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/* arch/arm/mach-msm/smp2p_loopback.c
*
* Copyright (c) 2013, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* 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.
*/
#include <linux/debugfs.h>
#include <linux/list.h>
#include <linux/ctype.h>
#include <linux/jiffies.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <linux/termios.h>
#include <linux/module.h>
#include <linux/remote_spinlock.h>
#include "smem_private.h"
#include "smp2p_private.h"
/**
* struct smp2p_loopback_ctx - Representation of remote loopback object.
*
* @proc_id: Processor id of the processor that sends the loopback commands.
* @out: Handle to the smem entry structure for providing the response.
* @out_nb: Notifies the opening of local entry.
* @out_is_active: Outbound entry events should be processed.
* @in_nb: Notifies changes in the remote entry.
* @in_is_active: Inbound entry events should be processed.
* @rmt_lpb_work: Work item that handles the incoming loopback commands.
* @rmt_cmd: Structure that holds the current and previous value of the entry.
*/
struct smp2p_loopback_ctx {
int proc_id;
struct msm_smp2p_out *out;
struct notifier_block out_nb;
bool out_is_active;
struct notifier_block in_nb;
bool in_is_active;
struct work_struct rmt_lpb_work;
struct msm_smp2p_update_notif rmt_cmd;
};
static struct smp2p_loopback_ctx remote_loopback[SMP2P_NUM_PROCS];
static struct msm_smp2p_remote_mock remote_mock;
/**
* remote_spinlock_test - Handles remote spinlock test.
*
* @ctx: Loopback context
*/
static void remote_spinlock_test(struct smp2p_loopback_ctx *ctx)
{
uint32_t test_request;
uint32_t test_response;
unsigned long flags;
int n;
unsigned lock_count = 0;
remote_spinlock_t *smem_spinlock;
test_request = 0x0;
SMP2P_SET_RMT_CMD_TYPE_REQ(test_request);
smem_spinlock = smem_get_remote_spinlock();
if (!smem_spinlock) {
pr_err("%s: unable to get remote spinlock\n", __func__);
return;
}
for (;;) {
remote_spin_lock_irqsave(smem_spinlock, flags);
++lock_count;
SMP2P_SET_RMT_CMD(test_request, SMP2P_LB_CMD_RSPIN_LOCKED);
(void)msm_smp2p_out_write(ctx->out, test_request);
for (n = 0; n < 10000; ++n) {
(void)msm_smp2p_in_read(ctx->proc_id,
"smp2p", &test_response);
test_response = SMP2P_GET_RMT_CMD(test_response);
if (test_response == SMP2P_LB_CMD_RSPIN_END)
break;
if (test_response != SMP2P_LB_CMD_RSPIN_UNLOCKED)
SMP2P_ERR("%s: invalid spinlock command %x\n",
__func__, test_response);
}
if (test_response == SMP2P_LB_CMD_RSPIN_END) {
SMP2P_SET_RMT_CMD_TYPE_RESP(test_request);
SMP2P_SET_RMT_CMD(test_request,
SMP2P_LB_CMD_RSPIN_END);
SMP2P_SET_RMT_DATA(test_request, lock_count);
(void)msm_smp2p_out_write(ctx->out, test_request);
break;
}
SMP2P_SET_RMT_CMD(test_request, SMP2P_LB_CMD_RSPIN_UNLOCKED);
(void)msm_smp2p_out_write(ctx->out, test_request);
remote_spin_unlock_irqrestore(smem_spinlock, flags);
}
remote_spin_unlock_irqrestore(smem_spinlock, flags);
}
/**
* smp2p_rmt_lpb_worker - Handles incoming remote loopback commands.
*
* @work: Work Item scheduled to handle the incoming commands.
*/
static void smp2p_rmt_lpb_worker(struct work_struct *work)
{
struct smp2p_loopback_ctx *ctx;
int lpb_cmd;
int lpb_cmd_type;
int lpb_data;
ctx = container_of(work, struct smp2p_loopback_ctx, rmt_lpb_work);
if (!ctx->in_is_active || !ctx->out_is_active)
return;
if (ctx->rmt_cmd.previous_value == ctx->rmt_cmd.current_value)
return;
lpb_cmd_type = SMP2P_GET_RMT_CMD_TYPE(ctx->rmt_cmd.current_value);
lpb_cmd = SMP2P_GET_RMT_CMD(ctx->rmt_cmd.current_value);
lpb_data = SMP2P_GET_RMT_DATA(ctx->rmt_cmd.current_value);
if (lpb_cmd & SMP2P_RLPB_IGNORE)
return;
switch (lpb_cmd) {
case SMP2P_LB_CMD_NOOP:
/* Do nothing */
break;
case SMP2P_LB_CMD_ECHO:
SMP2P_SET_RMT_CMD_TYPE(ctx->rmt_cmd.current_value, 0);
SMP2P_SET_RMT_DATA(ctx->rmt_cmd.current_value,
lpb_data);
(void)msm_smp2p_out_write(ctx->out,
ctx->rmt_cmd.current_value);
break;
case SMP2P_LB_CMD_CLEARALL:
ctx->rmt_cmd.current_value = 0;
(void)msm_smp2p_out_write(ctx->out,
ctx->rmt_cmd.current_value);
break;
case SMP2P_LB_CMD_PINGPONG:
SMP2P_SET_RMT_CMD_TYPE(ctx->rmt_cmd.current_value, 0);
if (lpb_data) {
lpb_data--;
SMP2P_SET_RMT_DATA(ctx->rmt_cmd.current_value,
lpb_data);
(void)msm_smp2p_out_write(ctx->out,
ctx->rmt_cmd.current_value);
}
break;
case SMP2P_LB_CMD_RSPIN_START:
remote_spinlock_test(ctx);
break;
case SMP2P_LB_CMD_RSPIN_LOCKED:
case SMP2P_LB_CMD_RSPIN_UNLOCKED:
case SMP2P_LB_CMD_RSPIN_END:
/* not used for remote spinlock test */
break;
default:
SMP2P_DBG("%s: Unknown loopback command %x\n",
__func__, lpb_cmd);
break;
}
}
/**
* smp2p_rmt_in_edge_notify - Schedules a work item to handle the commands.
