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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 | // 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); 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; } 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); } |