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1073 lines
30 KiB
1073 lines
30 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Virtio-based remote processor messaging bus |
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* |
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* Copyright (C) 2011 Texas Instruments, Inc. |
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* Copyright (C) 2011 Google, Inc. |
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* |
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* Ohad Ben-Cohen <[email protected]> |
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* Brian Swetland <[email protected]> |
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*/ |
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|
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#define pr_fmt(fmt) "%s: " fmt, __func__ |
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|
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#include <linux/dma-mapping.h> |
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#include <linux/idr.h> |
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#include <linux/jiffies.h> |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/mutex.h> |
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#include <linux/of_device.h> |
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#include <linux/rpmsg.h> |
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#include <linux/rpmsg/byteorder.h> |
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#include <linux/rpmsg/ns.h> |
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#include <linux/scatterlist.h> |
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#include <linux/slab.h> |
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#include <linux/sched.h> |
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#include <linux/virtio.h> |
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#include <linux/virtio_ids.h> |
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#include <linux/virtio_config.h> |
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#include <linux/wait.h> |
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|
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#include "rpmsg_internal.h" |
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|
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/** |
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* struct virtproc_info - virtual remote processor state |
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* @vdev: the virtio device |
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* @rvq: rx virtqueue |
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* @svq: tx virtqueue |
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* @rbufs: kernel address of rx buffers |
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* @sbufs: kernel address of tx buffers |
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* @num_bufs: total number of buffers for rx and tx |
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* @buf_size: size of one rx or tx buffer |
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* @last_sbuf: index of last tx buffer used |
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* @bufs_dma: dma base addr of the buffers |
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* @tx_lock: protects svq, sbufs and sleepers, to allow concurrent senders. |
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* sending a message might require waking up a dozing remote |
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* processor, which involves sleeping, hence the mutex. |
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* @endpoints: idr of local endpoints, allows fast retrieval |
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* @endpoints_lock: lock of the endpoints set |
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* @sendq: wait queue of sending contexts waiting for a tx buffers |
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* @sleepers: number of senders that are waiting for a tx buffer |
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* |
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* This structure stores the rpmsg state of a given virtio remote processor |
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* device (there might be several virtio proc devices for each physical |
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* remote processor). |
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*/ |
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struct virtproc_info { |
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struct virtio_device *vdev; |
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struct virtqueue *rvq, *svq; |
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void *rbufs, *sbufs; |
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unsigned int num_bufs; |
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unsigned int buf_size; |
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int last_sbuf; |
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dma_addr_t bufs_dma; |
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struct mutex tx_lock; |
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struct idr endpoints; |
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struct mutex endpoints_lock; |
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wait_queue_head_t sendq; |
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atomic_t sleepers; |
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}; |
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/* The feature bitmap for virtio rpmsg */ |
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#define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */ |
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|
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/** |
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* struct rpmsg_hdr - common header for all rpmsg messages |
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* @src: source address |
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* @dst: destination address |
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* @reserved: reserved for future use |
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* @len: length of payload (in bytes) |
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* @flags: message flags |
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* @data: @len bytes of message payload data |
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* |
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* Every message sent(/received) on the rpmsg bus begins with this header. |
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*/ |
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struct rpmsg_hdr { |
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__rpmsg32 src; |
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__rpmsg32 dst; |
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__rpmsg32 reserved; |
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__rpmsg16 len; |