*
* @nb: Notifier block, this is called when the value in remote entry changes.
* @event: Takes value SMP2P_ENTRY_UPDATE or SMP2P_OPEN based on the event.
* @data: Consists of previous and current value in case of entry update.
* @returns: 0 for success (return value required for notifier chains).
*/
static int smp2p_rmt_in_edge_notify(struct notifier_block *nb,
unsigned long event, void *data)
{
struct smp2p_loopback_ctx *ctx;
if (!(event == SMP2P_ENTRY_UPDATE || event == SMP2P_OPEN))
return 0;
ctx = container_of(nb, struct smp2p_loopback_ctx, in_nb);
if (data && ctx->in_is_active) {
ctx->rmt_cmd =
*(struct msm_smp2p_update_notif *)data;
schedule_work(&ctx->rmt_lpb_work);
}
return 0;
}
/**
* smp2p_rmt_out_edge_notify - Notifies on the opening of the outbound entry.
*
* @nb: Notifier block, this is called when the local entry is open.
* @event: Takes on value SMP2P_OPEN when the local entry is open.
* @data: Consist of current value of the remote entry, if entry is open.
* @returns: 0 for success (return value required for notifier chains).
*/
static int smp2p_rmt_out_edge_notify(struct notifier_block *nb,
unsigned long event, void *data)
{
struct smp2p_loopback_ctx *ctx;
ctx = container_of(nb, struct smp2p_loopback_ctx, out_nb);
if (event == SMP2P_OPEN)
SMP2P_DBG("%s: 'smp2p':%d opened\n", __func__,
ctx->proc_id);
return 0;
}
/**
* msm_smp2p_init_rmt_lpb - Initializes the remote loopback object.
*
* @ctx: Pointer to remote loopback object that needs to be initialized.
* @pid: Processor id of the processor that is sending the commands.
* @entry: Name of the entry that needs to be opened locally.
* @returns: 0 on success, standard Linux error code otherwise.
*/
static int msm_smp2p_init_rmt_lpb(struct smp2p_loopback_ctx *ctx,
int pid, const char *entry)
{
int ret = 0;
int tmp;
if (!ctx || !entry || pid > SMP2P_NUM_PROCS)
return -EINVAL;
ctx->in_nb.notifier_call = smp2p_rmt_in_edge_notify;
ctx->out_nb.notifier_call = smp2p_rmt_out_edge_notify;
ctx->proc_id = pid;
ctx->in_is_active = true;
ctx->out_is_active = true;
tmp = msm_smp2p_out_open(pid, entry, &ctx->out_nb,
&ctx->out);
if (tmp) {
SMP2P_ERR("%s: open failed outbound entry '%s':%d - ret %d\n",
__func__, entry, pid, tmp);
ret = tmp;
}
tmp = msm_smp2p_in_register(ctx->proc_id,
SMP2P_RLPB_ENTRY_NAME,
&ctx->in_nb);
if (tmp) {
SMP2P_ERR("%s: unable to open inbound entry '%s':%d - ret %d\n",
__func__, entry, pid, tmp);
ret = tmp;
}
return ret;
}
/**
* msm_smp2p_init_rmt_lpb_proc - Wrapper over msm_smp2p_init_rmt_lpb
*
* @remote_pid: Processor ID of the processor that sends loopback command.
* @returns: Pointer to outbound entry handle.
*/
void *msm_smp2p_init_rmt_lpb_proc(int remote_pid)
{
int tmp;
void *ret = NULL;
tmp = msm_smp2p_init_rmt_lpb(&remote_loopback[remote_pid],
remote_pid, SMP2P_RLPB_ENTRY_NAME);
if (!tmp)
ret = remote_loopback[remote_pid].out;
return ret;
}
EXPORT_SYMBOL(msm_smp2p_init_rmt_lpb_proc);
/**
* msm_smp2p_deinit_rmt_lpb_proc - Unregister support for remote processor.
