diff options
-rw-r--r-- | firmware/drivers/ata.c | 377 |
1 files changed, 189 insertions, 188 deletions
diff --git a/firmware/drivers/ata.c b/firmware/drivers/ata.c index d4a3856a76..9c37a15537 100644 --- a/firmware/drivers/ata.c +++ b/firmware/drivers/ata.c @@ -38,7 +38,9 @@ #if (CONFIG_CPU == MCF5249) || (CONFIG_CPU == MCF5250) -/* asm reading + writing */ +/* asm optimised read & write loops */ + +#define NOINLINE_ATTR __attribute__((noinline)) /* don't inline the loops */ #define ATA_IOBASE 0x20000000 #define ATA_DATA (*((volatile unsigned short*)(ATA_IOBASE + 0x20))) @@ -80,7 +82,7 @@ #elif (CONFIG_CPU == PP5002) || (CONFIG_CPU == PP5020) -/* don't use sh7034 assembler routines */ +/* Plain C read & write loops */ #define PREFER_C_READING #define PREFER_C_WRITING @@ -128,6 +130,10 @@ #elif CONFIG_CPU == SH7034 +/* asm optimised read & write loops */ + +#define NOINLINE_ATTR __attribute__((noinline)) /* don't inline the loops */ + #define SWAP_WORDS #define ATA_IOBASE 0x06100100 @@ -172,6 +178,7 @@ #elif CONFIG_CPU == TCC730 +/* Plain C read & write loops */ #define PREFER_C_READING #define PREFER_C_WRITING @@ -269,7 +276,7 @@ int ide_read_register(int reg) { #elif defined(TOSHIBA_GIGABEAT_F) -/* don't use sh7034 assembler routines */ +/* Plain C read & write loops */ #define PREFER_C_READING #define PREFER_C_WRITING @@ -311,6 +318,10 @@ int ide_read_register(int reg) { #endif +#ifndef NOINLINE_ATTR +#define NOINLINE_ATTR +#endif + #define ATA_FEATURE ATA_ERROR #define ATA_STATUS ATA_COMMAND #define ATA_ALT_STATUS ATA_CONTROL @@ -436,7 +447,8 @@ static int wait_for_end_of_transfer(void) * controller & cpu internal memory. */ /* the tight loop of ata_read_sectors(), to avoid the whole in IRAM */ -static void copy_read_sectors(unsigned char* buf, int wordcount) ICODE_ATTR; +static void copy_read_sectors(unsigned char* buf, int wordcount) + ICODE_ATTR NOINLINE_ATTR; static void copy_read_sectors(unsigned char* buf, int wordcount) { #ifdef PREFER_C_READING @@ -472,7 +484,7 @@ static void copy_read_sectors(unsigned char* buf, int wordcount) #endif } while (++wbuf < wbufend); /* tail loop is faster */ } -#else +#else /* !PREFER_C_READING */ #if CONFIG_CPU == TCC730 int sectorcount = wordcount / 0x100; do { @@ -483,17 +495,16 @@ static void copy_read_sectors(unsigned char* buf, int wordcount) sectorcount--; } while (sectorcount > 0); #elif defined(CPU_COLDFIRE) + unsigned char* bufend = buf + 2 * wordcount; /* coldfire asm reading, utilising line bursts */ /* this assumes there is at least one full line to copy */ - asm ( - "add.l %[wcnt],%[wcnt] \n" /* wordcount -> bytecount */ - "add.l %[buf],%[wcnt] \n" /* bytecount -> bufend */ + asm volatile ( "move.l %[buf],%%d0 \n" "btst.l #0,%%d0 \n" /* 16-bit aligned? */ "jeq .aligned \n" /* yes, do word copy */ /* not 16-bit aligned */ - "subq.l #1,%[wcnt] \n" /* last byte is done unconditionally */ + "subq.l #1,%[end] \n" /* last byte is done unconditionally */ "moveq.l #24,%%d1 \n" /* preload shift count */ "move.w (%[ata]),%%d2 \n" /* load initial word */ @@ -531,7 +542,7 @@ static void copy_read_sectors(unsigned char* buf, int wordcount) "bhi.b .loop_u_l1 \n" ".end_u_l1: \n" - "lea.l (-14,%[wcnt]),%[wcnt] \n" /* adjust end addr. to 16 bytes/pass */ + "lea.l (-14,%[end]),%[end] \n" /* adjust end addr. to 16 bytes/pass */ ".loop_u_line: \n" "move.w (%[ata]),%%d3 \n" /* load 1st word */ @@ -565,11 +576,11 @@ static void copy_read_sectors(unsigned char* buf, int wordcount) "movem.l %%d2-%%d5,(%[buf]) \n" /* store line */ "lea.l (16,%[buf]),%[buf] \n" "move.l %%d6,%%d2 \n" - "cmp.l %[buf],%[wcnt] \n" /* run up to last line bound */ + "cmp.l %[buf],%[end] \n" /* run up to last line bound */ "bhi.b .loop_u_line \n" - "lea.l (12,%[wcnt]),%[wcnt]\n" /* readjust for longword loop */ - "cmp.l %[buf],%[wcnt] \n" /* any trailing longwords? */ + "lea.l (12,%[end]),%[end] \n" /* readjust for longword loop */ + "cmp.l %[buf],%[end] \n" /* any trailing longwords? */ "bls.b .end_u_l2 \n" /* no: skip loop */ ".loop_u_l2: \n" @@ -582,12 +593,12 @@ static void copy_read_sectors(unsigned char* buf, int wordcount) "or.l %%d3,%%d2 \n" /* combine old low byte with new top 3 bytes */ "move.l %%d2,(%[buf])+ \n" /* store as long */ "move.l %%d4,%%d2 \n" - "cmp.l %[buf],%[wcnt] \n" /* run up to last long bound */ + "cmp.l %[buf],%[end] \n" /* run up to last long bound */ "bhi.b .loop_u_l2 \n" ".end_u_l2: \n" - "addq.l #2,%[wcnt] \n" /* back to final end address */ - "cmp.l %[buf],%[wcnt] \n" /* one word left? */ + "addq.l #2,%[end] \n" /* back to final end address */ + "cmp.l %[buf],%[end] \n" /* one word left? */ "bls.b .end_u_w2 \n" "swap %%d2 \n" /* move old word to upper 16 bits */ @@ -623,7 +634,7 @@ static void copy_read_sectors(unsigned char* buf, int wordcount) "bhi.b .loop_a_l1 \n" ".end_a_l1: \n" - "lea.l (-14,%[wcnt]),%[wcnt] \n" /* adjust end addr. to 16 bytes/pass */ + "lea.l (-14,%[end]),%[end] \n" /* adjust end addr. to 16 bytes/pass */ ".loop_a_line: \n" "move.w (%[ata]),%%d0 \n" /* load 1st word */ @@ -640,11 +651,11 @@ static void copy_read_sectors(unsigned char* buf, int wordcount) "move.w (%[ata]),%%d3 \n" /* load 8th word */ "movem.l %%d0-%%d3,(%[buf]) \n" /* store line */ "lea.l (16,%[buf]),%[buf] \n" - "cmp.l %[buf],%[wcnt] \n" /* run up to last line bound */ + "cmp.l %[buf],%[end] \n" /* run up to last line bound */ "bhi.b .loop_a_line \n" - "lea.l (12,%[wcnt]),%[wcnt]\n" /* readjust for longword loop */ - "cmp.l %[buf],%[wcnt] \n" /* any trailing longwords? */ + "lea.l (12,%[end]),%[end] \n" /* readjust for longword loop */ + "cmp.l %[buf],%[end] \n" /* any trailing longwords? */ "bls.b .end_a_l2 \n" /* no: skip loop */ ".loop_a_l2: \n" @@ -652,12 +663,12 @@ static void copy_read_sectors(unsigned char* buf, int wordcount) "swap %%d1 \n" /* move it to upper 16 bits */ "move.w (%[ata]),%%d1 \n" /* read second word */ "move.l %%d1,(%[buf])+ \n" /* store as long */ - "cmp.l %[buf],%[wcnt] \n" /* run up to last long bound */ + "cmp.l %[buf],%[end] \n" /* run up to last long bound */ "bhi.b .loop_a_l2 \n" ".end_a_l2: \n" - "addq.l #2,%[wcnt] \n" /* back to final end address */ - "cmp.l %[buf],%[wcnt] \n" /* one word left? */ + "addq.l #2,%[end] \n" /* back to final end address */ + "cmp.l %[buf],%[end] \n" /* one word left? */ "bls.b .end_a_w2 \n" "move.w (%[ata]),(%[buf])+ \n" /* copy final word */ @@ -666,110 +677,106 @@ static void copy_read_sectors(unsigned char* buf, int wordcount) ".exit: \n" : /* outputs */ + [buf]"+a"(buf), + [end]"+a"(bufend) : /* inputs */ - [buf] "a"(buf), - [wcnt]"a"(wordcount), - [ata] "a"(&ATA_DATA) + [ata]"a"(&ATA_DATA) : /*trashed */ "d0", "d1", "d2", "d3", "d4", "d5", "d6" ); #else /* SH1 turbo-charged assembler reading */ /* this assumes wordcount to be a multiple of 4 */ - asm ( - "add %1,%1 \n" /* wordcount -> bytecount */ - "add %0,%1 \n" /* bytecount -> bufend */ - "mov %0,r0 \n" - "tst #1,r0 \n" /* 16-bit aligned ? */ - "bt .aligned \n" /* yes, do word copy */ + asm volatile ( + "mov %[buf],r0 \n" + "tst #1,r0 \n" /* 16-bit aligned ? */ + "bt .aligned \n" /* yes, do word copy */ /* not 16-bit aligned */ - "mov #-1,r3 \n" /* prepare a bit mask for high byte */ - "shll8 r3 \n" /* r3 = 0xFFFFFF00 */ - - "mov.w @%2,r2 \n" /* read first word (1st round) */ - "add #-12,%1 \n" /* adjust end address for offsets */ - "mov.b r2,@%0 \n" /* store low byte of first word */ - "bra .start4_b \n" /* jump into loop after next instr. */ - "add #-5,%0 \n" /* adjust for dest. offsets; now even */ - - ".align 2 \n" - ".loop4_b: \n" /* main loop: copy 4 words in a row */ - "mov.w @%2,r2 \n" /* read first word (2+ round) */ - "and r3,r1 \n" /* get high byte of fourth word (2+ round) */ - "extu.b r2,r0 \n" /* get low byte of first word (2+ round) */ - "or r1,r0 \n" /* combine with high byte of fourth word */ - "mov.w r0,@(4,%0) \n" /* store at buf[4] */ - "nop \n" /* maintain alignment */ - ".start4_b: \n" - "mov.w @%2,r1 \n" /* read second word */ - "and r3,r2 \n" /* get high byte of first word */ - "extu.b r1,r0 \n" /* get low byte of second word */ - "or r2,r0 \n" /* combine with high byte of first word */ - "mov.w r0,@(6,%0) \n" /* store at buf[6] */ - "add #8,%0 \n" /* buf += 8 */ - "mov.w @%2,r2 \n" /* read third word */ - "and r3,r1 \n" /* get high byte of second word */ - "extu.b r2,r0 \n" /* get low byte of third word */ - "or r1,r0 \n" /* combine with high byte of second word */ - "mov.w r0,@%0 \n" /* store at buf[0] */ - "cmp/hi %0,%1 \n" /* check for end */ - "mov.w @%2,r1 \n" /* read fourth word */ - "and r3,r2 \n" /* get high byte of third word */ - "extu.b r1,r0 \n" /* get low byte of fourth word */ - "or r2,r0 \n" /* combine with high byte of third word */ - "mov.w r0,@(2,%0) \n" /* store at buf[2] */ - "bt .loop4_b \n" + "mov #-1,r3 \n" /* prepare a bit mask for high byte */ + "shll8 r3 \n" /* r3 = 