[PATCH v3] fusion: remove dead MTRR code

[PATCH v3] fusion: remove dead MTRR code

[Luis R. Rodriguez]

From: "Luis R. Rodriguez" <mcgrof@suse.com>

If and when this gets enabled the driver could should split
up IO memory space properly and that is quite a bit of work.
Just remove the uncommented dead MTRR code then.

There are a few motivations for this:

a) Take advantage of PAT when available

b) Help bury MTRR code away, MTRR is architecture specific and on
   x86 its replaced by PAT

c) Help with the goal of eventually using _PAGE_CACHE_UC over
   _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache() (see commit
   de33c442e titled "x86 PAT: fix performance drop for glx,
   use UC minus for ioremap(), ioremap_nocache() and
   pci_mmap_page_range()")

Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nagalakshmi Nandigama <nagalakshmi.nandigama@avagotech.com>
Cc: Praveen Krishnamoorthy <praveen.krishnamoorthy@avagotech.com>
Cc: Sreekanth Reddy <sreekanth.reddy@avagotech.com>
Cc: Abhijit Mahajan <abhijit.mahajan@avagotech.com>
Cc: linux-scsi@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Juergen Gross <jgross@suse.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Ville Syrjälä <syrjala@sci.fi>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Borislav Petkov <bp@suse.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: MPT-FusionLinux.pdl@avagotech.com
Cc: linux-scsi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
---
 drivers/message/fusion/mptbase.c | 24 ------------------------
 drivers/message/fusion/mptbase.h |  1 -
 2 files changed, 25 deletions(-)

diff --git a/drivers/message/fusion/mptbase.c b/drivers/message/fusion/mptbase.c
index 187f836..5dcc031 100644
--- a/drivers/message/fusion/mptbase.c
+++ b/drivers/message/fusion/mptbase.c
@@ -59,10 +59,6 @@
 #include <linux/delay.h>
 #include <linux/interrupt.h>		/* needed for in_interrupt() proto */
 #include <linux/dma-mapping.h>
-#include <asm/io.h>
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
 #include <linux/kthread.h>
 #include <scsi/scsi_host.h>
 
@@ -2820,13 +2816,6 @@ mpt_adapter_dispose(MPT_ADAPTER *ioc)
 	pci_disable_device(ioc->pcidev);
 	pci_release_selected_regions(ioc->pcidev, ioc->bars);
 
-#if defined(CONFIG_MTRR) && 0
-	if (ioc->mtrr_reg > 0) {
-		mtrr_del(ioc->mtrr_reg, 0, 0);
-		dprintk(ioc, printk(MYIOC_s_INFO_FMT "MTRR region de-registered\n", ioc->name));
-	}
-#endif
-
 	/*  Zap the adapter lookup ptr!  */
 	list_del(&ioc->list);
 
@@ -4512,19 +4501,6 @@ PrimeIocFifos(MPT_ADAPTER *ioc)
 
 		ioc->req_frames_low_dma = (u32) (alloc_dma & 0xFFFFFFFF);
 
-#if defined(CONFIG_MTRR) && 0
-		/*
-		 *  Enable Write Combining MTRR for IOC's memory region.
-		 *  (at least as much as we can; "size and base must be
-		 *  multiples of 4 kiB"
-		 */
-		ioc->mtrr_reg = mtrr_add(ioc->req_frames_dma,
-					 sz,
-					 MTRR_TYPE_WRCOMB, 1);
-		dprintk(ioc, printk(MYIOC_s_DEBUG_FMT "MTRR region registered (base:size=%08x:%x)\n",
-				ioc->name, ioc->req_frames_dma, sz));
-#endif
-
 		for (i = 0; i < ioc->req_depth; i++) {
 			alloc_dma += ioc->req_sz;
 			mem += ioc->req_sz;
diff --git a/drivers/message/fusion/mptbase.h b/drivers/message/fusion/mptbase.h
index 8f14090..813d463 100644
--- a/drivers/message/fusion/mptbase.h
+++ b/drivers/message/fusion/mptbase.h
@@ -671,7 +671,6 @@ typedef struct _MPT_ADAPTER
 	u8			*HostPageBuffer; /* SAS - host page buffer support */
 	u32			HostPageBuffer_sz;
 	dma_addr_t		HostPageBuffer_dma;
-	int			 mtrr_reg;
 	struct pci_dev		*pcidev;	/* struct pci_dev pointer */
 	int			bars;		/* bitmask of BAR's that must be configured */
 	int			msi_enable;
-- 
2.3.2.209.gd67f9d5.dirty

