ssssenai commented on code in PR #7762: URL: https://github.com/apache/nuttx/pull/7762#discussion_r1052949236
########## arch/xtensa/src/esp32/esp32_himem_chardev.c: ########## @@ -0,0 +1,414 @@ +/**************************************************************************** + * arch/xtensa/src/esp32/esp32_himem_chardev.c + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. The + * ASF licenses this file to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance with the + * License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the + * License for the specific language governing permissions and limitations + * under the License. + * + ****************************************************************************/ + +/**************************************************************************** + * Included Files + ****************************************************************************/ + +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <debug.h> +#include <sys/types.h> +#include <nuttx/list.h> +#include <nuttx/himem/himem.h> +#include <nuttx/semaphore.h> +#include <nuttx/fs/fs.h> +#include <arch/esp32/esp32_himem_chardev.h> +#include "esp32_himem.h" + +/**************************************************************************** + * Pre-processor Definitions + ****************************************************************************/ + +#define HIMEM_UNMAPPED (-1) + +struct himem_chardev +{ + struct list_node node; + size_t size; + esp_himem_handle_t mem_handle; + char name[32]; +}; + +struct himem_chardev_priv +{ + off_t offset; /* himem offset[byte]. update by seek(), read(), write(). */ +}; + +static struct list_node s_himem_chardev_list + = LIST_INITIAL_VALUE(s_himem_chardev_list); +static esp_himem_rangehandle_t s_range_handle; +static sem_t s_sem; +static size_t s_ram_offset; /* used by himem map/unmap */ + +static void *s_himem_ptr; /* mapped himem pointer */ + +static struct file *s_mapped_filep; /* for multi device */ + +/**************************************************************************** + * Priavte Functions + ****************************************************************************/ + +static int himem_chardev_open(struct file *filep) +{ + struct himem_chardev_priv *priv; + + priv = (struct himem_chardev_priv *)malloc( + sizeof(struct himem_chardev_priv)); + if (priv == NULL) + { + _err("Failed to malloc.\n"); + return -1; + } + priv->offset = 0; + filep->f_priv = priv; + + return 0; +} + +static int himem_chardev_close(struct file *filep) +{ + struct himem_chardev_priv *priv = filep->f_priv; + free(priv); + return 0; +} + +static int himem_chardev_read_write(int is_write, + struct file *filep, + char *buffer, + size_t length) +{ + struct himem_chardev *dev + = (struct himem_chardev *)filep->f_inode->i_private; + struct himem_chardev_priv *priv = filep->f_priv; + size_t mmap_offset = 0; + int ret = 0; + size_t i = 0; + size_t copy_size = 0; + void *himem_ptr; + size_t copy_range = 0; + + ret = nxsem_wait(&s_sem); + if (ret != 0) + { + _err("Failed to lock semaphore.\n"); + return -1; + } + + while (i < length) + { + mmap_offset = priv->offset / ESP_HIMEM_BLKSZ; + if (mmap_offset > (dev->size / ESP_HIMEM_BLKSZ)) + { + _err("copy size(%d) over himem phy mem size(%d).\n", + length, dev->size); + goto err; + } + if ((mmap_offset != s_ram_offset) || (s_mapped_filep != filep)) + { + if (s_ram_offset != HIMEM_UNMAPPED) + { + /* already mapped another page */ + + ret = esp_himem_unmap(s_range_handle, + s_himem_ptr, ESP_HIMEM_BLKSZ); + if (ret != 0) + { + _err("Failed to unmap himem.\n"); + goto err; + } + s_ram_offset = HIMEM_UNMAPPED; + s_mapped_filep = NULL; + } + ret = esp_himem_map(dev->mem_handle, s_range_handle, + mmap_offset * ESP_HIMEM_BLKSZ, + 0, ESP_HIMEM_BLKSZ, 0, &s_himem_ptr); + if (ret != 0) + { + _err("Failed to map himem.