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__rpmsg16 flags; |
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u8 data[]; |
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} __packed; |
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/** |
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* struct virtio_rpmsg_channel - rpmsg channel descriptor |
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* @rpdev: the rpmsg channel device |
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* @vrp: the virtio remote processor device this channel belongs to |
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* |
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* This structure stores the channel that links the rpmsg device to the virtio |
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* remote processor device. |
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*/ |
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struct virtio_rpmsg_channel { |
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struct rpmsg_device rpdev; |
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|
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struct virtproc_info *vrp; |
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}; |
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#define to_virtio_rpmsg_channel(_rpdev) \ |
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container_of(_rpdev, struct virtio_rpmsg_channel, rpdev) |
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/* |
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* We're allocating buffers of 512 bytes each for communications. The |
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* number of buffers will be computed from the number of buffers supported |
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* by the vring, upto a maximum of 512 buffers (256 in each direction). |
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* |
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* Each buffer will have 16 bytes for the msg header and 496 bytes for |
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* the payload. |
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* |
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* This will utilize a maximum total space of 256KB for the buffers. |
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* |
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* We might also want to add support for user-provided buffers in time. |
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* This will allow bigger buffer size flexibility, and can also be used |
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* to achieve zero-copy messaging. |
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* |
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* Note that these numbers are purely a decision of this driver - we |
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* can change this without changing anything in the firmware of the remote |
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* processor. |
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*/ |
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#define MAX_RPMSG_NUM_BUFS (512) |
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#define MAX_RPMSG_BUF_SIZE (512) |
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|
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/* |
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* Local addresses are dynamically allocated on-demand. |
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* We do not dynamically assign addresses from the low 1024 range, |
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* in order to reserve that address range for predefined services. |
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*/ |
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#define RPMSG_RESERVED_ADDRESSES (1024) |
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static void virtio_rpmsg_destroy_ept(struct rpmsg_endpoint *ept); |
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static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len); |
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static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, |
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u32 dst); |
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static int virtio_rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, |
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u32 dst, void *data, int len); |
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static int virtio_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len); |
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static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, |
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int len, u32 dst); |
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static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, |
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u32 dst, void *data, int len); |
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static struct rpmsg_device *__rpmsg_create_channel(struct virtproc_info *vrp, |
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struct rpmsg_channel_info *chinfo); |
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|
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static const struct rpmsg_endpoint_ops virtio_endpoint_ops = { |
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.destroy_ept = virtio_rpmsg_destroy_ept, |
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.send = virtio_rpmsg_send, |
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.sendto = virtio_rpmsg_sendto, |
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.send_offchannel = virtio_rpmsg_send_offchannel, |
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.trysend = virtio_rpmsg_trysend, |
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.trysendto = virtio_rpmsg_trysendto, |
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.trysend_offchannel = virtio_rpmsg_trysend_offchannel, |
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}; |
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/** |
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* rpmsg_sg_init - initialize scatterlist according to cpu address location |
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* @sg: scatterlist to fill |
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* @cpu_addr: virtual address of the buffer |
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* @len: buffer length |
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* |
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* An internal function filling scatterlist according to virtual address |
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* location (in vmalloc or in kernel). |
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*/ |
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static void |
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rpmsg_sg_init(struct scatterlist *sg, void *cpu_addr, unsigned int len) |
