[PATCH v3 01/23] g_ncr5380: Remove CONFIG_SCSI_GENERIC_NCR53C400

From: Finn Thain
Date: Mon Mar 21 2016 - 00:10:45 EST

This change brings a number of improvements: fewer macros, better test
coverage, simpler code and sane Kconfig options. The downside is a small
chance of incompatibility (which seems unavoidable).

CONFIG_SCSI_GENERIC_NCR53C400 exists to enable or inhibit pseudo DMA
transfers when the driver is used with 53C400-compatible cards. Thanks to
Ondrej Zary's patches, PDMA now works which means it can be enabled
unconditionally.

Due to bad design, CONFIG_SCSI_GENERIC_NCR53C400 ties together unrelated
functionality as it sets both PSEUDO_DMA and BIOSPARAM macros. This patch
effectively enables PSEUDO_DMA and disables BIOSPARAM.

The defconfigs and the Kconfig default leave CONFIG_SCSI_GENERIC_NCR53C400
undefined. Red Hat 9 and CentOS 2.1 were the same. This leaves both
PSEUDO_DMA and BIOSPARAM disabled. The effect of this patch should be
better performance from enabling PSEUDO_DMA.

On the other hand, Debian 4 and SLES 10 had CONFIG_SCSI_GENERIC_NCR53C400
enabled, so both PSEUDO_DMA and BIOSPARAM were enabled. This patch might
affect configurations like this by disabling BIOSPARAM. My best guess is
that this could be a problem only in the vanishingly rare case that
1) the CHS values stored in the boot device partition table are wrong and
2) a 5380 card is in use (because PDMA on 53C400 used to be broken).

Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>

---

Here are the distro kernel versions I looked at:

CentOS 2.1:

$ strings kernel-2.4.9-e.40.i686/lib/modules/2.4.9-e.40/kernel/drivers/scsi/g_NCR5380.o | grep extension
NO NCR53C400 driver extensions


Red Hat 7:

$ strings kernel-2.4.18-3.i386/lib/modules/2.4.18-3/kernel/drivers/scsi/g_NCR5380.o | grep extension
NO NCR53C400 driver extensions


Red Hat 9:

$ strings kernel-2.4.20-8.i586/lib/modules/2.4.20-8/kernel/drivers/scsi/g_NCR5380.o | grep extension
NO NCR53C400 driver extensions


Debian 4:

$ strings linux-image-2.6.24-etchnhalf.1-486_2.6.24-6-etchnhalf.9etch3_i386/lib/modules/2.6.24-etchnhalf.1-486/kernel/drivers/scsi/g_NCR5380_mmio.ko | grep extension
NCR53C400 extension version %d
$ strings kernel-image-2.6.8-2-386_2.6.8-13_i386/lib/modules/2.6.8-2-386/kernel/drivers/scsi/g_NCR5380_mmio.ko | grep extension
NCR53C400 extension version %d


SLES 10.2:

$ strings kernel-default-2.6.18.2-34.i586/lib/modules/2.6.18.2-34-default/kernel/drivers/scsi/g_NCR5380_mmio.ko | grep extension
NCR53C400 extension version %d

---
drivers/scsi/Kconfig | 11 ------
drivers/scsi/g_NCR5380.c | 75 ++++++++++++++---------------------------------
drivers/scsi/g_NCR5380.h | 16 +---------
3 files changed, 25 insertions(+), 77 deletions(-)

Index: linux/drivers/scsi/Kconfig
===================================================================
--- linux.orig/drivers/scsi/Kconfig 2016-03-21 13:31:07.000000000 +1100
+++ linux/drivers/scsi/Kconfig 2016-03-21 13:31:07.000000000 +1100
@@ -812,17 +812,6 @@ config SCSI_GENERIC_NCR5380_MMIO
To compile this driver as a module, choose M here: the
module will be called g_NCR5380_mmio.

