src/Unix/video_vosf.h

/*
 *  video_vosf.h - Video/graphics emulation, video on SEGV signals support
 *
 *  Basilisk II (C) 1997-2001 Christian Bauer
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef VIDEO_VOSF_H
#define VIDEO_VOSF_H

// Note: this file is #include'd in video_x.cpp
#ifdef ENABLE_VOSF

#include <fcntl.h>
#include <sys/mman.h>
#include "sigsegv.h"
#include "vm_alloc.h"

#ifdef ENABLE_MON
# include "mon.h"
#endif

// Variables for Video on SEGV support
static uint8 *the_host_buffer;  // Host frame buffer in VOSF mode

struct ScreenPageInfo {
    int top, bottom;                    // Mapping between this virtual page and Mac scanlines
};

struct ScreenInfo {
    uintptr memStart;                   // Start address aligned to page boundary
    uint32 memLength;                   // Length of the memory addressed by the screen pages
    
    uintptr pageSize;                   // Size of a page
    int pageBits;                               // Shift count to get the page number
    uint32 pageCount;                   // Number of pages allocated to the screen
    
        bool dirty;                                     // Flag: set if the frame buffer was touched
    char * dirtyPages;                  // Table of flags set if page was altered
    ScreenPageInfo * pageInfo;  // Table of mappings page -> Mac scanlines
};

static ScreenInfo mainBuffer;

#define PFLAG_SET_VALUE                 0x00
#define PFLAG_CLEAR_VALUE               0x01
#define PFLAG_SET_VALUE_4               0x00000000
#define PFLAG_CLEAR_VALUE_4             0x01010101
#define PFLAG_SET(page)                 mainBuffer.dirtyPages[page] = PFLAG_SET_VALUE
#define PFLAG_CLEAR(page)               mainBuffer.dirtyPages[page] = PFLAG_CLEAR_VALUE
#define PFLAG_ISSET(page)               (mainBuffer.dirtyPages[page] == PFLAG_SET_VALUE)
#define PFLAG_ISCLEAR(page)             (mainBuffer.dirtyPages[page] != PFLAG_SET_VALUE)

#ifdef UNALIGNED_PROFITABLE
# define PFLAG_ISSET_4(page)    (*((uint32 *)(mainBuffer.dirtyPages + (page))) == PFLAG_SET_VALUE_4)
# define PFLAG_ISCLEAR_4(page)  (*((uint32 *)(mainBuffer.dirtyPages + (page))) == PFLAG_CLEAR_VALUE_4)
#else
# define PFLAG_ISSET_4(page) \
                PFLAG_ISSET(page  ) && PFLAG_ISSET(page+1) \
        &&      PFLAG_ISSET(page+2) && PFLAG_ISSET(page+3)
# define PFLAG_ISCLEAR_4(page) \
                PFLAG_ISCLEAR(page  ) && PFLAG_ISCLEAR(page+1) \
        &&      PFLAG_ISCLEAR(page+2) && PFLAG_ISCLEAR(page+3)
#endif

// Set the selected page range [ first_page, last_page [ into the SET state
#define PFLAG_SET_RANGE(first_page, last_page) \
        memset(mainBuffer.dirtyPages + (first_page), PFLAG_SET_VALUE, \
                (last_page) - (first_page))

// Set the selected page range [ first_page, last_page [ into the CLEAR state
#define PFLAG_CLEAR_RANGE(first_page, last_page) \
        memset(mainBuffer.dirtyPages + (first_page), PFLAG_CLEAR_VALUE, \
                (last_page) - (first_page))

#define PFLAG_SET_ALL do { \
        PFLAG_SET_RANGE(0, mainBuffer.pageCount); \
        mainBuffer.dirty = true; \
} while (0)

#define PFLAG_CLEAR_ALL do { \
        PFLAG_CLEAR_RANGE(0, mainBuffer.pageCount); \
        mainBuffer.dirty = false; \
} while (0)

// Set the following macro definition to 1 if your system
// provides a really fast strchr() implementation
//#define HAVE_FAST_STRCHR 0

static inline int find_next_page_set(int page)
{
#if HAVE_FAST_STRCHR
        char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_SET_VALUE);
        return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
#else
        while (PFLAG_ISCLEAR_4(page))
                page += 4;
        while (PFLAG_ISCLEAR(page))
                page++;
        return page;
#endif
}

static inline int find_next_page_clear(int page)
{
#if HAVE_FAST_STRCHR
        char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_CLEAR_VALUE);
        return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
#else
        while (PFLAG_ISSET_4(page))
                page += 4;
        while (PFLAG_ISSET(page))
                page++;
        return page;
#endif
}

#ifdef HAVE_PTHREADS
static pthread_mutex_t vosf_lock = PTHREAD_MUTEX_INITIALIZER;   // Mutex to protect frame buffer (dirtyPages in fact)
#define LOCK_VOSF pthread_mutex_lock(&vosf_lock);
#define UNLOCK_VOSF pthread_mutex_unlock(&vosf_lock);
#else
#define LOCK_VOSF
#define UNLOCK_VOSF
#endif

static int log_base_2(uint32 x)
{
        uint32 mask = 0x80000000;
        int l = 31;
        while (l >= 0 && (x & mask) == 0) {
                mask >>= 1;
                l--;
        }
        return l;
}

