blob: fd4677081c0eb0125494ef3c620a70cd5786fe42 [file] [log] [blame]
/*
* Mailbox Daemon Window Helpers
*
* Copyright 2016 IBM
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#define _GNU_SOURCE
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <limits.h>
#include <poll.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/timerfd.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include <inttypes.h>
#include <mtd/mtd-abi.h>
#include "mbox.h"
#include "common.h"
#include "mboxd_msg.h"
#include "mboxd_windows.h"
#include "mboxd_flash.h"
/* Initialisation Functions */
/*
* init_window_state() - Initialise a new window to a known state
* @window: The window to initialise
* @size: The size of the window
*/
void init_window_state(struct window_context *window, uint32_t size)
{
window->mem = NULL;
window->flash_offset = FLASH_OFFSET_UNINIT;
window->size = size;
window->dirty_bmap = NULL;
window->age = 0;
}
/*
* init_window_mem() - Divide the reserved memory region among the windows
* @context: The mbox context pointer
*
* Return: 0 on success otherwise negative error code
*/
int init_window_mem(struct mbox_context *context)
{
void *mem_location = context->mem;
int i;
/*
* Carve up the reserved memory region and allocate it to each of the
* windows. The windows are placed one after the other in ascending
* order, so the first window will be first in memory and so on. We
* shouldn't have allocated more windows than we have memory, but if we
* did we will error out here
*/
for (i = 0; i < context->windows.num; i++) {
context->windows.window[i].mem = mem_location;
mem_location += context->windows.window[i].size;
if (mem_location > (context->mem + context->mem_size)) {
/* Tried to allocate window past the end of memory */
MSG_ERR("Total size of windows exceeds reserved mem\n");
MSG_ERR("Try smaller or fewer windows\n");
MSG_ERR("Mem size: 0x%.8x\n", context->mem_size);
return -1;
}
}
return 0;
}
/* Write from Window Functions */
/*
* write_from_window_v1() - Handle writing when erase and block size differ
* @context: The mbox context pointer
* @offset_bytes: The offset in the current window to write from (bytes)
* @count_bytes: Number of bytes to write
*
* Handle a write_from_window for dirty memory when block_size is less than the
* flash erase size
* This requires us to be a bit careful because we might have to erase more
* than we want to write which could result in data loss if we don't have the
* entire portion of flash to be erased already saved in memory (for us to
* write back after the erase)
*
* Return: 0 on success otherwise negative error code
*/
int write_from_window_v1(struct mbox_context *context,
uint32_t offset_bytes, uint32_t count_bytes)
{
int rc;
uint32_t flash_offset;
struct window_context low_mem = { 0 }, high_mem = { 0 };
/* Find where in phys flash this is based on the window.flash_offset */
flash_offset = context->current->flash_offset + offset_bytes;
/*
* low_mem.flash_offset = erase boundary below where we're writing
* low_mem.size = size from low_mem.flash_offset to where we're writing
*
* high_mem.flash_offset = end of where we're writing
* high_mem.size = size from end of where we're writing to next erase
* boundary
*/
low_mem.flash_offset = align_down(flash_offset,
context->mtd_info.erasesize);
low_mem.size = flash_offset - low_mem.flash_offset;
high_mem.flash_offset = flash_offset + count_bytes;
high_mem.size = align_up(high_mem.flash_offset,
context->mtd_info.erasesize) -
high_mem.flash_offset;
/*
* Check if we already have a copy of the required flash areas in
* memory as part of the existing window
*/
if (low_mem.flash_offset < context->current->flash_offset) {
/* Before the start of our current window */
low_mem.mem = malloc(low_mem.size);
if (!low_mem.mem) {
MSG_ERR("Unable to allocate memory\n");
return -MBOX_R_SYSTEM_ERROR;
}
rc = copy_flash(context, low_mem.flash_offset,
low_mem.mem, low_mem.size);
if (rc < 0) {
goto out;
}
}
if ((high_mem.flash_offset + high_mem.size) >
(context->current->flash_offset + context->current->size)) {
/* After the end of our current window */
high_mem.mem = malloc(high_mem.size);
if (!high_mem.mem) {
MSG_ERR("Unable to allocate memory\n");
rc = -MBOX_R_SYSTEM_ERROR;
goto out;
}
rc = copy_flash(context, high_mem.flash_offset,
high_mem.mem, high_mem.size);
if (rc < 0) {
goto out;
}
}
/*
* We need to erase the flash from low_mem.flash_offset->
* high_mem.flash_offset + high_mem.size
*/
rc = erase_flash(context, low_mem.flash_offset,
(high_mem.flash_offset - low_mem.flash_offset) +
high_mem.size);
if (rc < 0) {
MSG_ERR("Couldn't erase flash\n");
goto out;
}
/* Write back over the erased area */
if (low_mem.mem) {
/* Exceed window at the start */
rc = write_flash(context, low_mem.flash_offset, low_mem.mem,
low_mem.size);
if (rc < 0) {
goto out;
}
}
rc = write_flash(context, flash_offset,
context->current->mem + offset_bytes, count_bytes);
if (rc < 0) {
goto out;
}
/*
* We still need to write the last little bit that we erased - it's
* either in the current window or the high_mem window.
