/*
* Copyright (c) 2005 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup mips32mm
* @{
*/
/** @file
*/
#include <macros.h>
#include <arch/mm/frame.h>
#include <arch/mm/tlb.h>
#include <interrupt.h>
#include <mm/frame.h>
#include <mm/asid.h>
#include <config.h>
#include <arch/drivers/msim.h>
#include <arch/drivers/serial.h>
#include <print.h>
#define ZERO_PAGE_MASK TLB_PAGE_MASK_1M
#define ZERO_FRAMES 4096
#define ZERO_PAGE_WIDTH 20 /* 1M */
#define ZERO_PAGE_SIZE (1 << ZERO_PAGE_WIDTH)
#define ZERO_PAGE_ASID ASID_INVALID
#define ZERO_PAGE_TLBI 0
#define ZERO_PAGE_ADDR 0
#define ZERO_PAGE_OFFSET (ZERO_PAGE_SIZE / sizeof(uint32_t) - 1)
#define ZERO_PAGE_VALUE (((volatile uint32_t *) ZERO_PAGE_ADDR)[ZERO_PAGE_OFFSET])
#define MAX_REGIONS 32
typedef struct {
pfn_t start;
pfn_t count;
} phys_region_t;
static count_t phys_regions_count = 0;
static phys_region_t phys_regions[MAX_REGIONS];
/** Check whether frame is available
*
* Returns true if given frame is generally available for use.
* Returns false if given frame is used for physical memory
* mapped devices and cannot be used.
*
*/
static bool frame_available(pfn_t frame)
{
/* MSIM device (dprinter) */
if (frame == (KA2PA(MSIM_VIDEORAM) >> ZERO_PAGE_WIDTH))
return false;
/* MSIM device (dkeyboard) */
if (frame == (KA2PA(MSIM_KBD_ADDRESS) >> ZERO_PAGE_WIDTH))
return false;
/* Simics device (serial line) */
if (frame == (KA2PA(SERIAL_ADDRESS) >> ZERO_PAGE_WIDTH))
return false;
return true;
}
/** Check whether frame is safe to write
*
* Returns true if given frame is safe for read/write test.
* Returns false if given frame should not be touched.
*
*/
static bool frame_safe(pfn_t frame) __attribute__((unused));
static bool frame_safe(pfn_t frame)
{
/* Kernel structures */
if ((frame << ZERO_PAGE_WIDTH) < KA2PA(config.base))
return false;
/* Kernel */
if (overlaps(frame << ZERO_PAGE_WIDTH, ZERO_PAGE_SIZE,
KA2PA(config.base), config.kernel_size))
return false;
/* Kernel stack */
if (overlaps(frame << ZERO_PAGE_WIDTH, ZERO_PAGE_SIZE,
KA2PA(config.stack_base), config.stack_size))
return false;
/* Init tasks */
bool safe = true;
count_t i;
for (i = 0; i < init.cnt; i++)
if (overlaps(frame << ZERO_PAGE_WIDTH, ZERO_PAGE_SIZE,
KA2PA(init.tasks[i].addr), init.tasks[i].size)) {
safe = false;
break;
}
return safe;
}
static void frame_add_region(pfn_t start_frame, pfn_t end_frame)
{
if (end_frame > start_frame) {
/* Convert 1M frames to 16K frames */
pfn_t first = ADDR2PFN(start_frame << ZERO_PAGE_WIDTH);
pfn_t count = ADDR2PFN((end_frame - start_frame) << ZERO_PAGE_WIDTH);
/* Interrupt vector frame is blacklisted */
pfn_t conf_frame;
if (start_frame == 0)
conf_frame = 1;
else
conf_frame = first;
zone_create(first, count, conf_frame, 0);
if (phys_regions_count < MAX_REGIONS) {
phys_regions[phys_regions_count].start = first;
phys_regions[phys_regions_count].count = count;
phys_regions_count++;
}
}
}
/** Create memory zones
*
* Walk through available 1 MB chunks of physical
* memory and create zones.
*
* Note: It is assumed that the TLB is not yet being
* used in any way, thus there is no interference.
*
*/
void frame_arch_init(void)
{
ipl_t ipl = interrupts_disable();
/* Clear and initialize TLB */
cp0_pagemask_write(ZERO_PAGE_MASK);
cp0_entry_lo0_write(0);
cp0_entry_lo1_write(0);
cp0_entry_hi_write(0);
count_t i;
for (i = 0; i < TLB_ENTRY_COUNT; i++) {
cp0_index_write(i);
tlbwi();
}
pfn_t start_frame = 0;
pfn_t frame;
bool avail = true;
/* Walk through all 1 MB frames */
for (frame = 0; frame < ZERO_FRAMES; frame++) {
if (!frame_available(frame))
avail = false;
else {
if (frame_safe(frame)) {
entry_lo_t lo0;
entry_lo_t lo1;
entry_hi_t hi;
tlb_prepare_entry_lo(&lo0, false, true, true, false, frame << (ZERO_PAGE_WIDTH - 12));
tlb_prepare_entry_lo(&lo1, false, false, false, false, 0);
tlb_prepare_entry_hi(&hi, ZERO_PAGE_ASID, ZERO_PAGE_ADDR);
cp0_pagemask_write(ZERO_PAGE_MASK);
cp0_entry_lo0_write(lo0.value);
cp0_entry_lo1_write(lo1.value);
cp0_entry_hi_write(hi.value);
cp0_index_write(ZERO_PAGE_TLBI);
tlbwi();
ZERO_PAGE_VALUE = 0;
if (ZERO_PAGE_VALUE != 0)
avail = false;
else {
ZERO_PAGE_VALUE = 0xdeadbeef;
if (ZERO_PAGE_VALUE != 0xdeadbeef)
avail = false;
}
}
}
if (!avail) {
frame_add_region(start_frame, frame);
start_frame = frame + 1;
avail = true;
}
}
frame_add_region(start_frame, frame);
/* Blacklist interrupt vector frame */
frame_mark_unavailable(0, 1);
/* Cleanup */
cp0_pagemask_write(ZERO_PAGE_MASK);
cp0_entry_lo0_write(0);
cp0_entry_lo1_write(0);
cp0_entry_hi_write(0);
cp0_index_write(ZERO_PAGE_TLBI);
tlbwi();
interrupts_restore(ipl);
}
void physmem_print(void)
{
printf("---------- ----------\n");
count_t i;
for (i = 0; i < phys_regions_count; i++) {
PFN2ADDR(phys_regions[i].start), PFN2ADDR(phys_regions[i].count));
}
}
/** @}
*/