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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * ISHTP DMA I/F functions4 *5 * Copyright (c) 2003-2016, Intel Corporation.6 */7 8#include <linux/slab.h>9#include <linux/sched.h>10#include <linux/wait.h>11#include <linux/delay.h>12#include <linux/dma-mapping.h>13#include "ishtp-dev.h"14#include "client.h"15 16/**17 * ishtp_cl_alloc_dma_buf() - Allocate DMA RX and TX buffer18 * @dev: ishtp device19 *20 * Allocate RX and TX DMA buffer once during bus setup.21 * It allocates 1MB, RX and TX DMA buffer, which are divided22 * into slots.23 */24void ishtp_cl_alloc_dma_buf(struct ishtp_device *dev)25{26 dma_addr_t h;27 28 if (dev->ishtp_host_dma_tx_buf)29 return;30 31 dev->ishtp_host_dma_tx_buf_size = 1024*1024;32 dev->ishtp_host_dma_rx_buf_size = 1024*1024;33 34 /* Allocate Tx buffer and init usage bitmap */35 dev->ishtp_host_dma_tx_buf = dma_alloc_coherent(dev->devc,36 dev->ishtp_host_dma_tx_buf_size,37 &h, GFP_KERNEL);38 if (dev->ishtp_host_dma_tx_buf)39 dev->ishtp_host_dma_tx_buf_phys = h;40 41 dev->ishtp_dma_num_slots = dev->ishtp_host_dma_tx_buf_size /42 DMA_SLOT_SIZE;43 44 dev->ishtp_dma_tx_map = kcalloc(dev->ishtp_dma_num_slots,45 sizeof(uint8_t),46 GFP_KERNEL);47 spin_lock_init(&dev->ishtp_dma_tx_lock);48 49 /* Allocate Rx buffer */50 dev->ishtp_host_dma_rx_buf = dma_alloc_coherent(dev->devc,51 dev->ishtp_host_dma_rx_buf_size,52 &h, GFP_KERNEL);53 54 if (dev->ishtp_host_dma_rx_buf)55 dev->ishtp_host_dma_rx_buf_phys = h;56}57 58/**59 * ishtp_cl_free_dma_buf() - Free DMA RX and TX buffer60 * @dev: ishtp device61 *62 * Free DMA buffer when all clients are released. This is63 * only happens during error path in ISH built in driver64 * model65 */66void ishtp_cl_free_dma_buf(struct ishtp_device *dev)67{68 dma_addr_t h;69 70 if (dev->ishtp_host_dma_tx_buf) {71 h = dev->ishtp_host_dma_tx_buf_phys;72 dma_free_coherent(dev->devc, dev->ishtp_host_dma_tx_buf_size,73 dev->ishtp_host_dma_tx_buf, h);74 }75 76 if (dev->ishtp_host_dma_rx_buf) {77 h = dev->ishtp_host_dma_rx_buf_phys;78 dma_free_coherent(dev->devc, dev->ishtp_host_dma_rx_buf_size,79 dev->ishtp_host_dma_rx_buf, h);80 }81 82 kfree(dev->ishtp_dma_tx_map);83 dev->ishtp_host_dma_tx_buf = NULL;84 dev->ishtp_host_dma_rx_buf = NULL;85 dev->ishtp_dma_tx_map = NULL;86}87 88/*89 * ishtp_cl_get_dma_send_buf() - Get a DMA memory slot90 * @dev: ishtp device91 * @size: Size of memory to get92 *93 * Find and return free address of "size" bytes in dma tx buffer.94 * the function will mark this address as "in-used" memory.95 *96 * Return: NULL when no free buffer else a buffer to copy97 */98void *ishtp_cl_get_dma_send_buf(struct ishtp_device *dev,99 uint32_t size)100{101 unsigned long flags;102 int i, j, free;103 /* additional slot is needed if there is rem */104 int required_slots = (size / DMA_SLOT_SIZE)105 + 1 * (size % DMA_SLOT_SIZE != 0);106 107 if (!dev->ishtp_dma_tx_map) {108 dev_err(dev->devc, "Fail to allocate Tx map\n");109 return NULL;110 }111 112 spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags);113 for (i = 0; i <= (dev->ishtp_dma_num_slots - required_slots); i++) {114 free = 1;115 for (j = 0; j < required_slots; j++)116 if (dev->ishtp_dma_tx_map[i+j]) {117 free = 0;118 i += j;119 break;120 }121 if (free) {122 /* mark memory as "caught" */123 for (j = 0; j < required_slots; j++)124 dev->ishtp_dma_tx_map[i+j] = 1;125 spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);126 return (i * DMA_SLOT_SIZE) +127 (unsigned char *)dev->ishtp_host_dma_tx_buf;128 }129 }130 spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);131 dev_err(dev->devc, "No free DMA buffer to send msg\n");132 return NULL;133}134 135/*136 * ishtp_cl_release_dma_acked_mem() - Release DMA memory slot137 * @dev: ishtp device138 * @msg_addr: message address of slot139 * @size: Size of memory to get140 *141 * Release_dma_acked_mem - returnes the acked memory to free list.142 * (from msg_addr, size bytes long)143 */144void ishtp_cl_release_dma_acked_mem(struct ishtp_device *dev,145 void *msg_addr,146 uint8_t size)147{148 unsigned long flags;149 int acked_slots = (size / DMA_SLOT_SIZE)150 + 1 * (size % DMA_SLOT_SIZE != 0);151 int i, j;152 153 if ((msg_addr - dev->ishtp_host_dma_tx_buf) % DMA_SLOT_SIZE) {154 dev_err(dev->devc, "Bad DMA Tx ack address\n");155 return;156 }157 158 if (!dev->ishtp_dma_tx_map) {159 dev_err(dev->devc, "Fail to allocate Tx map\n");160 return;161 }162 163 i = (msg_addr - dev->ishtp_host_dma_tx_buf) / DMA_SLOT_SIZE;164 spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags);165 for (j = 0; j < acked_slots; j++) {166 if ((i + j) >= dev->ishtp_dma_num_slots ||167 !dev->ishtp_dma_tx_map[i+j]) {168 /* no such slot, or memory is already free */169 spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);170 dev_err(dev->devc, "Bad DMA Tx ack address\n");171 return;172 }173 dev->ishtp_dma_tx_map[i+j] = 0;174 }175 spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);176}177