source: soft/giet_vm/giet_drivers/bdv_driver.h @ 820

Last change on this file since 820 was 728, checked in by alain, 9 years ago

bloup

File size: 5.0 KB
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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_access() function supports both read and write access to block device,
13// and implement two operating modes:
14//
15// - in "synchronous" mode, it uses a polling policy on the BDV STATUS
16//   register to detect transfer completion, as interrupts are not activated.
17//   This mode must be 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//   As only one processor acces the block device, it doesn't take the _bdv_lock.
20//
21// - In "descheduling" mode, ir uses a descheduling + IRQ policy.
22//   This mode mus be used by the kernel code tho handle system calls.
23//   The ISR executed when transfer completes should restart the calling task,
24//   as the calling task global index has been saved in the _bdv_gtid variable.
25//   As the BDV component can be used by several programs running in parallel,
26//   it takes the _bdv_lock and registers it in the calling task context.
27//
28// The SEG_IOC_BASE address must be defined in the hard_config.h file.
29///////////////////////////////////////////////////////////////////////////////////
30
31#ifndef _GIET_BDV_DRIVER_H_
32#define _GIET_BDV_DRIVER_H_
33
34#include "kernel_locks.h"
35
36///////////////////////////////////////////////////////////////////////////////////
37// BDV registers, operations and status values
38///////////////////////////////////////////////////////////////////////////////////
39
40enum BDV_registers
41{
42    BLOCK_DEVICE_BUFFER,
43    BLOCK_DEVICE_LBA,
44    BLOCK_DEVICE_COUNT,
45    BLOCK_DEVICE_OP,
46    BLOCK_DEVICE_STATUS,
47    BLOCK_DEVICE_IRQ_ENABLE,
48    BLOCK_DEVICE_SIZE,
49    BLOCK_DEVICE_BLOCK_SIZE,
50    BLOCK_DEVICE_BUFFER_EXT,
51};
52
53enum BDV_operations
54{
55    BLOCK_DEVICE_NOOP,
56    BLOCK_DEVICE_READ,
57    BLOCK_DEVICE_WRITE,
58};
59
60enum BDV_status
61{
62    BLOCK_DEVICE_IDLE,
63    BLOCK_DEVICE_BUSY,
64    BLOCK_DEVICE_READ_SUCCESS,
65    BLOCK_DEVICE_WRITE_SUCCESS,
66    BLOCK_DEVICE_READ_ERROR,
67    BLOCK_DEVICE_WRITE_ERROR,
68    BLOCK_DEVICE_ERROR,
69};
70
71///////////////////////////////////////////////////////////////////////////////
72//           Global variables
73///////////////////////////////////////////////////////////////////////////////
74
75extern spin_lock_t  _bdv_lock;
76
77extern unsigned int _bdv_gtid;
78
79extern unsigned int _bdv_status;
80
81///////////////////////////////////////////////////////////////////////////////////
82//            Low level access function
83///////////////////////////////////////////////////////////////////////////////////
84
85unsigned int _bdv_get_register( unsigned int index );
86
87void _bdv_set_register( unsigned int index,
88                        unsigned int value );
89
90///////////////////////////////////////////////////////////////////////////////////
91// This function cheks block size == 512, and desactivates the interrupts.
92// Return 0 for success, > 0 if error
93///////////////////////////////////////////////////////////////////////////////////
94extern unsigned int _bdv_init();
95
96///////////////////////////////////////////////////////////////////////////////////
97// Transfer data to/from the block device from/to a memory buffer.
98// - use_irq  : descheduling + IRQ if non zero / polling if zero
99// - to_mem   : from external storage to memory when non 0.
100// - lba      : first block index on the block device
101// - buffer   : pbase address of the memory buffer (must be word aligned)
102// - count    : number of blocks to be transfered.
103// Returns 0 if success, > 0 if error.
104///////////////////////////////////////////////////////////////////////////////////
105extern unsigned int _bdv_access( unsigned int       use_irq,
106                                 unsigned int       to_mem,
107                                 unsigned int       lba, 
108                                 unsigned long long buffer,
109                                 unsigned int       count );
110
111///////////////////////////////////////////////////////////////////////////////////
112// This ISR save the status, acknowledge the IRQ, and activates the task
113// waiting on IO transfer. It can be an HWI or a SWI.
114//
115// TODO the _set_task_slot access should be replaced by an atomic LL/SC
116//      when the CTX_RUN bool will be replaced by a bit_vector.
117///////////////////////////////////////////////////////////////////////////////////
118extern void _bdv_isr( unsigned irq_type,
119                      unsigned irq_id,
120                      unsigned channel );
121
122
123#endif
124
125// Local Variables:
126// tab-width: 4
127// c-basic-offset: 4
128// c-file-offsets:((innamespace . 0)(inline-open . 0))
129// indent-tabs-mode: nil
130// End:
131// vim: filetype=c:expandtab:shiftwidth=4:tabstop=4:softtabstop=4
132
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