blob: a5bcf626a45ce4de451c44eedc7a3cffca95f6d7 [file] [log] [blame]
/*
* Mailbox Daemon MBOX Message 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 "mbox.h"
#include "common.h"
#include "mboxd_msg.h"
#include "mboxd_windows.h"
#include "mboxd_lpc.h"
static int mbox_handle_flush_window(struct mbox_context *context, union mbox_regs *req,
struct mbox_msg *resp);
typedef int (*mboxd_mbox_handler)(struct mbox_context *, union mbox_regs *,
struct mbox_msg *);
/*
* write_bmc_event_reg() - Write to the BMC controlled status register (reg 15)
* @context: The mbox context pointer
*
* Return: 0 on success otherwise negative error code
*/
static int write_bmc_event_reg(struct mbox_context *context)
{
int rc;
/* Seek mbox registers */
rc = lseek(context->fds[MBOX_FD].fd, MBOX_BMC_EVENT, SEEK_SET);
if (rc != MBOX_BMC_EVENT) {
MSG_ERR("Couldn't lseek mbox to byte %d: %s\n", MBOX_BMC_EVENT,
strerror(errno));
return -MBOX_R_SYSTEM_ERROR;
}
/* Write to mbox status register */
rc = write(context->fds[MBOX_FD].fd, &context->bmc_events, 1);
if (rc != 1) {
MSG_ERR("Couldn't write to BMC status reg: %s\n",
strerror(errno));
return -MBOX_R_SYSTEM_ERROR;
}
/* Reset to start */
rc = lseek(context->fds[MBOX_FD].fd, 0, SEEK_SET);
if (rc) {
MSG_ERR("Couldn't reset MBOX offset to zero: %s\n",
strerror(errno));
return -MBOX_R_SYSTEM_ERROR;
}
return 0;
}
/*
* set_bmc_events() - Set BMC events
* @context: The mbox context pointer
* @bmc_event: The bits to set
* @write_back: Whether to write back to the register -> will interrupt host
*
* Return: 0 on success otherwise negative error code
*/
int set_bmc_events(struct mbox_context *context, uint8_t bmc_event,
bool write_back)
{
uint8_t mask = 0x00;
switch (context->version) {
case API_VERSION_1:
mask = BMC_EVENT_V1_MASK;
break;
default:
mask = BMC_EVENT_V2_MASK;
break;
}
context->bmc_events |= (bmc_event & mask);
return write_back ? write_bmc_event_reg(context) : 0;
}
/*
* clr_bmc_events() - Clear BMC events
* @context: The mbox context pointer
* @bmc_event: The bits to clear
* @write_back: Whether to write back to the register -> will interrupt host
*
* Return: 0 on success otherwise negative error code
*/
int clr_bmc_events(struct mbox_context *context, uint8_t bmc_event,
bool write_back)
{
context->bmc_events &= ~bmc_event;
return write_back ? write_bmc_event_reg(context) : 0;
}
/* Command Handlers */
/*
* Command: RESET_STATE
* Reset the LPC mapping to point back at the flash
*/
static int mbox_handle_reset(struct mbox_context *context,
union mbox_regs *req, struct mbox_msg *resp)
{
/* Host requested it -> No BMC Event */
reset_all_windows(context, NO_BMC_EVENT);
return point_to_flash(context);
}
/*
* Command: GET_MBOX_INFO
* Get the API version, default window size and block size
* We also set the LPC mapping to point to the reserved memory region here so
* this command must be called before any window manipulation
*
* V1:
* ARGS[0]: API Version
*
* RESP[0]: API Version
* RESP[1:2]: Default read window size (number of blocks)
* RESP[3:4]: Default write window size (number of blocks)
* RESP[5]: Block size (as shift)
*
* V2:
* ARGS[0]: API Version
*
* RESP[0]: API Version
* RESP[1:2]: Default read window size (number of blocks)
* RESP[3:4]: Default write window size (number of blocks)
* RESP[5]: Block size (as shift)
*/
static int mbox_handle_mbox_info(struct mbox_context *context,
union mbox_regs *req, struct mbox_msg *resp)
{
uint8_t mbox_api_version = req->msg.args[0];
uint8_t old_api_version = context->version;
int rc;
/* Check we support the version requested */
if (mbox_api_version < API_MIN_VERSION)
return -MBOX_R_PARAM_ERROR;
if (mbox_api_version > API_MAX_VERSION)
mbox_api_version = API_MAX_VERSION;
context->version = mbox_api_version;
MSG_OUT("Using Protocol Version: %d\n", context->version);
/*
* The reset state is currently to have the LPC bus point directly to
* flash, since we got a mbox_info command we know the host can talk
* mbox so point the LPC bus mapping to the reserved memory region now
* so the host can access what we put in it.