*
* @remote_pid: Processor ID of the remote system.
* @returns: 0 on success, standard Linux error code otherwise.
*
* Unregister loopback support for remote processor.
*/
int msm_smp2p_deinit_rmt_lpb_proc(int remote_pid)
{
int ret = 0;
int tmp;
struct smp2p_loopback_ctx *ctx;
if (remote_pid >= SMP2P_NUM_PROCS)
return -EINVAL;
ctx = &remote_loopback[remote_pid];
/* abort any pending notifications */
remote_loopback[remote_pid].out_is_active = false;
remote_loopback[remote_pid].in_is_active = false;
flush_work(&ctx->rmt_lpb_work);
/* unregister entries */
tmp = msm_smp2p_out_close(&remote_loopback[remote_pid].out);
remote_loopback[remote_pid].out = NULL;
if (tmp) {
SMP2P_ERR("%s: outbound 'smp2p':%d close failed %d\n",
__func__, remote_pid, tmp);
ret = tmp;
}
tmp = msm_smp2p_in_unregister(remote_pid,
SMP2P_RLPB_ENTRY_NAME, &remote_loopback[remote_pid].in_nb);
if (tmp) {
SMP2P_ERR("%s: inbound 'smp2p':%d close failed %d\n",
__func__, remote_pid, tmp);
ret = tmp;
}
return ret;
}
EXPORT_SYMBOL(msm_smp2p_deinit_rmt_lpb_proc);
/**
* msm_smp2p_set_remote_mock_exists - Sets the remote mock configuration.
*
* @item_exists: true = Remote mock SMEM item exists
*
* This is used in the testing environment to simulate the existence of the
* remote smem item in order to test the negotiation algorithm.
*/
void msm_smp2p_set_remote_mock_exists(bool item_exists)
{
remote_mock.item_exists = item_exists;
}
EXPORT_SYMBOL(msm_smp2p_set_remote_mock_exists);
/**
* msm_smp2p_get_remote_mock - Get remote mock object.
*
* @returns: Point to the remote mock object.
*/
void *msm_smp2p_get_remote_mock(void)
{
return &remote_mock;
}
EXPORT_SYMBOL(msm_smp2p_get_remote_mock);
/**
* msm_smp2p_get_remote_mock_smem_item - Returns a pointer to remote item.
*
* @size: Size of item.
* @returns: Pointer to mock remote smem item.
*/
void *msm_smp2p_get_remote_mock_smem_item(uint32_t *size)
{
void *ptr = NULL;
if (remote_mock.item_exists) {
*size = sizeof(remote_mock.remote_item);
ptr = &(remote_mock.remote_item);
}
return ptr;
}
EXPORT_SYMBOL(msm_smp2p_get_remote_mock_smem_item);
/**
* smp2p_remote_mock_rx_interrupt - Triggers receive interrupt for mock proc.
*
* @returns: 0 for success
*
* This function simulates the receiving of interrupt by the mock remote
* processor in a testing environment.
*/
int smp2p_remote_mock_rx_interrupt(void)
{
remote_mock.rx_interrupt_count++;
if (remote_mock.initialized)
complete(&remote_mock.cb_completion);
return 0;
}
EXPORT_SYMBOL(smp2p_remote_mock_rx_interrupt);
/**
* smp2p_remote_mock_tx_interrupt - Calls the SMP2P interrupt handler.
*
* This function calls the interrupt handler of the Apps processor to simulate
* receiving interrupts from a remote processor.
*/
static void smp2p_remote_mock_tx_interrupt(void)
{
msm_smp2p_interrupt_handler(SMP2P_REMOTE_MOCK_PROC);
}
/**
* smp2p_remote_mock_init - Initialize the remote mock and loopback objects.
*
* @returns: 0 for success
*/
static int __init smp2p_remote_mock_init(void)
{
int i;
smp2p_init_header(&remote_mock.remote_item.header,
SMP2P_REMOTE_MOCK_PROC, SMP2P_APPS_PROC,
0, 0);
remote_mock.rx_interrupt_count = 0;
remote_mock.rx_interrupt = smp2p_remote_mock_rx_interrupt;
remote_mock.tx_interrupt = smp2p_remote_mock_tx_interrupt;
remote_mock.item_exists = false;
init_completion(&remote_mock.cb_completion);
remote_mock.initialized = true;
for (i = 0; i < SMP2P_NUM_PROCS; i++) {
INIT_WORK(&(remote_loopback[i].rmt_lpb_work),
smp2p_rmt_lpb_worker);
if (i == SMP2P_REMOTE_MOCK_PROC)
/* do not register loopback for remote mock proc */
continue;
msm_smp2p_init_rmt_lpb(&remote_loopback[i],
i, SMP2P_RLPB_ENTRY_NAME);
}
return 0;
}
module_init(smp2p_remote_mock_init);