diff --git a/drivers/scsi/mac_scsi.c b/drivers/scsi/mac_scsi.c index c80fb498a61e..643321fc152d 100644 --- a/drivers/scsi/mac_scsi.c +++ b/drivers/scsi/mac_scsi.c @@ -3,6 +3,8 @@ * * Copyright 1998, Michael Schmitz * + * Copyright 2019 Finn Thain + * * derived in part from: */ /* @@ -11,6 +13,7 @@ * Copyright 1995, Russell King */ +#include #include #include #include @@ -89,101 +92,217 @@ static int __init mac_scsi_setup(char *str) __setup("mac5380=", mac_scsi_setup); #endif /* !MODULE */ -/* Pseudo DMA asm originally by Ove Edlund */ - -#define CP_IO_TO_MEM(s,d,n) \ -__asm__ __volatile__ \ - (" cmp.w #4,%2\n" \ - " bls 8f\n" \ - " move.w %1,%%d0\n" \ - " neg.b %%d0\n" \ - " and.w #3,%%d0\n" \ - " sub.w %%d0,%2\n" \ - " bra 2f\n" \ - " 1: move.b (%0),(%1)+\n" \ - " 2: dbf %%d0,1b\n" \ - " move.w %2,%%d0\n" \ - " lsr.w #5,%%d0\n" \ - " bra 4f\n" \ - " 3: move.l (%0),(%1)+\n" \ - "31: move.l (%0),(%1)+\n" \ - "32: move.l (%0),(%1)+\n" \ - "33: move.l (%0),(%1)+\n" \ - "34: move.l (%0),(%1)+\n" \ - "35: move.l (%0),(%1)+\n" \ - "36: move.l (%0),(%1)+\n" \ - "37: move.l (%0),(%1)+\n" \ - " 4: dbf %%d0,3b\n" \ - " move.w %2,%%d0\n" \ - " lsr.w #2,%%d0\n" \ - " and.w #7,%%d0\n" \ - " bra 6f\n" \ - " 5: move.l (%0),(%1)+\n" \ - " 6: dbf %%d0,5b\n" \ - " and.w #3,%2\n" \ - " bra 8f\n" \ - " 7: move.b (%0),(%1)+\n" \ - " 8: dbf %2,7b\n" \ - " moveq.l #0, %2\n" \ - " 9: \n" \ - ".section .fixup,\"ax\"\n" \ - " .even\n" \ - "91: moveq.l #1, %2\n" \ - " jra 9b\n" \ - "94: moveq.l #4, %2\n" \ - " jra 9b\n" \ - ".previous\n" \ - ".section __ex_table,\"a\"\n" \ - " .align 4\n" \ - " .long 1b,91b\n" \ - " .long 3b,94b\n" \ - " .long 31b,94b\n" \ - " .long 32b,94b\n" \ - " .long 33b,94b\n" \ - " .long 34b,94b\n" \ - " .long 35b,94b\n" \ - " .long 36b,94b\n" \ - " .long 37b,94b\n" \ - " .long 5b,94b\n" \ - " .long 7b,91b\n" \ - ".previous" \ - : "=a"(s), "=a"(d), "=d"(n) \ - : "0"(s), "1"(d), "2"(n) \ - : "d0") +/* + * According to "Inside Macintosh: Devices", Mac OS requires disk drivers to + * specify the number of bytes between the delays expected from a SCSI target. + * This allows the operating system to "prevent bus errors when a target fails + * to deliver the next byte within the processor bus error timeout period." + * Linux SCSI drivers lack knowledge of the timing behaviour of SCSI targets + * so bus errors are unavoidable. + * + * If a MOVE.B instruction faults, we assume that zero bytes were transferred + * and simply retry. That assumption probably depends on target behaviour but + * seems to hold up okay. The NOP provides synchronization: without it the + * fault can sometimes occur after the program counter has moved past the + * offending instruction. Post-increment addressing can't be used. + */ + +#define MOVE_BYTE(operands) \ + asm volatile ( \ + "1: moveb " operands " \n" \ + "11: nop \n" \ + " addq #1,%0 \n" \ + " subq #1,%1 \n" \ + "40: \n" \ + " \n" \ + ".section .fixup,\"ax\" \n" \ + ".even \n" \ + "90: movel #1, %2 \n" \ + " jra 40b \n" \ + ".previous \n" \ + " \n" \ + ".section __ex_table,\"a\" \n" \ + ".align 4 \n" \ + ".long 1b,90b \n" \ + ".long 11b,90b \n" \ + ".previous \n" \ + : "+a" (addr), "+r" (n), "+r" (result) : "a" (io)) + +/* + * If a MOVE.W (or MOVE.L) instruction faults, it cannot be retried because + * the residual byte count would be uncertain. In that situation the MOVE_WORD + * macro clears n in the fixup section to abort the transfer. + */ + +#define MOVE_WORD(operands) \ + asm volatile ( \ + "1: movew " operands " \n" \ + "11: nop \n" \ + " subq #2,%1 \n" \ + "40: \n" \ + " \n" \ + ".section .fixup,\"ax\" \n" \ + ".even \n" \ + "90: movel #0, %1 \n" \ + " movel #2, %2 \n" \ + " jra 40b \n" \ + ".previous \n" \ + " \n" \ + ".section __ex_table,\"a\" \n" \ + ".align 4 \n" \ + ".long 1b,90b \n" \ + ".long 11b,90b \n" \ + ".previous \n" \ + : "+a" (addr), "+r" (n), "+r" (result) : "a" (io)) + +#define MOVE_16_WORDS(operands) \ + asm volatile ( \ + "1: movew " operands " \n" \ + "2: movew " operands " \n" \ + "3: movew " operands " \n" \ + "4: movew " operands " \n" \ + "5: movew " operands " \n" \ + "6: movew " operands " \n" \ + "7: movew " operands " \n" \ + "8: movew " operands " \n" \ + "9: movew " operands " \n" \ + "10: movew " operands " \n" \ + "11: movew " operands " \n" \ + "12: movew " operands " \n" \ + "13: movew " operands " \n" \ + "14: movew " operands " \n" \ + "15: movew " operands " \n" \ + "16: movew " operands " \n" \ + "17: nop \n" \ + " subl #32,%1 \n" \ + "40: \n" \ + " \n" \ + ".section .fixup,\"ax\" \n" \ + ".even \n" \ + "90: movel #0, %1 \n" \ + " movel #2, %2 \n" \ + " jra 40b \n" \ + ".previous \n" \ + " \n" \ + ".section __ex_table,\"a\" \n" \ + ".align 4 \n" \ + ".long 1b,90b \n" \ + ".long 2b,90b \n" \ + ".long 3b,90b \n" \ + ".long 4b,90b \n" \ + ".long 5b,90b \n" \ + ".long 6b,90b \n" \ + ".long 7b,90b \n" \ + ".long 8b,90b \n" \ + ".long 9b,90b \n" \ + ".long 10b,90b \n" \ + ".long 11b,90b \n" \ + ".long 12b,90b \n" \ + ".long 13b,90b \n" \ + ".long 14b,90b \n" \ + ".long 15b,90b \n" \ + ".long 16b,90b \n" \ + ".long 17b,90b \n" \ + ".previous \n" \ + : "+a" (addr), "+r" (n), "+r" (result) : "a" (io)) + +#define MAC_PDMA_DELAY 32 + +static inline int mac_pdma_recv(void __iomem *io, unsigned char *start, int n) +{ + unsigned char *addr = start; + int result = 0; + + if (n >= 1) { + MOVE_BYTE("%3@,%0@"); + if (result) + goto out; + } + if (n >= 1 && ((unsigned long)addr & 1)) { + MOVE_BYTE("%3@,%0@"); + if (result) + goto out; + } + while (n >= 32) + MOVE_16_WORDS("%3@,%0@+"); + while (n >= 2) + MOVE_WORD("%3@,%0@+"); + if (result) + return start - addr; /* Negated to indicate uncertain length */ + if (n == 1) + MOVE_BYTE("%3@,%0@"); +out: + return addr - start; +} + +static inline int mac_pdma_send(unsigned char *start, void __iomem *io, int n) +{ + unsigned char *addr = start; + int result = 0; + + if (n >= 1) { + MOVE_BYTE("%0@,%3@"); + if (result) + goto out; + } + if (n >= 1 && ((unsigned long)addr & 1)) { + MOVE_BYTE("%0@,%3@"); + if (result) + goto out; + } + while (n >= 32) + MOVE_16_WORDS("%0@+,%3@"); + while (n >= 2) + MOVE_WORD("%0@+,%3@"); + if (result) + return start - addr; /* Negated to indicate uncertain length */ + if (n == 1) + MOVE_BYTE("%0@,%3@"); +out: + return addr - start; +} static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, unsigned char *dst, int len) { u8 __iomem *s = hostdata->pdma_io + (INPUT_DATA_REG << 4); unsigned char *d = dst; - int n = len; - int transferred; + + hostdata->pdma_residual = len; while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_DRQ | BASR_PHASE_MATCH, BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) { - CP_IO_TO_MEM(s, d, n); + int bytes; - transferred = d - dst - n; - hostdata->pdma_residual = len - transferred; + bytes = mac_pdma_recv(s, d, min(hostdata->pdma_residual, 512)); - /* No bus error. */ - if (n == 0) + if (bytes > 0) { + d += bytes; + hostdata->pdma_residual -= bytes; + } + + if (hostdata->pdma_residual == 0) return 0; - /* Target changed phase early? */ if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ, - BUS_AND_STATUS_REG, BASR_ACK, BASR_ACK, HZ / 64) < 0) - scmd_printk(KERN_ERR, hostdata->connected, + BUS_AND_STATUS_REG, BASR_ACK, + BASR_ACK, HZ / 64) < 0) + scmd_printk(KERN_DEBUG, hostdata->connected, "%s: !REQ and !ACK\n", __func__); if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH)) return 0; + if (bytes == 0) + udelay(MAC_PDMA_DELAY); + + if (bytes >= 0) + continue; + dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host, - "%s: bus error (%d/%d)\n", __func__, transferred, len); + "%s: bus error (%d/%d)\n", __func__, d - dst, len); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - d = dst + transferred; - n = len - transferred; + return -1; } scmd_printk(KERN_ERR, hostdata->connected, @@ -192,93 +311,27 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, return -1; } - -#define CP_MEM_TO_IO(s,d,n) \ -__asm__ __volatile__ \ - (" cmp.w #4,%2\n" \ - " bls 8f\n" \ - " move.w %0,%%d0\n" \ - " neg.b %%d0\n" \ - " and.w #3,%%d0\n" \ - " sub.w %%d0,%2\n" \ - " bra 2f\n" \ - " 1: move.b (%0)+,(%1)\n" \ - " 2: dbf %%d0,1b\n" \ - " move.w %2,%%d0\n" \ - " lsr.w #5,%%d0\n" \ - " bra 4f\n" \ - " 3: move.l (%0)+,(%1)\n" \ - "31: move.l (%0)+,(%1)\n" \ - "32: move.l (%0)+,(%1)\n" \ - "33: move.l (%0)+,(%1)\n" \ - "34: move.l (%0)+,(%1)\n" \ - "35: move.l (%0)+,(%1)\n" \ - "36: move.l (%0)+,(%1)\n" \ - "37: move.l (%0)+,(%1)\n" \ - " 4: dbf %%d0,3b\n" \ - " move.w %2,%%d0\n" \ - " lsr.w #2,%%d0\n" \ - " and.w #7,%%d0\n" \ - " bra 6f\n" \ - " 5: move.l (%0)+,(%1)\n" \ - " 6: dbf %%d0,5b\n" \ - " and.w #3,%2\n" \ - " bra 8f\n" \ - " 7: move.b (%0)+,(%1)\n" \ - " 8: dbf %2,7b\n" \ - " moveq.l #0, %2\n" \ - " 9: \n" \ - ".section .fixup,\"ax\"\n" \ - " .even\n" \ - "91: moveq.l #1, %2\n" \ - " jra 9b\n" \ - "94: moveq.l #4, %2\n" \ - " jra 9b\n" \ - ".previous\n" \ - ".section __ex_table,\"a\"\n" \ - " .align 4\n" \ - " .long 1b,91b\n" \ - " .long 3b,94b\n" \ - " .long 31b,94b\n" \ - " .long 32b,94b\n" \ - " .long 33b,94b\n" \ - " .long 34b,94b\n" \ - " .long 35b,94b\n" \ - " .long 36b,94b\n" \ - " .long 37b,94b\n" \ - " .long 5b,94b\n" \ - " .long 7b,91b\n" \ - ".previous" \ - : "=a"(s), "=a"(d), "=d"(n) \ - : "0"(s), "1"(d), "2"(n) \ - : "d0") - static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, unsigned char *src, int len) { unsigned char *s = src; u8 __iomem *d = hostdata->pdma_io + (OUTPUT_DATA_REG << 4); - int n = len; - int transferred; + + hostdata->pdma_residual = len; while (!NCR5380_poll_politely(hostdata, BUS_AND_STATUS_REG, BASR_DRQ | BASR_PHASE_MATCH, BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) { - CP_MEM_TO_IO(s, d, n); + int bytes; - transferred = s - src - n; - hostdata->pdma_residual = len - transferred; + bytes = mac_pdma_send(s, d, min(hostdata->pdma_residual, 512)); - /* Target changed phase early? */ - if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ, - BUS_AND_STATUS_REG, BASR_ACK, BASR_ACK, HZ / 64) < 0) - scmd_printk(KERN_ERR, hostdata->connected, - "%s: !REQ and !ACK\n", __func__); - if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH)) - return 0; + if (bytes > 0) { + s += bytes; + hostdata->pdma_residual -= bytes; + } - /* No bus error. */ - if (n == 0) { + if (hostdata->pdma_residual == 0) { if (NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG, TCR_LAST_BYTE_SENT, TCR_LAST_BYTE_SENT, HZ / 64) < 0) @@ -287,17 +340,29 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, return 0; } + if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ, + BUS_AND_STATUS_REG, BASR_ACK, + BASR_ACK, HZ / 64) < 0) + scmd_printk(KERN_DEBUG, hostdata->connected, + "%s: !REQ and !ACK\n", __func__); + if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH)) + return 0; + + if (bytes == 0) + udelay(MAC_PDMA_DELAY); + + if (bytes >= 0) + continue; + dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host, - "%s: bus error (%d/%d)\n", __func__, transferred, len); + "%s: bus error (%d/%d)\n", __func__, s - src, len); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - s = src + transferred; - n = len - transferred; + return -1; } scmd_printk(KERN_ERR, hostdata->connected, "%s: phase mismatch or !DRQ\n", __func__); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - return -1; }