*/
if (high_mem.mem) {
/* Exceed window at the end */
rc = write_flash(context, high_mem.flash_offset, high_mem.mem,
high_mem.size);
if (rc < 0) {
goto out;
}
} else {
/* Write from the current window - it's atleast that big */
rc = write_flash(context, high_mem.flash_offset,
context->current->mem + offset_bytes +
count_bytes, high_mem.size);
if (rc < 0) {
goto out;
}
}
out:
free(low_mem.mem);
free(high_mem.mem);
return rc;
}
/*
* write_from_window() - Write back to the flash from the current window
* @context: The mbox context pointer
* @offset_bytes: The offset in the current window to write from (blocks)
* @count_bytes: Number of blocks to write
* @type: Whether this is an erase & write or just an erase
*
* Return: 0 on success otherwise negative error code
*/
int write_from_window(struct mbox_context *context, uint32_t offset,
uint32_t count, uint8_t type)
{
int rc;
uint32_t flash_offset, count_bytes = count << context->block_size_shift;
uint32_t offset_bytes = offset << context->block_size_shift;
switch (type) {
case WINDOW_ERASED: /* >= V2 ONLY -> block_size == erasesize */
flash_offset = context->current->flash_offset + offset_bytes;
rc = erase_flash(context, flash_offset, count_bytes);
if (rc < 0) {
MSG_ERR("Couldn't erase flash\n");
return rc;
}
break;
case WINDOW_DIRTY:
/*
* For protocol V1, block_size may be smaller than erase size
* so we have a special function to make sure that we do this
* correctly without losing data.
*/
if (log_2(context->mtd_info.erasesize) !=
context->block_size_shift) {
return write_from_window_v1(context, offset_bytes,
count_bytes);
}
flash_offset = context->current->flash_offset + offset_bytes;
/* Erase the flash */
rc = erase_flash(context, flash_offset, count_bytes);
if (rc < 0) {
return rc;
}
/* Write to the erased flash */
rc = write_flash(context, flash_offset,
context->current->mem + offset_bytes,
count_bytes);
if (rc < 0) {
return rc;
}
break;
default:
/* We shouldn't be able to get here */
MSG_ERR("Write from window with invalid type: %d\n", type);
return -MBOX_R_SYSTEM_ERROR;
}
return 0;
}
/* Window Management Functions */
/*
* alloc_window_dirty_bytemap() - (re)allocate all the window dirty bytemaps
* @context: The mbox context pointer
*/
void alloc_window_dirty_bytemap(struct mbox_context *context)
{
struct window_context *cur;
int i;
for (i = 0; i < context->windows.num; i++) {
cur = &context->windows.window[i];
/* There may already be one allocated */
free(cur->dirty_bmap);
/* Allocate the new one */
cur->dirty_bmap = calloc((cur->size >>
context->block_size_shift),
sizeof(*cur->dirty_bmap));
}
}
/*
* free_window_dirty_bytemap() - free all window dirty bytemaps
* @context: The mbox context pointer
*/
void free_window_dirty_bytemap(struct mbox_context *context)
{
int i;
for (i = 0; i < context->windows.num; i++) {
free(context->windows.window[i].dirty_bmap);
}
}
/*
* set_window_bytemap() - Set the window bytemap
* @context: The mbox context pointer
* @cur: The window to set the bytemap of
* @offset: Where in the window to set the bytemap (blocks)
* @size: The number of blocks to set
* @val: The value to set the bytemap to
*
* Return: 0 on success otherwise negative error code
*/
int set_window_bytemap(struct mbox_context *context, struct window_context *cur,
uint32_t offset, uint32_t size, uint8_t val)
{
