2015-06-09 00:22:55

by Luis Chamberlain

[permalink] [raw]
Subject: [PATCH v6 0/3] linux: address broken PAT drivers

From: "Luis R. Rodriguez" <[email protected]>

Mauro,

since the ivtv patch is already acked by the driver maintainer
and depends on an x86 symbol that went through Boris' tree are you
OK in it going through Boris' tree?

Boris,

provided the outcome of the above maintainer's preference for you
to merge these please consider these patches for your tree. The
maintainer path is the only thing pending for the 1 ivtv patch.
The Infiniband subsystem maintainer, Doug, already provided his
ACK for the ipath driver and for this to go through you.

Luis R. Rodriguez (3):
ivtv: use arch_phys_wc_add() and require PAT disabled
IB/ipath: add counting for MTRR
IB/ipath: use arch_phys_wc_add() and require PAT disabled

drivers/infiniband/hw/ipath/Kconfig | 3 ++
drivers/infiniband/hw/ipath/ipath_driver.c | 18 ++++++---
drivers/infiniband/hw/ipath/ipath_kernel.h | 4 +-
drivers/infiniband/hw/ipath/ipath_wc_x86_64.c | 43 +++++---------------
drivers/media/pci/ivtv/Kconfig | 3 ++
drivers/media/pci/ivtv/ivtvfb.c | 58 +++++++++++----------------
6 files changed, 52 insertions(+), 77 deletions(-)

--
2.3.2.209.gd67f9d5.dirty


2015-06-09 00:25:07

by Luis Chamberlain

[permalink] [raw]
Subject: [PATCH v6 1/3] ivtv: use arch_phys_wc_add() and require PAT disabled

From: "Luis R. Rodriguez" <[email protected]>

We are burrying direct access to MTRR code support on
x86 in order to take advantage of PAT. In the future we
also want to make the default behaviour of ioremap_nocache()
to use strong UC, use of mtrr_add() on those systems
would make write-combining void.

In order to help both enable us to later make strong
UC default and in order to phase out direct MTRR access
code port the driver over to arch_phys_wc_add() and
annotate that the device driver requires systems to
boot with PAT disabled, with the nopat kernel parameter.

This is a worthy comprmise given that the hardware is
really rare these days, and perhaps only some lost souls
in some third world country are expected to be using this
feature of the device driver.

Acked-by: Andy Walls <[email protected]>
Cc: Andy Walls <[email protected]>
Cc: Doug Ledford <[email protected]>
Cc: Mauro Carvalho Chehab <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Suresh Siddha <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Dave Airlie <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Antonino Daplas <[email protected]>
Cc: Jean-Christophe Plagniol-Villard <[email protected]>
Cc: Tomi Valkeinen <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Michael S. Tsirkin <[email protected]>
Cc: Stefan Bader <[email protected]>
Cc: Ville Syrjälä <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Roger Pau Monné <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Luis R. Rodriguez <[email protected]>
---
drivers/media/pci/ivtv/Kconfig | 3 +++
drivers/media/pci/ivtv/ivtvfb.c | 58 ++++++++++++++++-------------------------
2 files changed, 26 insertions(+), 35 deletions(-)

diff --git a/drivers/media/pci/ivtv/Kconfig b/drivers/media/pci/ivtv/Kconfig
index dd6ee57e..b2a7f88 100644
--- a/drivers/media/pci/ivtv/Kconfig
+++ b/drivers/media/pci/ivtv/Kconfig
@@ -57,5 +57,8 @@ config VIDEO_FB_IVTV
This is used in the Hauppauge PVR-350 card. There is a driver
homepage at <http://www.ivtvdriver.org>.

+ If you have this hardware you will need to boot with PAT disabled
+ on your x86 systems, use the nopat kernel parameter.
+
To compile this driver as a module, choose M here: the
module will be called ivtvfb.
diff --git a/drivers/media/pci/ivtv/ivtvfb.c b/drivers/media/pci/ivtv/ivtvfb.c
index 9ff1230..7685ae3 100644
--- a/drivers/media/pci/ivtv/ivtvfb.c
+++ b/drivers/media/pci/ivtv/ivtvfb.c
@@ -44,8 +44,8 @@
#include <linux/ivtvfb.h>
#include <linux/slab.h>

-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
+#ifdef CONFIG_X86_64
+#include <asm/pat.h>
#endif

#include "ivtv-driver.h"
@@ -155,12 +155,11 @@ struct osd_info {
/* Buffer size */
u32 video_buffer_size;

-#ifdef CONFIG_MTRR
/* video_base rounded down as required by hardware MTRRs */
unsigned long fb_start_aligned_physaddr;
/* video_base rounded up as required by hardware MTRRs */
unsigned long fb_end_aligned_physaddr;
-#endif
+ int wc_cookie;

