From mboxrd@z Thu Jan 1 00:00:00 1970 From: Finn Thain Subject: [PATCH 6/7] scsi: mac_scsi: Enable PDMA on Mac IIfx Date: Sun, 02 Jun 2019 11:24:12 +1000 Message-ID: References: Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: "James E.J. Bottomley" , "Martin K. Petersen" Cc: Michael Schmitz , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Joshua Thompson , Geert Uytterhoeven , linux-m68k@lists.linux-m68k.org List-Id: linux-scsi@vger.kernel.org Add support for Apple's custom "SCSI DMA" chip. This patch doesn't make use of its DMA capability. Just the PDMA capability is sufficient to improve sequential read throughput by a factor of 5. Cc: Michael Schmitz Cc: Joshua Thompson Cc: Geert Uytterhoeven Tested-by: Stan Johnson Signed-off-by: Finn Thain --- arch/m68k/mac/config.c | 10 +++++++-- drivers/scsi/mac_scsi.c | 47 ++++++++++++++++++++++++++++++++++------- 2 files changed, 47 insertions(+), 10 deletions(-) diff --git a/arch/m68k/mac/config.c b/arch/m68k/mac/config.c index 39835ca5a474..611f73bfc87c 100644 --- a/arch/m68k/mac/config.c +++ b/arch/m68k/mac/config.c @@ -911,6 +911,10 @@ static const struct resource mac_scsi_iifx_rsrc[] __initconst = { .flags = IORESOURCE_MEM, .start = 0x50008000, .end = 0x50009FFF, + }, { + .flags = IORESOURCE_MEM, + .start = 0x50008000, + .end = 0x50009FFF, }, }; @@ -1012,10 +1016,12 @@ int __init mac_platform_init(void) case MAC_SCSI_IIFX: /* Addresses from The Guide to Mac Family Hardware. * $5000 8000 - $5000 9FFF: SCSI DMA + * $5000 A000 - $5000 BFFF: Alternate SCSI * $5000 C000 - $5000 DFFF: Alternate SCSI (DMA) * $5000 E000 - $5000 FFFF: Alternate SCSI (Hsk) - * The SCSI DMA custom IC embeds the 53C80 core. mac_scsi does - * not make use of its DMA or hardware handshaking logic. + * The A/UX header file sys/uconfig.h says $50F0 8000. + * The "SCSI DMA" custom IC embeds the 53C80 core and + * supports Programmed IO, DMA and PDMA (hardware handshake). */ platform_device_register_simple("mac_scsi", 0, mac_scsi_iifx_rsrc, ARRAY_SIZE(mac_scsi_iifx_rsrc)); diff --git a/drivers/scsi/mac_scsi.c b/drivers/scsi/mac_scsi.c index e83b47a7e4b5..2e503f06ac99 100644 --- a/drivers/scsi/mac_scsi.c +++ b/drivers/scsi/mac_scsi.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include @@ -90,11 +91,22 @@ static int __init mac_scsi_setup(char *str) __setup("mac5380=", mac_scsi_setup); #endif /* !MODULE */ +/* The "SCSI DMA" chip on the IIfx implements this register. */ +#define CTRL_REG 0x8 +#define CTRL_INTERRUPTS_ENABLE BIT(1) +#define CTRL_HANDSHAKE_MODE BIT(3) + +static inline void write_ctrl_reg(struct NCR5380_hostdata *hostdata, u32 value) +{ + out_be32(hostdata->io + (CTRL_REG << 4), value); +} + 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 result = 0; hostdata->pdma_residual = len; @@ -103,6 +115,10 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) { int bytes; + if (macintosh_config->ident == MAC_MODEL_IIFX) + write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE | + CTRL_INTERRUPTS_ENABLE); + bytes = mac_pdma_recv(s, d, min(hostdata->pdma_residual, 512)); if (bytes > 0) { @@ -111,7 +127,7 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, } if (hostdata->pdma_residual == 0) - return 0; + goto out; if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ, BUS_AND_STATUS_REG, BASR_ACK, @@ -119,7 +135,7 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, scmd_printk(KERN_DEBUG, hostdata->connected, "%s: !REQ and !ACK\n", __func__); if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH)) - return 0; + goto out; if (bytes == 0) udelay(MAC_PDMA_DELAY); @@ -130,13 +146,18 @@ static inline int macscsi_pread(struct NCR5380_hostdata *hostdata, dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host, "%s: bus error (%d/%d)\n", __func__, d - dst, len); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - return -1; + result = -1; + goto out; } scmd_printk(KERN_ERR, hostdata->connected, "%s: phase mismatch or !DRQ\n", __func__); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - return -1; + result = -1; +out: + if (macintosh_config->ident == MAC_MODEL_IIFX) + write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE); + return result; } static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, @@ -144,6 +165,7 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, { unsigned char *s = src; u8 __iomem *d = hostdata->pdma_io + (OUTPUT_DATA_REG << 4); + int result = 0; hostdata->pdma_residual = len; @@ -152,6 +174,10 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, BASR_DRQ | BASR_PHASE_MATCH, HZ / 64)) { int bytes; + if (macintosh_config->ident == MAC_MODEL_IIFX) + write_ctrl_reg(hostdata, CTRL_HANDSHAKE_MODE | + CTRL_INTERRUPTS_ENABLE); + bytes = mac_pdma_send(s, d, min(hostdata->pdma_residual, 512)); if (bytes > 0) { @@ -165,7 +191,7 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, TCR_LAST_BYTE_SENT, HZ / 64) < 0) scmd_printk(KERN_ERR, hostdata->connected, "%s: Last Byte Sent timeout\n", __func__); - return 0; + goto out; } if (NCR5380_poll_politely2(hostdata, STATUS_REG, SR_REQ, SR_REQ, @@ -174,7 +200,7 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, scmd_printk(KERN_DEBUG, hostdata->connected, "%s: !REQ and !ACK\n", __func__); if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_PHASE_MATCH)) - return 0; + goto out; if (bytes == 0) udelay(MAC_PDMA_DELAY); @@ -185,13 +211,18 @@ static inline int macscsi_pwrite(struct NCR5380_hostdata *hostdata, dsprintk(NDEBUG_PSEUDO_DMA, hostdata->host, "%s: bus error (%d/%d)\n", __func__, s - src, len); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - return -1; + result = -1; + goto out; } scmd_printk(KERN_ERR, hostdata->connected, "%s: phase mismatch or !DRQ\n", __func__); NCR5380_dprint(NDEBUG_PSEUDO_DMA, hostdata->host); - return -1; + result = -1; +out: + if (macintosh_config->ident == MAC_MODEL_IIFX) + write_ctrl_reg(hostdata, CTRL_INTERRUPTS_ENABLE); + return result; } static int macscsi_dma_xfer_len(struct NCR5380_hostdata *hostdata, -- 2.21.0