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{ |
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if (is_vmalloc_addr(cpu_addr)) { |
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sg_init_table(sg, 1); |
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sg_set_page(sg, vmalloc_to_page(cpu_addr), len, |
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offset_in_page(cpu_addr)); |
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} else { |
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WARN_ON(!virt_addr_valid(cpu_addr)); |
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sg_init_one(sg, cpu_addr, len); |
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} |
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} |
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/** |
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* __ept_release() - deallocate an rpmsg endpoint |
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* @kref: the ept's reference count |
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* |
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* This function deallocates an ept, and is invoked when its @kref refcount |
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* drops to zero. |
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* |
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* Never invoke this function directly! |
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*/ |
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static void __ept_release(struct kref *kref) |
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{ |
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struct rpmsg_endpoint *ept = container_of(kref, struct rpmsg_endpoint, |
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refcount); |
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/* |
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* At this point no one holds a reference to ept anymore, |
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* so we can directly free it |
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*/ |
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kfree(ept); |
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} |
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|
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/* for more info, see below documentation of rpmsg_create_ept() */ |
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static struct rpmsg_endpoint *__rpmsg_create_ept(struct virtproc_info *vrp, |
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struct rpmsg_device *rpdev, |
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rpmsg_rx_cb_t cb, |
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void *priv, u32 addr) |
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{ |
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int id_min, id_max, id; |
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struct rpmsg_endpoint *ept; |
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struct device *dev = rpdev ? &rpdev->dev : &vrp->vdev->dev; |
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ept = kzalloc(sizeof(*ept), GFP_KERNEL); |
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if (!ept) |
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return NULL; |
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kref_init(&ept->refcount); |
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mutex_init(&ept->cb_lock); |
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ept->rpdev = rpdev; |
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ept->cb = cb; |
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ept->priv = priv; |
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ept->ops = &virtio_endpoint_ops; |
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/* do we need to allocate a local address ? */ |
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if (addr == RPMSG_ADDR_ANY) { |
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id_min = RPMSG_RESERVED_ADDRESSES; |
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id_max = 0; |
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} else { |
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id_min = addr; |
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id_max = addr + 1; |
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} |
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mutex_lock(&vrp->endpoints_lock); |
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/* bind the endpoint to an rpmsg address (and allocate one if needed) */ |
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id = idr_alloc(&vrp->endpoints, ept, id_min, id_max, GFP_KERNEL); |
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if (id < 0) { |
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dev_err(dev, "idr_alloc failed: %d\n", id); |
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goto free_ept; |
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} |
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ept->addr = id; |
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mutex_unlock(&vrp->endpoints_lock); |
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return ept; |
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free_ept: |
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mutex_unlock(&vrp->endpoints_lock); |
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kref_put(&ept->refcount, __ept_release); |
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return NULL; |
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} |
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static struct rpmsg_device *virtio_rpmsg_create_channel(struct rpmsg_device *rpdev, |
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struct rpmsg_channel_info *chinfo) |
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{ |
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struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
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struct virtproc_info *vrp = vch->vrp; |
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return __rpmsg_create_channel(vrp, chinfo); |
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} |
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static int virtio_rpmsg_release_channel(struct rpmsg_device *rpdev, |
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struct rpmsg_channel_info *chinfo) |
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{ |
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struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
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struct virtproc_info *vrp = vch->vrp; |
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return rpmsg_unregister_device(&vrp->vdev->dev, chinfo); |
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} |
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static struct rpmsg_endpoint *virtio_rpmsg_create_ept(struct rpmsg_device *rpdev, |
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rpmsg_rx_cb_t cb, |