*/
rc = point_to_memory(context);
if (rc < 0) {
return rc;
}
switch (context->version) {
case API_VERSION_1:
context->block_size_shift = BLOCK_SIZE_SHIFT_V1;
break;
default:
context->block_size_shift = log_2(context->mtd_info.erasesize);
break;
}
MSG_OUT("Block Size Shift: %d\n", context->block_size_shift);
/* Now we know the blocksize we can allocate the window dirty_bytemap */
if (mbox_api_version != old_api_version) {
alloc_window_dirty_bytemap(context);
}
/* Reset if we were V1 since this required exact window mapping */
if (old_api_version == API_VERSION_1) {
/*
* This will only set the BMC event if there was a current
* window -> In which case we are better off notifying the
* host.
*/
reset_all_windows(context, SET_BMC_EVENT);
}
resp->args[0] = mbox_api_version;
if (context->version == API_VERSION_1) {
put_u16(&resp->args[1], context->windows.default_size >>
context->block_size_shift);
put_u16(&resp->args[3], context->windows.default_size >>
context->block_size_shift);
}
if (context->version >= API_VERSION_2) {
resp->args[5] = context->block_size_shift;
}
return 0;
}
/*
* Command: GET_FLASH_INFO
* Get the flash size and erase granularity
*
* V1:
* RESP[0:3]: Flash Size (bytes)
* RESP[4:7]: Erase Size (bytes)
* V2:
* RESP[0:1]: Flash Size (number of blocks)
* RESP[2:3]: Erase Size (number of blocks)
*/
static int mbox_handle_flash_info(struct mbox_context *context,
union mbox_regs *req, struct mbox_msg *resp)
{
switch (context->version) {
case API_VERSION_1:
/* Both Sizes in Bytes */
put_u32(&resp->args[0], context->flash_size);
put_u32(&resp->args[4], context->mtd_info.erasesize);
break;
case API_VERSION_2:
/* Both Sizes in Block Size */
put_u16(&resp->args[0],
context->flash_size >> context->block_size_shift);
put_u16(&resp->args[2],
context->mtd_info.erasesize >>
context->block_size_shift);
break;
default:
MSG_ERR("API Version Not Valid - Invalid System State\n");
return -MBOX_R_SYSTEM_ERROR;
break;
}
return 0;
}
/*
* get_lpc_addr_shifted() - Get lpc address of the current window
* @context: The mbox context pointer
*
* Return: The lpc address to access that offset shifted by block size
*/
static inline uint16_t get_lpc_addr_shifted(struct mbox_context *context)
{
uint32_t lpc_addr, mem_offset;
/* Offset of the current window in the reserved memory region */
mem_offset = context->current->mem - context->mem;
/* Total LPC Address */
lpc_addr = context->lpc_base + mem_offset;
return lpc_addr >> context->block_size_shift;
}
/*
* Command: CREATE_READ_WINDOW
* Opens a read window
* First checks if any current window with the requested data, if so we just
* point the host to that. Otherwise we read the request data in from flash and
* point the host there.
*
* V1:
* ARGS[0:1]: Window Location as Offset into Flash (number of blocks)
*
* RESP[0:1]: LPC bus address for host to access this window (number of blocks)
*
* V2:
* ARGS[0:1]: Window Location as Offset into Flash (number of blocks)
* ARGS[2:3]: Requested window size (number of blocks)
*
* RESP[0:1]: LPC bus address for host to access this window (number of blocks)
* RESP[2:3]: Actual window size that the host can access (number of blocks)
*/
static int mbox_handle_read_window(struct mbox_context *context,
union mbox_regs *req, struct mbox_msg *resp)
{
uint32_t flash_offset;
int rc;
/* Close the current window if there is one */
if (context->current) {
/* There is an implicit flush if it was a write window */
if (context->current_is_write) {
rc = mbox_handle_flush_window(context, NULL, NULL);
if (rc < 0) {
MSG_ERR("Couldn't Flush Write Window\n");
return rc;
}
}
close_current_window(context, NO_BMC_EVENT, FLAGS_NONE);
}
/* Offset the host has requested */
flash_offset = get_u16(&req->msg.args[0]) << context->block_size_shift;
MSG_OUT("Host Requested Flash @ 0x%.8x\n", flash_offset);
/* Check if we have an existing window */
context->current = search_windows(context, flash_offset,
context->version == API_VERSION_1);
if (!context->current) { /* No existing window */
rc = create_map_window(context, &context->current, flash_offset,
context->version == API_VERSION_1);
if (rc < 0) { /* Unable to map offset */
MSG_ERR("Couldn't create window mapping for offset 0x%.8x\n"
, flash_offset);
return rc;
}
}
put_u16(&resp->args[0], get_lpc_addr_shifted(context));
if (context->version >= API_VERSION_2) {
put_u16(&resp->args[2], context->current->size >>
context->block_size_shift);
put_u16(&resp->args[4], context->current->flash_offset >>
context->block_size_shift);
}
context->current_is_write = false;
return 0;
}
/*
* Command: CREATE_WRITE_WINDOW
* Opens a write window
* First checks if any current window with the requested data, if so we just
* point the host to that. Otherwise we read the request data in from flash and
* point the host there.