Re: [PATCH v3] fusion: remove dead MTRR code

[Luis R. Rodriguez]

On Tue, Apr 21, 2015 at 1:46 PM, Luis R. Rodriguez
<mcgrof@do-not-panic.com> wrote:
> From: "Luis R. Rodriguez" <mcgrof@suse.com>
>
> If and when this gets enabled the driver could should split
> up IO memory space properly and that is quite a bit of work.
> Just remove the uncommented dead MTRR code then.
>
> There are a few motivations for this:
>
> a) Take advantage of PAT when available
>
> b) Help bury MTRR code away, MTRR is architecture specific and on
>    x86 its replaced by PAT
>
> c) Help with the goal of eventually using _PAGE_CACHE_UC over
>    _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache() (see commit
>    de33c442e titled "x86 PAT: fix performance drop for glx,
>    use UC minus for ioremap(), ioremap_nocache() and
>    pci_mmap_page_range()")

Hey folks, who's tree should this go through if agreeable?

 Luis

Re: [PATCH v3] fusion: remove dead MTRR code

[Luis R. Rodriguez]

On Wed, Apr 29, 2015 at 12:50:40PM -0700, Luis R. Rodriguez wrote:
> On Tue, Apr 21, 2015 at 1:46 PM, Luis R. Rodriguez
> <mcgrof@do-not-panic.com> wrote:
> > From: "Luis R. Rodriguez" <mcgrof@suse.com>
> >
> > If and when this gets enabled the driver could should split
> > up IO memory space properly and that is quite a bit of work.
> > Just remove the uncommented dead MTRR code then.
> >
> > There are a few motivations for this:
> >
> > a) Take advantage of PAT when available
> >
> > b) Help bury MTRR code away, MTRR is architecture specific and on
> >    x86 its replaced by PAT
> >
> > c) Help with the goal of eventually using _PAGE_CACHE_UC over
> >    _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache() (see commit
> >    de33c442e titled "x86 PAT: fix performance drop for glx,
> >    use UC minus for ioremap(), ioremap_nocache() and
> >    pci_mmap_page_range()")
> 
> Hey folks, who's tree should this go through if agreeable?

Hey folks, can this be applied? Thanks.

 Luis

Re: [PATCH v3] fusion: remove dead MTRR code

[Luis R. Rodriguez]

On Wed, Apr 29, 2015 at 12:50 PM, Luis R. Rodriguez <mcgrof@suse.com> wrote:
> On Tue, Apr 21, 2015 at 1:46 PM, Luis R. Rodriguez
> <mcgrof@do-not-panic.com> wrote:
>> From: "Luis R. Rodriguez" <mcgrof@suse.com>
>>
>> If and when this gets enabled the driver could should split
>> up IO memory space properly and that is quite a bit of work.
>> Just remove the uncommented dead MTRR code then.
>>
>> There are a few motivations for this:
>>
>> a) Take advantage of PAT when available
>>
>> b) Help bury MTRR code away, MTRR is architecture specific and on
>>    x86 its replaced by PAT
>>
>> c) Help with the goal of eventually using _PAGE_CACHE_UC over
>>    _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache() (see commit
>>    de33c442e titled "x86 PAT: fix performance drop for glx,
>>    use UC minus for ioremap(), ioremap_nocache() and
>>    pci_mmap_page_range()")
>
> Hey folks, who's tree should this go through if agreeable?

OK its been over 1 month without any replies on this patch which just
removes commented out code.

All the maintainers below bounce and the only e-mail not bouncing is
for Sreekanth Reddy <sreekanth.reddy@avagotech.com>, he hasn't been
seen active on linux-next since Jan 12 2015 when he did a driver bump
for mpt2sas to 20.100.00.00.

