t[1]
		case 10:
			return &thread->arch.t[2]
		case 11:
			return &thread->arch.t[3]
		case 12:
			return &thread->arch.t[4]
		case 13:
			return &thread->arch.t[5]
		case 14:
			return &thread->arch.t[6]
		case 15:
			return &thread->arch.t[7]
		case 16:
			return &thread->arch.s[0]
		case 17:
			return &thread->arch.s[1]
		case 18:
			return &thread->arch.s[2]
		case 19:
			return &thread->arch.s[3]
		case 20:
			return &thread->arch.s[4]
		case 21:
			return &thread->arch.s[5]
		case 22:
			return &thread->arch.s[6]
		case 23:
			return &thread->arch.s[7]
		case 24:
			return &thread->arch.t[8]
		case 25:
			return &thread->arch.t[9]
		case 26:
			return &thread->arch.k[0]
		case 27:
			return &thread->arch.k[1]
		case 28:
			return &thread->arch.gp
		case 29:
			return &thread->sp
		case 30:
			return &thread->arch.fp
		case 31:
			return &thread->arch.ra
		default:
			return NULL

void kMemory_arch_init (kMemory *mem):
	mem->arch.asid = 1
	mem->arch.directory = NULL
	mem->arch.shadow = NULL

static void tlb_reset (kMemory *mem, unsigned address, unsigned value):
	//dbg_log_line ()
	unsigned asid = mem->arch.asid
	if asids[asid] != (unsigned)mem:
		//dbg_log ("not resetting tlb, because the asid is not in use.\n")
		return
	//dbg_log ("resetting tlb for ")
	//dbg_log_num (address)
	//dbg_log ("\n")
	cp0_set (CP0_ENTRY_HI, address | asid)
	__asm__ volatile ("tlbp")
	unsigned idx
	cp0_get (CP0_INDEX, idx)
	if ~idx & 0x80000000:
		__asm__ volatile ("tlbr")
		if address & (1 << PAGE_BITS):
			cp0_set (CP0_ENTRY_LO1, value)
		else:
			cp0_set (CP0_ENTRY_LO0, value)
		__asm__ volatile ("tlbwi")

static unsigned make_entry_lo (kPage *page):
	//dbg_log_line ()
	if !page->frame:
		//dbg_log ("not mapping because there is no frame\n")
		return 0
	unsigned flags
	if page->flags & Kernel::Page::UNCACHED:
		flags = 0x10 | 0x2
	else:
		// 18 is write-back cache; 00 is write-through cache.
		flags = 0x18 | 0x2
	if ~page->flags & Kernel::Page::MAPPED_READONLY:
		flags |= 0x4
	return ((page->frame & ~0x80000000) >> 6) | flags

bool kMemory_arch_map (kMemory *mem, kPage *page, unsigned address):
	//dbg_log_line ()
	if address >= 0x80000000:
		dpanic (address, "trying to map to kernel address")
		return false
	if page->mapping != ~0:
		mem->unmap (page)
	if address == ~0:
		return true
	if address & ~PAGE_MASK:
		dpanic (address, "mapping not page-aligned")
		address &= PAGE_MASK
	if !mem->arch.directory:
		//dbg_log ("creating directory\n")
		mem->arch.directory = (Table **)mem->zalloc ()
		if !mem->arch.directory:
			dpanic (0, "unable to allocate directory")
			return false
		mem->arch.shadow = (kPageP *)mem->zalloc ()
		if !mem->arch.shadow:
			dpanic (0, "unable to allocate shadow directory")
			mem->zfree ((unsigned)mem->arch.directory)
			mem->arch.directory = NULL
			return false
	Table *table = mem->arch.directory[address >> 21]
	if !table:
		//dbg_log ("creating table\n")
		table = (Table *)mem->zalloc ()
		if !table:
			dpanic (0, "unable to allocate table")
			//if mem->arch.first_table == ~0:
			//	mem->zfree ((unsigned)mem->arch.directory)
			//	mem->zfree ((unsigned)mem->arch.shadow)
			//	mem->arch.directory = NULL
			//	mem->arch.shadow = NULL
			return false
		mem->arch.directory[address >> 21] = table
	unsigned idx = (address >> 12) & ((1 << 9) - 1)
	if table->entrylo[idx]:
		dbg_log ("page already mapped: ")
		dbg_log_num (idx, 3)
		dbg_log (";")
		dbg_log_num (table->entrylo[idx])
		dbg_log ("/")
		dbg_log_num ((unsigned)table->page[idx])
		dbg_log (" table: ")
		dbg_log_num ((unsigned)table)
		dbg_log ("\n")
		mem->unmap (table->page[idx])
	table->entrylo[idx] = make_entry_lo (page)
	table->page[idx] = page
	//dbg_log ("mapped at address ")
	//dbg_log_num (address)
	//dbg_log_char ('\n')
	page->mapping = address
	page->arch.next_mapped = mem->arch.shadow[address >> 21]
	if page->arch.next_mapped:
		page->arch.next_mapped->arch.prev_mapped = page
	mem->arch.shadow[address >> 21] = page
	tlb_reset (mem, address, table->entrylo[idx])
	return true

void kMemory_arch_unmap (kMemory *mem, kPage *page):
	//dbg_log_line ()
	unsigned didx = page->mapping >> 21
	unsigned tidx = (page->mapping >> 12) & ((1 << 9) - 1)
	Table *table = mem->arch.directory[didx]
	table->entrylo[tidx] = 0
	table->page[tidx] = NULL
	if page->arch.next_mapped:
		page->arch.next_mapped->arch.prev_mapped = page->arch.prev_mapped
	if page->arch.prev_mapped:
		page->arch.prev_mapped->arch.next_mapped = page->arch.next_mapped
	else:
		mem->arch.shadow[didx] = page->arch.next_mapped
	page->arch.prev_mapped = NULL
	page->arch.next_mapped = NULL
	tlb_reset (mem, page->mapping, 0)
	page->mapping = ~0

kPage *kMemory_arch_get_mapping (kMemory *mem, unsigned address):
	//dbg_log_line ()
	if address >= 0x80000000 || !mem->arch.directory:
		return NULL
	Table *table = mem->arch.directory[address >> 21]
	if !table:
		return NULL
	return table->page[(address >> 12) & ((1 << 9) - 1)]

void kPage_arch_update_mapping (kPage *page):
	//dbg_log_line ()
	if page->mapping == ~0:
		return
	unsigned target = make_entry_lo (page)
	unsigned de = page->mapping >> 21
	unsigned te = (page->mapping >> 12) & ((1 << 9) - 1)
	page->address_space->arch.directory[de]->entrylo[te] = target
	tlb_reset (page->address_space, page->mapping, target)

typedef unsigned cacheline[8]
void arch_uncache_page (unsigned page):
	for cacheline *line = (cacheline *)page; line < (cacheline *)(page + PAGE_SIZE); ++line:
		__asm__ volatile ("lw $k0, %0; cache 0x10, 0($k0); cache 0x11, 0($k0)" :: "m"(line))

void arch_register_interrupt (unsigned num, kReceiver *r):
	arch_interrupt_receiver[num] = r
	// And enable or disable the interrupt.
	if r:
		intc_unmask_irq (num)
	else:
		intc_mask_irq (num)