Re: [PATCH] drivers/scsi/emcctd: drivers/scsi/emcctd: Client driver implementation for EMC-Symmetrix GuestOS emulated Cut-Through Device
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From: Greg KH <hidden>
Date: 2016-01-19 18:12:39
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On Tue, Jan 19, 2016 at 11:58:06AM +0000, Singhal, Maneesh wrote:
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Hello, Kindly review the following patch for the following driver to be added in SCSI subsystem - Regards Maneesh ----------------------------------------------------------------------------quoted
From f3c4b836d6f130b1d7ded618002c8164f8f4a06d Mon Sep 17 00:00:00 2001From: "maneesh.singhal" <redacted> Date: Tue, 19 Jan 2016 06:39:35 -0500 Subject: [PATCH] [PATCH] drivers/scsi/emcctd: Client driver implementation for EMC-Symmetrix GuestOS emulated Cut-Through Device. The patch is a driver implementation EMC-Symmetrix GuestOS emulated Cut-Through Device. The Cut-Through Device PCI emulation is implemented for GuestOS environments in the HyperMax OS. GuestOS environments allows loading of any x86 compliant operating systems like Linux/FreeBSD etc. The client driver is a SCSI HBA implementation which interfaces with SCSI midlayer in the north-bound interfaces and connects with the emulated PCI device on the south side. The PCI vendor ID:product ID for emulated Cut-Through Device is 0x1120:0x1B00. Signed-off-by: maneesh.singhal <redacted> --- Documentation/scsi/emcctd.txt | 57 + MAINTAINERS | 9 + drivers/scsi/Kconfig | 1 + drivers/scsi/Makefile | 1 + drivers/scsi/emcctd/Kconfig | 7 + drivers/scsi/emcctd/Makefile | 1 + drivers/scsi/emcctd/README | 10 + drivers/scsi/emcctd/emc_ctd_interface.h | 386 +++++ drivers/scsi/emcctd/emcctd.c | 2840 +++++++++++++++++++++++++++++++ drivers/scsi/emcctd/emcctd.h | 232 +++ 10 files changed, 3544 insertions(+) create mode 100644 Documentation/scsi/emcctd.txt create mode 100644 drivers/scsi/emcctd/Kconfig create mode 100644 drivers/scsi/emcctd/Makefile create mode 100644 drivers/scsi/emcctd/README create mode 100644 drivers/scsi/emcctd/emc_ctd_interface.h create mode 100644 drivers/scsi/emcctd/emcctd.c create mode 100644 drivers/scsi/emcctd/emcctd.hdiff --git a/Documentation/scsi/emcctd.txt b/Documentation/scsi/emcctd.txt new file mode 100644 index 0000000..bcafc87 --- /dev/null +++ b/Documentation/scsi/emcctd.txt@@ -0,0 +1,56 @@ +This file contains brief information about the EMC Cut-Through Driver (emcctd). +The driver is currently maintained by Singhal, Maneesh (maneesh.singhal-mb1K0bWo544@public.gmane.org) + +Last modified: Mon Jan 18 2016 by Maneesh Singhal + +BASICS + +Its a client driver implementation for EMC-Symmetrix GuestOS emulated +Cut-Through Device. The Cut-Through Device PCI emulation is implemented for +GuestOS environments in the HyperMax OS. GuestOS environments allows loading of +any x86 compliant operating systems like Linux/FreeBSD etc. + +The client driver is a SCSI HBA implementation which interfaces with SCSI +midlayer in the north-bound interfaces and connects with the emulated PCI device +on the south side. + +The PCI vendor ID:product ID for emulated Cut-Through Device is 0x1120:0x1B00. + +VERSIONING + +The Version of the driver is maintained as 2.0.0.X, where 2 refers to the CTD +protocol in use, and X refers to the ongoing version of the driver. + + +SYSFS SUPPORT + +The driver creates the directory /sys/module/emcctd and populates it with +version file and a directory for various parameters as described in MODULE +PARAMETERS section. + +PROCFS SUPPORT + +The driver creates the directory /proc/emc and creates files emcctd_stats_x +where 'x' refers to the PCI emulation number this client driver connected to. +These files cotains WWN information and IO statistics for the particular PCI +emulation.
No, no driver should be adding proc files, please use sysfs or debugfs for debugging things.
+MODULE PARAMETERS
No driver should be using module parameters anymore, again, please use the correct interfaces.
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+ +The supported parameters which could add debuggability or change the runtime +behavior of the driver are as following: + +ctd_debug=0 | 1 Enable driver debug messages(0=off, 1=on)
Use the dynamic debugging interface, don't make a custom one just for your tiny, single, driver.
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+ +max_luns=xx Specify the maximum number of LUN's per + host(default=16384)
Why can't this be dynamic? Why do you need a static number?
+ +cmd_per_lun=xx Specify the maximum commands per lun(default=16)
Why do you need to change this? Why can't it be dynamic?
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+ +DEBUGGING HINTS + +Debugging code is now compiled in by default but debugging is turned off +with the kernel module parameter debug_flag defaulting to 0.
Again, no, use the dynamic debug interface, don't make something "special" just for a single driver, we spent a lot of time trying to unify everything, don't go backwards. thanks, greg k-h