// Extend size to page boundary
static uint32 page_extend(uint32 size)
{
        const uint32 page_size = getpagesize();
        const uint32 page_mask = page_size - 1;
        return (size + page_mask) & ~page_mask;
}


/*
 *  Initialize the VOSF system (mainBuffer structure, SIGSEGV handler)
 */

static bool screen_fault_handler(sigsegv_address_t fault_address, sigsegv_address_t fault_instruction);

static bool video_vosf_init(void)
{
        const uintptr page_size = getpagesize();
        const uintptr page_mask = page_size - 1;
        
        // Round up frame buffer base to page boundary
        mainBuffer.memStart = (((uintptr) the_buffer) + page_mask) & ~page_mask;
        
        // The frame buffer size shall already be aligned to page boundary (use page_extend)
        mainBuffer.memLength = the_buffer_size;
        
        mainBuffer.pageSize = page_size;
        mainBuffer.pageBits = log_base_2(mainBuffer.pageSize);
        mainBuffer.pageCount =  (mainBuffer.memLength + page_mask)/mainBuffer.pageSize;
        
        // The "2" more bytes requested are a safety net to insure the
        // loops in the update routines will terminate.
        // See "How can we deal with array overrun conditions ?" hereunder for further details.
        mainBuffer.dirtyPages = (char *) malloc(mainBuffer.pageCount + 2);
        if (mainBuffer.dirtyPages == NULL)
                return false;
                
        PFLAG_CLEAR_ALL;
        PFLAG_CLEAR(mainBuffer.pageCount);
        PFLAG_SET(mainBuffer.pageCount+1);
        
        // Allocate and fill in pageInfo with start and end (inclusive) row in number of bytes
        mainBuffer.pageInfo = (ScreenPageInfo *) malloc(mainBuffer.pageCount * sizeof(ScreenPageInfo));
        if (mainBuffer.pageInfo == NULL)
                return false;
        
        uint32 a = 0;
        for (unsigned i = 0; i < mainBuffer.pageCount; i++) {
                unsigned y1 = a / VideoMonitor.mode.bytes_per_row;
                if (y1 >= VideoMonitor.mode.y)
                        y1 = VideoMonitor.mode.y - 1;

                unsigned y2 = (a + mainBuffer.pageSize) / VideoMonitor.mode.bytes_per_row;
                if (y2 >= VideoMonitor.mode.y)
                        y2 = VideoMonitor.mode.y - 1;

                mainBuffer.pageInfo[i].top = y1;
                mainBuffer.pageInfo[i].bottom = y2;

                a += mainBuffer.pageSize;
                if (a > mainBuffer.memLength)
                        a = mainBuffer.memLength;
        }
        
        // We can now write-protect the frame buffer
        if (vm_protect((char *)mainBuffer.memStart, mainBuffer.memLength, VM_PAGE_READ) != 0)
                return false;
        
        // Initialize the handler for SIGSEGV
        if (!sigsegv_install_handler(screen_fault_handler))
                return false;
        
        // The frame buffer is sane, i.e. there is no write to it yet
        mainBuffer.dirty = false;
        return true;
}


/*
 * Deinitialize VOSF system
 */

static void video_vosf_exit(void)
{
        if (mainBuffer.pageInfo) {
                free(mainBuffer.pageInfo);
                mainBuffer.pageInfo = NULL;
        }
        if (mainBuffer.dirtyPages) {
                free(mainBuffer.dirtyPages);
                mainBuffer.dirtyPages = NULL;
        }
}


/*
 * Screen fault handler
 */

static bool screen_fault_handler(sigsegv_address_t fault_address, sigsegv_address_t fault_instruction)
{
//      D(bug("screen_fault_handler: ADDR=%p from IP=%p\n", fault_address, fault_instruction));
        const uintptr addr = (uintptr)fault_address;
        
        /* Someone attempted to write to the frame buffer. Make it writeable
         * now so that the data could actually be written to. It will be made
         * read-only back in one of the screen update_*() functions.
         */
        if (((uintptr)addr - mainBuffer.memStart) < mainBuffer.memLength) {
                const int page  = ((uintptr)addr - mainBuffer.memStart) >> mainBuffer.pageBits;
                LOCK_VOSF;
                PFLAG_SET(page);
                vm_protect((char *)(addr & -mainBuffer.pageSize), mainBuffer.pageSize, VM_PAGE_READ | VM_PAGE_WRITE);
                mainBuffer.dirty = true;
                UNLOCK_VOSF;
                return true;
        }
        
