scsi: esp_scsi: De-duplicate PIO routines

As a temporary measure, the code to implement PIO transfers was
duplicated in zorro_esp and mac_esp. Now that it has stabilized move the
common code into the core driver but don't build it unless needed.

This replaces the inline assembler with more portable writesb() calls.
Optimizing the m68k writesb() implementation is a separate patch.

[mkp: applied by hand]

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Stan Johnson <userm57@yahoo.com>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 34 insertions, 198 deletions

diff --git a/drivers/scsi/zorro_esp.c b/drivers/scsi/zorro_esp.c
index b0ed062b2341..ca8e3abeb2c7 100644
--- a/drivers/scsi/zorro_esp.c
+++ b/drivers/scsi/zorro_esp.c
@@ -9,8 +9,6 @@
  *
  * Copyright (C) 2013 Tuomas Vainikka (tuomas.vainikka@aalto.fi) for
  *               Blizzard 1230 DMA and probe function fixes
- *
- * Copyright (C) 2017 Finn Thain for PIO code from Mac ESP driver adapted here
  */
 /*
  * ZORRO bus code from:
@@ -159,7 +157,6 @@ struct fastlane_dma_registers {
 struct zorro_esp_priv {
 	struct esp *esp;		/* our ESP instance - for Scsi_host* */
 	void __iomem *board_base;	/* virtual address (Zorro III board) */
-	int error;			/* PIO error flag */
 	int zorro3;			/* board is Zorro III */
 	unsigned char ctrl_data;	/* shadow copy of ctrl_reg */
 };
@@ -250,192 +247,29 @@ static void fastlane_esp_dma_invalidate(struct esp *esp)
 	z_writel(0, zep->board_base);
 }
 
-/*
- * Programmed IO routines follow.
- */
-
-static inline unsigned int zorro_esp_wait_for_fifo(struct esp *esp)
-{
-	int i = 500000;
-
-	do {
-		unsigned int fbytes = zorro_esp_read8(esp, ESP_FFLAGS)
-							& ESP_FF_FBYTES;
-
-		if (fbytes)
-			return fbytes;
-
-		udelay(2);
-	} while (--i);
-
-	pr_err("FIFO is empty (sreg %02x)\n",
-	       zorro_esp_read8(esp, ESP_STATUS));
-	return 0;
-}
-
-static inline int zorro_esp_wait_for_intr(struct esp *esp)
-{
-	struct zorro_esp_priv *zep = dev_get_drvdata(esp->dev);
-	int i = 500000;
-
-	do {
-		esp->sreg = zorro_esp_read8(esp, ESP_STATUS);
-		if (esp->sreg & ESP_STAT_INTR)
-			return 0;
-
-		udelay(2);
-	} while (--i);
-
-	pr_err("IRQ timeout (sreg %02x)\n", esp->sreg);
-	zep->error = 1;
-	return 1;
-}
-
-/*
- * PIO macros as used in mac_esp.c.
- * Note that addr and fifo arguments are local-scope variables declared
- * in zorro_esp_send_pio_cmd(), the macros are only used in that function,
- * and addr and fifo are referenced in each use of the macros so there
- * is no need to pass them as macro parameters.
- */
-#define ZORRO_ESP_PIO_LOOP(operands, reg1) \
-	asm volatile ( \
-	     "1:     moveb " operands "\n" \
-	     "       subqw #1,%1       \n" \
-	     "       jbne 1b           \n" \
-	     : "+a" (addr), "+r" (reg1) \
-	     : "a" (fifo));
-
-#define ZORRO_ESP_PIO_FILL(operands, reg1) \
-	asm volatile ( \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       moveb " operands "\n" \
-	     "       subqw #8,%1       \n" \
-	     "       subqw #8,%1       \n" \
-	     : "+a" (addr), "+r" (reg1) \
-	     : "a" (fifo));
-
-#define ZORRO_ESP_FIFO_SIZE 16
-
-static void zorro_esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count,
-				 u32 dma_count, int write, u8 cmd)
-{
-	struct zorro_esp_priv *zep = dev_get_drvdata(esp->dev);
-	u8 __iomem *fifo = esp->regs + ESP_FDATA * 16;
-	u8 phase = esp->sreg & ESP_STAT_PMASK;
-
-	cmd &= ~ESP_CMD_DMA;
-
-	if (write) {
-		u8 *dst = (u8 *)addr;
-		u8 mask = ~(phase == ESP_MIP ? ESP_INTR_FDONE : ESP_INTR_BSERV);
-
-		scsi_esp_cmd(esp, cmd);
-
-		while (1) {
-			if (!zorro_esp_wait_for_fifo(esp))
-				break;
-
-			*dst++ = zorro_esp_read8(esp, ESP_FDATA);
-			--esp_count;
-
-			if (!esp_count)
-				break;
-
-			if (zorro_esp_wait_for_intr(esp))
-				break;
-
-			if ((esp->sreg & ESP_STAT_PMASK) != phase)
-				break;
-
-			esp->ireg = zorro_esp_read8(esp, ESP_INTRPT);
-			if (esp->ireg & mask) {
-				zep->error = 1;
-				break;
-			}
-
-			if (phase == ESP_MIP)
-				scsi_esp_cmd(esp, ESP_CMD_MOK);
-
-			scsi_esp_cmd(esp, ESP_CMD_TI);
-		}
-	} else {	/* unused, as long as we only handle MIP here */
-		scsi_esp_cmd(esp, ESP_CMD_FLUSH);
-
-		if (esp_count >= ZORRO_ESP_FIFO_SIZE)
-			ZORRO_ESP_PIO_FILL("%0@+,%2@", esp_count)
-		else
-			ZORRO_ESP_PIO_LOOP("%0@+,%2@", esp_count)
-
-		scsi_esp_cmd(esp, cmd);
-
-		while (esp_count) {
-			unsigned int n;
-
-			if (zorro_esp_wait_for_intr(esp))
-				break;
-
-			if ((esp->sreg & ESP_STAT_PMASK) != phase)
-				break;
-
-			esp->ireg = zorro_esp_read8(esp, ESP_INTRPT);
-			if (esp->ireg & ~ESP_INTR_BSERV) {
-				zep->error = 1;
-				break;
-			}
-
-			n = ZORRO_ESP_FIFO_SIZE -
-			    (zorro_esp_read8(esp, ESP_FFLAGS) & ESP_FF_FBYTES);
-			if (n > esp_count)
-				n = esp_count;
-
-			if (n == ZORRO_ESP_FIFO_SIZE)
-				ZORRO_ESP_PIO_FILL("%0@+,%2@", esp_count)
-			else {
-				esp_count -= n;
-				ZORRO_ESP_PIO_LOOP("%0@+,%2@", n)
-			}
-
-			scsi_esp_cmd(esp, ESP_CMD_TI);
-		}
-	}
-}
-
 /* Blizzard 1230/60 SCSI-IV DMA */
 
