Hi,
On 06.03.2023 22:33, Jeffrey Hugo wrote:
> Add the control path component that talks to the management processor (QSM)
> to load workloads onto the AIC100 device. This implements the KMD portion
> of the NNC protocol over the QAIC_CONTROL MHI channel and the
> DRM_IOCTL_QAIC_MANAGE IOCTL to userspace. With this functionality, QAIC
> clients are able to load, run, and cleanup their workloads on the device
> but not interact with the workloads (run inferences).
>
> Signed-off-by: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx>
> Reviewed-by: Carl Vanderlip <quic_carlv@xxxxxxxxxxx>
> Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@xxxxxxxxxxx>
> ---
> drivers/accel/qaic/qaic_control.c | 1496 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 1496 insertions(+)
> create mode 100644 drivers/accel/qaic/qaic_control.c
>
> diff --git a/drivers/accel/qaic/qaic_control.c b/drivers/accel/qaic/qaic_control.c
> new file mode 100644
> index 0000000..2643747
> --- /dev/null
> +++ b/drivers/accel/qaic/qaic_control.c
> @@ -0,0 +1,1496 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +/* Copyright (c) 2019-2021, The Linux Foundation. All rights reserved. */
> +/* Copyright (c) 2021-2023 Qualcomm Innovation Center, Inc. All rights reserved. */
> +
> +#include <asm/byteorder.h>
> +#include <linux/completion.h>
> +#include <linux/crc32.h>
> +#include <linux/delay.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/kref.h>
> +#include <linux/list.h>
> +#include <linux/mhi.h>
> +#include <linux/mm.h>
> +#include <linux/moduleparam.h>
> +#include <linux/mutex.h>
> +#include <linux/pci.h>
> +#include <linux/scatterlist.h>
> +#include <linux/types.h>
> +#include <linux/uaccess.h>
> +#include <linux/workqueue.h>
> +#include <linux/wait.h>
> +#include <drm/drm_device.h>
> +#include <drm/drm_file.h>
> +#include <uapi/drm/qaic_accel.h>
> +
> +#include "qaic.h"
> +
> +#define MANAGE_MAGIC_NUMBER ((__force __le32)0x43494151) /* "QAIC" in little endian */
> +#define QAIC_DBC_Q_GAP SZ_256
> +#define QAIC_DBC_Q_BUF_ALIGN SZ_4K
> +#define QAIC_MANAGE_EXT_MSG_LENGTH SZ_64K /* Max DMA message length */
> +#define QAIC_WRAPPER_MAX_SIZE SZ_4K
> +#define QAIC_MHI_RETRY_WAIT_MS 100
> +#define QAIC_MHI_RETRY_MAX 20
> +
> +static unsigned int control_resp_timeout = 60; /* 60 sec default */
> +module_param(control_resp_timeout, uint, 0600);
I suggest adding _sec postfix or at least document this param.
> +
> +struct manage_msg {
> + u32 len;
> + u32 count;
> + u8 data[];
> +};
> +
> +/*
> + * wire encoding structures for the manage protocol.
> + * All fields are little endian on the wire
> + */
> +struct _msg_hdr {
> + __le32 crc32; /* crc of everything following this field in the message */
> + __le32 magic_number;
> + __le32 sequence_number;
> + __le32 len; /* length of this message */
> + __le32 count; /* number of transactions in this message */
> + __le32 handle; /* unique id to track the resources consumed */
> + __le32 partition_id; /* partition id for the request (signed)*/
> + __le32 padding; /* must be 0 */
> +} __packed;
> +
> +struct _msg {
I don't love these underlines prefixes.
I would suggest removing them and making the structure names a little longer.
> + struct _msg_hdr hdr;
> + u8 data[];
> +} __packed;
> +
> +struct _trans_hdr {
> + __le32 type;
> + __le32 len;
> +} __packed;
> +
> +/* Each message sent from driver to device are organized in a list of wrapper_msg */
> +struct wrapper_msg {
> + struct list_head list;
> + struct kref ref_count;
> + u32 len; /* length of data to transfer */
> + struct wrapper_list *head;
> + union {
> + struct _msg msg;
> + struct _trans_hdr trans;
> + };
> +};
> +
> +struct wrapper_list {
> + struct list_head list;
> + spinlock_t lock;
> +};
> +
> +struct _trans_passthrough {
> + struct _trans_hdr hdr;
> + u8 data[];
> +} __packed;
> +
> +struct _addr_size_pair {
> + __le64 addr;
> + __le64 size;
> +} __packed;
> +
> +struct _trans_dma_xfer {
> + struct _trans_hdr hdr;
> + __le32 tag;
> + __le32 count;
> + __le32 dma_chunk_id;
> + __le32 padding;
> + struct _addr_size_pair data[];
> +} __packed;
> +
> +/* Initiated by device to continue the DMA xfer of a large piece of data */
> +struct _trans_dma_xfer_cont {
> + struct _trans_hdr hdr;
> + __le32 dma_chunk_id;
> + __le32 padding;
> + __le64 xferred_size;
> +} __packed;
> +
> +struct _trans_activate_to_dev {
> + struct _trans_hdr hdr;
> + __le64 req_q_addr;
> + __le64 rsp_q_addr;
> + __le32 req_q_size;
> + __le32 rsp_q_size;
> + __le32 buf_len;
> + __le32 options; /* unused, but BIT(16) has meaning to the device */
> +} __packed;
> +
> +struct _trans_activate_from_dev {
> + struct _trans_hdr hdr;
> + __le32 status;
> + __le32 dbc_id;
> + __le64 options; /* unused */
> +} __packed;
> +
> +struct _trans_deactivate_from_dev {
> + struct _trans_hdr hdr;
> + __le32 status;
> + __le32 dbc_id;
> +} __packed;
> +
> +struct _trans_terminate_to_dev {
> + struct _trans_hdr hdr;
> + __le32 handle;
> + __le32 padding;
> +} __packed;
> +
> +struct _trans_terminate_from_dev {
> + struct _trans_hdr hdr;
> + __le32 status;
> + __le32 padding;
> +} __packed;
> +
> +struct _trans_status_to_dev {
> + struct _trans_hdr hdr;
> +} __packed;
> +
> +struct _trans_status_from_dev {
> + struct _trans_hdr hdr;
> + __le16 major;
> + __le16 minor;
> + __le32 status;
> + __le64 status_flags;
> +} __packed;
> +
> +struct _trans_validate_part_to_dev {
> + struct _trans_hdr hdr;
> + __le32 part_id;
> + __le32 padding;
> +} __packed;
> +
> +struct _trans_validate_part_from_dev {
> + struct _trans_hdr hdr;
> + __le32 status;
> + __le32 padding;
> +} __packed;
> +
> +struct xfer_queue_elem {
> + /*
> + * Node in list of ongoing transfer request on control channel.