if (offset + size > (cur->size >> context->block_size_shift)) {
MSG_ERR("Tried to set window bytemap past end of window\n");
MSG_ERR("Requested offset: 0x%x size: 0x%x window size: 0x%x\n",
offset << context->block_size_shift,
size << context->block_size_shift,
cur->size << context->block_size_shift);
return -MBOX_R_PARAM_ERROR;
}
memset(cur->dirty_bmap + offset, val, size);
return 0;
}
/*
* close_current_window() - Close the current (active) window
* @context: The mbox context pointer
* @set_bmc_event: Whether to set the bmc event bit
* @flags: Flags as defined for a close command in the protocol
*
* This closes the current window. If the host has requested the current window
* be closed then we don't need to set the bmc event bit
* (set_bmc_event == false), otherwise if the current window has been closed
* without the host requesting it the bmc event bit must be set to indicate this
* to the host (set_bmc_event == true).
*/
void close_current_window(struct mbox_context *context, bool set_bmc_event,
uint8_t flags)
{
if (set_bmc_event) {
set_bmc_events(context, BMC_EVENT_WINDOW_RESET, SET_BMC_EVENT);
}
if (flags & FLAGS_SHORT_LIFETIME) {
context->current->age = 0;
}
context->current->size = context->windows.default_size;
context->current = NULL;
context->current_is_write = false;
}
/*
* reset_window() - Reset a window context to a well defined default state
* @context: The mbox context pointer
* @window: The window to reset
*/
void reset_window(struct mbox_context *context, struct window_context *window)
{
window->flash_offset = FLASH_OFFSET_UNINIT;
window->size = context->windows.default_size;
if (window->dirty_bmap) { /* Might not have been allocated */
set_window_bytemap(context, window, 0,
window->size >> context->block_size_shift,
WINDOW_CLEAN);
}
window->age = 0;
}
/*
* reset_all_windows() - Reset all windows to a well defined default state
* @context: The mbox context pointer
* @set_bmc_event: If any state change should be indicated to the host
*/
void reset_all_windows(struct mbox_context *context, bool set_bmc_event)
{
int i;
/* We might have an open window which needs closing */
if (context->current) {
close_current_window(context, set_bmc_event, FLAGS_NONE);
}
for (i = 0; i < context->windows.num; i++) {
reset_window(context, &context->windows.window[i]);
}
context->windows.max_age = 0;
}
/*
* find_oldest_window() - Find the oldest (Least Recently Used) window
* @context: The mbox context pointer
*
* Return: Pointer to the least recently used window
*/
struct window_context *find_oldest_window(struct mbox_context *context)
{
struct window_context *oldest = NULL, *cur;
uint32_t min_age = context->windows.max_age + 1;
int i;
for (i = 0; i < context->windows.num; i++) {
cur = &context->windows.window[i];
if (cur->age < min_age) {
min_age = cur->age;
oldest = cur;
}
}
return oldest;
}
/*
* search_windows() - Search the window cache for a window containing offset
* @context: The mbox context pointer
* @offset: Absolute flash offset to search for (bytes)
* @exact: If the window must exactly map the requested offset
*
* This will search the cache of windows for one containing the requested
* offset. For V1 of the protocol windows must exactly map the offset since we
* can't tell the host how much of its request we actually mapped and it will
* thus assume it can access window->size from the offset we give it.
