Re: [PATCH v2 5/6] esp_scsi: De-duplicate PIO routines

Hannes Reinecke
2018-10-15T06:14:39Z

On 10/14/18 8:12 AM, Finn Thain wrote:
> 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.
>
> Tested-by: Stan Johnson <userm57@yahoo.com>
> Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
> Tested-by: Michael Schmitz <schmitzmic@gmail.com>
> ---
> Changed since v1:
> - Use shost_printk() instead of pr_err().
> - Add new symbol CONFIG_SCSI_ESP_PIO to Kconfig.
> ---
> drivers/scsi/Kconfig | 6 +
> drivers/scsi/esp_scsi.c | 128 +++++++++++++++++++++
> drivers/scsi/esp_scsi.h | 5 +
> drivers/scsi/mac_esp.c | 173 +----------------------------
> drivers/scsi/zorro_esp.c | 232 ++++++---------------------------------
> 5 files changed, 179 insertions(+), 365 deletions(-)
>
> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> index 35c909bbf8ba..81c6872f24f8 100644
> --- a/drivers/scsi/Kconfig
> +++ b/drivers/scsi/Kconfig
> @@ -42,6 +42,10 @@ config SCSI_DMA
> bool
> default n
>
> +config SCSI_ESP_PIO
> + bool
> + default n
> +
> config SCSI_NETLINK
> bool
> default n
> @@ -1355,6 +1359,7 @@ config SCSI_ZORRO_ESP
> tristate "Zorro ESP SCSI support"
> depends on ZORRO && SCSI
> select SCSI_SPI_ATTRS
> + select SCSI_ESP_PIO
> help
> Support for various NCR53C9x (ESP) based SCSI controllers on Zorro
> expansion boards for the Amiga.
> @@ -1397,6 +1402,7 @@ config SCSI_MAC_ESP
> tristate "Macintosh NCR53c9[46] SCSI"
> depends on MAC && SCSI
> select SCSI_SPI_ATTRS
> + select SCSI_ESP_PIO
> help
> This is the NCR 53c9x SCSI controller found on most of the 68040
> based Macintoshes.
> diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c
> index 6ccaf818357e..305a322ad13c 100644
> --- a/drivers/scsi/esp_scsi.c
> +++ b/drivers/scsi/esp_scsi.c
> @@ -2776,3 +2776,131 @@ MODULE_PARM_DESC(esp_debug,
>
> module_init(esp_init);
> module_exit(esp_exit);
> +
> +#ifdef CONFIG_SCSI_ESP_PIO
> +static inline unsigned int esp_wait_for_fifo(struct esp *esp)
> +{
> + int i = 500000;
> +
> + do {
> + unsigned int fbytes = esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES;
> +
> + if (fbytes)
> + return fbytes;
> +
> + udelay(2);
> + } while (--i);
> +
> + shost_printk(KERN_ERR, esp->host, "FIFO is empty (sreg %02x)\n",
> + esp_read8(ESP_STATUS));
> + return 0;
> +}
> +
> +static inline int esp_wait_for_intr(struct esp *esp)
> +{
> + int i = 500000;
> +
> + do {
> + esp->sreg = esp_read8(ESP_STATUS);
> + if (esp->sreg & ESP_STAT_INTR)
> + return 0;
> +
> + udelay(2);
> + } while (--i);
> +
> + shost_printk(KERN_ERR, esp->host, "IRQ timeout (sreg %02x)\n",
> + esp->sreg);
> + return 1;
> +}
> +
> +#define ESP_FIFO_SIZE 16
> +
> +void esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count,
> + u32 dma_count, int write, u8 cmd)
> +{
> + u8 phase = esp->sreg & ESP_STAT_PMASK;
> +
> + cmd &= ~ESP_CMD_DMA;
> + esp->send_cmd_error = 0;
> +
> + 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 (!esp_wait_for_fifo(esp))
> + break;
> +
> + *dst++ = esp_read8(ESP_FDATA);
> + --esp_count;
> +
> + if (!esp_count)
> + break;
> +
> + if (esp_wait_for_intr(esp)) {
> + esp->send_cmd_error = 1;
> + break;
> + }
> +
> + if ((esp->sreg & ESP_STAT_PMASK) != phase)
> + break;
> +
> + esp->ireg = esp_read8(ESP_INTRPT);
> + if (esp->ireg & mask) {
> + esp->send_cmd_error = 1;
> + break;
> + }
> +
> + if (phase == ESP_MIP)
> + scsi_esp_cmd(esp, ESP_CMD_MOK);
> +
> + scsi_esp_cmd(esp, ESP_CMD_TI);
> + }
> + } else {
> + unsigned int n = ESP_FIFO_SIZE;
> + u8 *src = (u8 *)addr;
> +
> + scsi_esp_cmd(esp, ESP_CMD_FLUSH);
> +
> + if (n > esp_count)
> + n = esp_count;
> + writesb(esp->fifo_reg, src, n);
> + src += n;
> + esp_count -= n;
> +
> + scsi_esp_cmd(esp, cmd);
> +
> + while (esp_count) {
> + if (esp_wait_for_intr(esp)) {
> + esp->send_cmd_error = 1;
> + break;
> + }
> +
> + if ((esp->sreg & ESP_STAT_PMASK) != phase)
> + break;
> +
> + esp->ireg = esp_read8(ESP_INTRPT);
> + if (esp->ireg & ~ESP_INTR_BSERV) {
> + esp->send_cmd_error = 1;
> + break;
> + }
> +
> + n = ESP_FIFO_SIZE -
> + (esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES);
> +
> + if (n > esp_count)
> + n = esp_count;
> + writesb(esp->fifo_reg, src, n);
> + src += n;
> + esp_count -= n;
> +
> + scsi_esp_cmd(esp, ESP_CMD_TI);
> + }
> + }
> +
> + esp->send_cmd_residual = esp_count;
> +}
> +EXPORT_SYMBOL(esp_send_pio_cmd);
> +#endif
> diff --git a/drivers/scsi/esp_scsi.h b/drivers/scsi/esp_scsi.h
> index d0c032803749..2590e5eda595 100644
> --- a/drivers/scsi/esp_scsi.h
> +++ b/drivers/scsi/esp_scsi.h
> @@ -431,6 +431,7 @@ struct esp_driver_ops {
> struct esp {
> void __iomem *regs;
> void __iomem *dma_regs;
> + u8 __iomem *fifo_reg;
>
> const struct esp_driver_ops *ops;
>
> @@ -540,6 +541,7 @@ struct esp {
> void *dma;
> int dmarev;
>
> + int send_cmd_error;
> int send_cmd_residual;
> };
>
These variables are only used within esp_send_pio_cmd(); consider making
them conditional based on the config option.

> @@ -581,4 +583,7 @@ extern void scsi_esp_unregister(struct esp *);
> extern irqreturn_t scsi_esp_intr(int, void *);
> extern void scsi_esp_cmd(struct esp *, u8);
>
> +extern void esp_send_pio_cmd(struct esp *esp, u32 dma_addr, u32 esp_count,
> + u32 dma_count, int write, u8 cmd);
> +
> #endif /* !(_ESP_SCSI_H) */
Same here; the declaration only makes sense when the config option is set.

Cheers,

Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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