> + * Maintained by root device struct
> + */
> + struct list_head list;
> + /* Sequence number of this transfer request */
> + u32 seq_num;
> + /* This is used to wait on until completion of transfer request */
> + struct completion xfer_done;
> + /* Received data from device */
> + void *buf;
> +};
> +
> +struct dma_xfer {
> + /* Node in list of DMA transfers which is used for cleanup */
> + struct list_head list;
> + /* SG table of memory used for DMA */
> + struct sg_table *sgt;
> + /* Array pages used for DMA */
> + struct page **page_list;
> + /* Number of pages used for DMA */
> + unsigned long nr_pages;
> +};
> +
> +struct ioctl_resources {
> + /* List of all DMA transfers which is used later for cleanup */
> + struct list_head dma_xfers;
> + /* Base address of request queue which belongs to a DBC */
> + void *buf;
> + /*
> + * Base bus address of request queue which belongs to a DBC. Response
> + * queue base bus address can be calculated by adding size of request
> + * queue to base bus address of request queue.
> + */
> + dma_addr_t dma_addr;
> + /* Total size of request queue and response queue in byte */
> + u32 total_size;
> + /* Total number of elements that can be queued in each of request and response queue */
> + u32 nelem;
> + /* Base address of response queue which belongs to a DBC */
> + void *rsp_q_base;
> + /* Status of the NNC message received */
> + u32 status;
> + /* DBC id of the DBC received from device */
> + u32 dbc_id;
> + /*
> + * DMA transfer request messages can be big in size and it may not be
> + * possible to send them in one shot. In such cases the messages are
> + * broken into chunks, this field stores ID of such chunks.
> + */
> + u32 dma_chunk_id;
> + /* Total number of bytes transferred for a DMA xfer request */
> + u64 xferred_dma_size;
> + /* Header of transaction message received from user. Used during DMA xfer request */
> + void *trans_hdr;
> +};
> +
> +struct resp_work {
> + struct work_struct work;
> + struct qaic_device *qdev;
> + void *buf;
> +};
> +
> +/*
> + * Since we're working with little endian messages, its useful to be able to
> + * increment without filling a whole line with conversions back and forth just
> + * to add one(1) to a message count.
> + */
> +static __le32 incr_le32(__le32 val)
> +{
> + return cpu_to_le32(le32_to_cpu(val) + 1);
> +}
> +
> +static u32 gen_crc(void *msg)
> +{
> + struct wrapper_list *wrappers = msg;
> + struct wrapper_msg *w;
> + u32 crc = ~0;
> +
> + list_for_each_entry(w, &wrappers->list, list)
> + crc = crc32(crc, &w->msg, w->len);
> +
> + return crc ^ ~0;
> +}
> +
> +static u32 gen_crc_stub(void *msg)
> +{
> + return 0;
> +}
> +
> +static bool valid_crc(void *msg)
> +{
> + struct _msg_hdr *hdr = msg;
> + bool ret;
> + u32 crc;
> +
> + /*
> + * The output of this algorithm is always converted to the native
> + * endianness.
> + */
> + crc = le32_to_cpu(hdr->crc32);
> + hdr->crc32 = 0;
> + ret = (crc32(~0, msg, le32_to_cpu(hdr->len)) ^ ~0) == crc;
I think it would be better to use sized U32_MAX instead of ~0 here.
> + hdr->crc32 = cpu_to_le32(crc);
> + return ret;
> +}
> +
> +static bool valid_crc_stub(void *msg)
> +{
> + return true;
> +}
> +
> +static void free_wrapper(struct kref *ref)
> +{
> + struct wrapper_msg *wrapper = container_of(ref, struct wrapper_msg, ref_count);
> +
> + list_del(&wrapper->list);
> + kfree(wrapper);
> +}
> +
> +static void save_dbc_buf(struct qaic_device *qdev, struct ioctl_resources *resources,
> + struct qaic_user *usr)
> +{
> + u32 dbc_id = resources->dbc_id;
> +
> + if (resources->buf) {
> + wait_event_interruptible(qdev->dbc[dbc_id].dbc_release, !qdev->dbc[dbc_id].in_use);
> + qdev->dbc[dbc_id].req_q_base = resources->buf;
> + qdev->dbc[dbc_id].rsp_q_base = resources->rsp_q_base;
> + qdev->dbc[dbc_id].dma_addr = resources->dma_addr;
> + qdev->dbc[dbc_id].total_size = resources->total_size;
> + qdev->dbc[dbc_id].nelem = resources->nelem;
> + enable_dbc(qdev, dbc_id, usr);
> + qdev->dbc[dbc_id].in_use = true;
> + resources->buf = NULL;
> + }
> +}
> +
> +static void free_dbc_buf(struct qaic_device *qdev, struct ioctl_resources *resources)
> +{
> + if (resources->buf)
> + dma_free_coherent(&qdev->pdev->dev, resources->total_size, resources->buf,
> + resources->dma_addr);
> + resources->buf = NULL;
> +}
> +
> +static void free_dma_xfers(struct qaic_device *qdev, struct ioctl_resources *resources)
> +{
> + struct dma_xfer *xfer;
> + struct dma_xfer *x;
> + int i;
> +
> + list_for_each_entry_safe(xfer, x, &resources->dma_xfers, list) {
> + dma_unmap_sgtable(&qdev->pdev->dev, xfer->sgt, DMA_TO_DEVICE, 0);
> + sg_free_table(xfer->sgt);
> + kfree(xfer->sgt);
> + for (i = 0; i < xfer->nr_pages; ++i)
> + put_page(xfer->page_list[i]);
> + kfree(xfer->page_list);
> + list_del(&xfer->list);
> + kfree(xfer);
> + }
> +}
> +
> +static struct wrapper_msg *add_wrapper(struct wrapper_list *wrappers, u32 size)
> +{
> + struct wrapper_msg *w = kzalloc(size, GFP_KERNEL);
> +
> + if (!w)
> + return NULL;
> + list_add_tail(&w->list, &wrappers->list);
> + kref_init(&w->ref_count);
> + w->head = wrappers;
> + return w;
> +}
> +
> +static int encode_passthrough(struct qaic_device *qdev, void *trans, struct wrapper_list *wrappers,
> + u32 *user_len)
> +{
> + struct qaic_manage_trans_passthrough *in_trans = trans;
> + struct _trans_passthrough *out_trans;
> + struct wrapper_msg *trans_wrapper;
> + struct wrapper_msg *wrapper;
> + struct _msg *msg;
> + u32 msg_hdr_len;
> +
> + wrapper = list_first_entry(&wrappers->list, struct wrapper_msg, list);
> + msg = &wrapper->msg;
> + msg_hdr_len = le32_to_cpu(msg->hdr.len);
> +
> + if (in_trans->hdr.len % 8 != 0)
> + return -EINVAL;
> +
> + if (msg_hdr_len + in_trans->hdr.len > QAIC_MANAGE_EXT_MSG_LENGTH)
> + return -ENOSPC;
> +
> + trans_wrapper = add_wrapper(wrappers,
> + offsetof(struct wrapper_msg, trans) + in_trans->hdr.len);
> + if (!trans_wrapper)
> + return -ENOMEM;
> + trans_wrapper->len = in_trans->hdr.len;
> + out_trans = (struct _trans_passthrough *)&trans_wrapper->trans;
> +
> + memcpy(out_trans->data, in_trans->data, in_trans->hdr.len - sizeof(in_trans->hdr));
> + msg->hdr.len = cpu_to_le32(msg_hdr_len + in_trans->hdr.len);
> + msg->hdr.count = incr_le32(msg->hdr.count);
> + *user_len += in_trans->hdr.len;
> + out_trans->hdr.type = cpu_to_le32(QAIC_TRANS_PASSTHROUGH_TO_DEV);
> + out_trans->hdr.len = cpu_to_le32(in_trans->hdr.len);
> +
> + return 0;
> +}
> +
> +static int encode_dma(struct qaic_device *qdev, void *trans, struct wrapper_list *wrappers,
> + u32 *user_len, struct ioctl_resources *resources, struct qaic_user *usr)
> +{
> + struct qaic_manage_trans_dma_xfer *in_trans = trans;
> + struct _trans_dma_xfer *out_trans;
> + struct wrapper_msg *trans_wrapper;
> + struct wrapper_msg *wrapper;
> + struct _addr_size_pair *asp;
> + unsigned long need_pages;
> + struct page **page_list;
> + unsigned long nr_pages;
> + struct scatterlist *sg;
> + struct wrapper_msg *w;
> + struct dma_xfer *xfer;
> + struct sg_table *sgt;
> + unsigned int dma_len;
> + u64 dma_chunk_len;
> + struct _msg *msg;
> + u32 msg_hdr_len;
> + void *boundary;
> + int nents_dma;
> + int nents;
> + u32 size;
> + int ret;
> + int i;
These definitions look like ASCII art :)
I think it is a sign this function should be divided into smaller ones.