/* Store the buffer offset */
int set_osd_coords_x;
@@ -1099,6 +1098,8 @@ static int ivtvfb_init_vidmode(struct ivtv *itv)
static int ivtvfb_init_io(struct ivtv *itv)
{
struct osd_info *oi = itv->osd_info;
+ /* Find the largest power of two that maps the whole buffer */
+ int size_shift = 31;

mutex_lock(&itv->serialize_lock);
if (ivtv_init_on_first_open(itv)) {
@@ -1132,29 +1133,16 @@ static int ivtvfb_init_io(struct ivtv *itv)
oi->video_pbase, oi->video_vbase,
oi->video_buffer_size / 1024);

-#ifdef CONFIG_MTRR
- {
- /* Find the largest power of two that maps the whole buffer */
- int size_shift = 31;
-
- while (!(oi->video_buffer_size & (1 << size_shift))) {
- size_shift--;
- }
- size_shift++;
- oi->fb_start_aligned_physaddr = oi->video_pbase & ~((1 << size_shift) - 1);
- oi->fb_end_aligned_physaddr = oi->video_pbase + oi->video_buffer_size;
- oi->fb_end_aligned_physaddr += (1 << size_shift) - 1;
- oi->fb_end_aligned_physaddr &= ~((1 << size_shift) - 1);
- if (mtrr_add(oi->fb_start_aligned_physaddr,
- oi->fb_end_aligned_physaddr - oi->fb_start_aligned_physaddr,
- MTRR_TYPE_WRCOMB, 1) < 0) {
- IVTVFB_INFO("disabled mttr\n");
- oi->fb_start_aligned_physaddr = 0;
- oi->fb_end_aligned_physaddr = 0;
- }
- }
-#endif
-
+ while (!(oi->video_buffer_size & (1 << size_shift)))
+ size_shift--;
+ size_shift++;
+ oi->fb_start_aligned_physaddr = oi->video_pbase & ~((1 << size_shift) - 1);
+ oi->fb_end_aligned_physaddr = oi->video_pbase + oi->video_buffer_size;
+ oi->fb_end_aligned_physaddr += (1 << size_shift) - 1;
+ oi->fb_end_aligned_physaddr &= ~((1 << size_shift) - 1);
+ oi->wc_cookie = arch_phys_wc_add(oi->fb_start_aligned_physaddr,
+ oi->fb_end_aligned_physaddr -
+ oi->fb_start_aligned_physaddr);
/* Blank the entire osd. */
memset_io(oi->video_vbase, 0, oi->video_buffer_size);

@@ -1172,14 +1160,7 @@ static void ivtvfb_release_buffers (struct ivtv *itv)

/* Release pseudo palette */
kfree(oi->ivtvfb_info.pseudo_palette);
-
-#ifdef CONFIG_MTRR
- if (oi->fb_end_aligned_physaddr) {
- mtrr_del(-1, oi->fb_start_aligned_physaddr,
- oi->fb_end_aligned_physaddr - oi->fb_start_aligned_physaddr);
- }
-#endif
-
+ arch_phys_wc_del(oi->wc_cookie);
kfree(oi);
itv->osd_info = NULL;
}
@@ -1284,6 +1265,13 @@ static int __init ivtvfb_init(void)
int registered = 0;
int err;

+#ifdef CONFIG_X86_64
+ if (WARN(pat_enabled(),
+ "ivtvfb needs PAT disabled, boot with nopat kernel parameter\n")) {
+ return EINVAL;
+ }
+#endif
+
if (ivtvfb_card_id < -1 || ivtvfb_card_id >= IVTV_MAX_CARDS) {
printk(KERN_ERR "ivtvfb: ivtvfb_card_id parameter is out of range (valid range: -1 - %d)\n",
IVTV_MAX_CARDS - 1);
--
2.3.2.209.gd67f9d5.dirty

2015-06-09 00:27:19

by Luis Chamberlain

[permalink] [raw]
Subject: [PATCH v6 2/3] IB/ipath: add counting for MTRR

From: "Luis R. Rodriguez" <[email protected]>

There is no good reason not to, we eventually delete it as well.

Cc: Toshi Kani <[email protected]>
Cc: Roland Dreier <[email protected]>
Cc: Sean Hefty <[email protected]>
Cc: Hal Rosenstock <[email protected]>
Cc: Suresh Siddha <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Dave Airlie <[email protected]>
Cc: Antonino Daplas <[email protected]>
Cc: Jean-Christophe Plagniol-Villard <[email protected]>
Cc: Tomi Valkeinen <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Luis R. Rodriguez <[email protected]>
---
drivers/infiniband/hw/ipath/ipath_wc_x86_64.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c b/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c
index 4ad0b93..70c1f3a 100644
--- a/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c
+++ b/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c
@@ -127,7 +127,7 @@ int ipath_enable_wc(struct ipath_devdata *dd)
"(addr %llx, len=0x%llx)\n",
(unsigned long long) pioaddr,
(unsigned long long) piolen);
- cookie = mtrr_add(pioaddr, piolen, MTRR_TYPE_WRCOMB, 0);
+ cookie = mtrr_add(pioaddr, piolen, MTRR_TYPE_WRCOMB, 1);
if (cookie < 0) {
{
dev_info(&dd->pcidev->dev,
--
2.3.2.209.gd67f9d5.dirty

2015-06-09 00:29:35

by Luis Chamberlain

[permalink] [raw]
Subject: [PATCH v6 3/3] IB/ipath: use arch_phys_wc_add() and require PAT disabled

From: "Luis R. Rodriguez" <[email protected]>

We are burrying direct access to MTRR code support on
x86 in order to take advantage of PAT. In the future we
also want to make the default behaviour of ioremap_nocache()
to use strong UC, use of mtrr_add() on those systems
would make write-combining void.

