source: soft/giet_vm/giet_drivers/bdv_driver.h @ 445

Last change on this file since 445 was 437, checked in by alain, 10 years ago

Introducing dynamic allocation of peripheral channel(TTY, NIC, TIM, CMA)
Removint the ICU driver : ICU component not supported anymore.
Removing the FBF driver.

File size: 6.7 KB
Line 
1///////////////////////////////////////////////////////////////////////////////////
2// File      : bdv_driver.h
3// Date      : 01/11/2013
4// Author    : alain greiner
5// Maintainer: cesar fuguet
6// Copyright (c) UPMC-LIP6
7///////////////////////////////////////////////////////////////////////////////////
8// The bdv_driver.c and bdv_driver.h files are part ot the GIET-VM kernel.
9// This driver supports the SocLib vci_block_device component, that is
10// a single channel, block oriented, external storage contrÃŽler.
11//
12// The _bdv_read() and _bdv_write() functions are always blocking.
13// They can be called in 3 modes:
14//
15// - In BOOT mode, these functions use a polling policy on the BDV STATUS
16//   register to detect transfer completion, as interrupts are not activated.
17//   This mode is used by the boot code to load the map.bin file into memory
18//   (before MMU activation), or to load the .elf files (after MMU activation).
19//
20// - In KERNEL mode, these functions use a descheduling strategy:
21//   The ISR executed when transfer completes should restart the calling task.
22//   There is no checking of user access right to the memory buffer.
23//   This mode must be used, for an "open" system call.
24//
25// - In USER mode, these functions use a descheduling strategy:
26//   The ISR executed when transfer completes should restart the calling task,
27//   The user access right to the memory buffer must be checked.
28//   This mode must be used for a "read/write" system call.
29//
30// As the BDV component can be used by several programs running in parallel,
31// the _bdv_lock variable guaranties exclusive access to the device.  The
32// _bdv_read() and _bdv_write() functions use atomic LL/SC to get the lock.
33//
34// Finally, the memory buffer must fulfill the following conditions:
35// - The buffer must be word aligned,
36// - The buffer must be mapped in user space for an user access,
37// - The buffer must be writable in case of (to_mem) access,
38// - The total number of physical pages occupied by the user buffer cannot
39//   be larger than 512 pages if the IOMMU is activated,
40// - All physical pages occupied by the user buffer must be contiguous
41//   if the IOMMU is not activated.
42// An error code is returned if these conditions are not verified.
43//
44// The SEG_IOC_BASE address must be defined in the hard_config.h file.
45///////////////////////////////////////////////////////////////////////////////////
46
47#ifndef _GIET_BDV_DRIVER_H_
48#define _GIET_BDV_DRIVER_H_
49
50#include "utils.h"
51
52///////////////////////////////////////////////////////////////////////////////////
53// BDV global variables
54///////////////////////////////////////////////////////////////////////////////////
55
56extern giet_lock_t           _bdv_lock;    // BDV is a shared ressource
57extern volatile unsigned int _bdv_status;  // required for IRQ signaling
58extern volatile unsigned int _bdv_gtid;    // descheduled task id = gpid<<16 + ltid
59
60///////////////////////////////////////////////////////////////////////////////////
61// BDV registers, operations and status values
62///////////////////////////////////////////////////////////////////////////////////
63
64enum BDV_registers
65{
66    BLOCK_DEVICE_BUFFER,
67    BLOCK_DEVICE_LBA,
68    BLOCK_DEVICE_COUNT,
69    BLOCK_DEVICE_OP,
70    BLOCK_DEVICE_STATUS,
71    BLOCK_DEVICE_IRQ_ENABLE,
72    BLOCK_DEVICE_SIZE,
73    BLOCK_DEVICE_BLOCK_SIZE,
74    BLOCK_DEVICE_BUFFER_EXT,
75};
76
77enum BDV_operations
78{
79    BLOCK_DEVICE_NOOP,
80    BLOCK_DEVICE_READ,
81    BLOCK_DEVICE_WRITE,
82};
83
84enum BDV_status
85{
86    BLOCK_DEVICE_IDLE,
87    BLOCK_DEVICE_BUSY,
88    BLOCK_DEVICE_READ_SUCCESS,
89    BLOCK_DEVICE_WRITE_SUCCESS,
90    BLOCK_DEVICE_READ_ERROR,
91    BLOCK_DEVICE_WRITE_ERROR,
92    BLOCK_DEVICE_ERROR,
93};
94
95///////////////////////////////////////////////////////////////////////////////////
96//            Access functions
97///////////////////////////////////////////////////////////////////////////////////
98
99///////////////////////////////////////////////////////////////////////////////////
100// This function cheks block size == 512, and desactivates the interrupts.
101// Return 0 for success, > 0 if error
102///////////////////////////////////////////////////////////////////////////////////
103extern unsigned int _bdv_init();
104
105///////////////////////////////////////////////////////////////////////////////////
106// Transfer data from the block device to a memory buffer.
107// - mode     : BOOT / KERNEL / USER
108// - lba      : first block index on the block device
109// - buffer   : base address of the memory buffer (must be word aligned)
110// - count    : number of blocks to be transfered.
111// Returns 0 if success, > 0 if error.
112////////////////////////////////////////////////////////////////////////////////////
113extern unsigned int _bdv_read(  unsigned int       mode,
114                                unsigned int       lba, 
115                                unsigned long long buffer,
116                                unsigned int       count );
117
118///////////////////////////////////////////////////////////////////////////////////
119// Transfer data from a memory buffer to the block device.
120// - mode     : BOOT / KERNEL / USER
121// - lba      : first block index on the block device
122// - buffer   : base address of the memory buffer (must be word aligned)
123// - count    : number of blocks to be transfered.
124// Returns 0 if success, > 0 if error.
125///////////////////////////////////////////////////////////////////////////////////
126extern unsigned int _bdv_write( unsigned int       mode,
127                                unsigned int       lba, 
128                                unsigned long long buffer, 
129                                unsigned int       count );
130
131///////////////////////////////////////////////////////////////////////////////////
132// Returns device status.
133///////////////////////////////////////////////////////////////////////////////////
134extern unsigned int _bdv_get_status();
135
136///////////////////////////////////////////////////////////////////////////////////
137// Returns block size.
138///////////////////////////////////////////////////////////////////////////////////
139extern unsigned int _bdv_get_block_size();
140
141///////////////////////////////////////////////////////////////////////////////////
142// This ISR save the status, acknowledge the IRQ, and activates the task
143// waiting on IO transfer. It can be an HWI or a SWI.
144//
145// TODO the _set_task_slot access should be replaced by an atomic LL/SC
146//      when the CTX_RUN bool will be replaced by a bit_vector.
147///////////////////////////////////////////////////////////////////////////////////
148extern void _bdv_isr( unsigned irq_type,
149                      unsigned irq_id,
150                      unsigned channel );
151
152
153#endif
154
155// Local Variables:
156// tab-width: 4
157// c-basic-offset: 4
158// c-file-offsets:((innamespace . 0)(inline-open . 0))
159// indent-tabs-mode: nil
160// End:
161// vim: filetype=c:expandtab:shiftwidth=4:tabstop=4:softtabstop=4
162
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