        /* Otherwise, we don't know how to handle the fault, let it crash */
        fprintf(stderr, "do_handle_screen_fault: unhandled address %p", fault_address);
        if (fault_instruction != SIGSEGV_INVALID_PC)
                fprintf(stderr, " [IP=%p]", fault_instruction);
        fprintf(stderr, "\n");
#if EMULATED_68K
        uaecptr nextpc;
        extern void m68k_dumpstate(uaecptr *nextpc);
        m68k_dumpstate(&nextpc);
#endif
        VideoQuitFullScreen();
#ifdef ENABLE_MON
        char *arg[4] = {"mon", "-m", "-r", NULL};
        mon(3, arg);
        QuitEmulator();
#endif
        return false;
}


/*
 *      Update display for Windowed mode and VOSF
 */

// From video_blit.cpp
extern void (*Screen_blit)(uint8 * dest, const uint8 * source, uint32 length);
extern bool Screen_blitter_init(XVisualInfo * visual_info, bool native_byte_order, video_depth mac_depth);
extern uint32 ExpandMap[256];

/*      How can we deal with array overrun conditions ?
        
        The state of the framebuffer pages that have been touched are maintained
        in the dirtyPages[] table. That table is (pageCount + 2) bytes long.

Terminology
        
        "Last Page" denotes the pageCount-nth page, i.e. dirtyPages[pageCount - 1].
        "CLEAR Page Guard" refers to the page following the Last Page but is always
        in the CLEAR state. "SET Page Guard" refers to the page following the CLEAR
        Page Guard but is always in the SET state.

Rough process
        
        The update routines must determine which pages have to be blitted to the
        screen. This job consists in finding the first_page that was touched.
        i.e. find the next page that is SET. Then, finding how many pages were
        touched starting from first_page. i.e. find the next page that is CLEAR.

There are two cases to check:

        - Last Page is CLEAR: find_next_page_set() will reach the SET Page Guard
        but it is beyond the valid pageCount value. Therefore, we exit from the
        update routine.
        
        - Last Page is SET: first_page equals (pageCount - 1) and
        find_next_page_clear() will reach the CLEAR Page Guard. We blit the last
        page to the screen. On the next iteration, page equals pageCount and
        find_next_page_set() will reach the SET Page Guard. We still safely exit
        from the update routine because the SET Page Guard position is greater
        than pageCount.
*/

static inline void update_display_window_vosf(driver_window *drv)
{
        int page = 0;
        for (;;) {
                const unsigned first_page = find_next_page_set(page);
                if (first_page >= mainBuffer.pageCount)
                        break;

                page = find_next_page_clear(first_page);
                PFLAG_CLEAR_RANGE(first_page, page);

                // Make the dirty pages read-only again
                const int32 offset  = first_page << mainBuffer.pageBits;
                const uint32 length = (page - first_page) << mainBuffer.pageBits;
                vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
                
                // There is at least one line to update
                const int y1 = mainBuffer.pageInfo[first_page].top;
                const int y2 = mainBuffer.pageInfo[page - 1].bottom;
                const int height = y2 - y1 + 1;
                
                if (VideoMonitor.mode.depth < VDEPTH_8BIT) {

                        // Update the_host_buffer and copy of the_buffer
                        const int src_bytes_per_row = VideoMonitor.mode.bytes_per_row;
                        const int dst_bytes_per_row = drv->img->bytes_per_line;
                        const int pixels_per_byte = VideoMonitor.mode.x / src_bytes_per_row;
                        int i1 = y1 * src_bytes_per_row, i2 = y1 * dst_bytes_per_row, j;
                        for (j = y1; j <= y2; j++) {
                                Screen_blit(the_host_buffer + i2, the_buffer + i1, VideoMonitor.mode.x / pixels_per_byte);
                                i1 += src_bytes_per_row;
                                i2 += dst_bytes_per_row;
                        }

                } else {

                        // Update the_host_buffer and copy of the_buffer
                        const int src_bytes_per_row = VideoMonitor.mode.bytes_per_row;
                        const int dst_bytes_per_row = drv->img->bytes_per_line;
                        const int bytes_per_pixel = src_bytes_per_row / VideoMonitor.mode.x;
                        int i1 = y1 * src_bytes_per_row, i2 = y1 * dst_bytes_per_row, j;
                        for (j = y1; j <= y2; j++) {
                                Screen_blit(the_host_buffer + i2, the_buffer + i1, bytes_per_pixel * VideoMonitor.mode.x);
                                i1 += src_bytes_per_row;
                                i2 += dst_bytes_per_row;
                        }
                }

                if (drv->have_shm)
                        XShmPutImage(x_display, drv->w, drv->gc, drv->img, 0, y1, 0, y1, VideoMonitor.mode.x, height, 0);
                else
                        XPutImage(x_display, drv->w, drv->gc, drv->img, 0, y1, 0, y1, VideoMonitor.mode.x, height);
        }
        mainBuffer.dirty = false;
}


/*
 *      Update display for DGA mode and VOSF
 *      (only in Real or Direct Addressing mode)
 */

#if REAL_ADDRESSING || DIRECT_ADDRESSING
static inline void update_display_dga_vosf(void)
{
        int page = 0;
        for (;;) {
                const unsigned first_page = find_next_page_set(page);
                if (first_page >= mainBuffer.pageCount)
                        break;

                page = find_next_page_clear(first_page);
                PFLAG_CLEAR_RANGE(first_page, page);