*
* V1:
* ARGS[0:1]: Window Location as Offset into Flash (number of blocks)
*
* RESP[0:1]: LPC bus address for host to access this window (number of blocks)
*
* V2:
* ARGS[0:1]: Window Location as Offset into Flash (number of blocks)
* ARGS[2:3]: Requested window size (number of blocks)
*
* RESP[0:1]: LPC bus address for host to access this window (number of blocks)
* RESP[2:3]: Actual window size that was mapped/host can access (n.o. blocks)
*/
static int mbox_handle_write_window(struct mbox_context *context,
union mbox_regs *req, struct mbox_msg *resp)
{
int rc;
/*
* This is very similar to opening a read window (exactly the same
* for now infact)
*/
rc = mbox_handle_read_window(context, req, resp);
if (rc < 0) {
return rc;
}
context->current_is_write = true;
return rc;
}
/*
* Commands: MARK_WRITE_DIRTY
* Marks a portion of the current (write) window dirty, informing the daemon
* that is has been written to and thus must be at some point written to the
* backing store
* These changes aren't written back to the backing store unless flush is then
* called or the window closed
*
* V1:
* ARGS[0:1]: Where within flash to start (number of blocks)
* ARGS[2:5]: Number to mark dirty (number of bytes)
*
* V2:
* ARGS[0:1]: Where within window to start (number of blocks)
* ARGS[2:3]: Number to mark dirty (number of blocks)
*/
static int mbox_handle_dirty_window(struct mbox_context *context,
union mbox_regs *req, struct mbox_msg *resp)
{
uint32_t offset, size;
if (!(context->current && context->current_is_write)) {
MSG_ERR("Tried to call mark dirty without open write window\n");
return context->version >= API_VERSION_2 ? -MBOX_R_WINDOW_ERROR
: -MBOX_R_PARAM_ERROR;
}
offset = get_u16(&req->msg.args[0]);
if (context->version >= API_VERSION_2) {
size = get_u16(&req->msg.args[2]);
} else {
uint32_t off;
/* For V1 offset given relative to flash - we want the window */
off = offset - ((context->current->flash_offset) >>
context->block_size_shift);
if (off > offset) { /* Underflow - before current window */
MSG_ERR("Tried to mark dirty before start of window\n");
MSG_ERR("requested offset: 0x%x window start: 0x%x\n",
offset << context->block_size_shift,
context->current->flash_offset);
return -MBOX_R_PARAM_ERROR;
}
offset = off;
size = get_u32(&req->msg.args[2]);
/*
* We only track dirty at the block level.
* For protocol V1 we can get away with just marking the whole
* block dirty.
*/
size = align_up(size, 1 << context->block_size_shift);
size >>= context->block_size_shift;
}
return set_window_bytemap(context, context->current, offset, size,
WINDOW_DIRTY);
}
/*
* Commands: MARK_WRITE_ERASE
* Erases a portion of the current window
* These changes aren't written back to the backing store unless flush is then
* called or the window closed
*
* V1:
* Unimplemented
*
* V2:
* ARGS[0:1]: Where within window to start (number of blocks)
* ARGS[2:3]: Number to erase (number of blocks)
*/
static int mbox_handle_erase_window(struct mbox_context *context,
union mbox_regs *req, struct mbox_msg *resp)
{
uint32_t offset, size;
int rc;
if (context->version < API_VERSION_2) {
MSG_ERR("Protocol Version invalid for Erase Command\n");
return -MBOX_R_PARAM_ERROR;
}
if (!(context->current && context->current_is_write)) {
MSG_ERR("Tried to call erase without open write window\n");
return -MBOX_R_WINDOW_ERROR;
}
offset = get_u16(&req->msg.args[0]);
size = get_u16(&req->msg.args[2]);
rc = set_window_bytemap(context, context->current, offset, size,
WINDOW_ERASED);
if (rc < 0) {
return rc;
}
/* Write 0xFF to mem -> This ensures consistency between flash & ram */
memset(context->current->mem + (offset << context->block_size_shift),
0xFF, size << context->block_size_shift);
return 0;
}
/*
* Command: WRITE_FLUSH
* Flushes any dirty or erased blocks in the current window back to the backing
* store
* NOTE: For V1 this behaves much the same as the dirty command in that it
* takes an offset and number of blocks to dirty, then also performs a flush as
* part of the same command. For V2 this will only flush blocks already marked
* dirty/erased with the appropriate commands and doesn't take any arguments
* directly.