> + wrapper = list_first_entry(&wrappers->list, struct wrapper_msg, list);
> + msg = &wrapper->msg;
> + msg_hdr_len = le32_to_cpu(msg->hdr.len);
> +
> + if (msg_hdr_len > (UINT_MAX - QAIC_MANAGE_EXT_MSG_LENGTH)) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + /* There should be enough space to hold at least one ASP entry. */
> + if (msg_hdr_len + sizeof(*out_trans) + sizeof(*asp) > QAIC_MANAGE_EXT_MSG_LENGTH) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + if (in_trans->addr + in_trans->size < in_trans->addr || !in_trans->size) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + xfer = kmalloc(sizeof(*xfer), GFP_KERNEL);
> + if (!xfer) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + need_pages = DIV_ROUND_UP(in_trans->size + offset_in_page(in_trans->addr +
> + resources->xferred_dma_size) - resources->xferred_dma_size,
> + PAGE_SIZE);
> +
> + nr_pages = need_pages;
> +
> + while (1) {
> + page_list = kmalloc_array(nr_pages, sizeof(*page_list), GFP_KERNEL | __GFP_NOWARN);
> + if (!page_list) {
> + nr_pages = nr_pages / 2;
> + if (!nr_pages) {
> + ret = -ENOMEM;
> + goto free_resource;
> + }
> + } else {
> + break;
> + }
> + }
> +
> + ret = get_user_pages_fast(in_trans->addr + resources->xferred_dma_size, nr_pages, 0,
> + page_list);
> + if (ret < 0 || ret != nr_pages) {
> + ret = -EFAULT;
> + goto free_page_list;
> + }
> +
> + sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
> + if (!sgt) {
> + ret = -ENOMEM;
> + goto put_pages;
> + }
> +
> + ret = sg_alloc_table_from_pages(sgt, page_list, nr_pages,
> + offset_in_page(in_trans->addr +
> + resources->xferred_dma_size),
> + in_trans->size - resources->xferred_dma_size, GFP_KERNEL);
> + if (ret) {
> + ret = -ENOMEM;
> + goto free_sgt;
> + }
> +
> + ret = dma_map_sgtable(&qdev->pdev->dev, sgt, DMA_TO_DEVICE, 0);
> + if (ret)
> + goto free_table;
> +
> + nents = sgt->nents;
> + nents_dma = nents;
> + size = QAIC_MANAGE_EXT_MSG_LENGTH - msg_hdr_len - sizeof(*out_trans);
> + for_each_sgtable_sg(sgt, sg, i) {
> + size -= sizeof(*asp);
> + /* Save 1K for possible follow-up transactions. */
> + if (size < SZ_1K) {
> + nents_dma = i;
> + break;
> + }
> + }
> +
> + trans_wrapper = add_wrapper(wrappers, QAIC_WRAPPER_MAX_SIZE);
> + if (!trans_wrapper) {
> + ret = -ENOMEM;
> + goto dma_unmap;
> + }
> + out_trans = (struct _trans_dma_xfer *)&trans_wrapper->trans;
> +
> + asp = out_trans->data;
> + boundary = (void *)trans_wrapper + QAIC_WRAPPER_MAX_SIZE;
> + size = 0;
> +
> + dma_len = 0;
> + w = trans_wrapper;
> + dma_chunk_len = 0;
> + for_each_sg(sgt->sgl, sg, nents_dma, i) {
> + asp->size = cpu_to_le64(dma_len);
> + dma_chunk_len += dma_len;
> + if (dma_len) {
> + asp++;
> + if ((void *)asp + sizeof(*asp) > boundary) {
> + w->len = (void *)asp - (void *)&w->msg;
> + size += w->len;
> + w = add_wrapper(wrappers, QAIC_WRAPPER_MAX_SIZE);
> + if (!w) {
> + ret = -ENOMEM;
> + goto dma_unmap;
> + }
> + boundary = (void *)w + QAIC_WRAPPER_MAX_SIZE;
> + asp = (struct _addr_size_pair *)&w->msg;
> + }
> + }
> + dma_len = 0;
> + asp->addr = cpu_to_le64(sg_dma_address(sg));
> + dma_len += sg_dma_len(sg);
> + }
> + /* finalize the last segment */
> + asp->size = cpu_to_le64(dma_len);
> + w->len = (void *)asp + sizeof(*asp) - (void *)&w->msg;
> + size += w->len;
> +
> + msg->hdr.len = cpu_to_le32(msg_hdr_len + size);
> + msg->hdr.count = incr_le32(msg->hdr.count);
> +
> + out_trans->hdr.type = cpu_to_le32(QAIC_TRANS_DMA_XFER_TO_DEV);
> + out_trans->hdr.len = cpu_to_le32(size);
> + out_trans->tag = cpu_to_le32(in_trans->tag);
> + out_trans->count = cpu_to_le32((size - sizeof(*out_trans)) / sizeof(*asp));
> + dma_chunk_len += dma_len;
> +
> + *user_len += in_trans->hdr.len;
> +
> + if (resources->dma_chunk_id) {
> + out_trans->dma_chunk_id = cpu_to_le32(resources->dma_chunk_id);
> + } else if (need_pages > nr_pages || nents_dma < nents) {
> + while (resources->dma_chunk_id == 0)
> + resources->dma_chunk_id = atomic_inc_return(&usr->chunk_id);
> +
> + out_trans->dma_chunk_id = cpu_to_le32(resources->dma_chunk_id);
> + }
> + resources->xferred_dma_size += dma_chunk_len;
> + resources->trans_hdr = trans;
> +
> + xfer->sgt = sgt;
> + xfer->page_list = page_list;
> + xfer->nr_pages = nr_pages;
> + list_add(&xfer->list, &resources->dma_xfers);
> + return 0;
> +
> +dma_unmap:
> + dma_unmap_sgtable(&qdev->pdev->dev, sgt, DMA_TO_DEVICE, 0);
> +free_table:
> + sg_free_table(sgt);
> +free_sgt:
> + kfree(sgt);
> +put_pages:
> + for (i = 0; i < nr_pages; ++i)
> + put_page(page_list[i]);
> +free_page_list:
> + kfree(page_list);
> +free_resource:
> + kfree(xfer);
> +out:
> + return ret;
> +}
> +
> +static int encode_activate(struct qaic_device *qdev, void *trans, struct wrapper_list *wrappers,
> + u32 *user_len, struct ioctl_resources *resources)
> +{
> + struct qaic_manage_trans_activate_to_dev *in_trans = trans;
> + struct _trans_activate_to_dev *out_trans;
> + struct wrapper_msg *trans_wrapper;
> + struct wrapper_msg *wrapper;
> + dma_addr_t dma_addr;
> + struct _msg *msg;
> + u32 msg_hdr_len;
> + void *buf;
> + u32 nelem;
> + u32 size;
> + int ret;
> +
> + wrapper = list_first_entry(&wrappers->list, struct wrapper_msg, list);
> + msg = &wrapper->msg;
> + msg_hdr_len = le32_to_cpu(msg->hdr.len);
> +
> + if (msg_hdr_len + sizeof(*out_trans) > QAIC_MANAGE_MAX_MSG_LENGTH)
> + return -ENOSPC;
> +
> + if (!in_trans->queue_size)
> + return -EINVAL;
> +
> + if (in_trans->pad)
> + return -EINVAL;
> +
> + nelem = in_trans->queue_size;