What's going on folks? And can this patch go in?

diff --git a/MAINTAINERS b/MAINTAINERS
index aca2886..73dbc02 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6205,10 +6205,7 @@ S:       Maintained
 F:     arch/arm/mach-lpc32xx/

 LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)
-M:     Nagalakshmi Nandigama <nagalakshmi.nandigama@avagotech.com>
-M:     Praveen Krishnamoorthy <praveen.krishnamoorthy@avagotech.com>
 M:     Sreekanth Reddy <sreekanth.reddy@avagotech.com>
-M:     Abhijit Mahajan <abhijit.mahajan@avagotech.com>
 L:     MPT-FusionLinux.pdl@avagotech.com
 L:     linux-scsi@vger.kernel.org
 W:     http://www.lsilogic.com/support

Re: [PATCH v3] fusion: remove dead MTRR code

[Luis R. Rodriguez]

On Fri, May 29, 2015 at 1:23 PM, Luis R. Rodriguez <mcgrof@suse.com> wrote:
> On Wed, Apr 29, 2015 at 12:50 PM, Luis R. Rodriguez <mcgrof@suse.com> wrote:
>> On Tue, Apr 21, 2015 at 1:46 PM, Luis R. Rodriguez
>> <mcgrof@do-not-panic.com> wrote:
>>> From: "Luis R. Rodriguez" <mcgrof@suse.com>
>>>
>>> If and when this gets enabled the driver could should split
>>> up IO memory space properly and that is quite a bit of work.
>>> Just remove the uncommented dead MTRR code then.
>>>
>>> There are a few motivations for this:
>>>
>>> a) Take advantage of PAT when available
>>>
>>> b) Help bury MTRR code away, MTRR is architecture specific and on
>>>    x86 its replaced by PAT
>>>
>>> c) Help with the goal of eventually using _PAGE_CACHE_UC over
>>>    _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache() (see commit
>>>    de33c442e titled "x86 PAT: fix performance drop for glx,
>>>    use UC minus for ioremap(), ioremap_nocache() and
>>>    pci_mmap_page_range()")
>>
>> Hey folks, who's tree should this go through if agreeable?
>
> OK its been over 1 month without any replies on this patch which just
> removes commented out code.
>
> All the maintainers below bounce and the only e-mail not bouncing is
> for Sreekanth Reddy <sreekanth.reddy@avagotech.com>, he hasn't been
> seen active on linux-next since Jan 12 2015 when he did a driver bump
> for mpt2sas to 20.100.00.00.
>
> What's going on folks? And can this patch go in?
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index aca2886..73dbc02 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -6205,10 +6205,7 @@ S:       Maintained
>  F:     arch/arm/mach-lpc32xx/
>
>  LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)
> -M:     Nagalakshmi Nandigama <nagalakshmi.nandigama@avagotech.com>
> -M:     Praveen Krishnamoorthy <praveen.krishnamoorthy@avagotech.com>
>  M:     Sreekanth Reddy <sreekanth.reddy@avagotech.com>
> -M:     Abhijit Mahajan <abhijit.mahajan@avagotech.com>
>  L:     MPT-FusionLinux.pdl@avagotech.com
>  L:     linux-scsi@vger.kernel.org
>  W:     http://www.lsilogic.com/support

OK so Avago bought Broadcom.

Does that impact how Avago will contribute to the Linux kernel? It has
been well over 1 month and I haven't seen any reply from Avago folks.

Andrew, is the silence sufficient enough reason for this patch to go
instead through your tree?

 Luis

Re: [PATCH v3] fusion: remove dead MTRR code

[Sreekanth Reddy]

Hi Luis,

Sorry for delay in response. Actually I was looking for the history of
this section of code but I couldn't find it. Anyway this is dead code
and we are fine with removing this dead code.