                // Make the dirty pages read-only again
                const int32 offset  = first_page << mainBuffer.pageBits;
                const uint32 length = (page - first_page) << mainBuffer.pageBits;
                vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
                
                // I am sure that y2 >= y1 and depth != 1
                const int y1 = mainBuffer.pageInfo[first_page].top;
                const int y2 = mainBuffer.pageInfo[page - 1].bottom;
                
                const int bytes_per_row = VideoMonitor.mode.bytes_per_row;
                const int bytes_per_pixel = VideoMonitor.mode.bytes_per_row / VideoMonitor.mode.x;
                int i, j;
                
                // Check for first column from left and first column
                // from right that have changed
                int x1 = VideoMonitor.mode.x * bytes_per_pixel - 1;
                for (j = y1; j <= y2; j++) {
                        uint8 * const p1 = &the_buffer[j * bytes_per_row];
                        uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
                        for (i = 0; i < x1; i++) {
                                if (p1[i] != p2[i]) {
                                        x1 = i;
                                        break;
                                }
                        }
                }
                x1 /= bytes_per_pixel;
                
                int x2 = x1 * bytes_per_pixel;
                for (j = y2; j >= y1; j--) {
                        uint8 * const p1 = &the_buffer[j * bytes_per_row];
                        uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
                        for (i = VideoMonitor.mode.x * bytes_per_pixel - 1; i > x2; i--) {
                                if (p1[i] != p2[i]) {
                                        x2 = i;
                                        break;
                                }
                        }
                }
                x2 /= bytes_per_pixel;
                
                // Update the_host_buffer and copy of the_buffer
                // There should be at least one pixel to copy
                const int width = x2 - x1 + 1;
                i = y1 * bytes_per_row + x1 * bytes_per_pixel;
                for (j = y1; j <= y2; j++) {
                        Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * width);
                        memcpy(the_buffer_copy + i, the_buffer + i, bytes_per_pixel * width);
                        i += bytes_per_row;
                }
        }
        mainBuffer.dirty = false;
}
#endif