> + size = (get_dbc_req_elem_size() + get_dbc_rsp_elem_size()) * nelem;
> + if (size / nelem != get_dbc_req_elem_size() + get_dbc_rsp_elem_size())
> + return -EINVAL;
> +
> + if (size + QAIC_DBC_Q_GAP + QAIC_DBC_Q_BUF_ALIGN < size)
> + return -EINVAL;
> +
> + size = ALIGN((size + QAIC_DBC_Q_GAP), QAIC_DBC_Q_BUF_ALIGN);
> +
> + buf = dma_alloc_coherent(&qdev->pdev->dev, size, &dma_addr, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + trans_wrapper = add_wrapper(wrappers,
> + offsetof(struct wrapper_msg, trans) + sizeof(*out_trans));
> + if (!trans_wrapper) {
> + ret = -ENOMEM;
> + goto free_dma;
> + }
> + trans_wrapper->len = sizeof(*out_trans);
> + out_trans = (struct _trans_activate_to_dev *)&trans_wrapper->trans;
> +
> + out_trans->hdr.type = cpu_to_le32(QAIC_TRANS_ACTIVATE_TO_DEV);
> + out_trans->hdr.len = cpu_to_le32(sizeof(*out_trans));
> + out_trans->buf_len = cpu_to_le32(size);
> + out_trans->req_q_addr = cpu_to_le64(dma_addr);
> + out_trans->req_q_size = cpu_to_le32(nelem);
> + out_trans->rsp_q_addr = cpu_to_le64(dma_addr + size - nelem * get_dbc_rsp_elem_size());
> + out_trans->rsp_q_size = cpu_to_le32(nelem);
> + out_trans->options = cpu_to_le32(in_trans->options);
> +
> + *user_len += in_trans->hdr.len;
> + msg->hdr.len = cpu_to_le32(msg_hdr_len + sizeof(*out_trans));
> + msg->hdr.count = incr_le32(msg->hdr.count);
> +
> + resources->buf = buf;
> + resources->dma_addr = dma_addr;
> + resources->total_size = size;
> + resources->nelem = nelem;
> + resources->rsp_q_base = buf + size - nelem * get_dbc_rsp_elem_size();
> + return 0;
> +
> +free_dma:
> + dma_free_coherent(&qdev->pdev->dev, size, buf, dma_addr);
> + return ret;
> +}
> +
> +static int encode_deactivate(struct qaic_device *qdev, void *trans,
> + u32 *user_len, struct qaic_user *usr)
> +{
> + struct qaic_manage_trans_deactivate *in_trans = trans;
> +
> + if (in_trans->dbc_id >= qdev->num_dbc || in_trans->pad)
> + return -EINVAL;
> +
> + *user_len += in_trans->hdr.len;
> +
> + return disable_dbc(qdev, in_trans->dbc_id, usr);
> +}
> +
> +static int encode_status(struct qaic_device *qdev, void *trans, struct wrapper_list *wrappers,
> + u32 *user_len)
> +{
> + struct qaic_manage_trans_status_to_dev *in_trans = trans;
> + struct _trans_status_to_dev *out_trans;
> + struct wrapper_msg *trans_wrapper;
> + struct wrapper_msg *wrapper;
> + struct _msg *msg;
> + u32 msg_hdr_len;
> +
> + wrapper = list_first_entry(&wrappers->list, struct wrapper_msg, list);
> + msg = &wrapper->msg;
> + msg_hdr_len = le32_to_cpu(msg->hdr.len);
> +
> + if (msg_hdr_len + in_trans->hdr.len > QAIC_MANAGE_MAX_MSG_LENGTH)
> + return -ENOSPC;
> +
> + trans_wrapper = add_wrapper(wrappers, sizeof(*trans_wrapper));
> + if (!trans_wrapper)
> + return -ENOMEM;
> +
> + trans_wrapper->len = sizeof(*out_trans);
> + out_trans = (struct _trans_status_to_dev *)&trans_wrapper->trans;
> +
> + out_trans->hdr.type = cpu_to_le32(QAIC_TRANS_STATUS_TO_DEV);
> + out_trans->hdr.len = cpu_to_le32(in_trans->hdr.len);
> + msg->hdr.len = cpu_to_le32(msg_hdr_len + in_trans->hdr.len);
> + msg->hdr.count = incr_le32(msg->hdr.count);
> + *user_len += in_trans->hdr.len;
> +
> + return 0;
> +}
> +
> +static int encode_message(struct qaic_device *qdev, struct manage_msg *user_msg,
> + struct wrapper_list *wrappers, struct ioctl_resources *resources,
> + struct qaic_user *usr)
> +{
> + struct qaic_manage_trans_hdr *trans_hdr;
> + struct wrapper_msg *wrapper;
> + struct _msg *msg;
> + u32 user_len = 0;
> + int ret;
> + int i;
> +
> + if (!user_msg->count) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + wrapper = list_first_entry(&wrappers->list, struct wrapper_msg, list);
> + msg = &wrapper->msg;
> +
> + msg->hdr.len = cpu_to_le32(sizeof(msg->hdr));
> +
> + if (resources->dma_chunk_id) {
> + ret = encode_dma(qdev, resources->trans_hdr, wrappers, &user_len, resources, usr);
> + msg->hdr.count = cpu_to_le32(1);
> + goto out;
> + }
> +
> + for (i = 0; i < user_msg->count; ++i) {
> + if (user_len >= user_msg->len) {
> + ret = -EINVAL;
> + break;
> + }
> + trans_hdr = (struct qaic_manage_trans_hdr *)(user_msg->data + user_len);
> + if (user_len + trans_hdr->len > user_msg->len) {
> + ret = -EINVAL;
> + break;
> + }
> +
> + switch (trans_hdr->type) {
> + case QAIC_TRANS_PASSTHROUGH_FROM_USR:
> + ret = encode_passthrough(qdev, trans_hdr, wrappers, &user_len);
> + break;
> + case QAIC_TRANS_DMA_XFER_FROM_USR:
> + ret = encode_dma(qdev, trans_hdr, wrappers, &user_len, resources, usr);
> + break;
> + case QAIC_TRANS_ACTIVATE_FROM_USR:
> + ret = encode_activate(qdev, trans_hdr, wrappers, &user_len, resources);
> + break;
> + case QAIC_TRANS_DEACTIVATE_FROM_USR:
> + ret = encode_deactivate(qdev, trans_hdr, &user_len, usr);
> + break;
> + case QAIC_TRANS_STATUS_FROM_USR:
> + ret = encode_status(qdev, trans_hdr, wrappers, &user_len);
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + if (ret)
> + break;
> + }
> +
> + if (user_len != user_msg->len)
> + ret = -EINVAL;
> +out:
> + if (ret) {
> + free_dma_xfers(qdev, resources);
> + free_dbc_buf(qdev, resources);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int decode_passthrough(struct qaic_device *qdev, void *trans, struct manage_msg *user_msg,
> + u32 *msg_len)
> +{
> + struct qaic_manage_trans_passthrough *out_trans;
> + struct _trans_passthrough *in_trans = trans;
> + u32 len;
> +
> + out_trans = (void *)user_msg->data + user_msg->len;
> +
> + len = le32_to_cpu(in_trans->hdr.len);
> + if (len % 8 != 0)
> + return -EINVAL;
> +
> + if (user_msg->len + len > QAIC_MANAGE_MAX_MSG_LENGTH)