James,

Please consider this patch as Acked-by: "Sreekanth Reddy"
<Sreekanth.reddy@avagotech.com>

Regards,
Sreekanth


On Wed, Apr 22, 2015 at 2:16 AM, Luis R. Rodriguez
<mcgrof@do-not-panic.com> wrote:
> From: "Luis R. Rodriguez" <mcgrof@suse.com>
>
> If and when this gets enabled the driver could should split
> up IO memory space properly and that is quite a bit of work.
> Just remove the uncommented dead MTRR code then.
>
> There are a few motivations for this:
>
> a) Take advantage of PAT when available
>
> b) Help bury MTRR code away, MTRR is architecture specific and on
>    x86 its replaced by PAT
>
> c) Help with the goal of eventually using _PAGE_CACHE_UC over
>    _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache() (see commit
>    de33c442e titled "x86 PAT: fix performance drop for glx,
>    use UC minus for ioremap(), ioremap_nocache() and
>    pci_mmap_page_range()")
>
> Cc: Toshi Kani <toshi.kani@hp.com>
> Cc: Christoph Hellwig <hch@infradead.org>
> Cc: Nagalakshmi Nandigama <nagalakshmi.nandigama@avagotech.com>
> Cc: Praveen Krishnamoorthy <praveen.krishnamoorthy@avagotech.com>
> Cc: Sreekanth Reddy <sreekanth.reddy@avagotech.com>
> Cc: Abhijit Mahajan <abhijit.mahajan@avagotech.com>
> Cc: linux-scsi@vger.kernel.org
> Cc: Andy Lutomirski <luto@amacapital.net>
> Cc: Suresh Siddha <sbsiddha@gmail.com>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Juergen Gross <jgross@suse.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Juergen Gross <jgross@suse.com>
> Cc: Dave Airlie <airlied@redhat.com>
> Cc: Antonino Daplas <adaplas@gmail.com>
> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
> Cc: Ville Syrjälä <syrjala@sci.fi>
> Cc: Mel Gorman <mgorman@suse.de>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> Cc: Borislav Petkov <bp@suse.de>
> Cc: Davidlohr Bueso <dbueso@suse.de>
> Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
> Cc: MPT-FusionLinux.pdl@avagotech.com
> Cc: linux-scsi@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
> ---
>  drivers/message/fusion/mptbase.c | 24 ------------------------
>  drivers/message/fusion/mptbase.h |  1 -
>  2 files changed, 25 deletions(-)
>
> diff --git a/drivers/message/fusion/mptbase.c b/drivers/message/fusion/mptbase.c
> index 187f836..5dcc031 100644
> --- a/drivers/message/fusion/mptbase.c
> +++ b/drivers/message/fusion/mptbase.c
> @@ -59,10 +59,6 @@
>  #include <linux/delay.h>
>  #include <linux/interrupt.h>           /* needed for in_interrupt() proto */
>  #include <linux/dma-mapping.h>
> -#include <asm/io.h>
> -#ifdef CONFIG_MTRR
> -#include <asm/mtrr.h>
> -#endif
>  #include <linux/kthread.h>
>  #include <scsi/scsi_host.h>
>
> @@ -2820,13 +2816,6 @@ mpt_adapter_dispose(MPT_ADAPTER *ioc)
>         pci_disable_device(ioc->pcidev);
>         pci_release_selected_regions(ioc->pcidev, ioc->bars);
>
> -#if defined(CONFIG_MTRR) && 0
> -       if (ioc->mtrr_reg > 0) {
> -               mtrr_del(ioc->mtrr_reg, 0, 0);
> -               dprintk(ioc, printk(MYIOC_s_INFO_FMT "MTRR region de-registered\n", ioc->name));
> -       }
> -#endif
> -
>         /*  Zap the adapter lookup ptr!  */
>         list_del(&ioc->list);
>
> @@ -4512,19 +4501,6 @@ PrimeIocFifos(MPT_ADAPTER *ioc)
>
>                 ioc->req_frames_low_dma = (u32) (alloc_dma & 0xFFFFFFFF);
>
> -#if defined(CONFIG_MTRR) && 0
> -               /*
> -                *  Enable Write Combining MTRR for IOC's memory region.
> -                *  (at least as much as we can; "size and base must be
> -                *  multiples of 4 kiB"
> -                */
> -               ioc->mtrr_reg = mtrr_add(ioc->req_frames_dma,
> -                                        sz,
> -                                        MTRR_TYPE_WRCOMB, 1);
> -               dprintk(ioc, printk(MYIOC_s_DEBUG_FMT "MTRR region registered (base:size=%08x:%x)\n",
> -                               ioc->name, ioc->req_frames_dma, sz));
> -#endif
> -
>                 for (i = 0; i < ioc->req_depth; i++) {
>                         alloc_dma += ioc->req_sz;
>                         mem += ioc->req_sz;
> diff --git a/drivers/message/fusion/mptbase.h b/drivers/message/fusion/mptbase.h
> index 8f14090..813d463 100644
> --- a/drivers/message/fusion/mptbase.h
> +++ b/drivers/message/fusion/mptbase.h
> @@ -671,7 +671,6 @@ typedef struct _MPT_ADAPTER
>         u8                      *HostPageBuffer; /* SAS - host page buffer support */
>         u32                     HostPageBuffer_sz;
>         dma_addr_t              HostPageBuffer_dma;
> -       int                      mtrr_reg;
>         struct pci_dev          *pcidev;        /* struct pci_dev pointer */
>         int                     bars;           /* bitmask of BAR's that must be configured */
>         int                     msi_enable;
> --
> 2.3.2.209.gd67f9d5.dirty
>
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Re: [PATCH v3] fusion: remove dead MTRR code