In order to help both enable us to later make strong
UC default and in order to phase out direct MTRR access
code port the driver over to arch_phys_wc_add() and
annotate that the device driver requires systems to
boot with PAT disabled, with the nopat kernel parameter.

This is a worthy compromise given that the ipath device
driver powers the old HTX bus cards that only work in
AMD systems, while the newer IB/qib device driver
powers all PCI-e cards. The ipath device driver is
obsolete, hardware hard to find and because of this
this its a reasonable compromise to make to require
users of ipath to boot with nopat.

Acked-by: Doug Ledford <[email protected]>
Cc: Doug Ledford <[email protected]>
Cc: Andy Walls <[email protected]>
Cc: Hal Rosenstock <[email protected]>
Cc: Sean Hefty <[email protected]>
Cc: Suresh Siddha <[email protected]>
Cc: Rickard Strandqvist <[email protected]>
Cc: Mike Marciniszyn <[email protected]>
Cc: Roland Dreier <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Dave Airlie <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Antonino Daplas <[email protected]>
Cc: Jean-Christophe Plagniol-Villard <[email protected]>
Cc: Tomi Valkeinen <[email protected]>
Cc: Ville Syrjälä <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Michael S. Tsirkin <[email protected]>
Cc: Stefan Bader <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: Roger Pau Monné <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Luis R. Rodriguez <[email protected]>
---
drivers/infiniband/hw/ipath/Kconfig | 3 ++
drivers/infiniband/hw/ipath/ipath_driver.c | 18 +++++++----
drivers/infiniband/hw/ipath/ipath_kernel.h | 4 +--
drivers/infiniband/hw/ipath/ipath_wc_x86_64.c | 43 ++++++---------------------
4 files changed, 26 insertions(+), 42 deletions(-)

diff --git a/drivers/infiniband/hw/ipath/Kconfig b/drivers/infiniband/hw/ipath/Kconfig
index 1d9bb11..8fe54ff 100644
--- a/drivers/infiniband/hw/ipath/Kconfig
+++ b/drivers/infiniband/hw/ipath/Kconfig
@@ -9,3 +9,6 @@ config INFINIBAND_IPATH
as IP-over-InfiniBand as well as with userspace applications
(in conjunction with InfiniBand userspace access).
For QLogic PCIe QLE based cards, use the QIB driver instead.
+
+ If you have this hardware you will need to boot with PAT disabled
+ on your x86-64 systems, use the nopat kernel parameter.
diff --git a/drivers/infiniband/hw/ipath/ipath_driver.c b/drivers/infiniband/hw/ipath/ipath_driver.c
index bd0caed..441cfe5 100644
--- a/drivers/infiniband/hw/ipath/ipath_driver.c
+++ b/drivers/infiniband/hw/ipath/ipath_driver.c
@@ -42,6 +42,9 @@
#include <linux/bitmap.h>
#include <linux/slab.h>
#include <linux/module.h>
+#ifdef CONFIG_X86_64
+#include <asm/pat.h>
+#endif

#include "ipath_kernel.h"
#include "ipath_verbs.h"
@@ -395,6 +398,14 @@ static int ipath_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
unsigned long long addr;
u32 bar0 = 0, bar1 = 0;

+#ifdef CONFIG_X86_64
+ if (WARN(pat_enabled(),
+ "ipath needs PAT disabled, boot with nopat kernel parameter\n")) {
+ ret = EINVAL;
+ goto bail;
+ }
+#endif
+
dd = ipath_alloc_devdata(pdev);
if (IS_ERR(dd)) {
ret = PTR_ERR(dd);
@@ -542,6 +553,7 @@ static int ipath_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
dd->ipath_kregbase = __ioremap(addr, len,
(_PAGE_NO_CACHE|_PAGE_WRITETHRU));
#else
+ /* XXX: split this properly to enable on PAT */
dd->ipath_kregbase = ioremap_nocache(addr, len);
#endif

@@ -587,12 +599,8 @@ static int ipath_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)

ret = ipath_enable_wc(dd);