0xFFFFFF00 */ + + "mov.w @%[ata],r2 \n" /* read first word (1st round) */ + "mov.b r2,@%[buf] \n" /* store low byte of first word */ + "bra .start4_b \n" /* jump into loop after next instr. */ + "add #-5,%[buf] \n" /* adjust for dest. offsets; now even */ + + ".align 2 \n" + ".loop4_b: \n" /* main loop: copy 4 words in a row */ + "mov.w @%[ata],r2 \n" /* read first word (2+ round) */ + "and r3,r1 \n" /* get high byte of fourth word (2+ round) */ + "extu.b r2,r0 \n" /* get low byte of first word (2+ round) */ + "or r1,r0 \n" /* combine with high byte of fourth word */ + "mov.w r0,@(4,%[buf]) \n" /* store at buf[4] */ + "nop \n" /* maintain alignment */ + ".start4_b: \n" + "mov.w @%[ata],r1 \n" /* read second word */ + "and r3,r2 \n" /* get high byte of first word */ + "extu.b r1,r0 \n" /* get low byte of second word */ + "or r2,r0 \n" /* combine with high byte of first word */ + "mov.w r0,@(6,%[buf]) \n" /* store at buf[6] */ + "add #8,%[buf] \n" /* buf += 8 */ + "mov.w @%[ata],r2 \n" /* read third word */ + "and r3,r1 \n" /* get high byte of second word */ + "extu.b r2,r0 \n" /* get low byte of third word */ + "or r1,r0 \n" /* combine with high byte of second word */ + "mov.w r0,@%[buf] \n" /* store at buf[0] */ + "cmp/hi %[buf],%[end] \n" /* check for end */ + "mov.w @%[ata],r1 \n" /* read fourth word */ + "and r3,r2 \n" /* get high byte of third word */ + "extu.b r1,r0 \n" /* get low byte of fourth word */ + "or r2,r0 \n" /* combine with high byte of third word */ + "mov.w r0,@(2,%[buf]) \n" /* store at buf[2] */ + "bt .loop4_b \n" /* 24 instructions for 4 copies, takes 30 clock cycles (4 wait) */ /* avg. 7.5 cycles per word - 86% faster */ - "swap.b r1,r0 \n" /* get high byte of last word */ - "bra .exit \n" - "mov.b r0,@(4,%0) \n" /* and store it */ + "swap.b r1,r0 \n" /* get high byte of last word */ + "bra .exit \n" + "mov.b r0,@(4,%[buf]) \n" /* and store it */ - ".align 2 \n" /* 16-bit aligned, loop(read and store word) */ - ".aligned: \n" - "mov.w @%2,r2 \n" /* read first word (1st round) */ - "add #-12,%1 \n" /* adjust end address for offsets */ - "bra .start4_w \n" /* jump into loop after next instr. */ - "add #-6,%0 \n" /* adjust for destination offsets */ - - ".loop4_w: \n" /* main loop: copy 4 words in a row */ - "mov.w @%2,r2 \n" /* read first word (2+ round) */ - "swap.b r1,r0 \n" /* swap fourth word (2+ round) */ - "mov.w r0,@(4,%0) \n" /* store fourth word (2+ round) */ - "nop \n" /* maintain alignment */ - ".start4_w: \n" - "mov.w @%2,r1 \n" /* read second word */ - "swap.b r2,r0 \n" /* swap first word */ - "mov.w r0,@(6,%0) \n" /* store first word in buf[6] */ - "add #8,%0 \n" /* buf += 8 */ - "mov.w @%2,r2 \n" /* read third word */ - "swap.b r1,r0 \n" /* swap second word */ - "mov.w r0,@%0 \n" /* store second word in buf[0] */ - "cmp/hi %0,%1 \n" /* check for end */ - "mov.w @%2,r1 \n" /* read fourth word */ - "swap.b r2,r0 \n" /* swap third word */ - "mov.w r0,@(2,%0) \n" /* store