source: trunk/kernel/kern/chdev.h @ 317

Last change on this file since 317 was 317, checked in by alain, 4 years ago

1) Introduce the TSAR hal_cpu_context_switch() function.
2) Introduce the generic vfs_kernel_move() function.

File size: 12.2 KB
Line 
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_ioc.h>
33#include <dev_nic.h>
34#include <dev_pic.h>
35#include <dev_fbf.h>
36
37/******************************************************************************************
38 *       Channel Device descriptor definition
39 *
40 * This file defines the kernel representation of a generic (i.e. implementation
41 * independant) Channel Device descriptor (in brief "chdev").
42 * ALMOS-MKH supports multi-channels peripherals, and defines one separated chdev
43 * descriptor for each channel (and for each RX/TX direction for the NIC device).
44 * Each chdev contains a waiting queue, registering the "client threads" requests,
45 * and an associated "server thread", handling these requests.
46 * These descriptors are physically distributed on all clusters to minimize contention.
47 * Therefore a given I/O operation involve generally three clusters:
48 * - the client cluster, containing the client thread,
49 * - the server cluster, containing the chdev and the server thread,
50 * - the I/O cluster, containing the physical device.
51 *****************************************************************************************/
52
53/****  Forward declarations  ****/
54
55struct  chdev_s;
56struct  thread_s;
57struct  boot_info_s;
58
59/******************************************************************************************
60 * These macros extract the functionality and the implementation from the peripheral type.
61 *****************************************************************************************/
62 
63#define FUNC_FROM_TYPE( type )    ((uint32_t)(type>>16))
64#define IMPL_FROM_TYPE( type )    ((uint32_t)(type & 0x0000FFFF))
65
66/******************************************************************************************
67 * This define the generic prototypes for the two functions that must be defined
68 * by all drivers implementing a generic device:
69 * - "cmd"     : start an I/O operation.
70 * - "isr"     : complete an I/O operation.
71 * The "cmd" and "isr" are registered in the generic chdev descriptor at kernel init,
72 * and are called to start and complete an I/O operation. 
73*****************************************************************************************/
74
75typedef void (dev_ini_t) ( xptr_t dev );     
76typedef void (dev_cmd_t) ( xptr_t thread ); 
77typedef void (dev_isr_t) ( struct chdev_s * dev ); 
78
79/******************************************************************************************
80 * This enum defines the supported generic device types.
81 * These types are functionnal types: all (architecture specific) implementations
82 * provide the same set of operations and the same driver API.
83 * This enum must be consistent with the enum in files arch_info.h, and arch_class.py.
84 *
85 * WARNING : The ICU device exist in boot_info to specify the base address of the
86 *           distributed LAPIC controler, but it does not exist as a chdev in the kernel,
87 *           as it is hidden in the driver associated to the PIC device.
88 *****************************************************************************************/
89 
90enum dev_func_type
91{
92        DEV_FUNC_RAM   =  0,
93        DEV_FUNC_ROM   =  1,
94        DEV_FUNC_FBF   =  2,
95    DEV_FUNC_IOB   =  3,
96    DEV_FUNC_IOC   =  4,
97        DEV_FUNC_MMC   =  5,
98        DEV_FUNC_DMA   =  6,
99        DEV_FUNC_NIC   =  7,
100        DEV_FUNC_TIM   =  8,
101        DEV_FUNC_TXT   =  9,
102    DEV_FUNC_ICU   = 10,   
103    DEV_FUNC_PIC   = 11,
104
105    DEV_FUNC_NR    = 12,
106};
107
108/******************************************************************************************
109 * This structure defines a chdev descriptor.
110 * For multi-channels device, there is one chdev descriptor per channel.
111 * This structure is NOT replicated, and can be located in any cluster.
112 * One kernel thread, in charge of handling the commands registered in the waiting queue
113 * of client threads is associated to each chdev descriptor (not for ICU, PIC, IOB).
114 * For each device type ***, the specific extensions are defined in the "dev_***.h" file.
115 *****************************************************************************************/
116
117typedef struct chdev_s
118{
119        uint32_t             func;        /*! peripheral functionnal type                    */
120        uint32_t             impl;        /*! peripheral inplementation subtype              */
121    uint32_t             channel;     /*! channel index                                  */
122    bool_t               is_rx;       /*! relevant for NIC peripheral channels only      */
123        xptr_t               base;        /*! extended pointer on channel device segment     */
124    char                 name[16];    /*! name (required by DEVFS)                       */
125
126    dev_cmd_t          * cmd;         /*! local pointer on driver command function       */
127    dev_isr_t          * isr;         /*! local pointer on driver ISR function           */ 
128    struct thread_s    * server;      /*! local pointer on associated server thread      */
129
130    uint32_t             irq_type;    /*! associated IRQ type in local ICU               */
131    uint32_t             irq_id;      /*! associated IRQ index in local ICU              */
132
133    metafs_t             node;        /*! Metafs node associated with this device        */
134
135        remote_spinlock_t    wait_lock;   /*! lock protecting exclusive access to queue      */
136    xlist_entry_t        wait_root;   /*! root of waiting threads queue                  */
137
138    union
139    {
140        ioc_extend_t     ioc;         /*! IOC specific extension                         */
141        nic_extend_t     nic;         /*! NIC specific extension                         */
142        pic_extend_t     pic;         /*! PIC specific extension                         */