-config SCSI_GENERIC_NCR53C400
- bool "Enable NCR53c400 extensions"
- depends on SCSI_GENERIC_NCR5380
- help
- This enables certain optimizations for the NCR53c400 SCSI cards.
- You might as well try it out. Note that this driver will only probe
- for the Trantor T130B in its default configuration; you might have
- to pass a command line option to the kernel at boot time if it does
- not detect your card. See the file
- <file:Documentation/scsi/g_NCR5380.txt> for details.
-
config SCSI_IPS
tristate "IBM ServeRAID support"
depends on PCI && SCSI
Index: linux/drivers/scsi/g_NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/g_NCR5380.c 2016-03-21 13:31:07.000000000 +1100
+++ linux/drivers/scsi/g_NCR5380.c 2016-03-21 13:31:07.000000000 +1100
@@ -57,10 +57,7 @@
*/

#define AUTOPROBE_IRQ
-
-#ifdef CONFIG_SCSI_GENERIC_NCR53C400
#define PSEUDO_DMA
-#endif

#include <asm/io.h>
#include <linux/blkdev.h>
@@ -270,7 +267,7 @@ static int __init generic_NCR5380_detect
#ifndef SCSI_G_NCR5380_MEM
int i;
int port_idx = -1;
- unsigned long region_size = 16;
+ unsigned long region_size;
#endif
static unsigned int __initdata ncr_53c400a_ports[] = {
0x280, 0x290, 0x300, 0x310, 0x330, 0x340, 0x348, 0x350, 0
@@ -290,6 +287,7 @@ static int __init generic_NCR5380_detect
#ifdef SCSI_G_NCR5380_MEM
unsigned long base;
void __iomem *iomem;
+ resource_size_t iomem_size;
#endif

if (ncr_irq)
@@ -353,9 +351,7 @@ static int __init generic_NCR5380_detect
flags = FLAG_NO_PSEUDO_DMA;
break;
case BOARD_NCR53C400:
-#ifdef PSEUDO_DMA
flags = FLAG_NO_DMA_FIXUP;
-#endif
break;
case BOARD_NCR53C400A:
flags = FLAG_NO_DMA_FIXUP;
@@ -381,20 +377,22 @@ static int __init generic_NCR5380_detect
/* Disable the adapter and look for a free io port */
magic_configure(-1, 0, magic);

+ region_size = 16;
+
if (overrides[current_override].NCR5380_map_name != PORT_AUTO)
for (i = 0; ports[i]; i++) {
- if (!request_region(ports[i], 16, "ncr53c80"))
+ if (!request_region(ports[i], region_size, "ncr53c80"))
continue;
if (overrides[current_override].NCR5380_map_name == ports[i])
break;
- release_region(ports[i], 16);
+ release_region(ports[i], region_size);
} else
for (i = 0; ports[i]; i++) {
- if (!request_region(ports[i], 16, "ncr53c80"))
+ if (!request_region(ports[i], region_size, "ncr53c80"))
continue;
if (inb(ports[i]) == 0xff)
break;
- release_region(ports[i], 16);
+ release_region(ports[i], region_size);
}
if (ports[i]) {
/* At this point we have our region reserved */
@@ -410,17 +408,19 @@ static int __init generic_NCR5380_detect
else
{
/* Not a 53C400A style setup - just grab */
- if(!(request_region(overrides[current_override].NCR5380_map_name, NCR5380_region_size, "ncr5380")))
+ region_size = 8;
+ if (!request_region(overrides[current_override].NCR5380_map_name,
+ region_size, "ncr5380"))
continue;
- region_size = NCR5380_region_size;
}
#else
base = overrides[current_override].NCR5380_map_name;
- if (!request_mem_region(base, NCR5380_region_size, "ncr5380"))
+ iomem_size = NCR53C400_region_size;
+ if (!request_mem_region(base, iomem_size, "ncr5380"))
continue;
- iomem = ioremap(base, NCR5380_region_size);
+ iomem = ioremap(base, iomem_size);
if (!iomem) {
- release_mem_region(base, NCR5380_region_size);
+ release_mem_region(base, iomem_size);
continue;
}
#endif
@@ -458,6 +458,7 @@ static int __init generic_NCR5380_detect
#else
instance->base = overrides[current_override].NCR5380_map_name;
hostdata->iomem = iomem;
+ hostdata->iomem_size = iomem_size;
switch (overrides[current_override].board) {
case BOARD_NCR53C400:
hostdata->c400_ctl_status = 0x100;
@@ -524,7 +525,7 @@ out_release:
release_region(overrides[current_override].NCR5380_map_name, region_size);
#else
iounmap(iomem);
- release_mem_region(base, NCR5380_region_size);
+ release_mem_region(base, iomem_size);
#endif
return count;
}
@@ -546,42 +547,15 @@ static int generic_NCR5380_release_resou
#ifndef SCSI_G_NCR5380_MEM
release_region(instance->io_port, instance->n_io_port);
#else
- iounmap(((struct NCR5380_hostdata *)instance->hostdata)->iomem);
- release_mem_region(instance->base, NCR5380_region_size);
-#endif
- return 0;
-}
+ {
+ struct NCR5380_hostdata *hostdata = shost_priv(instance);