*
* V1:
* ARGS[0:1]: Where within window to start (number of blocks)
* ARGS[2:5]: Number to mark dirty (number of bytes)
*
* V2:
* NONE
*/
static int mbox_handle_flush_window(struct mbox_context *context,
union mbox_regs *req, struct mbox_msg *resp)
{
int rc, i, offset, count;
uint8_t prev;
if (!(context->current && context->current_is_write)) {
MSG_ERR("Tried to call flush without open write window\n");
return context->version >= API_VERSION_2 ? -MBOX_R_WINDOW_ERROR
: -MBOX_R_PARAM_ERROR;
}
/*
* For V1 the Flush command acts much the same as the dirty command
* except with a flush as well. Only do this on an actual flush
* command not when we call flush because we've implicitly closed a
* window because we might not have the required args in req.
*/
if (context->version == API_VERSION_1 && req &&
req->msg.command == MBOX_C_WRITE_FLUSH) {
rc = mbox_handle_dirty_window(context, req, NULL);
if (rc < 0) {
return rc;
}
}
offset = 0;
count = 0;
prev = WINDOW_CLEAN;
/*
* We look for streaks of the same type and keep a count, when the type
* (dirty/erased) changes we perform the required action on the backing
* store and update the current streak-type
*/
for (i = 0; i < (context->current->size >> context->block_size_shift);
i++) {
uint8_t cur = context->current->dirty_bmap[i];
if (cur != WINDOW_CLEAN) {
if (cur == prev) { /* Same as previous block, incrmnt */
count++;
} else if (prev == WINDOW_CLEAN) { /* Start of run */
offset = i;
count++;
} else { /* Change in streak type */
rc = write_from_window(context, offset, count,
prev);
if (rc < 0) {
return rc;
}
offset = i;
count = 1;
}
} else {
if (prev != WINDOW_CLEAN) { /* End of a streak */
rc = write_from_window(context, offset, count,
prev);
if (rc < 0) {
return rc;
}
offset = 0;
count = 0;
}
}
prev = cur;
}
if (prev != WINDOW_CLEAN) { /* Still the last streak to write */
rc = write_from_window(context, offset, count, prev);
if (rc < 0) {
return rc;
}
}
/* Clear the dirty bytemap since we have written back all changes */
return set_window_bytemap(context, context->current, 0,
context->current->size >>
context->block_size_shift,
WINDOW_CLEAN);
}
/*
* Command: CLOSE_WINDOW
* Close the current window
* NOTE: There is an implicit flush
*
* V1:
* NONE
*
* V2:
* ARGS[0]: FLAGS
*/
static int mbox_handle_close_window(struct mbox_context *context,
union mbox_regs *req, struct mbox_msg *resp)
{
uint8_t flags = 0;
int rc;
/* Close the current window if there is one */
if (context->current) {
/* There is an implicit flush if it was a write window */
if (context->current_is_write) {
rc = mbox_handle_flush_window(context, NULL, NULL);
if (rc < 0) {
MSG_ERR("Couldn't Flush Write Window\n");
return rc;
}
}
if (context->version >= API_VERSION_2) {
flags = req->msg.args[0];
}
/* Host asked for it -> Don't set the BMC Event */
close_current_window(context, NO_BMC_EVENT, flags);
}
return 0;
}
/*
* Command: BMC_EVENT_ACK
* Sent by the host to acknowledge BMC events supplied in mailbox register 15
*
* ARGS[0]: Bitmap of bits to ack (by clearing)
*/
static int mbox_handle_ack(struct mbox_context *context, union mbox_regs *req,
struct mbox_msg *resp)
{
uint8_t bmc_events = req->msg.args[0];
return clr_bmc_events(context, (bmc_events & BMC_EVENT_ACK_MASK),
SET_BMC_EVENT);
}
/*
* check_req_valid() - Check if the given request is a valid mbox request
* @context: The mbox context pointer
* @cmd: The request registers
*
* Return: 0 if request is valid otherwise negative error code
*/