> + return -ENOSPC;
> +
> + memcpy(out_trans->data, in_trans->data, len - sizeof(in_trans->hdr));
> + user_msg->len += len;
> + *msg_len += len;
> + out_trans->hdr.type = le32_to_cpu(in_trans->hdr.type);
> + out_trans->hdr.len = len;
> +
> + return 0;
> +}
> +
> +static int decode_activate(struct qaic_device *qdev, void *trans, struct manage_msg *user_msg,
> + u32 *msg_len, struct ioctl_resources *resources, struct qaic_user *usr)
> +{
> + struct qaic_manage_trans_activate_from_dev *out_trans;
> + struct _trans_activate_from_dev *in_trans = trans;
> + u32 len;
> +
> + out_trans = (void *)user_msg->data + user_msg->len;
> +
> + len = le32_to_cpu(in_trans->hdr.len);
> + if (user_msg->len + len > QAIC_MANAGE_MAX_MSG_LENGTH)
> + return -ENOSPC;
> +
> + user_msg->len += len;
> + *msg_len += len;
> + out_trans->hdr.type = le32_to_cpu(in_trans->hdr.type);
> + out_trans->hdr.len = len;
> + out_trans->status = le32_to_cpu(in_trans->status);
> + out_trans->dbc_id = le32_to_cpu(in_trans->dbc_id);
> + out_trans->options = le64_to_cpu(in_trans->options);
> +
> + if (!resources->buf)
> + /* how did we get an activate response without a request? */
> + return -EINVAL;
> +
> + if (out_trans->dbc_id >= qdev->num_dbc)
> + /*
> + * The device assigned an invalid resource, which should never
> + * happen. Return an error so the user can try to recover.
> + */
> + return -ENODEV;
> +
> + if (out_trans->status)
> + /*
> + * Allocating resources failed on device side. This is not an
> + * expected behaviour, user is expected to handle this situation.
> + */
> + return -ECANCELED;
> +
> + resources->status = out_trans->status;
> + resources->dbc_id = out_trans->dbc_id;
> + save_dbc_buf(qdev, resources, usr);
> +
> + return 0;
> +}
> +
> +static int decode_deactivate(struct qaic_device *qdev, void *trans, u32 *msg_len,
> + struct qaic_user *usr)
> +{
> + struct _trans_deactivate_from_dev *in_trans = trans;
> + u32 dbc_id = le32_to_cpu(in_trans->dbc_id);
> + u32 status = le32_to_cpu(in_trans->status);
> +
> + if (dbc_id >= qdev->num_dbc)
> + /*
> + * The device assigned an invalid resource, which should never
> + * happen. Inject an error so the user can try to recover.
> + */
> + return -ENODEV;
> +
> + if (status) {
> + /*
> + * Releasing resources failed on the device side, which puts
> + * us in a bind since they may still be in use, so enable the
> + * dbc. User is expected to retry deactivation.
> + */
> + enable_dbc(qdev, dbc_id, usr);
> + return -ECANCELED;
> + }
> +
> + release_dbc(qdev, dbc_id);
> + *msg_len += sizeof(*in_trans);
> +
> + return 0;
> +}
> +
> +static int decode_status(struct qaic_device *qdev, void *trans, struct manage_msg *user_msg,
> + u32 *user_len, struct _msg *msg)
> +{
> + struct qaic_manage_trans_status_from_dev *out_trans;
> + struct _trans_status_from_dev *in_trans = trans;
> + u32 len;
> +
> + out_trans = (void *)user_msg->data + user_msg->len;
> +
> + len = le32_to_cpu(in_trans->hdr.len);
> + if (user_msg->len + len > QAIC_MANAGE_MAX_MSG_LENGTH)
> + return -ENOSPC;
> +
> + out_trans->hdr.type = QAIC_TRANS_STATUS_FROM_DEV;
> + out_trans->hdr.len = len;
> + out_trans->major = le16_to_cpu(in_trans->major);
> + out_trans->minor = le16_to_cpu(in_trans->minor);
> + out_trans->status_flags = le64_to_cpu(in_trans->status_flags);
> + out_trans->status = le32_to_cpu(in_trans->status);
> + *user_len += le32_to_cpu(in_trans->hdr.len);
> + user_msg->len += len;
> +
> + if (out_trans->status)
> + return -ECANCELED;
> + if (out_trans->status_flags & BIT(0) && !valid_crc(msg))
> + return -EPIPE;
> +
> + return 0;
> +}
> +
> +static int decode_message(struct qaic_device *qdev, struct manage_msg *user_msg, struct _msg *msg,
> + struct ioctl_resources *resources, struct qaic_user *usr)
> +{
> + struct _trans_hdr *trans_hdr;
> + u32 msg_len = 0;
> + u32 msg_hdr_len = le32_to_cpu(msg->hdr.len);
> + int ret;
> + int i;
> +
> + if (msg_hdr_len > QAIC_MANAGE_MAX_MSG_LENGTH)
> + return -EINVAL;
> +
> + user_msg->len = 0;
> + user_msg->count = le32_to_cpu(msg->hdr.count);
> +
> + for (i = 0; i < user_msg->count; ++i) {
> + trans_hdr = (struct _trans_hdr *)(msg->data + msg_len);
> + if (msg_len + le32_to_cpu(trans_hdr->len) > msg_hdr_len)
> + return -EINVAL;
> +
> + switch (le32_to_cpu(trans_hdr->type)) {
> + case QAIC_TRANS_PASSTHROUGH_FROM_DEV:
> + ret = decode_passthrough(qdev, trans_hdr, user_msg, &msg_len);
> + break;
> + case QAIC_TRANS_ACTIVATE_FROM_DEV:
> + ret = decode_activate(qdev, trans_hdr, user_msg, &msg_len, resources, usr);
> + break;
> + case QAIC_TRANS_DEACTIVATE_FROM_DEV:
> + ret = decode_deactivate(qdev, trans_hdr, &msg_len, usr);
> + break;
> + case QAIC_TRANS_STATUS_FROM_DEV:
> + ret = decode_status(qdev, trans_hdr, user_msg, &msg_len, msg);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + if (ret)
> + return ret;
> + }
> +
> + if (msg_len != (msg_hdr_len - sizeof(msg->hdr)))
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static void *msg_xfer(struct qaic_device *qdev, struct wrapper_list *wrappers, u32 seq_num,
> + bool ignore_signal)
> +{
> + struct xfer_queue_elem elem;
> + struct wrapper_msg *w;
> + struct _msg *out_buf;
> + int retry_count;
> + long ret;
> +
> + if (qdev->in_reset) {
> + mutex_unlock(&qdev->cntl_mutex);
> + return ERR_PTR(-ENODEV);
> + }
> +
> + elem.seq_num = seq_num;
> + elem.buf = NULL;
> + init_completion(&elem.xfer_done);
> + if (likely(!qdev->cntl_lost_buf)) {
> + /*
> + * The max size of request to device is QAIC_MANAGE_EXT_MSG_LENGTH.