-#ifdef BIOSPARAM
-/**
- * generic_NCR5380_biosparam
- * @disk: disk to compute geometry for
- * @dev: device identifier for this disk
- * @ip: sizes to fill in
- *
- * Generates a BIOS / DOS compatible H-C-S mapping for the specified
- * device / size.
- *
- * XXX Most SCSI boards use this mapping, I could be incorrect. Someone
- * using hard disks on a trantor should verify that this mapping
- * corresponds to that used by the BIOS / ASPI driver by running the linux
- * fdisk program and matching the H_C_S coordinates to what DOS uses.
- *
- * Locks: none
- */
-
-static int
-generic_NCR5380_biosparam(struct scsi_device *sdev, struct block_device *bdev,
- sector_t capacity, int *ip)
-{
- ip[0] = 64;
- ip[1] = 32;
- ip[2] = capacity >> 11;
+ iounmap(hostdata->iomem);
+ release_mem_region(instance->base, hostdata->iomem_size);
+ }
+#endif
return 0;
}
-#endif
-
-#ifdef PSEUDO_DMA

/**
* NCR5380_pread - pseudo DMA read
@@ -756,8 +730,6 @@ static int generic_NCR5380_dma_xfer_len(
return transfersize;
}

-#endif /* PSEUDO_DMA */
-
/*
* Include the NCR5380 core code that we build our driver around
*/
@@ -773,7 +745,6 @@ static struct scsi_host_template driver_
.queuecommand = generic_NCR5380_queue_command,
.eh_abort_handler = generic_NCR5380_abort,
.eh_bus_reset_handler = generic_NCR5380_bus_reset,
- .bios_param = NCR5380_BIOSPARAM,
.can_queue = 16,
.this_id = 7,
.sg_tablesize = SG_ALL,
Index: linux/drivers/scsi/g_NCR5380.h
===================================================================
--- linux.orig/drivers/scsi/g_NCR5380.h 2016-03-21 13:31:07.000000000 +1100
+++ linux/drivers/scsi/g_NCR5380.h 2016-03-21 13:31:07.000000000 +1100
@@ -14,13 +14,6 @@
#ifndef GENERIC_NCR5380_H
#define GENERIC_NCR5380_H

-#ifdef CONFIG_SCSI_GENERIC_NCR53C400
-#define BIOSPARAM
-#define NCR5380_BIOSPARAM generic_NCR5380_biosparam
-#else
-#define NCR5380_BIOSPARAM NULL
-#endif
-
#define __STRVAL(x) #x
#define STRVAL(x) __STRVAL(x)

@@ -30,12 +23,6 @@
#define NCR5380_map_type int
#define NCR5380_map_name port

-#ifdef CONFIG_SCSI_GENERIC_NCR53C400
-#define NCR5380_region_size 16
-#else
-#define NCR5380_region_size 8
-#endif
-
#define NCR5380_read(reg) \
inb(instance->io_port + (reg))
#define NCR5380_write(reg, value) \
@@ -55,7 +42,7 @@
#define NCR5380_map_name base
#define NCR53C400_mem_base 0x3880
#define NCR53C400_host_buffer 0x3900
-#define NCR5380_region_size 0x3a00
+#define NCR53C400_region_size 0x3a00

#define NCR5380_read(reg) \
readb(((struct NCR5380_hostdata *)shost_priv(instance))->iomem + \
@@ -66,6 +53,7 @@

#define NCR5380_implementation_fields \
void __iomem *iomem; \
+ resource_size_t iomem_size; \
int c400_ctl_status; \
int c400_blk_cnt; \
int c400_host_buf;