\n"); + goto err; + } + s_ram_offset = mmap_offset; + s_mapped_filep = filep; + } + himem_ptr = s_himem_ptr + priv->offset % ESP_HIMEM_BLKSZ; + copy_range = ESP_HIMEM_BLKSZ - priv->offset % ESP_HIMEM_BLKSZ; + + /* The case of crossing a phy mem page boundary */ + + if (copy_range < (length - i)) + { + if (is_write) + { + memcpy(himem_ptr, buffer + i, copy_range); + } + else + { + memcpy(buffer + i, himem_ptr, copy_range); + } + priv->offset += copy_range; + copy_size += copy_range; + i += copy_range; + } + else + { + if (is_write) + { + memcpy(himem_ptr, buffer + i, length - i); + } + else + { + memcpy(buffer + i, himem_ptr, length - i); + } + priv->offset += length - i; + copy_size += length - i; + i += length - i; + } + } + nxsem_post(&s_sem); + return (int)(copy_size & INT_MAX); +err: + nxsem_post(&s_sem); + return copy_size > 0 ? (int)(copy_size & INT_MAX) : -1; +} + +static int himem_chardev_read(struct file *filep, + char *dst, size_t length) +{ + return himem_chardev_read_write(0, filep, dst, length); +} + +static int himem_chardev_write(struct file *filep, + const char *src, size_t length) +{ + return himem_chardev_read_write(1, filep, (char *)src, length); +} + +static off_t himem_chardev_seek(struct file *filep, + off_t offset, int whence) +{ + struct himem_chardev_priv *priv = filep->f_priv; + struct himem_chardev *dev = filep->f_inode->i_private; + nxsem_wait(&s_sem); + switch (whence) + { + case SEEK_SET: + priv->offset = offset; + break; + case SEEK_CUR: + priv->offset += offset; + break; + case SEEK_END: + priv->offset = dev->size + offset; + break; + default: + _err("invalid parameter: whence:%d\n", whence); + nxsem_post(&s_sem); + return -1; + } + filep->f_pos = priv->offset; + nxsem_post(&s_sem); + return priv->offset; +} + +static int himem_chardev_ioctl(struct file *filep, + int cmd, unsigned long arg) +{ + return 0; +} + +static const struct file_operations fops = +{ + .open = himem_chardev_open, + .close = himem_chardev_close, + .read = himem_chardev_read, + .write = himem_chardev_write, + .seek = himem_chardev_seek, + .ioctl = himem_chardev_ioctl, +}; + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +int himem_chardev_init(void) +{ + int ret = 0; + ret = esp_himem_init(); + if (ret != 0) + { + _err("Failed to himem init.\n"); + return ret; + } + + ret = esp_himem_alloc_map_range(ESP_HIMEM_BLKSZ, &s_range_handle); /* 32KB */ + if (ret != 0) + { + _err("Failed to alloc himem map.\n"); + return ret; + } + + ret = nxsem_init(&s_sem, 0, 1); + if (ret != 0) + { + _err("Failed to init semaphore.\n"); + esp_himem_free_map_range(s_range_handle); + return ret; + } + + s_ram_offset = HIMEM_UNMAPPED; + s_mapped_filep = NULL; + return ret; +} + +int himem_chardev_exit(void) +{ + int ret = 0; + ret = nxsem_destroy(&s_sem); + if (ret != 0) + { + _err("Failed to destroy semaphore.\n"); + esp_himem_free_map_range(s_range_handle); + return ret; + } + + ret = esp_himem_free_map_range(s_range_handle); + return ret; +} + +int himem_chardev_register(char *name, size_t size) +{ + int ret = 0; + struct himem_chardev *dev; + dev = (struct himem_chardev *)malloc(sizeof(struct himem_chardev)); + if (dev == NULL) + { + _err("Failed to malloc.\n"); + return -1; + } + + /* 32KB Alignment */ + + size_t mod = size % ESP_HIMEM_BLKSZ; + if (mod != 0) + { + size += (ESP_HIMEM_BLKSZ - mod); + } + + dev->size = size; + + strncpy(dev->name, name, 32); + ret = esp_himem_alloc(dev->size, &dev->mem_handle); + if (ret != 0) + { + _err("Failed to alloc himem. size=%d\n", dev->size); + free(dev); + return ret; + } + + ret = register_driver(dev->name, &fops, 0666, dev); + if (ret != 0) + { + _err("Failed to register driver. dev=%s\n", dev->name); + esp_himem_free(dev->mem_handle); + free(dev); + return ret; + } + + ret = nxsem_wait(&s_sem); + if (ret != 0) + { + _err("Failed to lock semaphore.\n"); + unregister_driver(dev->name); + esp_himem_free(dev->mem_handle); + free(dev); + return ret; + } + + list_add_tail(&s_himem_chardev_list, &dev->node); Review Comment: Because it is necessary to dynamically record and store the information of multiple character devices -- This is an automated message from the Apache Git Service. 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