static int check_req_valid(struct mbox_context *context, union mbox_regs *req)
{
uint8_t cmd = req->msg.command;
uint8_t seq = req->msg.seq;
if (cmd > NUM_MBOX_CMDS) {
MSG_ERR("Unknown mbox command: %d\n", cmd);
return -MBOX_R_PARAM_ERROR;
}
if (seq == context->prev_seq && cmd != MBOX_C_GET_MBOX_INFO) {
MSG_ERR("Invalid sequence number: %d\n", seq);
return -MBOX_R_SEQ_ERROR;
}
if (context->state & STATE_SUSPENDED) {
if (cmd != MBOX_C_GET_MBOX_INFO && cmd != MBOX_C_ACK) {
MSG_ERR("Cannot use that cmd while suspended: %d\n",
cmd);
return context->version >= API_VERSION_2 ? -MBOX_R_BUSY
: -MBOX_R_PARAM_ERROR;
}
}
if (!(context->state & MAPS_MEM)) {
if (cmd != MBOX_C_RESET_STATE && cmd != MBOX_C_GET_MBOX_INFO
&& cmd != MBOX_C_ACK) {
MSG_ERR("Must call GET_MBOX_INFO before %d\n", cmd);
return -MBOX_R_PARAM_ERROR;
}
}
return 0;
}
static const mboxd_mbox_handler mbox_handlers[] = {
mbox_handle_reset,
mbox_handle_mbox_info,
mbox_handle_flash_info,
mbox_handle_read_window,
mbox_handle_close_window,
mbox_handle_write_window,
mbox_handle_dirty_window,
mbox_handle_flush_window,
mbox_handle_ack,
mbox_handle_erase_window
};
/*
* handle_mbox_req() - Handle an incoming mbox command request
* @context: The mbox context pointer
* @req: The mbox request message
*
* Return: 0 if handled successfully otherwise negative error code
*/
static int handle_mbox_req(struct mbox_context *context, union mbox_regs *req)
{
struct mbox_msg resp = {
.command = req->msg.command,
.seq = req->msg.seq,
.args = { 0 },
.response = MBOX_R_SUCCESS
};
int rc = 0, len;
MSG_OUT("Got data in with command %d\n", req->msg.command);
rc = check_req_valid(context, req);
if (rc < 0) {
resp.response = -rc;
} else {
/* Commands start at 1 so we have to subtract 1 from the cmd */
rc = mbox_handlers[req->msg.command - 1](context, req, &resp);
if (rc < 0) {
MSG_ERR("Error handling mbox cmd: %d\n",
req->msg.command);
resp.response = -rc;
}
}
context->prev_seq = req->msg.seq;
MSG_OUT("Writing response to MBOX regs: %d\n", resp.response);
len = write(context->fds[MBOX_FD].fd, &resp, sizeof(resp));
if (len < sizeof(resp)) {
MSG_ERR("Didn't write the full response\n");
rc = -errno;
}
return rc;
}
/*
* get_message() - Read an mbox request message from the mbox registers
* @context: The mbox context pointer
* @msg: Where to put the received message
*
* Return: 0 if read successfully otherwise negative error code
*/
static int get_message(struct mbox_context *context, union mbox_regs *msg)
{
int rc;
rc = read(context->fds[MBOX_FD].fd, msg, sizeof(msg->raw));
if (rc < 0) {
MSG_ERR("Couldn't read: %s\n", strerror(errno));
return -errno;
} else if (rc < sizeof(msg->raw)) {
MSG_ERR("Short read: %d expecting %zu\n", rc, sizeof(msg->raw));
return -1;
}
return 0;
}
/*
* dispatch_mbox() - handle an mbox interrupt
* @context: The mbox context pointer
*
* Return: 0 if handled successfully otherwise negative error code
*/
int dispatch_mbox(struct mbox_context *context)
{
int rc = 0;
union mbox_regs req = { 0 };
assert(context);
MSG_OUT("Dispatched to mbox\n");
rc = get_message(context, &req);
if (rc) {
return rc;
}
return handle_mbox_req(context, &req);
}
int init_mbox_dev(struct mbox_context *context)
{
int fd;
/* Open MBOX Device */
fd = open(MBOX_HOST_PATH, O_RDWR | O_NONBLOCK);
if (fd < 0) {
MSG_ERR("Couldn't open %s with flags O_RDWR: %s\n",
MBOX_HOST_PATH, strerror(errno));
return -errno;
}
context->fds[MBOX_FD].fd = fd;
return 0;
}
void free_mbox_dev(struct mbox_context *context)
{
close(context->fds[MBOX_FD].fd);
}