third word */ - "bt .loop4_w \n" + ".aligned: \n" + "mov.w @%[ata],r2 \n" /* read first word (1st round) */ + "bra .start4_w \n" /* jump into loop after next instr. */ + "add #-6,%[buf] \n" /* adjust for destination offsets */ + + ".align 2 \n" + ".loop4_w: \n" /* main loop: copy 4 words in a row */ + "mov.w @%[ata],r2 \n" /* read first word (2+ round) */ + "swap.b r1,r0 \n" /* swap fourth word (2+ round) */ + "mov.w r0,@(4,%[buf]) \n" /* store fourth word (2+ round) */ + "nop \n" /* maintain alignment */ + ".start4_w: \n" + "mov.w @%[ata],r1 \n" /* read second word */ + "swap.b r2,r0 \n" /* swap first word */ + "mov.w r0,@(6,%[buf]) \n" /* store first word in buf[6] */ + "add #8,%[buf] \n" /* buf += 8 */ + "mov.w @%[ata],r2 \n" /* read third word */ + "swap.b r1,r0 \n" /* swap second word */ + "mov.w r0,@%[buf] \n" /* store second word in buf[0] */ + "cmp/hi %[buf],%[end] \n" /* check for end */ + "mov.w @%[ata],r1 \n" /* read fourth word */ + "swap.b r2,r0 \n" /* swap third word */ + "mov.w r0,@(2,%[buf]) \n" /* store third word */ + "bt .loop4_w \n" /* 16 instructions for 4 copies, takes 22 clock cycles (4 wait) */ /* avg. 5.5 cycles per word - 118% faster */ - "swap.b r1,r0 \n" /* swap fourth word (last round) */ - "mov.w r0,@(4,%0) \n" /* and store it */ + "swap.b r1,r0 \n" /* swap fourth word (last round) */ + "mov.w r0,@(4,%[buf]) \n" /* and store it */ - ".exit: \n" + ".exit: \n" : /* outputs */ + [buf]"+r"(buf) : /* inputs */ - /* %0 */ "r"(buf), - /* %1 */ "r"(wordcount), - /* %2 */ "r"(&ATA_DATA) + [end]"r"(buf + 2 * wordcount - 12), /* adjusted for offsets */ + [ata]"r"(&ATA_DATA) : /*trashed */ "r0","r1","r2","r3" ); -#endif -#endif +#endif /* CPU */ +#endif /* !PREFER_C_READING */ } #if CONFIG_LED == LED_REAL @@ -938,9 +945,8 @@ int ata_read_sectors(IF_MV2(int drive,) } /* the tight loop of ata_write_sectors(), to avoid the whole in IRAM */ -static void copy_write_sectors(const unsigned char* buf, - int wordcount) ICODE_ATTR; - +static void copy_write_sectors(const unsigned char* buf, int wordcount) + ICODE_ATTR NOINLINE_ATTR; static void copy_write_sectors(const unsigned char* buf, int wordcount) { #ifdef PREFER_C_WRITING @@ -979,18 +985,17 @@ static void copy_write_sectors(const unsigned char* buf, int wordcount) #endif } while (++wbuf < wbufend); /* tail loop is faster */ } -#else +#else /* !PREFER_C_WRITING */ #ifdef CPU_COLDFIRE + const unsigned char* bufend = buf + 2 * wordcount; /* coldfire asm writing, utilising line bursts */ - asm ( - "add.l %[wcnt],%[wcnt] \n" /* wordcount -> bytecount */ - "add.l %[buf],%[wcnt] \n" /* bytecount -> bufend */ + asm volatile ( "move.l %[buf],%%d0 \n" "btst.l #0,%%d0 \n" /* 16-bit aligned? */ "jeq .w_aligned \n" /* yes, do word copy */ /* not 16-bit aligned */ - "subq.l #1,%[wcnt] \n" /* last byte is done unconditionally */ + "subq.l #1,%[end] \n" /* last byte is done unconditionally */ "moveq.l #24,%%d1 \n" /* preload shift count */ "move.b (%[buf])+,%%d2 \n" @@ -1026,7 +1031,7 @@ static void copy_write_sectors(const unsigned char* buf, int wordcount) "bhi.b .w_loop_u_l1 \n" ".w_end_u_l1: \n" - "lea.l (-14,%[wcnt]),%[wcnt] \n" /* adjust end addr. to 16 bytes/pass */ + "lea.l (-14,%[end]),%[end] \n" /* adjust end addr. to 16 bytes/pass */ ".w_loop_u_line: \n" "movem.l (%[buf]),%%d3-%%d6 \n" @@ -1064,11 +1069,11 @@ static void copy_write_sectors(const unsigned char* buf, int wordcount) "swap %%d5 \n" "move.w %%d5,(%[ata]) \n" "move.l %%d6,%%d2 \n" - "cmp.l %[buf],%[wcnt] \n" /* run up to last line bound */ + "cmp.l %[buf],%[end] \n" /* run up to last line bound */ "bhi.b .w_loop_u_line \n" - "lea.l (12,%[wcnt]),%[wcnt]\n" /* readjust for longword loop */ - "cmp.l %[buf],%[wcnt] \n" /* any trailing longwords? */ + "lea.l (12,%[end]),%[end] \n" /* readjust for longword loop */ + "cmp.l %[buf],%[end] \n" /* any trailing longwords? */ "bls.b .w_end_u_l2 \n" /* no: skip loop */ ".w_loop_u_l2: \n" @@ -1082,12 +1087,12 @@ static void copy_write_sectors(const unsigned char* buf, int wordcount) "swap %%d2 \n" "move.w %%d2,(%[ata]) \n" "move.l %%d4,%%d2 \n" - "cmp.l %[buf],%[wcnt] \n" /* run up to first line bound */ + "cmp.l %[buf],%[end] \n" /* run up to first line bound */ "bhi.b .w_loop_u_l2 \n" ".w_end_u_l2: \n" - "addq.l #2,%[wcnt] \n" /* back to final end address */ - "cmp.l %[buf],%[wcnt] \n" /* one word left? */ + "addq.l #2,%[end] \n" /* back to final end address */ + "cmp.l %[buf],%[end] \n" /* one word left? */ "bls.b .w_end_u_w2 \n" "swap %%d2 \n" @@ -1100,7 +1105,7 @@ static void copy_write_sectors(const unsigned char* buf, int wordcount) "lsl.l #8,%%d2 \n" "move.b (%[buf])+,%%d2 \n" "move.w %%d2,(%[ata]) \n" - "bra.b .w_exit \n" + "bra.b .w_exit \n" /* 16-bit aligned */ ".w_aligned: \n" @@ -1126,7 +1131,7 @@ static void copy_write_sectors(const unsigned char* buf, int wordcount) "bhi.b .w_loop_a_l1 \n" ".w_end_a_l1: \n" - "lea.l (-14,%[wcnt]),%[wcnt] \n" /* adjust end addr. to 16 bytes/pass */ + "lea.l (-14,%[end]),%[end] \n" /* adjust end addr. to 16 bytes/pass */ ".w_loop_a_line: \n" "movem.l (%[buf]),%%d0-%%d3 \n" @@ -1147,11 +1152,11 @@ static void copy_write_sectors(const unsigned char* buf, int wordcount) "move.w %%d3,(%[ata]) \n" "swap %%d3 \n" "move.w %%d3,(%[ata]) \n" - "cmp.l %[buf],%[wcnt] \n" /* run up to last line bound */ + "cmp.l %[buf],%[end] \n" /* run up to last line bound */ "bhi.b .w_loop_a_line \n" - "lea.l (12,%[wcnt]),%[wcnt]\n" /* readjust for longword loop */ - "cmp.l %[buf],%[wcnt] \n" /* any trailing longwords? */ + "lea.l (12,%[end]),%[end] \n" /* readjust for longword loop */ + "cmp.l %[buf],%[end] \n" /* any trailing longwords? */ "bls.b .w_end_a_l2 \n" /* no: skip loop */ ".w_loop_a_l2: \n" @@ -1160,12 +1165,12 @@ static void copy_write_sectors(const unsigned char* buf, int wordcount) "move.w %%d1,(%[ata]) \n" "swap %%d1 \n" "move.w %%d1,(%[ata]) \n" - "cmp.l %[buf],%[wcnt] \n" /* run