 static void zorro_esp_send_blz1230_dma_cmd(struct esp *esp, u32 addr,
 			u32 esp_count, u32 dma_count, int write, u8 cmd)
 {
-	struct zorro_esp_priv *zep = dev_get_drvdata(esp->dev);
 	struct blz1230_dma_registers __iomem *dregs = esp->dma_regs;
 	u8 phase = esp->sreg & ESP_STAT_PMASK;
 
-	zep->error = 0;
 	/*
 	 * Use PIO if transferring message bytes to esp->command_block_dma.
 	 * PIO requires a virtual address, so substitute esp->command_block
 	 * for addr.
 	 */
 	if (phase == ESP_MIP && addr == esp->command_block_dma) {
-		zorro_esp_send_pio_cmd(esp, (u32) esp->command_block,
-					esp_count, dma_count, write, cmd);
+		esp_send_pio_cmd(esp, (u32)esp->command_block, esp_count,
+				 dma_count, write, cmd);
 		return;
 	}
 
+	/* Clear the results of a possible prior esp->ops->send_dma_cmd() */
+	esp->send_cmd_error = 0;
+	esp->send_cmd_residual = 0;
+
 	if (write)
 		/* DMA receive */
 		dma_sync_single_for_device(esp->dev, addr, esp_count,
@@ -469,18 +303,19 @@ static void zorro_esp_send_blz1230_dma_cmd(struct esp *esp, u32 addr,
 static void zorro_esp_send_blz1230II_dma_cmd(struct esp *esp, u32 addr,
 			u32 esp_count, u32 dma_count, int write, u8 cmd)
 {
-	struct zorro_esp_priv *zep = dev_get_drvdata(esp->dev);
 	struct blz1230II_dma_registers __iomem *dregs = esp->dma_regs;
 	u8 phase = esp->sreg & ESP_STAT_PMASK;
 
-	zep->error = 0;
 	/* Use PIO if transferring message bytes to esp->command_block_dma */
 	if (phase == ESP_MIP && addr == esp->command_block_dma) {
-		zorro_esp_send_pio_cmd(esp, (u32) esp->command_block,
-					esp_count, dma_count, write, cmd);
+		esp_send_pio_cmd(esp, (u32)esp->command_block, esp_count,
+				 dma_count, write, cmd);
 		return;
 	}
 
+	esp->send_cmd_error = 0;
+	esp->send_cmd_residual = 0;
+
 	if (write)
 		/* DMA receive */
 		dma_sync_single_for_device(esp->dev, addr, esp_count,
@@ -513,18 +348,19 @@ static void zorro_esp_send_blz1230II_dma_cmd(struct esp *esp, u32 addr,
 static void zorro_esp_send_blz2060_dma_cmd(struct esp *esp, u32 addr,
 			u32 esp_count, u32 dma_count, int write, u8 cmd)
 {
-	struct zorro_esp_priv *zep = dev_get_drvdata(esp->dev);
 	struct blz2060_dma_registers __iomem *dregs = esp->dma_regs;
 	u8 phase = esp->sreg & ESP_STAT_PMASK;
 