- if (ret) {
- ipath_dev_err(dd, "Write combining not enabled "
- "(err %d): performance may be poor\n",
- -ret);
+ if (ret)
ret = 0;
- }

ipath_verify_pioperf(dd);

diff --git a/drivers/infiniband/hw/ipath/ipath_kernel.h b/drivers/infiniband/hw/ipath/ipath_kernel.h
index e08db70..f0f9471 100644
--- a/drivers/infiniband/hw/ipath/ipath_kernel.h
+++ b/drivers/infiniband/hw/ipath/ipath_kernel.h
@@ -463,9 +463,7 @@ struct ipath_devdata {
/* offset in HT config space of slave/primary interface block */
u8 ipath_ht_slave_off;
/* for write combining settings */
- unsigned long ipath_wc_cookie;
- unsigned long ipath_wc_base;
- unsigned long ipath_wc_len;
+ int wc_cookie;
/* ref count for each pkey */
atomic_t ipath_pkeyrefs[4];
/* shadow copy of struct page *'s for exp tid pages */
diff --git a/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c b/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c
index 70c1f3a..7b6e4c8 100644
--- a/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c
+++ b/drivers/infiniband/hw/ipath/ipath_wc_x86_64.c
@@ -37,7 +37,6 @@
*/

#include <linux/pci.h>
-#include <asm/mtrr.h>
#include <asm/processor.h>

#include "ipath_kernel.h"
@@ -122,27 +121,14 @@ int ipath_enable_wc(struct ipath_devdata *dd)
}

if (!ret) {
- int cookie;
- ipath_cdbg(VERBOSE, "Setting mtrr for chip to WC "
- "(addr %llx, len=0x%llx)\n",
- (unsigned long long) pioaddr,
- (unsigned long long) piolen);
- cookie = mtrr_add(pioaddr, piolen, MTRR_TYPE_WRCOMB, 1);
- if (cookie < 0) {
- {
- dev_info(&dd->pcidev->dev,
- "mtrr_add() WC for PIO bufs "
- "failed (%d)\n",
- cookie);
- ret = -EINVAL;
- }
- } else {
- ipath_cdbg(VERBOSE, "Set mtrr for chip to WC, "
- "cookie is %d\n", cookie);
- dd->ipath_wc_cookie = cookie;
- dd->ipath_wc_base = (unsigned long) pioaddr;
- dd->ipath_wc_len = (unsigned long) piolen;
- }
+ dd->wc_cookie = arch_phys_wc_add(pioaddr, piolen);
+ if (dd->wc_cookie < 0) {
+ ipath_dev_err(dd, "Seting mtrr failed on PIO buffers\n");
+ ret = -ENODEV;
+ } else if (dd->wc_cookie == 0)
+ ipath_cdbg(VERBOSE, "Set mtrr for chip to WC not needed\n");
+ else
+ ipath_cdbg(VERBOSE, "Set mtrr for chip to WC\n");
}

return ret;
@@ -154,16 +140,5 @@ int ipath_enable_wc(struct ipath_devdata *dd)
*/
void ipath_disable_wc(struct ipath_devdata *dd)
{
- if (dd->ipath_wc_cookie) {
- int r;
- ipath_cdbg(VERBOSE, "undoing WCCOMB on pio buffers\n");
- r = mtrr_del(dd->ipath_wc_cookie, dd->ipath_wc_base,
- dd->ipath_wc_len);
- if (r < 0)
- dev_info(&dd->pcidev->dev,
- "mtrr_del(%lx, %lx, %lx) failed: %d\n",
- dd->ipath_wc_cookie, dd->ipath_wc_base,
- dd->ipath_wc_len, r);
- dd->ipath_wc_cookie = 0; /* even on failure */
- }
+ arch_phys_wc_del(dd->wc_cookie);
}
--
2.3.2.209.gd67f9d5.dirty

2015-06-09 00:56:43

by Mauro Carvalho Chehab

[permalink] [raw]
Subject: Re: [PATCH v6 1/3] ivtv: use arch_phys_wc_add() and require PAT disabled

Em Mon, 08 Jun 2015 17:20:20 -0700
"Luis R. Rodriguez" <[email protected]> escreveu:

> From: "Luis R. Rodriguez" <[email protected]>
>
> We are burrying direct access to MTRR code support on
> x86 in order to take advantage of PAT. In the future we
> also want to make the default behaviour of ioremap_nocache()
> to use strong UC, use of mtrr_add() on those systems
> would make write-combining void.
>
> In order to help both enable us to later make strong
> UC default and in order to phase out direct MTRR access
> code port the driver over to arch_phys_wc_add() and
> annotate that the device driver requires systems to
> boot with PAT disabled, with the nopat kernel parameter.
>
> This is a worthy comprmise given that the hardware is
> really rare these days, and perhaps only some lost souls
> in some third world country are expected to be using this
> feature of the device driver.
>
> Acked-by: Andy Walls <[email protected]>
> Cc: Andy Walls <[email protected]>
> Cc: Doug Ledford <[email protected]>
> Cc: Mauro Carvalho Chehab <[email protected]>

Provided that you fix the issues below:
Acked-by: Mauro Carvalho Chehab <[email protected]>