[Luis R. Rodriguez]

On Thu, Jun 04, 2015 at 10:20:23AM +0530, Sreekanth Reddy wrote:
> Hi Luis,
> 
> Sorry for delay in response. Actually I was looking for the history of
> this section of code but I couldn't find it. Anyway this is dead code
> and we are fine with removing this dead code.
> 
> James,
> 
> Please consider this patch as:
>
> Acked-by: Sreekanth Reddy <ureekanth.reddy@avagotech.com>

Great thanks, now who's tree should this patch go through? Last patch for this
driver was in 2014 and went through Christoph, but if Christoph doesn't want to
take it can it go through Andrew's tree?

Sreekanth, can you also update the MAINTAINERS file to reflect recent changes
at your company ?

  Luis

Re: [PATCH v3] fusion: remove dead MTRR code

[Sreekanth Reddy]

On Thu, Jun 4, 2015 at 11:11 PM, Luis R. Rodriguez <mcgrof@suse.com> wrote:
> On Thu, Jun 04, 2015 at 10:20:23AM +0530, Sreekanth Reddy wrote:
>> Hi Luis,
>>
>> Sorry for delay in response. Actually I was looking for the history of
>> this section of code but I couldn't find it. Anyway this is dead code
>> and we are fine with removing this dead code.
>>
>> James,
>>
>> Please consider this patch as:
>>
>> Acked-by: Sreekanth Reddy <ureekanth.reddy@avagotech.com>
>
> Great thanks, now who's tree should this patch go through? Last patch for this
> driver was in 2014 and went through Christoph, but if Christoph doesn't want to
> take it can it go through Andrew's tree?
>
> Sreekanth, can you also update the MAINTAINERS file to reflect recent changes
> at your company ?

Sure I will do this.

>
>   Luis

Thanks,
Sreekanth

Re: [PATCH v3] fusion: remove dead MTRR code

[Luis R. Rodriguez]

On Fri, Jun 05, 2015 at 05:17:08PM +0530, Sreekanth Reddy wrote:
> On Thu, Jun 4, 2015 at 11:11 PM, Luis R. Rodriguez <mcgrof@suse.com> wrote:
> > On Thu, Jun 04, 2015 at 10:20:23AM +0530, Sreekanth Reddy wrote:
> >> Hi Luis,
> >>
> >> Sorry for delay in response. Actually I was looking for the history of
> >> this section of code but I couldn't find it. Anyway this is dead code
> >> and we are fine with removing this dead code.
> >>
> >> James,
> >>
> >> Please consider this patch as:
> >>
> >> Acked-by: Sreekanth Reddy <ureekanth.reddy@avagotech.com>
> >
> > Great thanks, now who's tree should this patch go through? Last patch for this
> > driver was in 2014 and went through Christoph, but if Christoph doesn't want to
> > take it can it go through Andrew's tree?
> >
> > Sreekanth, can you also update the MAINTAINERS file to reflect recent changes
> > at your company ?
> 
> Sure I will do this.

Christoph, do you mind this going through Andrew's tree? Or do you want to take it?

  Luis