176 lines
4.8 KiB
C
176 lines
4.8 KiB
C
/*
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* ISHTP DMA I/F functions
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*
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* Copyright (c) 2003-2016, Intel Corporation.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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*/
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#include <linux/slab.h>
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#include <linux/sched.h>
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#include <linux/wait.h>
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#include <linux/delay.h>
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#include <linux/dma-mapping.h>
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#include "ishtp-dev.h"
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#include "client.h"
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/**
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* ishtp_cl_alloc_dma_buf() - Allocate DMA RX and TX buffer
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* @dev: ishtp device
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*
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* Allocate RX and TX DMA buffer once during bus setup.
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* It allocates 1MB, RX and TX DMA buffer, which are divided
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* into slots.
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*/
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void ishtp_cl_alloc_dma_buf(struct ishtp_device *dev)
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{
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dma_addr_t h;
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if (dev->ishtp_host_dma_tx_buf)
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return;
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dev->ishtp_host_dma_tx_buf_size = 1024*1024;
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dev->ishtp_host_dma_rx_buf_size = 1024*1024;
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/* Allocate Tx buffer and init usage bitmap */
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dev->ishtp_host_dma_tx_buf = dma_alloc_coherent(dev->devc,
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dev->ishtp_host_dma_tx_buf_size,
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&h, GFP_KERNEL);
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if (dev->ishtp_host_dma_tx_buf)
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dev->ishtp_host_dma_tx_buf_phys = h;
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dev->ishtp_dma_num_slots = dev->ishtp_host_dma_tx_buf_size /
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DMA_SLOT_SIZE;
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dev->ishtp_dma_tx_map = kcalloc(dev->ishtp_dma_num_slots,
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sizeof(uint8_t),
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GFP_KERNEL);
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spin_lock_init(&dev->ishtp_dma_tx_lock);
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/* Allocate Rx buffer */
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dev->ishtp_host_dma_rx_buf = dma_alloc_coherent(dev->devc,
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dev->ishtp_host_dma_rx_buf_size,
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&h, GFP_KERNEL);
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if (dev->ishtp_host_dma_rx_buf)
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dev->ishtp_host_dma_rx_buf_phys = h;
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}
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/**
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* ishtp_cl_free_dma_buf() - Free DMA RX and TX buffer
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* @dev: ishtp device
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*
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* Free DMA buffer when all clients are released. This is
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* only happens during error path in ISH built in driver
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* model
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*/
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void ishtp_cl_free_dma_buf(struct ishtp_device *dev)
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{
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dma_addr_t h;
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if (dev->ishtp_host_dma_tx_buf) {
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h = dev->ishtp_host_dma_tx_buf_phys;
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dma_free_coherent(dev->devc, dev->ishtp_host_dma_tx_buf_size,
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dev->ishtp_host_dma_tx_buf, h);
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}
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if (dev->ishtp_host_dma_rx_buf) {
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h = dev->ishtp_host_dma_rx_buf_phys;
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dma_free_coherent(dev->devc, dev->ishtp_host_dma_rx_buf_size,
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dev->ishtp_host_dma_rx_buf, h);
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}
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kfree(dev->ishtp_dma_tx_map);
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dev->ishtp_host_dma_tx_buf = NULL;
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dev->ishtp_host_dma_rx_buf = NULL;
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dev->ishtp_dma_tx_map = NULL;
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}
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/*
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* ishtp_cl_get_dma_send_buf() - Get a DMA memory slot
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* @dev: ishtp device
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* @size: Size of memory to get
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*
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* Find and return free address of "size" bytes in dma tx buffer.
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* the function will mark this address as "in-used" memory.
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*
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* Return: NULL when no free buffer else a buffer to copy
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*/
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void *ishtp_cl_get_dma_send_buf(struct ishtp_device *dev,
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uint32_t size)
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{
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unsigned long flags;
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int i, j, free;
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/* additional slot is needed if there is rem */
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int required_slots = (size / DMA_SLOT_SIZE)
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+ 1 * (size % DMA_SLOT_SIZE != 0);
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spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags);
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for (i = 0; i <= (dev->ishtp_dma_num_slots - required_slots); i++) {
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free = 1;
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for (j = 0; j < required_slots; j++)
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if (dev->ishtp_dma_tx_map[i+j]) {
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free = 0;
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i += j;
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break;
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}
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if (free) {
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/* mark memory as "caught" */
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for (j = 0; j < required_slots; j++)
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dev->ishtp_dma_tx_map[i+j] = 1;
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spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);
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return (i * DMA_SLOT_SIZE) +
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(unsigned char *)dev->ishtp_host_dma_tx_buf;
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}
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}
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spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);
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dev_err(dev->devc, "No free DMA buffer to send msg\n");
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return NULL;
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}
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/*
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* ishtp_cl_release_dma_acked_mem() - Release DMA memory slot
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* @dev: ishtp device
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* @msg_addr: message address of slot
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* @size: Size of memory to get
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*
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* Release_dma_acked_mem - returnes the acked memory to free list.
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* (from msg_addr, size bytes long)
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*/
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void ishtp_cl_release_dma_acked_mem(struct ishtp_device *dev,
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void *msg_addr,
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uint8_t size)
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{
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unsigned long flags;
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int acked_slots = (size / DMA_SLOT_SIZE)
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+ 1 * (size % DMA_SLOT_SIZE != 0);
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int i, j;
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if ((msg_addr - dev->ishtp_host_dma_tx_buf) % DMA_SLOT_SIZE) {
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dev_err(dev->devc, "Bad DMA Tx ack address\n");
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return;
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}
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i = (msg_addr - dev->ishtp_host_dma_tx_buf) / DMA_SLOT_SIZE;
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spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags);
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for (j = 0; j < acked_slots; j++) {
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if ((i + j) >= dev->ishtp_dma_num_slots ||
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!dev->ishtp_dma_tx_map[i+j]) {
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/* no such slot, or memory is already free */
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spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);
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dev_err(dev->devc, "Bad DMA Tx ack address\n");
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return;
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}
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dev->ishtp_dma_tx_map[i+j] = 0;
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}
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spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);
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}
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