> Cc: Andy Lutomirski <[email protected]>
> Cc: Suresh Siddha <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> Cc: Thomas Gleixner <[email protected]>
> Cc: Juergen Gross <[email protected]>
> Cc: Daniel Vetter <[email protected]>
> Cc: Dave Airlie <[email protected]>
> Cc: Bjorn Helgaas <[email protected]>
> Cc: Antonino Daplas <[email protected]>
> Cc: Jean-Christophe Plagniol-Villard <[email protected]>
> Cc: Tomi Valkeinen <[email protected]>
> Cc: Dave Hansen <[email protected]>
> Cc: Arnd Bergmann <[email protected]>
> Cc: Michael S. Tsirkin <[email protected]>
> Cc: Stefan Bader <[email protected]>
> Cc: Ville Syrjälä <[email protected]>
> Cc: Mel Gorman <[email protected]>
> Cc: Vlastimil Babka <[email protected]>
> Cc: Borislav Petkov <[email protected]>
> Cc: Davidlohr Bueso <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: Roger Pau Monné <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Signed-off-by: Luis R. Rodriguez <[email protected]>
> ---
> drivers/media/pci/ivtv/Kconfig | 3 +++
> drivers/media/pci/ivtv/ivtvfb.c | 58 ++++++++++++++++-------------------------
> 2 files changed, 26 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/media/pci/ivtv/Kconfig b/drivers/media/pci/ivtv/Kconfig
> index dd6ee57e..b2a7f88 100644
> --- a/drivers/media/pci/ivtv/Kconfig
> +++ b/drivers/media/pci/ivtv/Kconfig
> @@ -57,5 +57,8 @@ config VIDEO_FB_IVTV
> This is used in the Hauppauge PVR-350 card. There is a driver
> homepage at <http://www.ivtvdriver.org>.
>
> + If you have this hardware you will need to boot with PAT disabled
> + on your x86 systems, use the nopat kernel parameter.
> +

Hmm... FB_IVTV is not hardware... it is framebuffer support for IVTV.
It is optional to use FB API for the video output port of this board,
instead of using V4L2 API.

I would say, instead, something like:

"In order to use this module, you will need to boot with PAT disabled
on x86 systems, using the nopat kernel parameter."

> To compile this driver as a module, choose M here: the
> module will be called ivtvfb.
> diff --git a/drivers/media/pci/ivtv/ivtvfb.c b/drivers/media/pci/ivtv/ivtvfb.c
> index 9ff1230..7685ae3 100644
> --- a/drivers/media/pci/ivtv/ivtvfb.c
> +++ b/drivers/media/pci/ivtv/ivtvfb.c
> @@ -44,8 +44,8 @@
> #include <linux/ivtvfb.h>
> #include <linux/slab.h>
>
> -#ifdef CONFIG_MTRR
> -#include <asm/mtrr.h>
> +#ifdef CONFIG_X86_64
> +#include <asm/pat.h>
> #endif
>
> #include "ivtv-driver.h"
> @@ -155,12 +155,11 @@ struct osd_info {
> /* Buffer size */
> u32 video_buffer_size;
>
> -#ifdef CONFIG_MTRR
> /* video_base rounded down as required by hardware MTRRs */
> unsigned long fb_start_aligned_physaddr;
> /* video_base rounded up as required by hardware MTRRs */
> unsigned long fb_end_aligned_physaddr;
> -#endif
> + int wc_cookie;
>
> /* Store the buffer offset */
> int set_osd_coords_x;
> @@ -1099,6 +1098,8 @@ static int ivtvfb_init_vidmode(struct ivtv *itv)
> static int ivtvfb_init_io(struct ivtv *itv)
> {
> struct osd_info *oi = itv->osd_info;
> + /* Find the largest power of two that maps the whole buffer */
> + int size_shift = 31;
>
> mutex_lock(&itv->serialize_lock);
> if (ivtv_init_on_first_open(itv)) {
> @@ -1132,29 +1133,16 @@ static int ivtvfb_init_io(struct ivtv *itv)
> oi->video_pbase, oi->video_vbase,
> oi->video_buffer_size / 1024);
>
> -#ifdef CONFIG_MTRR
> - {
> - /* Find the largest power of two that maps the whole buffer */
> - int size_shift = 31;
> -
> - while (!(oi->video_buffer_size & (1 << size_shift))) {
> - size_shift--;
> - }
> - size_shift++;
> - oi->fb_start_aligned_physaddr = oi->video_pbase & ~((1 << size_shift) - 1);
> - oi->fb_end_aligned_physaddr = oi->video_pbase + oi->video_buffer_size;
> - oi->fb_end_aligned_physaddr += (1 << size_shift) - 1;
> - oi->fb_end_aligned_physaddr &= ~((1 << size_shift) - 1);
> - if (mtrr_add(oi->fb_start_aligned_physaddr,
> - oi->fb_end_aligned_physaddr - oi->fb_start_aligned_physaddr,
> - MTRR_TYPE_WRCOMB, 1) < 0) {
> - IVTVFB_INFO("disabled mttr\n");
> - oi->fb_start_aligned_physaddr = 0;
> - oi->fb_end_aligned_physaddr = 0;
> - }
> - }
> -#endif
> -
> + while (!(oi->video_buffer_size & (1 << size_shift)))
> + size_shift--;
> + size_shift++;
> + oi->fb_start_aligned_physaddr = oi->video_pbase & ~((1 << size_shift) - 1);
> + oi->fb_end_aligned_physaddr = oi->video_pbase + oi->video_buffer_size;
> + oi->fb_end_aligned_physaddr += (1 << size_shift) - 1;
> + oi->fb_end_aligned_physaddr &= ~((1 << size_shift) - 1);
> + oi->wc_cookie = arch_phys_wc_add(oi->fb_start_aligned_physaddr,
> + oi->fb_end_aligned_physaddr -
> + oi->fb_start_aligned_physaddr);
> /* Blank the entire osd. */
> memset_io(oi->video_vbase, 0, oi->video_buffer_size);
>
> @@ -1172,14 +1160,7 @@ static void ivtvfb_release_buffers (struct ivtv *itv)
>
> /* Release pseudo palette */
> kfree(oi->ivtvfb_info.pseudo_palette);
> -
> -#ifdef CONFIG_MTRR
> - if (oi->fb_end_aligned_physaddr) {
> - mtrr_del(-1, oi->fb_start_aligned_physaddr,
> - oi->fb_end_aligned_physaddr - oi->fb_start_aligned_physaddr);
> - }
> -#endif
> -
> + arch_phys_wc_del(oi->wc_cookie);
> kfree(oi);
> itv->osd_info = NULL;
> }
> @@ -1284,6 +1265,13 @@ static int __init ivtvfb_init(void)
> int registered = 0;
> int err;
>
> +#ifdef CONFIG_X86_64
> + if (WARN(pat_enabled(),
> + "ivtvfb needs PAT disabled, boot with nopat kernel parameter\n")) {
> + return EINVAL;