#endif /* ENABLE_VOSF */

#endif /* VIDEO_VOSF_H */
Revision:	1.29
Committed:	2001-07-14T18:41:01Z (22 years, 11 months ago) by gbeauche
Content type:	text/plain
Branch:	MAIN
Changes since 1.28:	+10 -10 lines
Log Message:	- video_x.cpp: the_buffer shall always be mapped through vm_alloc() so that it can be vm_protect()'ed at will afterwards - video_x.cpp: let driver_base free() the_buffer_copy and the_host_buffer, if necessary - video_vosf.h: reverted to use malloc() for mainBuffer.dirtyPages and mainBuffer.pageInfo - vm_alloc.cpp: small cleanups - fixed typos
#	User	Rev	Content
1	gbeauche	1.1	/*
2			* video_vosf.h - Video/graphics emulation, video on SEGV signals support
3			*
4	gbeauche	1.13	* Basilisk II (C) 1997-2001 Christian Bauer
5	gbeauche	1.1	*
6			* This program is free software; you can redistribute it and/or modify
7			* it under the terms of the GNU General Public License as published by
8			* the Free Software Foundation; either version 2 of the License, or
9			* (at your option) any later version.
10			*
11			* This program is distributed in the hope that it will be useful,
12			* but WITHOUT ANY WARRANTY; without even the implied warranty of
13			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14			* GNU General Public License for more details.
15			*
16			* You should have received a copy of the GNU General Public License
17			* along with this program; if not, write to the Free Software
18			* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19			*/
20
21			#ifndef VIDEO_VOSF_H
22			#define VIDEO_VOSF_H
23
24			// Note: this file is #include'd in video_x.cpp
25			#ifdef ENABLE_VOSF
26
27	cebix	1.19	#include <fcntl.h>
28			#include <sys/mman.h>
29			#include "sigsegv.h"
30			#include "vm_alloc.h"
31
32			#ifdef ENABLE_MON
33			# include "mon.h"
34			#endif
35
36			// Variables for Video on SEGV support
37	gbeauche	1.20	static uint8 *the_host_buffer; // Host frame buffer in VOSF mode
38	cebix	1.19
39			struct ScreenPageInfo {
40			int top, bottom; // Mapping between this virtual page and Mac scanlines
41			};
42
43			struct ScreenInfo {
44			uintptr memStart; // Start address aligned to page boundary
45			uint32 memLength; // Length of the memory addressed by the screen pages
46
47	gbeauche	1.27	uintptr pageSize; // Size of a page
48	cebix	1.19	int pageBits; // Shift count to get the page number
49			uint32 pageCount; // Number of pages allocated to the screen
50
51			bool dirty; // Flag: set if the frame buffer was touched
52			char * dirtyPages; // Table of flags set if page was altered
53			ScreenPageInfo * pageInfo; // Table of mappings page -> Mac scanlines
54			};
55
56			static ScreenInfo mainBuffer;
57
58			#define PFLAG_SET_VALUE 0x00
59			#define PFLAG_CLEAR_VALUE 0x01
60			#define PFLAG_SET_VALUE_4 0x00000000
61			#define PFLAG_CLEAR_VALUE_4 0x01010101
62			#define PFLAG_SET(page) mainBuffer.dirtyPages[page] = PFLAG_SET_VALUE
63			#define PFLAG_CLEAR(page) mainBuffer.dirtyPages[page] = PFLAG_CLEAR_VALUE
64			#define PFLAG_ISSET(page) (mainBuffer.dirtyPages[page] == PFLAG_SET_VALUE)
65			#define PFLAG_ISCLEAR(page) (mainBuffer.dirtyPages[page] != PFLAG_SET_VALUE)
66
67			#ifdef UNALIGNED_PROFITABLE
68			# define PFLAG_ISSET_4(page) (((uint32 )(mainBuffer.dirtyPages + (page))) == PFLAG_SET_VALUE_4)
69			# define PFLAG_ISCLEAR_4(page) (((uint32 )(mainBuffer.dirtyPages + (page))) == PFLAG_CLEAR_VALUE_4)
70			#else
71			# define PFLAG_ISSET_4(page) \
72			PFLAG_ISSET(page ) && PFLAG_ISSET(page+1) \
73			&& PFLAG_ISSET(page+2) && PFLAG_ISSET(page+3)
74			# define PFLAG_ISCLEAR_4(page) \
75			PFLAG_ISCLEAR(page ) && PFLAG_ISCLEAR(page+1) \
76			&& PFLAG_ISCLEAR(page+2) && PFLAG_ISCLEAR(page+3)
77			#endif
78
79			// Set the selected page range [ first_page, last_page [ into the SET state
80			#define PFLAG_SET_RANGE(first_page, last_page) \
81			memset(mainBuffer.dirtyPages + (first_page), PFLAG_SET_VALUE, \
82			(last_page) - (first_page))
83
84			// Set the selected page range [ first_page, last_page [ into the CLEAR state
85			#define PFLAG_CLEAR_RANGE(first_page, last_page) \
86			memset(mainBuffer.dirtyPages + (first_page), PFLAG_CLEAR_VALUE, \
87			(last_page) - (first_page))
88
89			#define PFLAG_SET_ALL do { \
90			PFLAG_SET_RANGE(0, mainBuffer.pageCount); \
91			mainBuffer.dirty = true; \
92			} while (0)
93
94			#define PFLAG_CLEAR_ALL do { \
95			PFLAG_CLEAR_RANGE(0, mainBuffer.pageCount); \
96			mainBuffer.dirty = false; \
97			} while (0)
98
99			// Set the following macro definition to 1 if your system
100			// provides a really fast strchr() implementation