> + * The max size of response from device is QAIC_MANAGE_MAX_MSG_LENGTH.
> + */
> + out_buf = kmalloc(QAIC_MANAGE_MAX_MSG_LENGTH, GFP_KERNEL);
> + if (!out_buf) {
> + mutex_unlock(&qdev->cntl_mutex);
> + return ERR_PTR(-ENOMEM);
> + }
> +
> + ret = mhi_queue_buf(qdev->cntl_ch, DMA_FROM_DEVICE, out_buf,
> + QAIC_MANAGE_MAX_MSG_LENGTH, MHI_EOT);
> + if (ret) {
> + mutex_unlock(&qdev->cntl_mutex);
> + return ERR_PTR(ret);
> + }
> + } else {
> + /*
> + * we lost a buffer because we queued a recv buf, but then
> + * queuing the corresponding tx buf failed. To try to avoid
> + * a memory leak, lets reclaim it and use it for this
> + * transaction.
> + */
> + qdev->cntl_lost_buf = false;
> + }
> +
> + list_for_each_entry(w, &wrappers->list, list) {
> + kref_get(&w->ref_count);
> + retry_count = 0;
> +retry:
> + ret = mhi_queue_buf(qdev->cntl_ch, DMA_TO_DEVICE, &w->msg, w->len,
> + list_is_last(&w->list, &wrappers->list) ? MHI_EOT : MHI_CHAIN);
> + if (ret) {
> + if (ret == -EAGAIN && retry_count++ < QAIC_MHI_RETRY_MAX) {
> + msleep_interruptible(QAIC_MHI_RETRY_WAIT_MS);
> + if (!signal_pending(current))
> + goto retry;
> + }
> +
> + qdev->cntl_lost_buf = true;
> + kref_put(&w->ref_count, free_wrapper);
> + mutex_unlock(&qdev->cntl_mutex);
> + return ERR_PTR(ret);
> + }
> + }
> +
> + list_add_tail(&elem.list, &qdev->cntl_xfer_list);
> + mutex_unlock(&qdev->cntl_mutex);
> +
> + if (ignore_signal)
> + ret = wait_for_completion_timeout(&elem.xfer_done, control_resp_timeout * HZ);
> + else
> + ret = wait_for_completion_interruptible_timeout(&elem.xfer_done,
> + control_resp_timeout * HZ);
> + /*
> + * not using _interruptable because we have to cleanup or we'll
> + * likely cause memory corruption
> + */
> + mutex_lock(&qdev->cntl_mutex);
> + if (!list_empty(&elem.list))
> + list_del(&elem.list);
> + if (!ret && !elem.buf)
> + ret = -ETIMEDOUT;
> + else if (ret > 0 && !elem.buf)
> + ret = -EIO;
> + mutex_unlock(&qdev->cntl_mutex);
> +
> + if (ret < 0) {
> + kfree(elem.buf);
> + return ERR_PTR(ret);
> + } else if (!qdev->valid_crc(elem.buf)) {
> + kfree(elem.buf);
> + return ERR_PTR(-EPIPE);
> + }
> +
> + return elem.buf;
> +}
> +
> +/* Add a transaction to abort the outstanding DMA continuation */
> +static int abort_dma_cont(struct qaic_device *qdev, struct wrapper_list *wrappers, u32 dma_chunk_id)
> +{
> + struct _trans_dma_xfer *out_trans;
> + u32 size = sizeof(*out_trans);
> + struct wrapper_msg *wrapper;
> + struct wrapper_msg *w;
> + struct _msg *msg;
> +
> + wrapper = list_first_entry(&wrappers->list, struct wrapper_msg, list);
> + msg = &wrapper->msg;
> +
> + /* Remove all but the first wrapper which has the msg header */
> + list_for_each_entry_safe(wrapper, w, &wrappers->list, list)
> + if (!list_is_first(&wrapper->list, &wrappers->list))
> + kref_put(&wrapper->ref_count, free_wrapper);
> +
> + wrapper = add_wrapper(wrappers, offsetof(struct wrapper_msg, trans) + sizeof(*out_trans));
> +
> + if (!wrapper)
> + return -ENOMEM;
> +
> + out_trans = (struct _trans_dma_xfer *)&wrapper->trans;
> + out_trans->hdr.type = cpu_to_le32(QAIC_TRANS_DMA_XFER_TO_DEV);
> + out_trans->hdr.len = cpu_to_le32(size);
> + out_trans->tag = cpu_to_le32(0);
> + out_trans->count = cpu_to_le32(0);
> + out_trans->dma_chunk_id = cpu_to_le32(dma_chunk_id);
> +
> + msg->hdr.len = cpu_to_le32(size + sizeof(*msg));
> + msg->hdr.count = cpu_to_le32(1);
> + wrapper->len = size;
> +
> + return 0;
> +}
> +
> +static struct wrapper_list *alloc_wrapper_list(void)
> +{
> + struct wrapper_list *wrappers;
> +
> + wrappers = kmalloc(sizeof(*wrappers), GFP_KERNEL);
> + if (!wrappers)
> + return NULL;
> + INIT_LIST_HEAD(&wrappers->list);
> + spin_lock_init(&wrappers->lock);
> +
> + return wrappers;
> +}
> +
> +static int __qaic_manage(struct qaic_device *qdev, struct qaic_user *usr,
> + struct manage_msg *user_msg, struct ioctl_resources *resources,
> + struct _msg **rsp)
> +{
> + struct wrapper_list *wrappers;
> + struct wrapper_msg *wrapper;
> + struct wrapper_msg *w;
> + bool all_done = false;
> + struct _msg *msg;
> + int ret;
> +
> + wrappers = alloc_wrapper_list();
> + if (!wrappers)
> + return -ENOMEM;
> +
> + wrapper = add_wrapper(wrappers, sizeof(*wrapper));
> + if (!wrapper) {
> + kfree(wrappers);
> + return -ENOMEM;
> + }
> +
> + msg = &wrapper->msg;
> + wrapper->len = sizeof(*msg);
> +
> + ret = encode_message(qdev, user_msg, wrappers, resources, usr);
> + if (ret && resources->dma_chunk_id)
> + ret = abort_dma_cont(qdev, wrappers, resources->dma_chunk_id);
> + if (ret)
> + goto encode_failed;
> +
> + ret = mutex_lock_interruptible(&qdev->cntl_mutex);
> + if (ret)
> + goto lock_failed;
> +
> + msg->hdr.magic_number = MANAGE_MAGIC_NUMBER;
> + msg->hdr.sequence_number = cpu_to_le32(qdev->next_seq_num++);
> +
> + if (usr) {
> + msg->hdr.handle = cpu_to_le32(usr->handle);
> + msg->hdr.partition_id = cpu_to_le32(usr->qddev->partition_id);
> + } else {
> + msg->hdr.handle = 0;
> + msg->hdr.partition_id = cpu_to_le32(QAIC_NO_PARTITION);
> + }
> +
> + msg->hdr.padding = cpu_to_le32(0);
> + msg->hdr.crc32 = cpu_to_le32(qdev->gen_crc(wrappers));
> +
> + /* msg_xfer releases the mutex */
> + *rsp = msg_xfer(qdev, wrappers, qdev->next_seq_num - 1, false);
> + if (IS_ERR(*rsp))
> + ret = PTR_ERR(*rsp);
> +
> +lock_failed:
> + free_dma_xfers(qdev, resources);
> +encode_failed:
> + spin_lock(&wrappers->lock);