Errors are always negative. So:
return -EINVAL

Or, perhaps, -ENODEV.

> + }
> +#endif
> +
> if (ivtvfb_card_id < -1 || ivtvfb_card_id >= IVTV_MAX_CARDS) {
> printk(KERN_ERR "ivtvfb: ivtvfb_card_id parameter is out of range (valid range: -1 - %d)\n",
> IVTV_MAX_CARDS - 1);

2015-06-09 00:57:22

by Mauro Carvalho Chehab

[permalink] [raw]
Subject: Re: [PATCH v6 0/3] linux: address broken PAT drivers

Em Mon, 08 Jun 2015 17:20:19 -0700
"Luis R. Rodriguez" <[email protected]> escreveu:

> From: "Luis R. Rodriguez" <[email protected]>
>
> Mauro,
>
> since the ivtv patch is already acked by the driver maintainer
> and depends on an x86 symbol that went through Boris' tree are you
> OK in it going through Boris' tree?

Sure. I just find a minor issues there. After they got solved, feel
free to submit to Boris with my ack.

>
> Boris,
>
> provided the outcome of the above maintainer's preference for you
> to merge these please consider these patches for your tree. The
> maintainer path is the only thing pending for the 1 ivtv patch.
> The Infiniband subsystem maintainer, Doug, already provided his
> ACK for the ipath driver and for this to go through you.
>
> Luis R. Rodriguez (3):
> ivtv: use arch_phys_wc_add() and require PAT disabled
> IB/ipath: add counting for MTRR
> IB/ipath: use arch_phys_wc_add() and require PAT disabled
>
> drivers/infiniband/hw/ipath/Kconfig | 3 ++
> drivers/infiniband/hw/ipath/ipath_driver.c | 18 ++++++---
> drivers/infiniband/hw/ipath/ipath_kernel.h | 4 +-
> drivers/infiniband/hw/ipath/ipath_wc_x86_64.c | 43 +++++---------------
> drivers/media/pci/ivtv/Kconfig | 3 ++
> drivers/media/pci/ivtv/ivtvfb.c | 58 +++++++++++----------------
> 6 files changed, 52 insertions(+), 77 deletions(-)
>

2015-06-09 06:24:25

by Hans Verkuil

[permalink] [raw]
Subject: Re: [PATCH v6 1/3] ivtv: use arch_phys_wc_add() and require PAT disabled

