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// SPDX-License-Identifier: GPL-2.0-only
/*
* ISHTP DMA I/F functions
*
* Copyright (c) 2003-2016, Intel Corporation.
*/
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include "ishtp-dev.h"
#include "client.h"
/**
* ishtp_cl_alloc_dma_buf() - Allocate DMA RX and TX buffer
* @dev: ishtp device
*
* Allocate RX and TX DMA buffer once during bus setup.
* It allocates 1MB, RX and TX DMA buffer, which are divided
* into slots.
*/
void ishtp_cl_alloc_dma_buf(struct ishtp_device *dev)
{
dma_addr_t h;
if (dev->ishtp_host_dma_tx_buf)
return;
dev->ishtp_host_dma_tx_buf_size = 1024*1024;
dev->ishtp_host_dma_rx_buf_size = 1024*1024;
/* Allocate Tx buffer and init usage bitmap */
dev->ishtp_host_dma_tx_buf = dma_alloc_coherent(dev->devc,
dev->ishtp_host_dma_tx_buf_size,
&h, GFP_KERNEL);
if (dev->ishtp_host_dma_tx_buf)
dev->ishtp_host_dma_tx_buf_phys = h;
dev->ishtp_dma_num_slots = dev->ishtp_host_dma_tx_buf_size /
DMA_SLOT_SIZE;
dev->ishtp_dma_tx_map = kcalloc(dev->ishtp_dma_num_slots,
sizeof(uint8_t),
GFP_KERNEL);
spin_lock_init(&dev->ishtp_dma_tx_lock);
/* Allocate Rx buffer */
dev->ishtp_host_dma_rx_buf = dma_alloc_coherent(dev->devc,
dev->ishtp_host_dma_rx_buf_size,
&h, GFP_KERNEL);
if (dev->ishtp_host_dma_rx_buf)
dev->ishtp_host_dma_rx_buf_phys = h;
}
/**
* ishtp_cl_free_dma_buf() - Free DMA RX and TX buffer
* @dev: ishtp device
*
* Free DMA buffer when all clients are released. This is
* only happens during error path in ISH built in driver
* model
*/
void ishtp_cl_free_dma_buf(struct ishtp_device *dev)
{
dma_addr_t h;
if (dev->ishtp_host_dma_tx_buf) {
h = dev->ishtp_host_dma_tx_buf_phys;
dma_free_coherent(dev->devc, dev->ishtp_host_dma_tx_buf_size,
dev->ishtp_host_dma_tx_buf, h);
}
if (dev->ishtp_host_dma_rx_buf) {
h = dev->ishtp_host_dma_rx_buf_phys;
dma_free_coherent(dev->devc, dev->ishtp_host_dma_rx_buf_size,
dev->ishtp_host_dma_rx_buf, h);
}
kfree(dev->ishtp_dma_tx_map);
dev->ishtp_host_dma_tx_buf = NULL;
dev->ishtp_host_dma_rx_buf = NULL;
dev->ishtp_dma_tx_map = NULL;
}
/*
* ishtp_cl_get_dma_send_buf() - Get a DMA memory slot
* @dev: ishtp device
* @size: Size of memory to get
*
* Find and return free address of "size" bytes in dma tx buffer.
* the function will mark this address as "in-used" memory.
*
* Return: NULL when no free buffer else a buffer to copy
*/
void *ishtp_cl_get_dma_send_buf(struct ishtp_device *dev,
uint32_t size)
{
unsigned long flags;
int i, j, free;
/* additional slot is needed if there is rem */
int required_slots = (size / DMA_SLOT_SIZE)
+ 1 * (size % DMA_SLOT_SIZE != 0);
if (!dev->ishtp_dma_tx_map) {
dev_err(dev->devc, "Fail to allocate Tx map\n");
return NULL;
}
spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags);
for (i = 0; i <= (dev->ishtp_dma_num_slots - required_slots); i++) {
free = 1;
for (j = 0; j < required_slots; j++)
if (dev->ishtp_dma_tx_map[i+j]) {
free = 0;
i += j;
break;
}
if (free) {
/* mark memory as "caught" */
for (j = 0; j < required_slots; j++)
dev->ishtp_dma_tx_map[i+j] = 1;
spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);
return (i * DMA_SLOT_SIZE) +
(unsigned char *)dev->ishtp_host_dma_tx_buf;
}
}
spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);
dev_err(dev->devc, "No free DMA buffer to send msg\n");
return NULL;
}
/*
* ishtp_cl_release_dma_acked_mem() - Release DMA memory slot
* @dev: ishtp device
* @msg_addr: message address of slot
* @size: Size of memory to get
*
* Release_dma_acked_mem - returnes the acked memory to free list.
* (from msg_addr, size bytes long)
*/
void ishtp_cl_release_dma_acked_mem(struct ishtp_device *dev,
void *msg_addr,
uint8_t size)
{
unsigned long flags;
int acked_slots = (size / DMA_SLOT_SIZE)
+ 1 * (size % DMA_SLOT_SIZE != 0);
int i, j;
if ((msg_addr - dev->ishtp_host_dma_tx_buf) % DMA_SLOT_SIZE) {
dev_err(dev->devc, "Bad DMA Tx ack address\n");
return;
}
if (!dev->ishtp_dma_tx_map) {
dev_err(dev->devc, "Fail to allocate Tx map\n");
return;
}
i = (msg_addr - dev->ishtp_host_dma_tx_buf) / DMA_SLOT_SIZE;
spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags);
for (j = 0; j < acked_slots; j++) {
if ((i + j) >= dev->ishtp_dma_num_slots ||
!dev->ishtp_dma_tx_map[i+j]) {
/* no such slot, or memory is already free */
spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);
dev_err(dev->devc, "Bad DMA Tx ack address\n");
return;
}
dev->ishtp_dma_tx_map[i+j] = 0;
}
spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);
}
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