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void *priv, |
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struct rpmsg_channel_info chinfo) |
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{ |
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struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
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return __rpmsg_create_ept(vch->vrp, rpdev, cb, priv, chinfo.src); |
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} |
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/** |
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* __rpmsg_destroy_ept() - destroy an existing rpmsg endpoint |
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* @vrp: virtproc which owns this ept |
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* @ept: endpoing to destroy |
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* |
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* An internal function which destroy an ept without assuming it is |
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* bound to an rpmsg channel. This is needed for handling the internal |
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* name service endpoint, which isn't bound to an rpmsg channel. |
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* See also __rpmsg_create_ept(). |
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*/ |
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static void |
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__rpmsg_destroy_ept(struct virtproc_info *vrp, struct rpmsg_endpoint *ept) |
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{ |
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/* make sure new inbound messages can't find this ept anymore */ |
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mutex_lock(&vrp->endpoints_lock); |
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idr_remove(&vrp->endpoints, ept->addr); |
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mutex_unlock(&vrp->endpoints_lock); |
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/* make sure in-flight inbound messages won't invoke cb anymore */ |
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mutex_lock(&ept->cb_lock); |
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ept->cb = NULL; |
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mutex_unlock(&ept->cb_lock); |
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kref_put(&ept->refcount, __ept_release); |
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} |
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static void virtio_rpmsg_destroy_ept(struct rpmsg_endpoint *ept) |
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{ |
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struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(ept->rpdev); |
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__rpmsg_destroy_ept(vch->vrp, ept); |
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} |
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static int virtio_rpmsg_announce_create(struct rpmsg_device *rpdev) |
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{ |
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struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
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struct virtproc_info *vrp = vch->vrp; |
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struct device *dev = &rpdev->dev; |
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int err = 0; |
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/* need to tell remote processor's name service about this channel ? */ |
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if (rpdev->announce && rpdev->ept && |
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virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) { |
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struct rpmsg_ns_msg nsm; |
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strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE); |
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nsm.addr = cpu_to_rpmsg32(rpdev, rpdev->ept->addr); |
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nsm.flags = cpu_to_rpmsg32(rpdev, RPMSG_NS_CREATE); |
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err = rpmsg_sendto(rpdev->ept, &nsm, sizeof(nsm), RPMSG_NS_ADDR); |
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if (err) |
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dev_err(dev, "failed to announce service %d\n", err); |
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} |
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return err; |
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} |
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static int virtio_rpmsg_announce_destroy(struct rpmsg_device *rpdev) |
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{ |
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struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
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struct virtproc_info *vrp = vch->vrp; |
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struct device *dev = &rpdev->dev; |
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int err = 0; |
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/* tell remote processor's name service we're removing this channel */ |
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if (rpdev->announce && rpdev->ept && |
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virtio_has_feature(vrp->vdev, VIRTIO_RPMSG_F_NS)) { |
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struct rpmsg_ns_msg nsm; |
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strncpy(nsm.name, rpdev->id.name, RPMSG_NAME_SIZE); |
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nsm.addr = cpu_to_rpmsg32(rpdev, rpdev->ept->addr); |
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nsm.flags = cpu_to_rpmsg32(rpdev, RPMSG_NS_DESTROY); |
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err = rpmsg_sendto(rpdev->ept, &nsm, sizeof(nsm), RPMSG_NS_ADDR); |
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if (err) |
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dev_err(dev, "failed to announce service %d\n", err); |
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} |
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return err; |
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} |
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static const struct rpmsg_device_ops virtio_rpmsg_ops = { |
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.create_channel = virtio_rpmsg_create_channel, |
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.release_channel = virtio_rpmsg_release_channel, |
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.create_ept = virtio_rpmsg_create_ept, |
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.announce_create = virtio_rpmsg_announce_create, |
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.announce_destroy = virtio_rpmsg_announce_destroy, |
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}; |