> + list_for_each_entry_safe(wrapper, w, &wrappers->list, list)
> + kref_put(&wrapper->ref_count, free_wrapper);
> + all_done = list_empty(&wrappers->list);
> + spin_unlock(&wrappers->lock);
> + if (all_done)
> + kfree(wrappers);
> +
> + return ret;
> +}
> +
> +static int qaic_manage(struct qaic_device *qdev, struct qaic_user *usr, struct manage_msg *user_msg)
> +{
> + struct _trans_dma_xfer_cont *dma_cont = NULL;
> + struct ioctl_resources resources;
> + struct _msg *rsp = NULL;
> + int ret;
> +
> + memset(&resources, 0, sizeof(struct ioctl_resources));
> +
> + INIT_LIST_HEAD(&resources.dma_xfers);
> +
> + if (user_msg->len > QAIC_MANAGE_MAX_MSG_LENGTH ||
> + user_msg->count > QAIC_MANAGE_MAX_MSG_LENGTH / sizeof(struct qaic_manage_trans_hdr))
> + return -EINVAL;
> +
> +dma_xfer_continue:
> + ret = __qaic_manage(qdev, usr, user_msg, &resources, &rsp);
Maybe something like qaic_manage_msg_xfer instead of __qaic_manage would be easier to read here.
> + if (ret)
> + return ret;
> + /* dma_cont should be the only transaction if present */
> + if (le32_to_cpu(rsp->hdr.count) == 1) {
> + dma_cont = (struct _trans_dma_xfer_cont *)rsp->data;
> + if (le32_to_cpu(dma_cont->hdr.type) != QAIC_TRANS_DMA_XFER_CONT)
> + dma_cont = NULL;
> + }
> + if (dma_cont) {
> + if (le32_to_cpu(dma_cont->dma_chunk_id) == resources.dma_chunk_id &&
> + le64_to_cpu(dma_cont->xferred_size) == resources.xferred_dma_size) {
> + kfree(rsp);
> + goto dma_xfer_continue;
> + }
> +
> + ret = -EINVAL;
> + goto dma_cont_failed;
> + }
> +
> + ret = decode_message(qdev, user_msg, rsp, &resources, usr);
> +
> +dma_cont_failed:
> + free_dbc_buf(qdev, &resources);
> + kfree(rsp);
> + return ret;
> +}
> +
> +int qaic_manage_ioctl(struct drm_device *dev, void *data, struct drm_file *file_priv)
> +{
> + struct qaic_manage_msg *user_msg;
> + struct qaic_device *qdev;
> + struct manage_msg *msg;
> + struct qaic_user *usr;
> + u8 __user *user_data;
> + int qdev_rcu_id;
> + int usr_rcu_id;
> + int ret;
> +
> + usr = file_priv->driver_priv;
> +
> + usr_rcu_id = srcu_read_lock(&usr->qddev_lock);
> + if (!usr->qddev) {
> + srcu_read_unlock(&usr->qddev_lock, usr_rcu_id);
> + return -ENODEV;
> + }
> +
> + qdev = usr->qddev->qdev;
> +
> + qdev_rcu_id = srcu_read_lock(&qdev->dev_lock);
> + if (qdev->in_reset) {
> + srcu_read_unlock(&qdev->dev_lock, qdev_rcu_id);
> + srcu_read_unlock(&usr->qddev_lock, usr_rcu_id);
> + return -ENODEV;
> + }
> +
> + user_msg = data;
> +
> + if (user_msg->len > QAIC_MANAGE_MAX_MSG_LENGTH) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + msg = kzalloc(QAIC_MANAGE_MAX_MSG_LENGTH + sizeof(*msg), GFP_KERNEL);
> + if (!msg) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + msg->len = user_msg->len;
> + msg->count = user_msg->count;
> +
> + user_data = u64_to_user_ptr(user_msg->data);
> +
> + if (copy_from_user(msg->data, user_data, user_msg->len)) {
> + ret = -EFAULT;
> + goto free_msg;
> + }
> +
> + ret = qaic_manage(qdev, usr, msg);
> +
> + /*
> + * If the qaic_manage() is successful then we copy the message onto
> + * userspace memory but we have an exception for -ECANCELED.
> + * For -ECANCELED, it means that device has NACKed the message with a
> + * status error code which userspace would like to know.
> + */
> + if (ret == -ECANCELED || !ret) {
> + if (copy_to_user(user_data, msg->data, msg->len)) {
> + ret = -EFAULT;
> + } else {
> + user_msg->len = msg->len;
> + user_msg->count = msg->count;
> + }
> + }
> +
> +free_msg:
> + kfree(msg);
> +out:
> + srcu_read_unlock(&qdev->dev_lock, qdev_rcu_id);
> + srcu_read_unlock(&usr->qddev_lock, usr_rcu_id);
> + return ret;
> +}
> +
> +int get_cntl_version(struct qaic_device *qdev, struct qaic_user *usr, u16 *major, u16 *minor)
> +{
> + struct qaic_manage_trans_status_from_dev *status_result;
> + struct qaic_manage_trans_status_to_dev *status_query;
> + struct manage_msg *user_msg;
> + int ret;
> +
> + user_msg = kmalloc(sizeof(*user_msg) + sizeof(*status_result), GFP_KERNEL);
> + if (!user_msg) {
> + ret = -ENOMEM;
> + goto out;
> + }
> + user_msg->len = sizeof(*status_query);
> + user_msg->count = 1;
> +
> + status_query = (struct qaic_manage_trans_status_to_dev *)user_msg->data;
> + status_query->hdr.type = QAIC_TRANS_STATUS_FROM_USR;
> + status_query->hdr.len = sizeof(status_query->hdr);
> +
> + ret = qaic_manage(qdev, usr, user_msg);
> + if (ret)
> + goto kfree_user_msg;
> + status_result = (struct qaic_manage_trans_status_from_dev *)user_msg->data;
> + *major = status_result->major;
> + *minor = status_result->minor;
> +
> + if (status_result->status_flags & BIT(0)) { /* device is using CRC */
> + /* By default qdev->gen_crc is programmed to generate CRC */
> + qdev->valid_crc = valid_crc;
> + } else {
> + /* By default qdev->valid_crc is programmed to bypass CRC */
> + qdev->gen_crc = gen_crc_stub;
> + }
> +
> +kfree_user_msg:
> + kfree(user_msg);
> +out:
> + return ret;
> +}
> +
> +static void resp_worker(struct work_struct *work)
> +{
> + struct resp_work *resp = container_of(work, struct resp_work, work);
> + struct qaic_device *qdev = resp->qdev;
> + struct _msg *msg = resp->buf;
> + struct xfer_queue_elem *elem;
> + struct xfer_queue_elem *i;
> + bool found = false;
> +
> + if (msg->hdr.magic_number != MANAGE_MAGIC_NUMBER) {
Woudn't it make sense to check this in qaic_mhi_dl_xfer_cb() before queuing the work?
