diff options
Diffstat (limited to 'drivers/misc/issei/dma.c')
| -rw-r--r-- | drivers/misc/issei/dma.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/drivers/misc/issei/dma.c b/drivers/misc/issei/dma.c new file mode 100644 index 000000000000..457d28f31c06 --- /dev/null +++ b/drivers/misc/issei/dma.c @@ -0,0 +1,154 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2023-2026 Intel Corporation */ +#include <linux/dev_printk.h> +#include <linux/dma-mapping.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/timekeeping.h> + +#include "issei_dev.h" +#include "hw_msg.h" + +static inline size_t __issei_dma_size(const struct issei_dma *dma) +{ + return dma->length.h2f + dma->length.f2h + dma->length.ctl; +} + +/** + * issei_dmam_setup - setup DMA buffer and clean it + * @idev: issei device object + * + * Return: 0 on success, <0 on failures + */ +int issei_dmam_setup(struct issei_device *idev) +{ + struct issei_dma *dma = &idev->dma; + size_t size; + + size = __issei_dma_size(dma); + if (!size) + return -EINVAL; + + if (!dma->vaddr) + dma->vaddr = dmam_alloc_coherent(idev->parent, size, &dma->daddr, + GFP_KERNEL | __GFP_ZERO); + if (dma->vaddr) + memset(dma->vaddr, 0, size); + return dma->vaddr ? 0 : -ENOMEM; +} + +static inline struct control_buffer *__dma_get_ctl_buf(struct issei_dma *dma) +{ + return dma->vaddr + dma->length.h2f + dma->length.f2h; +} + +static bool __issei_dma_is_read_busy(struct issei_dma *dma) +{ + struct control_buffer *ctl = __dma_get_ctl_buf(dma); + + return ctl->f2h_counter_wr != ctl->f2h_counter_rd; +} + +static bool __issei_dma_is_write_busy(struct issei_dma *dma) +{ + struct control_buffer *ctl = __dma_get_ctl_buf(dma); + + return ctl->h2f_counter_wr != ctl->h2f_counter_rd; +} + +static void __issei_dma_read_finalize(struct issei_device *idev) +{ + struct control_buffer *ctl = __dma_get_ctl_buf(&idev->dma); + + dev_dbg(&idev->dev, "ctl->f2h_counter_rd %u\n", ctl->f2h_counter_rd); + /* No need to check overflow - the firmware counters overflow the same way */ + ctl->f2h_counter_rd++; +} + +static void __issei_dma_write_finalize(struct issei_device *idev) +{ + struct control_buffer *ctl = __dma_get_ctl_buf(&idev->dma); + + dev_dbg(&idev->dev, "ctl->h2f_counter_wr %u\n", ctl->h2f_counter_wr); + /* No need to check overflow - the firmware counters overflow the same way */ + ctl->h2f_counter_wr++; +} + +/** + * issei_dma_write - write data package to DMA + * @idev: issei device object + * @data: data atructure + * + * Return: 0 on success, <0 on failures + */ +int issei_dma_write(struct issei_device *idev, const struct issei_dma_data *data) +{ + u8 *write_buf = idev->dma.vaddr; + struct ham_message_header *hdr = (struct ham_message_header *)write_buf; + + if (data->length > idev->dma.length.h2f - sizeof(*hdr)) { + dev_err(&idev->dev, "Message is too big\n"); + return -EMSGSIZE; + } + + if (__issei_dma_is_write_busy(&idev->dma)) { + if (ktime_ms_delta(ktime_get(), idev->last_write_ts) > ISSEI_WRITE_TIMEOUT_MSEC) { + dev_err(&idev->dev, "Write stuck in queue\n"); + return -EIO; + } + dev_info(&idev->dev, "Write is busy\n"); + return -EBUSY; + } + + hdr->length = data->length; + hdr->fw_id = data->fw_id; + hdr->host_id = data->host_id; + hdr->flags = data->flags; + hdr->status = data->status; + hdr->reserved = 0; + + memcpy(write_buf + sizeof(*hdr), data->buf, data->length); + + __issei_dma_write_finalize(idev); + idev->last_write_ts = ktime_get(); + return 0; +} + +/** + * issei_dma_read - read data package from DMA + * @idev: issei device object + * @data: data atructure + * + * Return: %0 on success, <0 on failures + */ +int issei_dma_read(struct issei_device *idev, struct issei_dma_data *data) +{ + u8 *read_buf = idev->dma.vaddr + idev->dma.length.h2f; + struct ham_message_header *hdr = (struct ham_message_header *)read_buf; + + if (!__issei_dma_is_read_busy(&idev->dma)) { + dev_dbg(&idev->dev, "Nothing to read\n"); + return -ENODATA; + } + + dev_dbg(&idev->dev, "Reading header\n"); + data->length = hdr->length; + data->fw_id = hdr->fw_id; + data->host_id = hdr->host_id; + data->flags = hdr->flags; + data->status = hdr->status; + + if (data->length > idev->dma.length.f2h - sizeof(*hdr)) { + dev_err(&idev->dev, "Message length %u is bigger than buffer %zu\n", + data->length, idev->dma.length.f2h - sizeof(*hdr)); + return -EIO; + } + + dev_dbg(&idev->dev, "Reading data (size %u)\n", data->length); + data->buf = kmemdup(read_buf + sizeof(*hdr), data->length, GFP_KERNEL); + if (!data->buf) + return -ENOMEM; + __issei_dma_read_finalize(idev); + return 0; +} |