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static void virtio_rpmsg_release_device(struct device *dev) |
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{ |
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struct rpmsg_device *rpdev = to_rpmsg_device(dev); |
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struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
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|
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kfree(vch); |
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} |
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|
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/* |
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* create an rpmsg channel using its name and address info. |
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* this function will be used to create both static and dynamic |
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* channels. |
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*/ |
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static struct rpmsg_device *__rpmsg_create_channel(struct virtproc_info *vrp, |
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struct rpmsg_channel_info *chinfo) |
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{ |
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struct virtio_rpmsg_channel *vch; |
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struct rpmsg_device *rpdev; |
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struct device *tmp, *dev = &vrp->vdev->dev; |
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int ret; |
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|
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/* make sure a similar channel doesn't already exist */ |
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tmp = rpmsg_find_device(dev, chinfo); |
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if (tmp) { |
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/* decrement the matched device's refcount back */ |
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put_device(tmp); |
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dev_err(dev, "channel %s:%x:%x already exist\n", |
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chinfo->name, chinfo->src, chinfo->dst); |
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return NULL; |
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} |
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vch = kzalloc(sizeof(*vch), GFP_KERNEL); |
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if (!vch) |
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return NULL; |
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|
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/* Link the channel to our vrp */ |
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vch->vrp = vrp; |
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|
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/* Assign public information to the rpmsg_device */ |
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rpdev = &vch->rpdev; |
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rpdev->src = chinfo->src; |
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rpdev->dst = chinfo->dst; |
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rpdev->ops = &virtio_rpmsg_ops; |
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rpdev->little_endian = virtio_is_little_endian(vrp->vdev); |
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|
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/* |
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* rpmsg server channels has predefined local address (for now), |
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* and their existence needs to be announced remotely |
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*/ |
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rpdev->announce = rpdev->src != RPMSG_ADDR_ANY; |
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|
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strncpy(rpdev->id.name, chinfo->name, RPMSG_NAME_SIZE); |
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|
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rpdev->dev.parent = &vrp->vdev->dev; |
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rpdev->dev.release = virtio_rpmsg_release_device; |
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ret = rpmsg_register_device(rpdev); |
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if (ret) |
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return NULL; |
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|
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return rpdev; |
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} |
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|
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/* super simple buffer "allocator" that is just enough for now */ |
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static void *get_a_tx_buf(struct virtproc_info *vrp) |
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{ |
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unsigned int len; |
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void *ret; |
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|
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/* support multiple concurrent senders */ |
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mutex_lock(&vrp->tx_lock); |
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|
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/* |
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* either pick the next unused tx buffer |
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* (half of our buffers are used for sending messages) |
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*/ |
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if (vrp->last_sbuf < vrp->num_bufs / 2) |
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ret = vrp->sbufs + vrp->buf_size * vrp->last_sbuf++; |
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/* or recycle a used one */ |
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else |
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ret = virtqueue_get_buf(vrp->svq, &len); |
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|
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mutex_unlock(&vrp->tx_lock); |
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|
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return ret; |
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} |
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|
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/** |
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* rpmsg_upref_sleepers() - enable "tx-complete" interrupts, if needed |
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* @vrp: virtual remote processor state |
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* |
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* This function is called before a sender is blocked, waiting for |