> + kfree(msg);
> + kfree(resp);
> + return;
> + }
> +
> + mutex_lock(&qdev->cntl_mutex);
> + list_for_each_entry_safe(elem, i, &qdev->cntl_xfer_list, list) {
> + if (elem->seq_num == le32_to_cpu(msg->hdr.sequence_number)) {
> + found = true;
> + list_del_init(&elem->list);
> + elem->buf = msg;
> + complete_all(&elem->xfer_done);
> + break;
> + }
> + }
> + mutex_unlock(&qdev->cntl_mutex);
> +
> + if (!found)
> + /* request must have timed out, drop packet */
> + kfree(msg);
> +
> + kfree(resp);
> +}
> +
> +static void free_wrapper_from_list(struct wrapper_list *wrappers, struct wrapper_msg *wrapper)
> +{
> + bool all_done = false;
> +
> + spin_lock(&wrappers->lock);
> + kref_put(&wrapper->ref_count, free_wrapper);
> + all_done = list_empty(&wrappers->list);
> + spin_unlock(&wrappers->lock);
> +
> + if (all_done)
> + kfree(wrappers);
> +}
> +
> +void qaic_mhi_ul_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result *mhi_result)
> +{
> + struct _msg *msg = mhi_result->buf_addr;
> + struct wrapper_msg *wrapper = container_of(msg, struct wrapper_msg, msg);
> +
> + free_wrapper_from_list(wrapper->head, wrapper);
> +}
> +
> +void qaic_mhi_dl_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result *mhi_result)
> +{
> + struct qaic_device *qdev = dev_get_drvdata(&mhi_dev->dev);
> + struct _msg *msg = mhi_result->buf_addr;
> + struct resp_work *resp;
> +
> + if (mhi_result->transaction_status) {
> + kfree(msg);
> + return;
> + }
> +
> + resp = kmalloc(sizeof(*resp), GFP_ATOMIC);
> + if (!resp) {
> + pci_err(qdev->pdev, "dl_xfer_cb alloc fail, dropping message\n");
> + kfree(msg);
> + return;
> + }
> +
> + INIT_WORK(&resp->work, resp_worker);
> + resp->qdev = qdev;
> + resp->buf = msg;
> + queue_work(qdev->cntl_wq, &resp->work);
> +}
> +
> +int qaic_control_open(struct qaic_device *qdev)
> +{
> + if (!qdev->cntl_ch)
> + return -ENODEV;
> +
> + qdev->cntl_lost_buf = false;
> + /*
> + * By default qaic should assume that device has CRC enabled.
> + * Qaic comes to know if device has CRC enabled or disabled during the
> + * device status transaction, which is the first transaction performed
> + * on control channel.
> + *
> + * So CRC validation of first device status transaction response is
> + * ignored (by calling valid_crc_stub) and is done later during decoding
> + * if device has CRC enabled.
> + * Now that qaic knows whether device has CRC enabled or not it acts
> + * accordingly
> + */
> + qdev->gen_crc = gen_crc;
> + qdev->valid_crc = valid_crc_stub;
> +
> + return mhi_prepare_for_transfer(qdev->cntl_ch);
> +}
> +
> +void qaic_control_close(struct qaic_device *qdev)
> +{
> + mhi_unprepare_from_transfer(qdev->cntl_ch);
> +}
> +
> +void qaic_release_usr(struct qaic_device *qdev, struct qaic_user *usr)
> +{
> + struct _trans_terminate_to_dev *trans;
> + struct wrapper_list *wrappers;
> + struct wrapper_msg *wrapper;
> + struct _msg *msg;
> + struct _msg *rsp;
> +
> + wrappers = alloc_wrapper_list();
> + if (!wrappers)
> + return;
> +
> + wrapper = add_wrapper(wrappers, sizeof(*wrapper) + sizeof(*msg) + sizeof(*trans));
> + if (!wrapper)
> + return;
> +
> + msg = &wrapper->msg;
> +
> + trans = (struct _trans_terminate_to_dev *)msg->data;
> +
> + trans->hdr.type = cpu_to_le32(QAIC_TRANS_TERMINATE_TO_DEV);
> + trans->hdr.len = cpu_to_le32(sizeof(*trans));
> + trans->handle = cpu_to_le32(usr->handle);
> +
> + mutex_lock(&qdev->cntl_mutex);
> + wrapper->len = sizeof(msg->hdr) + sizeof(*trans);
> + msg->hdr.magic_number = MANAGE_MAGIC_NUMBER;
> + msg->hdr.sequence_number = cpu_to_le32(qdev->next_seq_num++);
> + msg->hdr.len = cpu_to_le32(wrapper->len);
> + msg->hdr.count = cpu_to_le32(1);
> + msg->hdr.handle = cpu_to_le32(usr->handle);
> + msg->hdr.padding = cpu_to_le32(0);
> + msg->hdr.crc32 = cpu_to_le32(qdev->gen_crc(wrappers));
> +
> + /*
> + * msg_xfer releases the mutex
> + * We don't care about the return of msg_xfer since we will not do
> + * anything different based on what happens.
> + * We ignore pending signals since one will be set if the user is
> + * killed, and we need give the device a chance to cleanup, otherwise
> + * DMA may still be in progress when we return.
> + */
> + rsp = msg_xfer(qdev, wrappers, qdev->next_seq_num - 1, true);
> + if (!IS_ERR(rsp))
> + kfree(rsp);
> + free_wrapper_from_list(wrappers, wrapper);
> +}
> +
> +void wake_all_cntl(struct qaic_device *qdev)
> +{
> + struct xfer_queue_elem *elem;
> + struct xfer_queue_elem *i;
> +
> + mutex_lock(&qdev->cntl_mutex);
> + list_for_each_entry_safe(elem, i, &qdev->cntl_xfer_list, list) {
> + list_del_init(&elem->list);
> + complete_all(&elem->xfer_done);
> + }
> + mutex_unlock(&qdev->cntl_mutex);
> +}
Regards,
Jacek