*
* Return: Pointer to a window containing the requested offset otherwise
* NULL
*/
struct window_context *search_windows(struct mbox_context *context,
uint32_t offset, bool exact)
{
struct window_context *cur;
int i;
for (i = 0; i < context->windows.num; i++) {
cur = &context->windows.window[i];
if (cur->flash_offset == FLASH_OFFSET_UNINIT) {
/* Uninitialised Window */
if (offset == FLASH_OFFSET_UNINIT) {
return cur;
}
continue;
}
if ((offset >= cur->flash_offset) &&
(offset < (cur->flash_offset + cur->size))) {
if (exact && (cur->flash_offset != offset)) {
continue;
}
/* This window contains the requested offset */
cur->age = ++(context->windows.max_age);
return cur;
}
}
return NULL;
}
/*
* create_map_window() - Create a window mapping which maps the requested offset
* @context: The mbox context pointer
* @this_window: A pointer to update to the "new" window
* @offset: Absolute flash offset to create a mapping for (bytes)
* @exact: If the window must exactly map the requested offset
*
* This is used to create a window mapping for the requested offset when there
* is no existing window in the cache which satisfies the offset. This involves
* choosing an existing window from the window cache to evict so we can use it
* to store the flash contents from the requested offset, we then point the
* caller to that window since it now maps their request.
*
* Return: 0 on success otherwise negative error code
*/
int create_map_window(struct mbox_context *context,
struct window_context **this_window, uint32_t offset,
bool exact)
{
struct window_context *cur = NULL;
int rc;
/* Search for an uninitialised window, use this before evicting */
cur = search_windows(context, FLASH_OFFSET_UNINIT, true);
/* No uninitialised window found, we need to choose one to "evict" */
if (!cur) {
cur = find_oldest_window(context);
}
if (!exact) {
/*
* It would be nice to align the offsets which we map to window
* size, this will help prevent overlap which would be an
* inefficient use of our reserved memory area (we would like
* to "cache" as much of the acutal flash as possible in
* memory). If we're protocol V1 however we must ensure the
* offset requested is exactly mapped.
*/
offset &= ~(cur->size - 1);
}
if ((offset + cur->size) > context->flash_size) {
/*
* There is V1 skiboot implementations out there which don't
* mask offset with window size, meaning when we have
* window size == flash size we will never allow the host to
* open a window except at 0x0, which isn't always where the
* host requests it. Thus we have to ignore this check and just
* hope the host doesn't access past the end of the window
* (which it shouldn't) for V1 implementations to get around
* this.
*/
if (context->version == API_VERSION_1) {
cur->size = align_down(context->flash_size - offset,
1 << context->block_size_shift);
} else {
/* Trying to read past the end of flash */
MSG_ERR("Tried to open read window past flash limit\n");
return -MBOX_R_PARAM_ERROR;
}
}
/* Copy from flash into the window buffer */
rc = copy_flash(context, offset, cur->mem, cur->size);
if (rc < 0) {
/* We don't know how much we've copied -> better reset window */
reset_window(context, cur);
return rc;
}
/*
* Since for V1 windows aren't constrained to start at multiples of
* window size it's possible that something already maps this offset.
* Reset any windows which map this offset to avoid coherency problems.
* We just have to check for anything which maps the start or the end
* of the window since all windows are the same size so another window
* cannot map just the middle of this window.
*/
if (context->version == API_VERSION_1) {
uint32_t i;
for (i = offset; i < (offset + cur->size); i += (cur->size - 1)) {
struct window_context *tmp = NULL;
do {
tmp = search_windows(context, i, false);
if (tmp) {
reset_window(context, tmp);
}
} while (tmp);
}
}
/* Clear the bytemap of the window just loaded -> we know it's clean */
set_window_bytemap(context, cur, 0,
cur->size >> context->block_size_shift,
WINDOW_CLEAN);
/* Update so we know what's in the window */
cur->flash_offset = offset;
cur->age = ++(context->windows.max_age);
*this_window = cur;
return 0;
}