1 /* 2 * ISHTP DMA I/F functions 3 * 4 * Copyright (c) 2003-2016, Intel Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 */ 16 17 #include <linux/slab.h> 18 #include <linux/sched.h> 19 #include <linux/wait.h> 20 #include <linux/delay.h> 21 #include <linux/dma-mapping.h> 22 #include "ishtp-dev.h" 23 #include "client.h" 24 25 /** 26 * ishtp_cl_alloc_dma_buf() - Allocate DMA RX and TX buffer 27 * @dev: ishtp device 28 * 29 * Allocate RX and TX DMA buffer once during bus setup. 30 * It allocates 1MB, RX and TX DMA buffer, which are divided 31 * into slots. 32 */ 33 void ishtp_cl_alloc_dma_buf(struct ishtp_device *dev) 34 { 35 dma_addr_t h; 36 37 if (dev->ishtp_host_dma_tx_buf) 38 return; 39 40 dev->ishtp_host_dma_tx_buf_size = 1024*1024; 41 dev->ishtp_host_dma_rx_buf_size = 1024*1024; 42 43 /* Allocate Tx buffer and init usage bitmap */ 44 dev->ishtp_host_dma_tx_buf = dma_alloc_coherent(dev->devc, 45 dev->ishtp_host_dma_tx_buf_size, 46 &h, GFP_KERNEL); 47 if (dev->ishtp_host_dma_tx_buf) 48 dev->ishtp_host_dma_tx_buf_phys = h; 49 50 dev->ishtp_dma_num_slots = dev->ishtp_host_dma_tx_buf_size / 51 DMA_SLOT_SIZE; 52 53 dev->ishtp_dma_tx_map = kcalloc(dev->ishtp_dma_num_slots, 54 sizeof(uint8_t), 55 GFP_KERNEL); 56 spin_lock_init(&dev->ishtp_dma_tx_lock); 57 58 /* Allocate Rx buffer */ 59 dev->ishtp_host_dma_rx_buf = dma_alloc_coherent(dev->devc, 60 dev->ishtp_host_dma_rx_buf_size, 61 &h, GFP_KERNEL); 62 63 if (dev->ishtp_host_dma_rx_buf) 64 dev->ishtp_host_dma_rx_buf_phys = h; 65 } 66 67 /** 68 * ishtp_cl_free_dma_buf() - Free DMA RX and TX buffer 69 * @dev: ishtp device 70 * 71 * Free DMA buffer when all clients are released. This is 72 * only happens during error path in ISH built in driver 73 * model 74 */ 75 void ishtp_cl_free_dma_buf(struct ishtp_device *dev) 76 { 77 dma_addr_t h; 78 79 if (dev->ishtp_host_dma_tx_buf) { 80 h = dev->ishtp_host_dma_tx_buf_phys; 81 dma_free_coherent(dev->devc, dev->ishtp_host_dma_tx_buf_size, 82 dev->ishtp_host_dma_tx_buf, h); 83 } 84 85 if (dev->ishtp_host_dma_rx_buf) { 86 h = dev->ishtp_host_dma_rx_buf_phys; 87 dma_free_coherent(dev->devc, dev->ishtp_host_dma_rx_buf_size, 88 dev->ishtp_host_dma_rx_buf, h); 89 } 90 91 kfree(dev->ishtp_dma_tx_map); 92 dev->ishtp_host_dma_tx_buf = NULL; 93 dev->ishtp_host_dma_rx_buf = NULL; 94 dev->ishtp_dma_tx_map = NULL; 95 } 96 97 /* 98 * ishtp_cl_get_dma_send_buf() - Get a DMA memory slot 99 * @dev: ishtp device 100 * @size: Size of memory to get 101 * 102 * Find and return free address of "size" bytes in dma tx buffer. 103 * the function will mark this address as "in-used" memory. 104 * 105 * Return: NULL when no free buffer else a buffer to copy 106 */ 107 void *ishtp_cl_get_dma_send_buf(struct ishtp_device *dev, 108 uint32_t size) 109 { 110 unsigned long flags; 111 int i, j, free; 112 /* additional slot is needed if there is rem */ 113 int required_slots = (size / DMA_SLOT_SIZE) 114 + 1 * (size % DMA_SLOT_SIZE != 0); 115 116 spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags); 117 for (i = 0; i <= (dev->ishtp_dma_num_slots - required_slots); i++) { 118 free = 1; 119 for (j = 0; j < required_slots; j++) 120 if (dev->ishtp_dma_tx_map[i+j]) { 121 free = 0; 122 i += j; 123 break; 124 } 125 if (free) { 126 /* mark memory as "caught" */ 127 for (j = 0; j < required_slots; j++) 128 dev->ishtp_dma_tx_map[i+j] = 1; 129 spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags); 130 return (i * DMA_SLOT_SIZE) + 131 (unsigned char *)dev->ishtp_host_dma_tx_buf; 132 } 133 } 134 spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags); 135 dev_err(dev->devc, "No free DMA buffer to send msg\n"); 136 return NULL; 137 } 138 139 /* 140 * ishtp_cl_release_dma_acked_mem() - Release DMA memory slot 141 * @dev: ishtp device 142 * @msg_addr: message address of slot 143 * @size: Size of memory to get 144 * 145 * Release_dma_acked_mem - returnes the acked memory to free list. 146 * (from msg_addr, size bytes long) 147 */ 148 void ishtp_cl_release_dma_acked_mem(struct ishtp_device *dev, 149 void *msg_addr, 150 uint8_t size) 151 { 152 unsigned long flags; 153 int acked_slots = (size / DMA_SLOT_SIZE) 154 + 1 * (size % DMA_SLOT_SIZE != 0); 155 int i, j; 156 157 if ((msg_addr - dev->ishtp_host_dma_tx_buf) % DMA_SLOT_SIZE) { 158 dev_err(dev->devc, "Bad DMA Tx ack address\n"); 159 return; 160 } 161 162 i = (msg_addr - dev->ishtp_host_dma_tx_buf) / DMA_SLOT_SIZE; 163 spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags); 164 for (j = 0; j < acked_slots; j++) { 165 if ((i + j) >= dev->ishtp_dma_num_slots || 166 !dev->ishtp_dma_tx_map[i+j]) { 167 /* no such slot, or memory is already free */ 168 spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags); 169 dev_err(dev->devc, "Bad DMA Tx ack address\n"); 170 return; 171 } 172 dev->ishtp_dma_tx_map[i+j] = 0; 173 } 174 spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags); 175 } 176