On 06/09/2015 02:56 AM, Mauro Carvalho Chehab wrote:
> Em Mon, 08 Jun 2015 17:20:20 -0700
> "Luis R. Rodriguez" <[email protected]> escreveu:
>
>> From: "Luis R. Rodriguez" <[email protected]>
>>
>> We are burrying direct access to MTRR code support on
>> x86 in order to take advantage of PAT. In the future we
>> also want to make the default behaviour of ioremap_nocache()
>> to use strong UC, use of mtrr_add() on those systems
>> would make write-combining void.
>>
>> In order to help both enable us to later make strong
>> UC default and in order to phase out direct MTRR access
>> code port the driver over to arch_phys_wc_add() and
>> annotate that the device driver requires systems to
>> boot with PAT disabled, with the nopat kernel parameter.
>>
>> This is a worthy comprmise given that the hardware is
>> really rare these days, and perhaps only some lost souls
>> in some third world country are expected to be using this
>> feature of the device driver.
>>
>> Acked-by: Andy Walls <[email protected]>
>> Cc: Andy Walls <[email protected]>
>> Cc: Doug Ledford <[email protected]>
>> Cc: Mauro Carvalho Chehab <[email protected]>
>
> Provided that you fix the issues below:
> Acked-by: Mauro Carvalho Chehab <[email protected]>
>
>> Cc: Andy Lutomirski <[email protected]>
>> Cc: Suresh Siddha <[email protected]>
>> Cc: Ingo Molnar <[email protected]>
>> Cc: Thomas Gleixner <[email protected]>
>> Cc: Juergen Gross <[email protected]>
>> Cc: Daniel Vetter <[email protected]>
>> Cc: Dave Airlie <[email protected]>
>> Cc: Bjorn Helgaas <[email protected]>
>> Cc: Antonino Daplas <[email protected]>
>> Cc: Jean-Christophe Plagniol-Villard <[email protected]>
>> Cc: Tomi Valkeinen <[email protected]>
>> Cc: Dave Hansen <[email protected]>
>> Cc: Arnd Bergmann <[email protected]>
>> Cc: Michael S. Tsirkin <[email protected]>
>> Cc: Stefan Bader <[email protected]>
>> Cc: Ville Syrjälä <[email protected]>
>> Cc: Mel Gorman <[email protected]>
>> Cc: Vlastimil Babka <[email protected]>
>> Cc: Borislav Petkov <[email protected]>
>> Cc: Davidlohr Bueso <[email protected]>
>> Cc: [email protected]
>> Cc: [email protected]
>> Cc: [email protected]
>> Cc: [email protected]
>> Cc: [email protected]
>> Cc: Roger Pau Monné <[email protected]>
>> Cc: [email protected]
>> Cc: [email protected]
>> Cc: [email protected]
>> Cc: [email protected]
>> Cc: [email protected]
>> Signed-off-by: Luis R. Rodriguez <[email protected]>
>> ---
>> drivers/media/pci/ivtv/Kconfig | 3 +++
>> drivers/media/pci/ivtv/ivtvfb.c | 58 ++++++++++++++++-------------------------
>> 2 files changed, 26 insertions(+), 35 deletions(-)
>>
>> diff --git a/drivers/media/pci/ivtv/Kconfig b/drivers/media/pci/ivtv/Kconfig
>> index dd6ee57e..b2a7f88 100644
>> --- a/drivers/media/pci/ivtv/Kconfig
>> +++ b/drivers/media/pci/ivtv/Kconfig
>> @@ -57,5 +57,8 @@ config VIDEO_FB_IVTV
>> This is used in the Hauppauge PVR-350 card. There is a driver
>> homepage at <http://www.ivtvdriver.org>.
>>
>> + If you have this hardware you will need to boot with PAT disabled
>> + on your x86 systems, use the nopat kernel parameter.
>> +
>
> Hmm... FB_IVTV is not hardware... it is framebuffer support for IVTV.
> It is optional to use FB API for the video output port of this board,
> instead of using V4L2 API.

That's not true. It is hardware: it drives the video output OSD which overlays
the video output. The reason it is optional is that it is hard to unload a
framebuffer module and most people don't need it.

So V4L2 drives the video output and ivtvfb drives the OSD overlay. So it is
not a case of 'instead of'.

>
> I would say, instead, something like:
>
> "In order to use this module, you will need to boot with PAT disabled
> on x86 systems, using the nopat kernel parameter."

I do agree with this change, but that's because this module is optional and
not for the reasons you mentioned above.