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* a tx buffer to become available. |
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* |
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* If we already have blocking senders, this function merely increases |
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* the "sleepers" reference count, and exits. |
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* |
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* Otherwise, if this is the first sender to block, we also enable |
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* virtio's tx callbacks, so we'd be immediately notified when a tx |
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* buffer is consumed (we rely on virtio's tx callback in order |
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* to wake up sleeping senders as soon as a tx buffer is used by the |
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* remote processor). |
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*/ |
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static void rpmsg_upref_sleepers(struct virtproc_info *vrp) |
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{ |
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/* support multiple concurrent senders */ |
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mutex_lock(&vrp->tx_lock); |
|
|
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/* are we the first sleeping context waiting for tx buffers ? */ |
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if (atomic_inc_return(&vrp->sleepers) == 1) |
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/* enable "tx-complete" interrupts before dozing off */ |
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virtqueue_enable_cb(vrp->svq); |
|
|
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mutex_unlock(&vrp->tx_lock); |
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} |
|
|
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/** |
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* rpmsg_downref_sleepers() - disable "tx-complete" interrupts, if needed |
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* @vrp: virtual remote processor state |
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* |
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* This function is called after a sender, that waited for a tx buffer |
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* to become available, is unblocked. |
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* |
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* If we still have blocking senders, this function merely decreases |
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* the "sleepers" reference count, and exits. |
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* |
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* Otherwise, if there are no more blocking senders, we also disable |
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* virtio's tx callbacks, to avoid the overhead incurred with handling |
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* those (now redundant) interrupts. |
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*/ |
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static void rpmsg_downref_sleepers(struct virtproc_info *vrp) |
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{ |
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/* support multiple concurrent senders */ |
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mutex_lock(&vrp->tx_lock); |
|
|
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/* are we the last sleeping context waiting for tx buffers ? */ |
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if (atomic_dec_and_test(&vrp->sleepers)) |
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/* disable "tx-complete" interrupts */ |
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virtqueue_disable_cb(vrp->svq); |
|
|
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mutex_unlock(&vrp->tx_lock); |
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} |
|
|
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/** |
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* rpmsg_send_offchannel_raw() - send a message across to the remote processor |
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* @rpdev: the rpmsg channel |
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* @src: source address |
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* @dst: destination address |
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* @data: payload of message |
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* @len: length of payload |
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* @wait: indicates whether caller should block in case no TX buffers available |
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* |
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* This function is the base implementation for all of the rpmsg sending API. |
|
* |
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* It will send @data of length @len to @dst, and say it's from @src. The |
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* message will be sent to the remote processor which the @rpdev channel |
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* belongs to. |
|
* |
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* The message is sent using one of the TX buffers that are available for |
|
* communication with this remote processor. |
|
* |
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* If @wait is true, the caller will be blocked until either a TX buffer is |
|
* available, or 15 seconds elapses (we don't want callers to |
|
* sleep indefinitely due to misbehaving remote processors), and in that |
|
* case -ERESTARTSYS is returned. The number '15' itself was picked |
|
* arbitrarily; there's little point in asking drivers to provide a timeout |
|
* value themselves. |
|
* |
|
* Otherwise, if @wait is false, and there are no TX buffers available, |
|
* the function will immediately fail, and -ENOMEM will be returned. |
|
* |
|
* Normally drivers shouldn't use this function directly; instead, drivers |
|
* should use the appropriate rpmsg_{try}send{to, _offchannel} API |
|
* (see include/linux/rpmsg.h). |
|
* |
|
* Returns 0 on success and an appropriate error value on failure. |
|
*/ |
|
static int rpmsg_send_offchannel_raw(struct rpmsg_device *rpdev, |
|
u32 src, u32 dst, |
|
void *data, int len, bool wait) |
|
{ |
|
struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); |
|
struct virtproc_info *vrp = vch->vrp; |
|
struct device *dev = &rpdev->dev; |
|
struct scatterlist sg; |
|
struct rpmsg_hdr *msg; |
|
int err; |
|
|
|
/* bcasting isn't allowed */ |
|
if (src == RPMSG_ADDR_ANY || dst == RPMSG_ADDR_ANY) { |
|
dev_err(dev, "invalid addr (src 0x%x, dst 0x%x)\n", src, dst); |
|
return -EINVAL; |
|
} |
|
|
|
/* |
|
* We currently use fixed-sized buffers, and therefore the payload |
|
* length is limited. |
|
* |
|
* One of the possible improvements here is either to support |
|
* user-provided buffers (and then we can also support zero-copy |