101			//#define HAVE_FAST_STRCHR 0
102
103			static inline int find_next_page_set(int page)
104			{
105			#if HAVE_FAST_STRCHR
106			char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_SET_VALUE);
107			return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
108			#else
109			while (PFLAG_ISCLEAR_4(page))
110			page += 4;
111			while (PFLAG_ISCLEAR(page))
112			page++;
113			return page;
114			#endif
115			}
116
117			static inline int find_next_page_clear(int page)
118			{
119			#if HAVE_FAST_STRCHR
120			char *match = strchr(mainBuffer.dirtyPages + page, PFLAG_CLEAR_VALUE);
121			return match ? match - mainBuffer.dirtyPages : mainBuffer.pageCount;
122			#else
123			while (PFLAG_ISSET_4(page))
124			page += 4;
125			while (PFLAG_ISSET(page))
126			page++;
127			return page;
128			#endif
129			}
130
131			#ifdef HAVE_PTHREADS
132			static pthread_mutex_t vosf_lock = PTHREAD_MUTEX_INITIALIZER; // Mutex to protect frame buffer (dirtyPages in fact)
133			#define LOCK_VOSF pthread_mutex_lock(&vosf_lock);
134			#define UNLOCK_VOSF pthread_mutex_unlock(&vosf_lock);
135			#else
136			#define LOCK_VOSF
137			#define UNLOCK_VOSF
138			#endif
139
140			static int log_base_2(uint32 x)
141			{
142			uint32 mask = 0x80000000;
143			int l = 31;
144			while (l >= 0 && (x & mask) == 0) {
145			mask >>= 1;
146			l--;
147			}
148			return l;
149			}
150
151	gbeauche	1.20	// Extend size to page boundary
152			static uint32 page_extend(uint32 size)
153			{
154			const uint32 page_size = getpagesize();
155			const uint32 page_mask = page_size - 1;
156			return (size + page_mask) & ~page_mask;
157			}
158
159	cebix	1.19
160			/*
161	gbeauche	1.27	* Initialize the VOSF system (mainBuffer structure, SIGSEGV handler)
162	cebix	1.19	*/
163
164	gbeauche	1.27	static bool screen_fault_handler(sigsegv_address_t fault_address, sigsegv_address_t fault_instruction);
165
166			static bool video_vosf_init(void)
167	cebix	1.19	{
168	gbeauche	1.27	const uintptr page_size = getpagesize();
169			const uintptr page_mask = page_size - 1;
170
171			// Round up frame buffer base to page boundary
172			mainBuffer.memStart = (((uintptr) the_buffer) + page_mask) & ~page_mask;
173
174			// The frame buffer size shall already be aligned to page boundary (use page_extend)
175			mainBuffer.memLength = the_buffer_size;
176
177			mainBuffer.pageSize = page_size;
178			mainBuffer.pageBits = log_base_2(mainBuffer.pageSize);
179			mainBuffer.pageCount = (mainBuffer.memLength + page_mask)/mainBuffer.pageSize;
180
181			// The "2" more bytes requested are a safety net to insure the
182			// loops in the update routines will terminate.
183			// See "How can we deal with array overrun conditions ?" hereunder for further details.
184	gbeauche	1.29	mainBuffer.dirtyPages = (char *) malloc(mainBuffer.pageCount + 2);
185			if (mainBuffer.dirtyPages == NULL)
186	gbeauche	1.27	return false;
187	cebix	1.19
188	gbeauche	1.27	PFLAG_CLEAR_ALL;
189			PFLAG_CLEAR(mainBuffer.pageCount);
190			PFLAG_SET(mainBuffer.pageCount+1);
191
192			// Allocate and fill in pageInfo with start and end (inclusive) row in number of bytes
193	gbeauche	1.29	mainBuffer.pageInfo = (ScreenPageInfo ) malloc(mainBuffer.pageCount sizeof(ScreenPageInfo));
194			if (mainBuffer.pageInfo == NULL)
195	gbeauche	1.27	return false;
196
197			uint32 a = 0;
198	cebix	1.28	for (unsigned i = 0; i < mainBuffer.pageCount; i++) {
199			unsigned y1 = a / VideoMonitor.mode.bytes_per_row;
200	gbeauche	1.27	if (y1 >= VideoMonitor.mode.y)
201			y1 = VideoMonitor.mode.y - 1;
202
203	cebix	1.28	unsigned y2 = (a + mainBuffer.pageSize) / VideoMonitor.mode.bytes_per_row;
204	gbeauche	1.27	if (y2 >= VideoMonitor.mode.y)
205			y2 = VideoMonitor.mode.y - 1;
206
207			mainBuffer.pageInfo[i].top = y1;
208			mainBuffer.pageInfo[i].bottom = y2;
209
210			a += mainBuffer.pageSize;
211			if (a > mainBuffer.memLength)
212			a = mainBuffer.memLength;
213			}
214
215			// We can now write-protect the frame buffer
216			if (vm_protect((char *)mainBuffer.memStart, mainBuffer.memLength, VM_PAGE_READ) != 0)
217			return false;
218
219			// Initialize the handler for SIGSEGV
220			if (!sigsegv_install_handler(screen_fault_handler))
221			return false;
222
223			// The frame buffer is sane, i.e. there is no write to it yet
224			mainBuffer.dirty = false;
225			return true;
226			}
227	cebix	1.19
228
229	gbeauche	1.27	/*
230			* Deinitialize VOSF system
231			*/
232	cebix	1.19
233	gbeauche	1.27	static void video_vosf_exit(void)
234			{
235	gbeauche	1.29	if (mainBuffer.pageInfo) {
236			free(mainBuffer.pageInfo);
237			mainBuffer.pageInfo = NULL;
238	gbeauche	1.27	}