-	zep->error = 0;
 	/* Use PIO if transferring message bytes to esp->command_block_dma */
 	if (phase == ESP_MIP && addr == esp->command_block_dma) {
-		zorro_esp_send_pio_cmd(esp, (u32) esp->command_block,
-					esp_count, dma_count, write, cmd);
+		esp_send_pio_cmd(esp, (u32)esp->command_block, esp_count,
+				 dma_count, write, cmd);
 		return;
 	}
 
+	esp->send_cmd_error = 0;
+	esp->send_cmd_residual = 0;
+
 	if (write)
 		/* DMA receive */
 		dma_sync_single_for_device(esp->dev, addr, esp_count,
@@ -562,14 +398,16 @@ static void zorro_esp_send_cyber_dma_cmd(struct esp *esp, u32 addr,
 	u8 phase = esp->sreg & ESP_STAT_PMASK;
 	unsigned char *ctrl_data = &zep->ctrl_data;
 
-	zep->error = 0;
 	/* Use PIO if transferring message bytes to esp->command_block_dma */
 	if (phase == ESP_MIP && addr == esp->command_block_dma) {
-		zorro_esp_send_pio_cmd(esp, (u32) esp->command_block,
-					esp_count, dma_count, write, cmd);
+		esp_send_pio_cmd(esp, (u32)esp->command_block, esp_count,
+				 dma_count, write, cmd);
 		return;
 	}
 
+	esp->send_cmd_error = 0;
+	esp->send_cmd_residual = 0;
+
 	zorro_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
 	zorro_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
 
@@ -607,18 +445,19 @@ static void zorro_esp_send_cyber_dma_cmd(struct esp *esp, u32 addr,
 static void zorro_esp_send_cyberII_dma_cmd(struct esp *esp, u32 addr,
 			u32 esp_count, u32 dma_count, int write, u8 cmd)
 {
-	struct zorro_esp_priv *zep = dev_get_drvdata(esp->dev);
 	struct cyberII_dma_registers __iomem *dregs = esp->dma_regs;
 	u8 phase = esp->sreg & ESP_STAT_PMASK;
 
-	zep->error = 0;
 	/* Use PIO if transferring message bytes to esp->command_block_dma */
 	if (phase == ESP_MIP && addr == esp->command_block_dma) {
-		zorro_esp_send_pio_cmd(esp, (u32) esp->command_block,
-					esp_count, dma_count, write, cmd);
+		esp_send_pio_cmd(esp, (u32)esp->command_block, esp_count,
+				 dma_count, write, cmd);
 		return;
 	}
 
+	esp->send_cmd_error = 0;
+	esp->send_cmd_residual = 0;
+
 	zorro_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
 	zorro_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
 
@@ -652,14 +491,16 @@ static void zorro_esp_send_fastlane_dma_cmd(struct esp *esp, u32 addr,
 	u8 phase = esp->sreg & ESP_STAT_PMASK;
 	unsigned char *ctrl_data = &zep->ctrl_data;
 
-	zep->error = 0;
 	/* Use PIO if transferring message bytes to esp->command_block_dma */
 	if (phase == ESP_MIP && addr == esp->command_block_dma) {
-		zorro_esp_send_pio_cmd(esp, (u32) esp->command_block,
-					esp_count, dma_count, write, cmd);
+		esp_send_pio_cmd(esp, (u32)esp->command_block, esp_count,
+				 dma_count, write, cmd);
 		return;
 	}
 
+	esp->send_cmd_error = 0;
+	esp->send_cmd_residual = 0;
+
 	zorro_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
 	zorro_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
 
@@ -694,14 +535,7 @@ static void zorro_esp_send_fastlane_dma_cmd(struct esp *esp, u32 addr,
 
 static int zorro_esp_dma_error(struct esp *esp)
 {
-	struct zorro_esp_priv *zep = dev_get_drvdata(esp->dev);
-
-	/* check for error in case we've been doing PIO */
-	if (zep->error == 1)
-		return 1;
-
-	/* do nothing - there seems to be no way to check for DMA errors */
-	return 0;
+	return esp->send_cmd_error;
 }
 
 /* per-board ESP driver ops */
@@ -985,6 +819,8 @@ static int zorro_esp_probe(struct zorro_dev *z,
 		goto fail_unmap_fastlane;
 	}
 
+	esp->fifo_reg = esp->regs + ESP_FDATA * 4;
+
 	/* Check whether a Blizzard 12x0 or CyberstormII really has SCSI */
 	if (zdd->scsi_option) {
 		zorro_esp_write8(esp, (ESP_CONFIG1_PENABLE | 7), ESP_CFG1);