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authorFinn Thain <fthain@telegraphics.com.au>2019-06-09 04:19:11 +0300
committerMartin K. Petersen <martin.petersen@oracle.com>2019-06-20 22:37:03 +0300
commit8fb9a64eb6e6fe502187c154434729871d9e5578 (patch)
tree471ff98eae09173769e2f9d17f9b45d2a10fed6b /arch/m68k
parent78ff751f8e6a9446e9fb26b2bff0b8d3f8974cbd (diff)
downloadlinux-8fb9a64eb6e6fe502187c154434729871d9e5578.tar.xz
scsi: mac_scsi: Enable PDMA on Mac IIfx
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 <schmitzmic@gmail.com> Cc: Joshua Thompson <funaho@jurai.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Stan Johnson <userm57@yahoo.com> Tested-by: Michael Schmitz <schmitzmic@gmail.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'arch/m68k')
-rw-r--r--arch/m68k/mac/config.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/m68k/mac/config.c b/arch/m68k/mac/config.c
index 11be08f4f750..205ac75da13d 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));