239	gbeauche	1.29	if (mainBuffer.dirtyPages) {
240			free(mainBuffer.dirtyPages);
241			mainBuffer.dirtyPages = NULL;
242	cebix	1.19	}
243			}
244
245
246	gbeauche	1.1	/*
247	gbeauche	1.20	* Screen fault handler
248	gbeauche	1.1	*/
249
250	gbeauche	1.16	static bool screen_fault_handler(sigsegv_address_t fault_address, sigsegv_address_t fault_instruction)
251	gbeauche	1.1	{
252	gbeauche	1.27	// D(bug("screen_fault_handler: ADDR=%p from IP=%p\n", fault_address, fault_instruction));
253	gbeauche	1.16	const uintptr addr = (uintptr)fault_address;
254
255	gbeauche	1.11	/* Someone attempted to write to the frame buffer. Make it writeable
256	gbeauche	1.20	* now so that the data could actually be written to. It will be made
257	gbeauche	1.11	* read-only back in one of the screen update_*() functions.
258			*/
259	gbeauche	1.27	if (((uintptr)addr - mainBuffer.memStart) < mainBuffer.memLength) {
260			const int page = ((uintptr)addr - mainBuffer.memStart) >> mainBuffer.pageBits;
261	gbeauche	1.11	LOCK_VOSF;
262			PFLAG_SET(page);
263	gbeauche	1.27	vm_protect((char *)(addr & -mainBuffer.pageSize), mainBuffer.pageSize, VM_PAGE_READ \| VM_PAGE_WRITE);
264	gbeauche	1.13	mainBuffer.dirty = true;
265	gbeauche	1.11	UNLOCK_VOSF;
266	gbeauche	1.16	return true;
267	gbeauche	1.1	}
268
269	gbeauche	1.11	/* Otherwise, we don't know how to handle the fault, let it crash */
270	gbeauche	1.27	fprintf(stderr, "do_handle_screen_fault: unhandled address %p", fault_address);
271	gbeauche	1.16	if (fault_instruction != SIGSEGV_INVALID_PC)
272	gbeauche	1.27	fprintf(stderr, " [IP=%p]", fault_instruction);
273	gbeauche	1.11	fprintf(stderr, "\n");
274	cebix	1.19	#if EMULATED_68K
275			uaecptr nextpc;
276			extern void m68k_dumpstate(uaecptr *nextpc);
277			m68k_dumpstate(&nextpc);
278			#endif
279	cebix	1.25	VideoQuitFullScreen();
280	cebix	1.19	#ifdef ENABLE_MON
281			char *arg[4] = {"mon", "-m", "-r", NULL};
282			mon(3, arg);
283			QuitEmulator();
284			#endif
285	gbeauche	1.16	return false;
286	gbeauche	1.1	}
287
288	gbeauche	1.20
289	gbeauche	1.1	/*
290			* Update display for Windowed mode and VOSF
291			*/
292
293	gbeauche	1.13	// From video_blit.cpp
294			extern void (Screen_blit)(uint8 dest, const uint8 * source, uint32 length);
295	cebix	1.22	extern bool Screen_blitter_init(XVisualInfo * visual_info, bool native_byte_order, video_depth mac_depth);
296	cebix	1.23	extern uint32 ExpandMap[256];
297	gbeauche	1.13
298	gbeauche	1.12	/* How can we deal with array overrun conditions ?
299
300			The state of the framebuffer pages that have been touched are maintained
301			in the dirtyPages[] table. That table is (pageCount + 2) bytes long.
302
303			Terminology
304
305			"Last Page" denotes the pageCount-nth page, i.e. dirtyPages[pageCount - 1].
306			"CLEAR Page Guard" refers to the page following the Last Page but is always
307			in the CLEAR state. "SET Page Guard" refers to the page following the CLEAR
308			Page Guard but is always in the SET state.
309
310			Rough process
311
312	gbeauche	1.13	The update routines must determine which pages have to be blitted to the
313	gbeauche	1.12	screen. This job consists in finding the first_page that was touched.
314			i.e. find the next page that is SET. Then, finding how many pages were
315			touched starting from first_page. i.e. find the next page that is CLEAR.
316
317	gbeauche	1.13	There are two cases to check:
318	gbeauche	1.12
319			- Last Page is CLEAR: find_next_page_set() will reach the SET Page Guard
320			but it is beyond the valid pageCount value. Therefore, we exit from the
321			update routine.
322
323			- Last Page is SET: first_page equals (pageCount - 1) and
324			find_next_page_clear() will reach the CLEAR Page Guard. We blit the last
325			page to the screen. On the next iteration, page equals pageCount and
326			find_next_page_set() will reach the SET Page Guard. We still safely exit
327			from the update routine because the SET Page Guard position is greater
328			than pageCount.
329			*/
330
331	cebix	1.21	static inline void update_display_window_vosf(driver_window *drv)
332	gbeauche	1.1	{
333			int page = 0;
334			for (;;) {
335	cebix	1.28	const unsigned first_page = find_next_page_set(page);
336	gbeauche	1.11	if (first_page >= mainBuffer.pageCount)
337	gbeauche	1.1	break;
338	gbeauche	1.11
339			page = find_next_page_clear(first_page);
340			PFLAG_CLEAR_RANGE(first_page, page);
341	cebix	1.7
342	gbeauche	1.1	// Make the dirty pages read-only again
343			const int32 offset = first_page << mainBuffer.pageBits;
344			const uint32 length = (page - first_page) << mainBuffer.pageBits;