up to first line bound */ + "cmp.l %[buf],%[end] \n" /* run up to first line bound */ "bhi.b .w_loop_a_l2 \n" ".w_end_a_l2: \n" - "addq.l #2,%[wcnt] \n" /* back to final end address */ - "cmp.l %[buf],%[wcnt] \n" /* one word left? */ + "addq.l #2,%[end] \n" /* back to final end address */ + "cmp.l %[buf],%[end] \n" /* one word left? */ "bls.b .w_end_a_w2 \n" "move.w (%[buf])+,(%[ata]) \n" /* copy final word */ @@ -1174,10 +1179,10 @@ static void copy_write_sectors(const unsigned char* buf, int wordcount) ".w_exit: \n" : /* outputs */ + [buf]"+a"(buf), + [end]"+a"(bufend) : /* inputs */ - [buf] "a"(buf), - [wcnt]"a"(wordcount), - [ata] "a"(&ATA_DATA) + [ata]"a"(&ATA_DATA) : /*trashed */ "d0", "d1", "d2", "d3", "d4", "d5", "d6" ); @@ -1191,82 +1196,78 @@ static void copy_write_sectors(const unsigned char* buf, int wordcount) * - writing profits from warp mode * Both of these add up to have writing faster than the more unrolled reading. */ - asm ( - "add %1,%1 \n" /* wordcount -> bytecount */ - "add %0,%1 \n" /* bytecount -> bufend */ - "mov %0,r0 \n" - "tst #1,r0 \n" /* 16-bit aligned ? */ - "bt .w_aligned \n" /* yes, do word copy */ + asm volatile ( + "mov %[buf],r0 \n" + "tst #1,r0 \n" /* 16-bit aligned ? */ + "bt .w_aligned \n" /* yes, do word copy */ /* not 16-bit aligned */ - "mov #-1,r6 \n" /* prepare a bit mask for high byte */ - "shll8 r6 \n" /* r6 = 0xFFFFFF00 */ - - "mov.b @%0+,r2 \n" /* load (initial old second) first byte */ - "add #-4,%1 \n" /* adjust end address for early check */ - "mov.w @%0+,r3 \n" /* load (initial) first word */ - "bra .w_start2_b \n" - "extu.b r2,r0 \n" /* extend unsigned */ - - ".align 2 \n" - ".w_loop2_b: \n" /* main loop: copy 2 words in a row */ - "mov.w @%0+,r3 \n" /* load first word (2+ round) */ - "extu.b r2,r0 \n" /* put away low byte of second word (2+ round) */ - "and r6,r2 \n" /* get high byte of second word (2+ round) */ - "or r1,r2 \n" /* combine with low byte of old first word */ - "mov.w r2,@%2 \n" /* write that */ - ".w_start2_b: \n" - "cmp/hi %0,%1 \n" /* check for end */ - "mov.w @%0+,r2 \n" /* load second word */ - "extu.b r3,r1 \n" /* put away low byte of first word */ - "and r6,r3 \n" /* get high byte of first word */ - "or r0,r3 \n" /* combine with high byte of old second word */ - "mov.w r3,@%2 \n" /* write that */ - "bt .w_loop2_b \n" + "mov #-1,r6 \n" /* prepare a bit mask for high byte */ + "shll8 r6 \n" /* r6 = 0xFFFFFF00 */ + + "mov.b @%[buf]+,r2 \n" /* load (initial old second) first byte */ + "mov.w @%[buf]+,r3 \n" /* load (initial) first word */ + "bra .w_start2_b \n" + "extu.b r2,r0 \n" /* extend unsigned */ + + ".align 2 \n" + ".w_loop2_b: \n" /* main loop: copy 2 words in a row */ + "mov.w @%[buf]+,r3 \n" /* load first word (2+ round) */ + "extu.b r2,r0 \n" /* put away low byte of second word (2+ round) */ + "and r6,r2 \n" /* get high byte of second word (2+ round) */ + "or r1,r2 \n" /* combine with low byte of old first word */ + "mov.w r2,@%[ata] \n" /* write that */ + ".w_start2_b: \n" + "cmp/hi %[buf],%[end] \n" /* check for end */ + "mov.w @%[buf]+,r2 \n" /* load second word */ + "extu.b r3,r1 \n" /* put away low byte of first word */ + "and r6,r3 \n" /* get high byte of first word */ + "or r0,r3 \n" /* combine with high byte of old second word */ + "mov.w r3,@%[ata] \n" /* write that */ + "bt .w_loop2_b \n" /* 12 instructions for 2 copies, takes 14 clock cycles */ /* avg. 7 cycles per word - 85% faster */ /* the loop "overreads" 1 byte past the buffer end, however, the last */ /* byte is not written to disk */ - "and r6,r2 \n" /* get high byte of last word */ - "or r1,r2 \n" /* combine with low byte of old first word */ - "bra .w_exit \n" - "mov.w r2,@%2 \n" /* write last word */ + "and r6,r2 \n" /* get high byte of last word */ + "or r1,r2 \n" /* combine with low byte of old first word */ + "bra .w_exit \n" + "mov.w r2,@%[ata] \n" /* write last word */ /* 16-bit aligned, loop(load and write word) */ - ".w_aligned: \n" - "mov.w @%0+,r2 \n" /* load first word (1st round) */ - "bra .w_start2_w \n" /* jump into loop after next instr. */ - "add #-4,%1 \n" /* adjust end address for early check */ - - ".align 2 \n" - ".w_loop2_w: \n" /* main loop: copy 2 words in a row */ - "mov.w @%0+,r2 \n" /* load first word (2+ round) */ - "swap.b r1,r0 \n" /* swap second word (2+ round) */ - "mov.w r0,@%2 \n" /* write second word (2+ round) */ - ".w_start2_w: \n" - "cmp/hi %0,%1 \n" /* check for end */ - "mov.w @%0+,r1 \n" /* load second word */ - "swap.b r2,r0 \n" /* swap first word */ - "mov.w r0,@%2 \n" /* write first word */ - "bt .w_loop2_w \n" + ".w_aligned: \n" + "bra .w_start2_w \n" /* jump into loop after next instr. */ + "mov.w @%[buf]+,r2 \n" /* load first word (1st round) */ + + ".align 2 \n" + ".w_loop2_w: \n" /* main loop: copy 2 words in a row */ + "mov.w @%[buf]+,r2 \n" /* load first word (2+ round) */ + "swap.b r1,r0 \n" /* swap second word (2+ round) */ + "mov.w r0,@%[ata] \n" /* write second word (2+ round) */ + ".w_start2_w: \n" + "cmp/hi %[buf],%[end] \n" /* check for end */ + "mov.w @%[buf]+,r1 \n" /* load second word */ + "swap.b r2,r0 \n" /* swap first word */ + "mov.w r0,@%[ata] \n" /* write first word */ + "bt .w_loop2_w \n" /* 8 instructions for 2 copies, takes 10 clock cycles */ /* avg. 5 cycles per word - 100% faster */ - "swap.b r1,r0 \n" /* swap second word (last round) */ - "mov.w r0,@%2 \n" /* and write it */ + "swap.b r1,r0 \n" /* swap second word (last round) */ + "mov.w r0,@%[ata] \n" /* and write it */ - ".w_exit: \n" + ".w_exit: \n" : /* outputs */ + [buf]"+r"(buf) : /* inputs */ - /* %0 */ "r"(buf), - /* %1 */ "r"(wordcount), - /* %2 */ "r"(&ATA_DATA) + [end]"r"(buf + 2 * wordcount - 4), /* adjusted for earl check */ + [ata]"r"(&ATA_DATA) : /*trashed */ "r0","r1","r2","r3","r6" ); -#endif -#endif +#endif /* CPU */ +#endif /* !PREFER_C_WRITING */ } int ata_write_sectors(IF_MV2(int drive,) |