|
* messaging), or to improve the buffer allocator, to support |
|
* variable-length buffer sizes. |
|
*/ |
|
if (len > vrp->buf_size - sizeof(struct rpmsg_hdr)) { |
|
dev_err(dev, "message is too big (%d)\n", len); |
|
return -EMSGSIZE; |
|
} |
|
|
|
/* grab a buffer */ |
|
msg = get_a_tx_buf(vrp); |
|
if (!msg && !wait) |
|
return -ENOMEM; |
|
|
|
/* no free buffer ? wait for one (but bail after 15 seconds) */ |
|
while (!msg) { |
|
/* enable "tx-complete" interrupts, if not already enabled */ |
|
rpmsg_upref_sleepers(vrp); |
|
|
|
/* |
|
* sleep until a free buffer is available or 15 secs elapse. |
|
* the timeout period is not configurable because there's |
|
* little point in asking drivers to specify that. |
|
* if later this happens to be required, it'd be easy to add. |
|
*/ |
|
err = wait_event_interruptible_timeout(vrp->sendq, |
|
(msg = get_a_tx_buf(vrp)), |
|
msecs_to_jiffies(15000)); |
|
|
|
/* disable "tx-complete" interrupts if we're the last sleeper */ |
|
rpmsg_downref_sleepers(vrp); |
|
|
|
/* timeout ? */ |
|
if (!err) { |
|
dev_err(dev, "timeout waiting for a tx buffer\n"); |
|
return -ERESTARTSYS; |
|
} |
|
} |
|
|
|
msg->len = cpu_to_rpmsg16(rpdev, len); |
|
msg->flags = 0; |
|
msg->src = cpu_to_rpmsg32(rpdev, src); |
|
msg->dst = cpu_to_rpmsg32(rpdev, dst); |
|
msg->reserved = 0; |
|
memcpy(msg->data, data, len); |
|
|
|
dev_dbg(dev, "TX From 0x%x, To 0x%x, Len %d, Flags %d, Reserved %d\n", |
|
src, dst, len, msg->flags, msg->reserved); |
|
#if defined(CONFIG_DYNAMIC_DEBUG) |
|
dynamic_hex_dump("rpmsg_virtio TX: ", DUMP_PREFIX_NONE, 16, 1, |
|
msg, sizeof(*msg) + len, true); |
|
#endif |
|
|
|
rpmsg_sg_init(&sg, msg, sizeof(*msg) + len); |
|
|
|
mutex_lock(&vrp->tx_lock); |
|
|
|
/* add message to the remote processor's virtqueue */ |
|
err = virtqueue_add_outbuf(vrp->svq, &sg, 1, msg, GFP_KERNEL); |
|
if (err) { |
|
/* |
|
* need to reclaim the buffer here, otherwise it's lost |
|
* (memory won't leak, but rpmsg won't use it again for TX). |
|
* this will wait for a buffer management overhaul. |
|
*/ |
|
dev_err(dev, "virtqueue_add_outbuf failed: %d\n", err); |
|
goto out; |
|
} |
|
|
|
/* tell the remote processor it has a pending message to read */ |
|
virtqueue_kick(vrp->svq); |
|
out: |
|
mutex_unlock(&vrp->tx_lock); |
|
return err; |
|
} |
|
|
|
static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len) |
|
{ |
|
struct rpmsg_device *rpdev = ept->rpdev; |
|
u32 src = ept->addr, dst = rpdev->dst; |
|
|
|
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); |
|
} |
|
|
|
static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len, |
|
u32 dst) |
|
{ |
|
struct rpmsg_device *rpdev = ept->rpdev; |
|
u32 src = ept->addr; |
|
|
|
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); |
|
} |
|
|
|
static int virtio_rpmsg_send_offchannel(struct rpmsg_endpoint *ept, u32 src, |
|
u32 dst, void *data, int len) |
|
{ |
|
struct rpmsg_device *rpdev = ept->rpdev; |
|
|
|
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true); |
|
} |
|
|
|
static int virtio_rpmsg_trysend(struct rpmsg_endpoint *ept, void *data, int len) |
|
{ |
|
struct rpmsg_device *rpdev = ept->rpdev; |
|
u32 src = ept->addr, dst = rpdev->dst; |
|
|
|
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); |
|
} |
|
|
|
static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, |
|
int len, u32 dst) |
|
{ |
|
struct rpmsg_device *rpdev = ept->rpdev; |
|
u32 src = ept->addr; |
|
|
|
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); |
|
} |
|
|
|
static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, |
|
u32 dst, void *data, int len) |
|
{ |
|
struct rpmsg_device *rpdev = ept->rpdev; |
|
|
|
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); |
|
} |
|
|
|
static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev, |
|
struct rpmsg_hdr *msg, unsigned int len) |
|
{ |
|
struct rpmsg_endpoint *ept; |
|
struct scatterlist sg; |
|
bool little_endian = virtio_is_little_endian(vrp->vdev); |
|
unsigned int msg_len = __rpmsg16_to_cpu(little_endian, msg->len); |
|
int err; |
|
|
|
dev_dbg(dev, "From: 0x%x, To: 0x%x, Len: %d, Flags: %d, Reserved: %d\n", |
|
__rpmsg32_to_cpu(little_endian, msg->src), |
|
__rpmsg32_to_cpu(little_endian, msg->dst), msg_len, |
|
__rpmsg16_to_cpu(little_endian, msg->flags), |
|
__rpmsg32_to_cpu(little_endian, msg->reserved)); |
|
#if defined(CONFIG_DYNAMIC_DEBUG) |
|
dynamic_hex_dump("rpmsg_virtio RX: ", DUMP_PREFIX_NONE, 16, 1, |
|
msg, sizeof(*msg) + msg_len, true); |
|
#endif |
|
|
|
/* |
|
* We currently use fixed-sized buffers, so trivially sanitize |
|
* the reported payload length. |
|
*/ |
|
if (len > vrp->buf_size || |
|
msg_len > (len - sizeof(struct rpmsg_hdr))) { |
|
dev_warn(dev, "inbound msg too big: (%d, %d)\n", len, msg_len); |
|
return -EINVAL; |
|
} |
|
|
|
/* use the dst addr to fetch the callback of the appropriate user */ |
|
mutex_lock(&vrp->endpoints_lock); |
|
|
|
ept = idr_find(&vrp->endpoints, __rpmsg32_to_cpu(little_endian, msg->dst)); |
|
|
|
/* let's make sure no one deallocates ept while we use it */ |
|
if (ept) |
|
kref_get(&ept->refcount); |
|
|
|
mutex_unlock(&vrp->endpoints_lock); |
|
|
|
if (ept) { |
|
/* make sure ept->cb doesn't go away while we use it */ |
|
mutex_lock(&ept->cb_lock); |
|
|
|
if (ept->cb) |
|
ept->cb(ept->rpdev, msg->data, msg_len, ept->priv, |
|
__rpmsg32_to_cpu(little_endian, msg->src)); |
|
|
|
mutex_unlock(&ept->cb_lock); |
|
|
|
/* farewell, ept, we don't need you anymore */ |
|
kref_put(&ept->refcount, __ept_release); |
|
} else |
|
dev_warn(dev, "msg received with no recipient\n"); |
|
|
|
/* publish the real size of the buffer */ |
|
rpmsg_sg_init(&sg, msg, vrp->buf_size); |
|
|
|
/* add the buffer back to the remote processor's virtqueue */ |
|
err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, msg, GFP_KERNEL); |
|
if (err < 0) { |
|
dev_err(dev, "failed to add a virtqueue buffer: %d\n", err); |
|
return err; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/* called when an rx buffer is used, and it's time to digest a message */ |
|
static void rpmsg_recv_done(struct virtqueue *rvq) |
|
{ |
|
struct virtproc_info *vrp = rvq->vdev->priv; |
|
struct device *dev = &rvq->vdev->dev; |
|
struct rpmsg_hdr *msg; |
|
unsigned int len, msgs_received = 0; |
|
int err; |
|
|
|
msg = virtqueue_get_buf(rvq, &len); |
|
if (!msg) { |
|
dev_err(dev, "uhm, incoming signal, but no used buffer ?\n"); |
|
return; |
|
} |
|
|
|
while (msg) { |
|
err = rpmsg_recv_single(vrp, dev, msg, len); |
|
if (err) |
|
break; |
|
|
|
msgs_received++; |
|
|
|
msg = virtqueue_get_buf(rvq, &len); |
|
} |
|
|
|
dev_dbg(dev, "Received %u messages\n", msgs_received); |
|
|
|
/* tell the remote processor we added another available rx buffer */ |
|
if (msgs_received) |
|
virtqueue_kick(vrp->rvq); |
|
} |
|
|
|
/* |
|
* This is invoked whenever the remote processor completed processing |
|
* a TX msg we just sent it, and the buffer is put back to the used ring. |
|
* |
|
* Normally, though, we suppress this "tx complete" interrupt in order to |
|
* avoid the incurred overhead. |
|
*/ |
|
static void rpmsg_xmit_done(struct virtqueue *svq) |
|
{ |
|
struct virtproc_info *vrp = svq->vdev->priv; |