143        fbf_extend_t     fbf;         /*! FBF specific extension                         */
144    } 
145    ext;
146}
147chdev_t;
148
149/******************************************************************************************
150 * This structure defines the channel_devices descriptors directory.
151 * Each entry in this structure contains an extended pointer on a chdev descriptor.
152 * There is one entry per channel OR per cluster, depending on peripheral type.
153 * This structure is replicated in each cluster, and is initialised during kernel init.
154 * It is used for fast access to a device descriptor, from type and channel for an
155 * external peripheral, or from type and cluster for a hared internal peripheral.
156 * - a "shared" chdev can be accessed by any thread running in any cluster.
157 * - a "private" chdev can only be accessed by a thread running in local cluster.
158 *****************************************************************************************/
159
160typedef struct chdev_directory_s
161{
162    xptr_t   iob;                                // external / single channel / shared
163    xptr_t   pic;                                // external / single channel / shared
164
165    xptr_t   txt[CONFIG_MAX_TXT_CHANNELS];       // external / multi-channels / shared
166    xptr_t   ioc[CONFIG_MAX_IOC_CHANNELS];       // external / multi-channels / shared
167    xptr_t   fbf[CONFIG_MAX_FBF_CHANNELS];       // external / multi-channels / shared
168    xptr_t   nic_rx[CONFIG_MAX_NIC_CHANNELS];    // external / multi-channels / shared
169    xptr_t   nic_tx[CONFIG_MAX_NIC_CHANNELS];    // external / multi-channels / shared
170
171    xptr_t   mmc[CONFIG_MAX_CLUSTERS];           // internal / single channel / shared
172
173    xptr_t   dma[CONFIG_MAX_DMA_CHANNELS];       // internal / multi-channels / private
174}
175chdev_directory_t;
176
177/******************************************************************************************
178 * This function display relevant values for a chdev descriptor.
179 ******************************************************************************************
180 * @ chdev   : pointer on chdev.
181 *****************************************************************************************/
182void chdev_print( chdev_t * chdev );
183
184/******************************************************************************************
185 * This function returns a printable string for a device functionnal types.
186 ******************************************************************************************
187 * @ func_type  : functionnal type.
188 * @ return pointer on string.
189 *****************************************************************************************/
190char * chdev_func_str( uint32_t func_type );
191
192/******************************************************************************************
193 * This  function allocates memory and initializes a chdev descriptor in local cluster,
194 * from arguments values.  It should be called by a local thread.
195 * The device specific fields are initialised later.
196 ******************************************************************************************
197 * @ func      : functionnal type.
198 * @ impl      : implementation type.
199 * @ channel   : channel index / for multi-channels peripherals.
200 * @ is_rx     : for NIC peripheral / NIC RX if true / NIC TX if false.
201 * @ base      : extended pointer on peripheral segment base.
202 * @ return a local pointer on created chdev / return NULL if failure.
203 *****************************************************************************************/
204chdev_t * chdev_create( uint32_t    func,
205                        uint32_t    impl,
206                        uint32_t    channel,
207                        bool_t      is_rx,
208                        xptr_t      base );
209
210/******************************************************************************************
211 * This function registers a local client thread in the waiting queue of a remote
212 * chdev descriptor, activates (i.e. unblock) the server thread associated to chdev,
213 * and blocks itself on the THREAD_BLOCKED_IO condition.
214 ******************************************************************************************
215 * @ chdev_xp  : extended pointer on remote chdev descriptor.
216 * @ thread    : local pointer on client thread.
217 *****************************************************************************************/
218void chdev_register_command( xptr_t            chdev_xp,
219                             struct thread_s * thread );
220
221/******************************************************************************************
222 * This function is executed by the server thread associated to a chdev descriptor.
223 * It executes an infinite loop to handle sequencially all commands registered by the
224 * client threads in the device waiting queue, until the queue is empty.
225 * The driver CMD function being blocking, these functions return only when the command
226 * is completed. These functions can use either a busy waiting policy, or a descheduling
227 * policy, blocking on the THREAD_BLOCKED_IO_ISR condition, and reactivated by the ISR.
228 * When the waiting queue is empty, the server thread blocks on the THREAD_BLOCKED_IO_CMD
229 * condition and deschedule. It is re-activated by a client thread registering a command.
230 ******************************************************************************************
231 * @ chdev   : local pointer on device descriptor.
232 *****************************************************************************************/
233void chdev_sequencial_server( chdev_t * chdev );
234
235/******************************************************************************************
236 * This function displays the local copy of the external chdevs directory.
237 * (global variable replicated in all clusters)
238 *****************************************************************************************/
239void chdev_dir_display();
240
241
242
243#endif  /* _CHDEV_H_ */
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