Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.
The patch below presents a simple SCSI host lock push-down as an
equivalent transformation. No locking or other behavior should change
with this patch. All existing bugs and locking orders are preserved.
Additionally, add one parameter to queuecommand,
struct Scsi_Host *
and remove one parameter from queuecommand,
void (*done)(struct scsi_cmnd *)
Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.
Minimal code disturbance was attempted with this change. Most drivers
needed only two one-line modifications for their host lock push-down.
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
scsi_cmnd->cmnd was changed from a static array to a pointer post
2.6.25. It breaks mega_internal_command():
static int
mega_internal_command(adapter_t *adapter, megacmd_t *mc, mega_passthru *pthru)
{
...
scb = &adapter->int_scb;
memset(scb, 0, sizeof(scb_t));
scmd = &adapter->int_scmd;
memset(scmd, 0, sizeof(Scsi_Cmnd));
sdev = kzalloc(sizeof(struct scsi_device), GFP_KERNEL);
scmd->device = sdev;
scmd->device->host = adapter->host;
scmd->host_scribble = (void *)scb;
scmd->cmnd[0] = MEGA_INTERNAL_CMD;
mega_internal_command() uses scsi_cmnd allocated internally so
scmd->cmnd is NULL here. This patch adds a static array for cdb to
adapter_t and uses it here. This also uses
scsi_allocate_command/scsi_free_command, the recommended way to
allocate struct scsi_cmnd since the driver might use sense_buffer in
struct scsi_cmnd.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Boaz Harrosh <bharrosh@panasas.com>
Tested-by: Pascal Terjan <pterjan@gmail.com>
Reported-by: Pascal Terjan <pterjan@gmail.com>
Acked-by: "Yang, Bo" <Bo.Yang@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
drivers/scsi/megaraid.c: In function 'megaraid_probe_one':
drivers/scsi/megaraid.c:4893: warning: implicit declaration of function 'mega_create_proc_entry'
drivers/scsi/megaraid.c: In function 'megaraid_remove_one':
drivers/scsi/megaraid.c:4968: warning: unused variable 'buf'
Fix by adding #defines
Signed-off-by: walter harms <wharms@bfs.de>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
megaraid's MMIO RD*/WR* macros directly call readl() and writel() with
an 'unsigned long' argument. This throws a warning, but is otherwise OK
because the 'unsigned long' is really the result of ioremap(). This
setup is also OK because the variable can hold an ioremap cookie /or/ a
PCI I/O port (PIO).
However, to fix the warning thrown when readl() and writel() are passed
an unsigned long cookie, I introduce 'void __iomem *mmio_base', holding
the same value as 'base'. This will silence the warnings, and also
cause an oops whenever these MMIO-only functions are ever accidentally
passed an I/O address.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.
The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around. On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).
Where appropriate, an arch may override the generic storage facility and do
something different with the variable. On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.
Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions. Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller. A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.
I've build this code with allyesconfig for x86_64 and i386. I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.
This will affect all archs. Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:
struct pt_regs *old_regs = set_irq_regs(regs);
And put the old one back at the end:
set_irq_regs(old_regs);
Don't pass regs through to generic_handle_irq() or __do_IRQ().
In timer_interrupt(), this sort of change will be necessary:
- update_process_times(user_mode(regs));
- profile_tick(CPU_PROFILING, regs);
+ update_process_times(user_mode(get_irq_regs()));
+ profile_tick(CPU_PROFILING);
I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().
Some notes on the interrupt handling in the drivers:
(*) input_dev() is now gone entirely. The regs pointer is no longer stored in
the input_dev struct.
(*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does
something different depending on whether it's been supplied with a regs
pointer or not.
(*) Various IRQ handler function pointers have been moved to type
irq_handler_t.
Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
Attached patch fixes problem that cause kobject_register failure
during loading. Kobject_register would fail when there are more than
1 module with same module name. This patch will change module name of
megaraid_legacy from 'megaraid' to 'megaraid_legacy'.
Signed-Off-by: Seokmann Ju <seokmann.ju@lsil.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
the scsi layer is using semaphores in a mutex way, this patch converts
these into using mutexes instead
Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
just take the adapter lock in megaraid_queue. Additional benefit is
that we can get rid of the awkward conditional locking in
mega_internal_command.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
We never look at it except for the old megaraid driver that abuses it
for sending internal commands. That usage can be fixed easily because
those internal commands are single-threaded by a mutex and we can easily
use a completion there.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Jeff Garzik