345	gbeauche	1.17	vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
346	gbeauche	1.1
347			// There is at least one line to update
348			const int y1 = mainBuffer.pageInfo[first_page].top;
349			const int y2 = mainBuffer.pageInfo[page - 1].bottom;
350			const int height = y2 - y1 + 1;
351
352	cebix	1.24	if (VideoMonitor.mode.depth < VDEPTH_8BIT) {
353	cebix	1.6
354			// Update the_host_buffer and copy of the_buffer
355	cebix	1.24	const int src_bytes_per_row = VideoMonitor.mode.bytes_per_row;
356			const int dst_bytes_per_row = drv->img->bytes_per_line;
357			const int pixels_per_byte = VideoMonitor.mode.x / src_bytes_per_row;
358			int i1 = y1 * src_bytes_per_row, i2 = y1 * dst_bytes_per_row, j;
359	cebix	1.6	for (j = y1; j <= y2; j++) {
360	cebix	1.24	Screen_blit(the_host_buffer + i2, the_buffer + i1, VideoMonitor.mode.x / pixels_per_byte);
361			i1 += src_bytes_per_row;
362			i2 += dst_bytes_per_row;
363	cebix	1.6	}
364
365			} else {
366
367			// Update the_host_buffer and copy of the_buffer
368	cebix	1.23	const int src_bytes_per_row = VideoMonitor.mode.bytes_per_row;
369			const int dst_bytes_per_row = drv->img->bytes_per_line;
370			const int bytes_per_pixel = src_bytes_per_row / VideoMonitor.mode.x;
371			int i1 = y1 * src_bytes_per_row, i2 = y1 * dst_bytes_per_row, j;
372	cebix	1.6	for (j = y1; j <= y2; j++) {
373	cebix	1.23	Screen_blit(the_host_buffer + i2, the_buffer + i1, bytes_per_pixel * VideoMonitor.mode.x);
374			i1 += src_bytes_per_row;
375			i2 += dst_bytes_per_row;
376	cebix	1.6	}
377	gbeauche	1.1	}
378	cebix	1.15
379	cebix	1.21	if (drv->have_shm)
380			XShmPutImage(x_display, drv->w, drv->gc, drv->img, 0, y1, 0, y1, VideoMonitor.mode.x, height, 0);
381	gbeauche	1.1	else
382	cebix	1.21	XPutImage(x_display, drv->w, drv->gc, drv->img, 0, y1, 0, y1, VideoMonitor.mode.x, height);
383	gbeauche	1.1	}
384	gbeauche	1.13	mainBuffer.dirty = false;
385	gbeauche	1.1	}
386
387
388			/*
389			* Update display for DGA mode and VOSF
390	gbeauche	1.20	* (only in Real or Direct Addressing mode)
391	gbeauche	1.1	*/
392
393			#if REAL_ADDRESSING \|\| DIRECT_ADDRESSING
394			static inline void update_display_dga_vosf(void)
395			{
396			int page = 0;
397			for (;;) {
398	cebix	1.28	const unsigned first_page = find_next_page_set(page);
399	gbeauche	1.11	if (first_page >= mainBuffer.pageCount)
400	gbeauche	1.1	break;
401	gbeauche	1.11
402			page = find_next_page_clear(first_page);
403			PFLAG_CLEAR_RANGE(first_page, page);
404
405	gbeauche	1.1	// Make the dirty pages read-only again
406			const int32 offset = first_page << mainBuffer.pageBits;
407			const uint32 length = (page - first_page) << mainBuffer.pageBits;
408	gbeauche	1.17	vm_protect((char *)mainBuffer.memStart + offset, length, VM_PAGE_READ);
409	gbeauche	1.1
410			// I am sure that y2 >= y1 and depth != 1
411			const int y1 = mainBuffer.pageInfo[first_page].top;
412			const int y2 = mainBuffer.pageInfo[page - 1].bottom;
413
414	cebix	1.18	const int bytes_per_row = VideoMonitor.mode.bytes_per_row;
415			const int bytes_per_pixel = VideoMonitor.mode.bytes_per_row / VideoMonitor.mode.x;
416	gbeauche	1.1	int i, j;
417
418			// Check for first column from left and first column
419			// from right that have changed
420	cebix	1.18	int x1 = VideoMonitor.mode.x * bytes_per_pixel - 1;
421	gbeauche	1.1	for (j = y1; j <= y2; j++) {
422			uint8 * const p1 = &the_buffer[j * bytes_per_row];
423			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
424			for (i = 0; i < x1; i++) {
425			if (p1[i] != p2[i]) {
426			x1 = i;
427			break;
428			}
429			}
430			}
431			x1 /= bytes_per_pixel;
432
433			int x2 = x1 * bytes_per_pixel;
434			for (j = y2; j >= y1; j--) {
435			uint8 * const p1 = &the_buffer[j * bytes_per_row];
436			uint8 * const p2 = &the_buffer_copy[j * bytes_per_row];
437	cebix	1.18	for (i = VideoMonitor.mode.x * bytes_per_pixel - 1; i > x2; i--) {
438	gbeauche	1.1	if (p1[i] != p2[i]) {
439			x2 = i;
440			break;
441			}
442			}
443			}
444			x2 /= bytes_per_pixel;
445
446			// Update the_host_buffer and copy of the_buffer
447			// There should be at least one pixel to copy
448			const int width = x2 - x1 + 1;
449			i = y1 * bytes_per_row + x1 * bytes_per_pixel;
450			for (j = y1; j <= y2; j++) {
451	gbeauche	1.13	Screen_blit(the_host_buffer + i, the_buffer + i, bytes_per_pixel * width);
452	gbeauche	1.1	memcpy(the_buffer_copy + i, the_buffer + i, bytes_per_pixel * width);
453			i += bytes_per_row;
454			}
455			}
456	gbeauche	1.13	mainBuffer.dirty = false;
457	gbeauche	1.1	}
458			#endif
459
460			#endif /* ENABLE_VOSF */
461
462			#endif /* VIDEO_VOSF_H */