|
|
|
dev_dbg(&svq->vdev->dev, "%s\n", __func__); |
|
|
|
/* wake up potential senders that are waiting for a tx buffer */ |
|
wake_up_interruptible(&vrp->sendq); |
|
} |
|
|
|
/* |
|
* Called to expose to user a /dev/rpmsg_ctrlX interface allowing to |
|
* create endpoint-to-endpoint communication without associated RPMsg channel. |
|
* The endpoints are rattached to the ctrldev RPMsg device. |
|
*/ |
|
static struct rpmsg_device *rpmsg_virtio_add_ctrl_dev(struct virtio_device *vdev) |
|
{ |
|
struct virtproc_info *vrp = vdev->priv; |
|
struct virtio_rpmsg_channel *vch; |
|
struct rpmsg_device *rpdev_ctrl; |
|
int err = 0; |
|
|
|
vch = kzalloc(sizeof(*vch), GFP_KERNEL); |
|
if (!vch) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
/* Link the channel to the vrp */ |
|
vch->vrp = vrp; |
|
|
|
/* Assign public information to the rpmsg_device */ |
|
rpdev_ctrl = &vch->rpdev; |
|
rpdev_ctrl->ops = &virtio_rpmsg_ops; |
|
|
|
rpdev_ctrl->dev.parent = &vrp->vdev->dev; |
|
rpdev_ctrl->dev.release = virtio_rpmsg_release_device; |
|
rpdev_ctrl->little_endian = virtio_is_little_endian(vrp->vdev); |
|
|
|
err = rpmsg_chrdev_register_device(rpdev_ctrl); |
|
if (err) { |
|
kfree(vch); |
|
return ERR_PTR(err); |
|
} |
|
|
|
return rpdev_ctrl; |
|
} |
|
|
|
static void rpmsg_virtio_del_ctrl_dev(struct rpmsg_device *rpdev_ctrl) |
|
{ |
|
if (!rpdev_ctrl) |
|
return; |
|
kfree(to_virtio_rpmsg_channel(rpdev_ctrl)); |
|
} |
|
|
|
static int rpmsg_probe(struct virtio_device *vdev) |
|
{ |
|
vq_callback_t *vq_cbs[] = { rpmsg_recv_done, rpmsg_xmit_done }; |
|
static const char * const names[] = { "input", "output" }; |
|
struct virtqueue *vqs[2]; |
|
struct virtproc_info *vrp; |
|
struct virtio_rpmsg_channel *vch = NULL; |
|
struct rpmsg_device *rpdev_ns, *rpdev_ctrl; |
|
void *bufs_va; |
|
int err = 0, i; |
|
size_t total_buf_space; |
|
bool notify; |
|
|
|
vrp = kzalloc(sizeof(*vrp), GFP_KERNEL); |
|
if (!vrp) |
|
return -ENOMEM; |
|
|
|
vrp->vdev = vdev; |
|
|
|
idr_init(&vrp->endpoints); |
|
mutex_init(&vrp->endpoints_lock); |
|
mutex_init(&vrp->tx_lock); |
|
init_waitqueue_head(&vrp->sendq); |
|
|
|
/* We expect two virtqueues, rx and tx (and in this order) */ |
|
err = virtio_find_vqs(vdev, 2, vqs, vq_cbs, names, NULL); |
|
if (err) |
|
goto free_vrp; |
|
|
|
vrp->rvq = vqs[0]; |
|
vrp->svq = vqs[1]; |
|
|
|
/* we expect symmetric tx/rx vrings */ |
|
WARN_ON(virtqueue_get_vring_size(vrp->rvq) != |
|
virtqueue_get_vring_size(vrp->svq)); |
|
|
|
/* we need less buffers if vrings are small */ |
|
if (virtqueue_get_vring_size(vrp->rvq) < MAX_RPMSG_NUM_BUFS / 2) |
|
vrp->num_bufs = virtqueue_get_vring_size(vrp->rvq) * 2; |
|
else |
|
vrp->num_bufs = MAX_RPMSG_NUM_BUFS; |
|
|
|
vrp->buf_size = MAX_RPMSG_BUF_SIZE; |
|
|
|
total_buf_space = vrp->num_bufs * vrp->buf_size; |
|
|
|
/* allocate coherent memory for the buffers */ |
|
bufs_va = dma_alloc_coherent(vdev->dev.parent, |
|
total_buf_space, &vrp->bufs_dma, |
|
GFP_KERNEL); |
|
if (!bufs_va) { |
|
err = -ENOMEM; |
|
goto vqs_del; |
|
} |
|
|
|
dev_dbg(&vdev->dev, "buffers: va %pK, dma %pad\n", |
|
bufs_va, &vrp->bufs_dma); |
|
|
|
/* half of the buffers is dedicated for RX */ |
|
vrp->rbufs = bufs_va; |
|
|
|
/* and half is dedicated for TX */ |
|
vrp->sbufs = bufs_va + total_buf_space / 2; |
|
|
|
/* set up the receive buffers */ |
|
for (i = 0; i < vrp->num_bufs / 2; i++) { |
|
struct scatterlist sg; |
|
void *cpu_addr = vrp->rbufs + i * vrp->buf_size; |
|
|
|
rpmsg_sg_init(&sg, cpu_addr, vrp->buf_size); |
|
|
|
err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, cpu_addr, |
|
GFP_KERNEL); |
|
WARN_ON(err); /* sanity check; this can't really happen */ |
|
} |
|
|
|
/* suppress "tx-complete" interrupts */ |
|
virtqueue_disable_cb(vrp->svq); |
|
|
|
vdev->priv = vrp; |
|
|
|
rpdev_ctrl = rpmsg_virtio_add_ctrl_dev(vdev); |
|
if (IS_ERR(rpdev_ctrl)) { |
|
err = PTR_ERR(rpdev_ctrl); |
|
goto free_coherent; |
|
} |
|
|
|
/* if supported by the remote processor, enable the name service */ |
|
if (virtio_has_feature(vdev, VIRTIO_RPMSG_F_NS)) { |
|
vch = kzalloc(sizeof(*vch), GFP_KERNEL); |
|
if (!vch) { |
|
err = -ENOMEM; |
|
goto free_ctrldev; |
|
} |
|
|
|
/* Link the channel to our vrp */ |
|
vch->vrp = vrp; |
|
|
|
/* Assign public information to the rpmsg_device */ |
|
rpdev_ns = &vch->rpdev; |
|
rpdev_ns->ops = &virtio_rpmsg_ops; |
|
rpdev_ns->little_endian = virtio_is_little_endian(vrp->vdev); |
|
|
|
rpdev_ns->dev.parent = &vrp->vdev->dev; |
|
rpdev_ns->dev.release = virtio_rpmsg_release_device; |
|
|
|
err = rpmsg_ns_register_device(rpdev_ns); |
|
if (err) |
|
goto free_vch; |
|
} |
|
|
|
/* |
|
* Prepare to kick but don't notify yet - we can't do this before |
|
* device is ready. |
|
*/ |
|
notify = virtqueue_kick_prepare(vrp->rvq); |
|
|
|
/* From this point on, we can notify and get callbacks. */ |
|
virtio_device_ready(vdev); |
|
|
|
/* tell the remote processor it can start sending messages */ |
|
/* |
|
* this might be concurrent with callbacks, but we are only |
|
* doing notify, not a full kick here, so that's ok. |
|
*/ |
|
if (notify) |
|
virtqueue_notify(vrp->rvq); |
|
|
|
dev_info(&vdev->dev, "rpmsg host is online\n"); |
|
|
|
return 0; |
|
|
|
free_vch: |
|
kfree(vch); |
|
free_ctrldev: |
|
rpmsg_virtio_del_ctrl_dev(rpdev_ctrl); |
|
free_coherent: |
|
dma_free_coherent(vdev->dev.parent, total_buf_space, |
|
bufs_va, vrp->bufs_dma); |
|
vqs_del: |
|
vdev->config->del_vqs(vrp->vdev); |
|
free_vrp: |
|
kfree(vrp); |
|
return err; |
|
} |
|
|
|
static int rpmsg_remove_device(struct device *dev, void *data) |
|
{ |
|
device_unregister(dev); |
|
|
|
return 0; |
|
} |
|
|
|
static void rpmsg_remove(struct virtio_device *vdev) |
|
{ |
|
struct virtproc_info *vrp = vdev->priv; |
|
size_t total_buf_space = vrp->num_bufs * vrp->buf_size; |
|
int ret; |
|
|
|
vdev->config->reset(vdev); |
|
|
|
ret = device_for_each_child(&vdev->dev, NULL, rpmsg_remove_device); |
|
if (ret) |
|
dev_warn(&vdev->dev, "can't remove rpmsg device: %d\n", ret); |
|
|
|
idr_destroy(&vrp->endpoints); |
|
|
|
vdev->config->del_vqs(vrp->vdev); |
|
|
|
dma_free_coherent(vdev->dev.parent, total_buf_space, |
|
vrp->rbufs, vrp->bufs_dma); |
|
|
|
kfree(vrp); |
|
} |
|
|
|
static struct virtio_device_id id_table[] = { |
|
{ VIRTIO_ID_RPMSG, VIRTIO_DEV_ANY_ID }, |
|
{ 0 }, |
|
}; |
|
|
|
static unsigned int features[] = { |
|
VIRTIO_RPMSG_F_NS, |
|
}; |
|
|
|
static struct virtio_driver virtio_ipc_driver = { |
|
.feature_table = features, |
|
.feature_table_size = ARRAY_SIZE(features), |
|
.driver.name = KBUILD_MODNAME, |
|
.driver.owner = THIS_MODULE, |
|
.id_table = id_table, |
|
.probe = rpmsg_probe, |
|
.remove = rpmsg_remove, |
|
}; |
|
|
|
static int __init rpmsg_init(void) |
|
{ |
|
int ret; |
|
|
|
ret = register_virtio_driver(&virtio_ipc_driver); |
|
if (ret) |
|
pr_err("failed to register virtio driver: %d\n", ret); |
|
|
|
return ret; |
|
} |
|
subsys_initcall(rpmsg_init); |
|
|
|
static void __exit rpmsg_fini(void) |
|
{ |
|
unregister_virtio_driver(&virtio_ipc_driver); |
|
} |
|
module_exit(rpmsg_fini); |
|
|
|
MODULE_DEVICE_TABLE(virtio, id_table); |
|
MODULE_DESCRIPTION("Virtio-based remote processor messaging bus"); |
|
MODULE_LICENSE("GPL v2");
|
|
|