source: trunk/kernel/kern/chdev.h @ 377

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1/*
2 * chdev.h - channel device (chdev) descriptor definition.
3 *
4 * Authors  Alain Greiner    (2016)
5 *
6 * Copyright (c) UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MKH
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2.0 of the License.
13 *
14 * ALMOS-MKH is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#ifndef _CHDEV_H_
25#define _CHDEV_H_
26
27#include <kernel_config.h>
28#include <hal_types.h>
29#include <xlist.h>
30#include <metafs.h>
31#include <remote_spinlock.h>
32#include <dev_iob.h>
33#include <dev_ioc.h>
34#include <dev_nic.h>
35#include <dev_pic.h>
36#include <dev_fbf.h>
37
38/******************************************************************************************
39 *       Channel Device descriptor definition
40 *
41 * This file defines the kernel representation of a generic (i.e. implementation
42 * independant) Channel Device descriptor (in brief "chdev").
43 * ALMOS-MKH supports multi-channels peripherals, and defines one separated chdev
44 * descriptor for each channel (and for each RX/TX direction for the NIC device).
45 * Each chdev contains a waiting queue, registering the "client threads" requests,
46 * and an associated "server thread", handling these requests.
47 * These descriptors are physically distributed on all clusters to minimize contention.
48 * Therefore a given I/O operation involve generally three clusters:
49 * - the client cluster, containing the client thread,
50 * - the server cluster, containing the chdev and the server thread,
51 * - the I/O cluster, containing the physical device.
52 *****************************************************************************************/
53
54/****  Forward declarations  ****/
55
56struct  chdev_s;
57struct  thread_s;
58struct  boot_info_s;
59
60/******************************************************************************************
61 * These macros extract the functionality and the implementation from the peripheral type.
62 *****************************************************************************************/
63 
64#define FUNC_FROM_TYPE( type )    ((uint32_t)(type>>16))
65#define IMPL_FROM_TYPE( type )    ((uint32_t)(type & 0x0000FFFF))
66
67/******************************************************************************************
68 * This define the generic prototypes for the two functions that must be defined
69 * by all drivers implementing a generic device:
70 * - "cmd"     : start an I/O operation.
71 * - "isr"     : complete an I/O operation.
72 * The "cmd" and "isr" are registered in the generic chdev descriptor at kernel init,
73 * and are called to start and complete an I/O operation. 
74*****************************************************************************************/
75
76typedef void (dev_ini_t) ( xptr_t dev );     
77typedef void (dev_cmd_t) ( xptr_t thread ); 
78typedef void (dev_isr_t) ( struct chdev_s * dev ); 
79
80/******************************************************************************************
81 * This enum defines the supported generic device types.
82 * These types are functionnal types: all (architecture specific) implementations
83 * provide the same set of operations and the same driver API.
84 * This enum must be consistent with the enum in files arch_info.h, and arch_class.py.
85 *
86 * WARNING : The ICU device exist in boot_info to specify the base address of the
87 *           distributed LAPIC controler, but it does not exist as a chdev in the kernel,
88 *           as it is hidden in the driver associated to the PIC device.
89 *****************************************************************************************/
90 
91enum dev_func_type
92{
93        DEV_FUNC_RAM   =  0,
94        DEV_FUNC_ROM   =  1,
95        DEV_FUNC_FBF   =  2,
96    DEV_FUNC_IOB   =  3,
97    DEV_FUNC_IOC   =  4,
98        DEV_FUNC_MMC   =  5,
99        DEV_FUNC_DMA   =  6,
100        DEV_FUNC_NIC   =  7,
101        DEV_FUNC_TIM   =  8,
102        DEV_FUNC_TXT   =  9,
103    DEV_FUNC_ICU   = 10,   
104    DEV_FUNC_PIC   = 11,
105
106    DEV_FUNC_NR    = 12,
107};
108
109/******************************************************************************************
110 * This structure defines a chdev descriptor.
111 * For multi-channels device, there is one chdev descriptor per channel.
112 * This structure is NOT replicated, and can be located in any cluster.
113 * One kernel thread, in charge of handling the commands registered in the waiting queue
114 * of client threads is associated to each chdev descriptor (not for ICU, PIC, IOB).
115 * For each device type ***, the specific extensions are defined in the "dev_***.h" file.
116 *****************************************************************************************/
117
118typedef struct chdev_s
119{
120        uint32_t             func;        /*! peripheral functionnal type                    */
121        uint32_t             impl;        /*! peripheral inplementation subtype              */
122    uint32_t             channel;     /*! channel index                                  */
123    bool_t               is_rx;       /*! relevant for NIC peripheral channels only      */
124        xptr_t               base;        /*! extended pointer on channel device segment     */
125    char                 name[16];    /*! name (required by DEVFS)                       */
126
127    dev_cmd_t          * cmd;         /*! local pointer on driver command function       */
128    dev_isr_t          * isr;         /*! local pointer on driver ISR function           */ 
129    struct thread_s    * server;      /*! local pointer on associated server thread      */
130
131    uint32_t             irq_type;    /*! associated IRQ type in local ICU               */
132    uint32_t             irq_id;      /*! associated IRQ index in local ICU              */
133
134    metafs_t             node;        /*! Metafs node associated with this device        */
135
136        remote_spinlock_t    wait_lock;   /*! lock protecting exclusive access to queue      */
137    xlist_entry_t        wait_root;   /*! root of waiting threads queue                  */
138
139    union
140    {
141        iob_extend_t     iob;         /*! IOB specific extension                         */
142        ioc_extend_t     ioc;         /*! IOC specific extension                         */
143        nic_extend_t     nic;         /*! NIC specific extension                         */
144        pic_extend_t     pic;         /*! PIC specific extension                         */
145        fbf_extend_t     fbf;         /*! FBF specific extension                         */
146    } 
147    ext;
148}
149chdev_t;
150
151/******************************************************************************************
152 * This structure defines the channel_devices descriptors directory.
