drivers/thunderbolt/nhi.h

   1 /*
   2  * Thunderbolt Cactus Ridge driver - NHI driver
   3  *
   4  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
   5  */
   6
   7 #ifndef DSL3510_H_
   8 #define DSL3510_H_
   9
  10 #include <linux/mutex.h>
  11 #include <linux/workqueue.h>
  12
  13 /**
  14  * struct tb_nhi - thunderbolt native host interface
  15  */
  16 struct tb_nhi {
  17         struct mutex lock; /*
  18                             * Must be held during ring creation/destruction.
  19                             * Is acquired by interrupt_work when dispatching
  20                             * interrupts to individual rings.
  21                             **/
  22         struct pci_dev *pdev;
  23         void __iomem *iobase;
  24         struct tb_ring **tx_rings;
  25         struct tb_ring **rx_rings;
  26         struct work_struct interrupt_work;
  27         u32 hop_count; /* Number of rings (end point hops) supported by NHI. */
  28 };
  29
  30 /**
  31  * struct tb_ring - thunderbolt TX or RX ring associated with a NHI
  32  */
  33 struct tb_ring {
  34         struct mutex lock; /* must be acquired after nhi->lock */
  35         struct tb_nhi *nhi;
  36         int size;
  37         int hop;
  38         int head; /* write next descriptor here */
  39         int tail; /* complete next descriptor here */
  40         struct ring_desc *descriptors;
  41         dma_addr_t descriptors_dma;
  42         struct list_head queue;
  43         struct list_head in_flight;
  44         struct work_struct work;
  45         bool is_tx:1; /* rx otherwise */
  46         bool running:1;
  47 };
  48
  49 struct ring_frame;
  50 typedef void (*ring_cb)(struct tb_ring*, struct ring_frame*, bool canceled);
  51
  52 /**
  53  * struct ring_frame - for use with ring_rx/ring_tx
  54  */
  55 struct ring_frame {
  56         dma_addr_t buffer_phy;
  57         ring_cb callback;
  58         struct list_head list;
  59         u32 size:12; /* TX: in, RX: out*/
  60         u32 flags:12; /* RX: out */
  61         u32 eof:4; /* TX:in, RX: out */
  62         u32 sof:4; /* TX:in, RX: out */
  63 };
  64
  65 #define TB_FRAME_SIZE 0x100    /* minimum size for ring_rx */
  66
  67 struct tb_ring *ring_alloc_tx(struct tb_nhi *nhi, int hop, int size);
  68 struct tb_ring *ring_alloc_rx(struct tb_nhi *nhi, int hop, int size);
  69 void ring_start(struct tb_ring *ring);
  70 void ring_stop(struct tb_ring *ring);
  71 void ring_free(struct tb_ring *ring);
  72
  73 int __ring_enqueue(struct tb_ring *ring, struct ring_frame *frame);
  74
  75 /**
  76  * ring_rx() - enqueue a frame on an RX ring
  77  *
  78  * frame->buffer, frame->buffer_phy and frame->callback have to be set. The
  79  * buffer must contain at least TB_FRAME_SIZE bytes.
  80  *
  81  * frame->callback will be invoked with frame->size, frame->flags, frame->eof,
  82  * frame->sof set once the frame has been received.
  83  *
  84  * If ring_stop is called after the packet has been enqueued frame->callback
  85  * will be called with canceled set to true.
  86  *
  87  * Return: Returns ESHUTDOWN if ring_stop has been called. Zero otherwise.
  88  */
  89 static inline int ring_rx(struct tb_ring *ring, struct ring_frame *frame)
  90 {
  91         WARN_ON(ring->is_tx);
  92         return __ring_enqueue(ring, frame);
  93 }
  94
  95 /**
  96  * ring_tx() - enqueue a frame on an TX ring
  97  *
  98  * frame->buffer, frame->buffer_phy, frame->callback, frame->size, frame->eof
  99  * and frame->sof have to be set.
 100  *
 101  * frame->callback will be invoked with once the frame has been transmitted.
 102  *
 103  * If ring_stop is called after the packet has been enqueued frame->callback
 104  * will be called with canceled set to true.
 105  *
 106  * Return: Returns ESHUTDOWN if ring_stop has been called. Zero otherwise.
 107  */
 108 static inline int ring_tx(struct tb_ring *ring, struct ring_frame *frame)
 109 {
 110         WARN_ON(!ring->is_tx);
 111         return __ring_enqueue(ring, frame);
 112 }
 113
 114 #endif