Regards,

Hans

>
>> To compile this driver as a module, choose M here: the
>> module will be called ivtvfb.
>> diff --git a/drivers/media/pci/ivtv/ivtvfb.c b/drivers/media/pci/ivtv/ivtvfb.c
>> index 9ff1230..7685ae3 100644
>> --- a/drivers/media/pci/ivtv/ivtvfb.c
>> +++ b/drivers/media/pci/ivtv/ivtvfb.c
>> @@ -44,8 +44,8 @@
>> #include <linux/ivtvfb.h>
>> #include <linux/slab.h>
>>
>> -#ifdef CONFIG_MTRR
>> -#include <asm/mtrr.h>
>> +#ifdef CONFIG_X86_64
>> +#include <asm/pat.h>
>> #endif
>>
>> #include "ivtv-driver.h"
>> @@ -155,12 +155,11 @@ struct osd_info {
>> /* Buffer size */
>> u32 video_buffer_size;
>>
>> -#ifdef CONFIG_MTRR
>> /* video_base rounded down as required by hardware MTRRs */
>> unsigned long fb_start_aligned_physaddr;
>> /* video_base rounded up as required by hardware MTRRs */
>> unsigned long fb_end_aligned_physaddr;
>> -#endif
>> + int wc_cookie;
>>
>> /* Store the buffer offset */
>> int set_osd_coords_x;
>> @@ -1099,6 +1098,8 @@ static int ivtvfb_init_vidmode(struct ivtv *itv)
>> static int ivtvfb_init_io(struct ivtv *itv)
>> {
>> struct osd_info *oi = itv->osd_info;
>> + /* Find the largest power of two that maps the whole buffer */
>> + int size_shift = 31;
>>
>> mutex_lock(&itv->serialize_lock);
>> if (ivtv_init_on_first_open(itv)) {
>> @@ -1132,29 +1133,16 @@ static int ivtvfb_init_io(struct ivtv *itv)
>> oi->video_pbase, oi->video_vbase,
>> oi->video_buffer_size / 1024);
>>
>> -#ifdef CONFIG_MTRR
>> - {
>> - /* Find the largest power of two that maps the whole buffer */
>> - int size_shift = 31;
>> -
>> - while (!(oi->video_buffer_size & (1 << size_shift))) {
>> - size_shift--;
>> - }
>> - size_shift++;
>> - oi->fb_start_aligned_physaddr = oi->video_pbase & ~((1 << size_shift) - 1);
>> - oi->fb_end_aligned_physaddr = oi->video_pbase + oi->video_buffer_size;
>> - oi->fb_end_aligned_physaddr += (1 << size_shift) - 1;
>> - oi->fb_end_aligned_physaddr &= ~((1 << size_shift) - 1);
>> - if (mtrr_add(oi->fb_start_aligned_physaddr,
>> - oi->fb_end_aligned_physaddr - oi->fb_start_aligned_physaddr,
>> - MTRR_TYPE_WRCOMB, 1) < 0) {
>> - IVTVFB_INFO("disabled mttr\n");
>> - oi->fb_start_aligned_physaddr = 0;
>> - oi->fb_end_aligned_physaddr = 0;
>> - }
>> - }
>> -#endif
>> -
>> + while (!(oi->video_buffer_size & (1 << size_shift)))
>> + size_shift--;
>> + size_shift++;
>> + oi->fb_start_aligned_physaddr = oi->video_pbase & ~((1 << size_shift) - 1);
>> + oi->fb_end_aligned_physaddr = oi->video_pbase + oi->video_buffer_size;
>> + oi->fb_end_aligned_physaddr += (1 << size_shift) - 1;
>> + oi->fb_end_aligned_physaddr &= ~((1 << size_shift) - 1);
>> + oi->wc_cookie = arch_phys_wc_add(oi->fb_start_aligned_physaddr,
>> + oi->fb_end_aligned_physaddr -
>> + oi->fb_start_aligned_physaddr);
>> /* Blank the entire osd. */
>> memset_io(oi->video_vbase, 0, oi->video_buffer_size);
>>
>> @@ -1172,14 +1160,7 @@ static void ivtvfb_release_buffers (struct ivtv *itv)
>>
>> /* Release pseudo palette */
>> kfree(oi->ivtvfb_info.pseudo_palette);
>> -
>> -#ifdef CONFIG_MTRR
>> - if (oi->fb_end_aligned_physaddr) {
>> - mtrr_del(-1, oi->fb_start_aligned_physaddr,
>> - oi->fb_end_aligned_physaddr - oi->fb_start_aligned_physaddr);
>> - }
>> -#endif
>> -
>> + arch_phys_wc_del(oi->wc_cookie);
>> kfree(oi);
>> itv->osd_info = NULL;
>> }
>> @@ -1284,6 +1265,13 @@ static int __init ivtvfb_init(void)
>> int registered = 0;
>> int err;
>>
>> +#ifdef CONFIG_X86_64
>> + if (WARN(pat_enabled(),
>> + "ivtvfb needs PAT disabled, boot with nopat kernel parameter\n")) {
>> + return EINVAL;
>
> Errors are always negative. So:
> return -EINVAL
>
> Or, perhaps, -ENODEV.
>
>> + }
>> +#endif
>> +
>> if (ivtvfb_card_id < -1 || ivtvfb_card_id >= IVTV_MAX_CARDS) {
>> printk(KERN_ERR "ivtvfb: ivtvfb_card_id parameter is out of range (valid range: -1 - %d)\n",
>> IVTV_MAX_CARDS - 1);
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>

2015-06-11 17:30:07

by Luis Chamberlain

[permalink] [raw]
Subject: Re: [PATCH v6 0/3] linux: address broken PAT drivers

On Mon, Jun 08, 2015 at 09:57:12PM -0300, Mauro Carvalho Chehab wrote:
> Em Mon, 08 Jun 2015 17:20:19 -0700
> "Luis R. Rodriguez" <[email protected]> escreveu:
>
> > From: "Luis R. Rodriguez" <[email protected]>
> >
> > Mauro,
> >
> > since the ivtv patch is already acked by the driver maintainer
> > and depends on an x86 symbol that went through Boris' tree are you
> > OK in it going through Boris' tree?
>
> Sure. I just find a minor issues there. After they got solved, feel
> free to submit to Boris with my ack.

OK thanks, I just fixed that, will send now to Boris.

Luis