153 * Each entry in this structure contains an extended pointer on a chdev descriptor.
154 * There is one entry per channel OR per cluster, depending on peripheral type.
155 * This structure is replicated in each cluster, and is initialised during kernel init.
156 * It is used for fast access to a device descriptor, from type and channel for an
157 * external peripheral, or from type and cluster for a hared internal peripheral.
158 * - a "shared" chdev can be accessed by any thread running in any cluster.
159 * - a "private" chdev can only be accessed by a thread running in local cluster.
160 *****************************************************************************************/
161
162typedef struct chdev_directory_s
163{
164    xptr_t   iob;                                // external / single channel / shared
165    xptr_t   pic;                                // external / single channel / shared
166
167    xptr_t   txt[CONFIG_MAX_TXT_CHANNELS];       // external / multi-channels / shared
168    xptr_t   ioc[CONFIG_MAX_IOC_CHANNELS];       // external / multi-channels / shared
169    xptr_t   fbf[CONFIG_MAX_FBF_CHANNELS];       // external / multi-channels / shared
170    xptr_t   nic_rx[CONFIG_MAX_NIC_CHANNELS];    // external / multi-channels / shared
171    xptr_t   nic_tx[CONFIG_MAX_NIC_CHANNELS];    // external / multi-channels / shared
172
173    xptr_t   mmc[CONFIG_MAX_CLUSTERS];           // internal / single channel / shared
174
175    xptr_t   dma[CONFIG_MAX_DMA_CHANNELS];       // internal / multi-channels / private
176}
177chdev_directory_t;
178
179/******************************************************************************************
180 * This function display relevant values for a chdev descriptor.
181 ******************************************************************************************
182 * @ chdev   : pointer on chdev.
183 *****************************************************************************************/
184void chdev_print( chdev_t * chdev );
185
186/******************************************************************************************
187 * This function returns a printable string for a device functionnal types.
188 ******************************************************************************************
189 * @ func_type  : functionnal type.
190 * @ return pointer on string.
191 *****************************************************************************************/
192char * chdev_func_str( uint32_t func_type );
193
194/******************************************************************************************
195 * This  function allocates memory and initializes a chdev descriptor in local cluster,
196 * from arguments values.  It should be called by a local thread.
197 * The device specific fields are initialised later.
198 ******************************************************************************************
199 * @ func      : functionnal type.
200 * @ impl      : implementation type.
201 * @ channel   : channel index / for multi-channels peripherals.
202 * @ is_rx     : for NIC peripheral / NIC RX if true / NIC TX if false.
203 * @ base      : extended pointer on peripheral segment base.
204 * @ return a local pointer on created chdev / return NULL if failure.
205 *****************************************************************************************/
206chdev_t * chdev_create( uint32_t    func,
207                        uint32_t    impl,
208                        uint32_t    channel,
209                        bool_t      is_rx,
210                        xptr_t      base );
211
212/******************************************************************************************
213 * This function registers a local client thread in the waiting queue of a remote
214 * chdev descriptor, activates (i.e. unblock) the server thread associated to chdev,
215 * and blocks itself on the THREAD_BLOCKED_IO condition.
216 ******************************************************************************************
217 * @ chdev_xp  : extended pointer on remote chdev descriptor.
218 * @ thread    : local pointer on client thread.
219 *****************************************************************************************/
220void chdev_register_command( xptr_t            chdev_xp,
221                             struct thread_s * thread );
222
223/******************************************************************************************
224 * This function is executed by the server thread associated to a chdev descriptor.
225 * It executes an infinite loop to handle sequencially all commands registered by the
226 * client threads in the device waiting queue, until the queue is empty.
227 * The driver CMD function being blocking, these functions return only when the command
228 * is completed. These functions can use either a busy waiting policy, or a descheduling
229 * policy, blocking on the THREAD_BLOCKED_IO_ISR condition, and reactivated by the ISR.
230 * When the waiting queue is empty, the server thread blocks on the THREAD_BLOCKED_IO_CMD
231 * condition and deschedule. It is re-activated by a client thread registering a command.
232 ******************************************************************************************
233 * @ chdev   : local pointer on device descriptor.
234 *****************************************************************************************/
235void chdev_sequencial_server( chdev_t * chdev );
236
237/******************************************************************************************
238 * This function displays the local copy of the external chdevs directory.
239 * (global variable replicated in all clusters)
240 *****************************************************************************************/
241void chdev_dir_display();
242
243
244
245#endif  /* _CHDEV_H_ */
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