All of lore.kernel.org
 help / color / mirror / Atom feed
From: Stefano Stabellini <sstabellini@kernel.org>
To: Peng Fan <peng.fan@nxp.com>
Cc: Robin Murphy <robin.murphy@arm.com>,
	"sstabellini@kernel.org" <sstabellini@kernel.org>,
	"linux@armlinux.org.uk" <linux@armlinux.org.uk>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	dl-linux-imx <linux-imx@nxp.com>,
	"van.freenix@gmail.com" <van.freenix@gmail.com>,
	"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>
Subject: RE: [PATCH] arm: xen: mm: use __GPF_DMA32 for arm64
Date: Wed, 28 Aug 2019 11:09:46 -0700 (PDT)	[thread overview]
Message-ID: <alpine.DEB.2.21.1908281103290.25361@sstabellini-ThinkPad-T480s> (raw)
In-Reply-To: <AM0PR04MB4481386D2C54AEA6987E1B1588A30@AM0PR04MB4481.eurprd04.prod.outlook.com>

On Wed, 28 Aug 2019, Peng Fan wrote:
> Hi Robin,
> 
> > Subject: Re: [PATCH] arm: xen: mm: use __GPF_DMA32 for arm64
> > 
> > On 09/07/2019 09:22, Peng Fan wrote:
> > > arm64 shares some code under arch/arm/xen, including mm.c.
> > > However ZONE_DMA is removed by commit
> > > ad67f5a6545("arm64: replace ZONE_DMA with ZONE_DMA32").
> > > So to ARM64, need use __GFP_DMA32.

Hi Peng,

Sorry for being so late in replying, this email got lost in the noise.


> > > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > > ---
> > >   arch/arm/xen/mm.c | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index
> > > e1d44b903dfc..a95e76d18bf9 100644
> > > --- a/arch/arm/xen/mm.c
> > > +++ b/arch/arm/xen/mm.c
> > > @@ -27,7 +27,7 @@ unsigned long xen_get_swiotlb_free_pages(unsigned
> > > int order)
> > >
> > >   	for_each_memblock(memory, reg) {
> > >   		if (reg->base < (phys_addr_t)0xffffffff) {
> > > -			flags |= __GFP_DMA;
> > > +			flags |= __GFP_DMA | __GFP_DMA32;
> > 
> > Given the definition of GFP_ZONE_BAD, I'm not sure this combination of flags
> > is strictly valid, but rather is implicitly reliant on only one of those zones ever
> > actually existing. As such, it seems liable to blow up if the plans to add
> > ZONE_DMA to arm64[1] go ahead.
> 
> How about this, or do you have any suggestions?
> diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
> index d33b77e9add3..f61c29a4430f 100644
> --- a/arch/arm/xen/mm.c
> +++ b/arch/arm/xen/mm.c
> @@ -28,7 +28,11 @@ unsigned long xen_get_swiotlb_free_pages(unsigned int order)
> 
>         for_each_memblock(memory, reg) {
>                 if (reg->base < (phys_addr_t)0xffffffff) {
> +#ifdef CONFIG_ARM64
> +                       flags |= __GFP_DMA32;
> +#else
>                         flags |= __GFP_DMA;
> +#endif
>                         break;
>                 }
>         }

Yes I think this is the way to go, but we are trying not to add any
#ifdef CONFIG_ARM64 under arch/arm. Maybe you could introduce a static
inline function to set GFP_DMA:

  static inline void xen_set_gfp_dma(gfp_t *flags)

it could be implemented under arch/arm/include/asm/xen/page.h for arm
and under arch/arm64/include/asm/xen/page.h for arm64 using __GFP_DMA
for the former and __GFP_DMA32 for the latter.

WARNING: multiple messages have this Message-ID
From: Stefano Stabellini <sstabellini@kernel.org>
To: Peng Fan <peng.fan@nxp.com>
Cc: "sstabellini@kernel.org" <sstabellini@kernel.org>,
	"linux@armlinux.org.uk" <linux@armlinux.org.uk>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	dl-linux-imx <linux-imx@nxp.com>,
	"van.freenix@gmail.com" <van.freenix@gmail.com>,
	"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
	Robin Murphy <robin.murphy@arm.com>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: RE: [PATCH] arm: xen: mm: use __GPF_DMA32 for arm64
Date: Wed, 28 Aug 2019 11:09:46 -0700 (PDT)	[thread overview]
Message-ID: <alpine.DEB.2.21.1908281103290.25361@sstabellini-ThinkPad-T480s> (raw)
In-Reply-To: <AM0PR04MB4481386D2C54AEA6987E1B1588A30@AM0PR04MB4481.eurprd04.prod.outlook.com>

On Wed, 28 Aug 2019, Peng Fan wrote:
> Hi Robin,
> 
> > Subject: Re: [PATCH] arm: xen: mm: use __GPF_DMA32 for arm64
> > 
> > On 09/07/2019 09:22, Peng Fan wrote:
> > > arm64 shares some code under arch/arm/xen, including mm.c.
> > > However ZONE_DMA is removed by commit
> > > ad67f5a6545("arm64: replace ZONE_DMA with ZONE_DMA32").
> > > So to ARM64, need use __GFP_DMA32.

Hi Peng,

Sorry for being so late in replying, this email got lost in the noise.


> > > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > > ---
> > >   arch/arm/xen/mm.c | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index
> > > e1d44b903dfc..a95e76d18bf9 100644
> > > --- a/arch/arm/xen/mm.c
> > > +++ b/arch/arm/xen/mm.c
> > > @@ -27,7 +27,7 @@ unsigned long xen_get_swiotlb_free_pages(unsigned
> > > int order)
> > >
> > >   	for_each_memblock(memory, reg) {
> > >   		if (reg->base < (phys_addr_t)0xffffffff) {
> > > -			flags |= __GFP_DMA;
> > > +			flags |= __GFP_DMA | __GFP_DMA32;
> > 
> > Given the definition of GFP_ZONE_BAD, I'm not sure this combination of flags
> > is strictly valid, but rather is implicitly reliant on only one of those zones ever
> > actually existing. As such, it seems liable to blow up if the plans to add
> > ZONE_DMA to arm64[1] go ahead.
> 
> How about this, or do you have any suggestions?
> diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
> index d33b77e9add3..f61c29a4430f 100644
> --- a/arch/arm/xen/mm.c
> +++ b/arch/arm/xen/mm.c
> @@ -28,7 +28,11 @@ unsigned long xen_get_swiotlb_free_pages(unsigned int order)
> 
>         for_each_memblock(memory, reg) {
>                 if (reg->base < (phys_addr_t)0xffffffff) {
> +#ifdef CONFIG_ARM64
> +                       flags |= __GFP_DMA32;
> +#else
>                         flags |= __GFP_DMA;
> +#endif
>                         break;
>                 }
>         }

Yes I think this is the way to go, but we are trying not to add any
#ifdef CONFIG_ARM64 under arch/arm. Maybe you could introduce a static
inline function to set GFP_DMA:

  static inline void xen_set_gfp_dma(gfp_t *flags)

it could be implemented under arch/arm/include/asm/xen/page.h for arm
and under arch/arm64/include/asm/xen/page.h for arm64 using __GFP_DMA
for the former and __GFP_DMA32 for the latter.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

WARNING: multiple messages have this Message-ID
From: Stefano Stabellini <sstabellini@kernel.org>
To: Peng Fan <peng.fan@nxp.com>
Cc: "sstabellini@kernel.org" <sstabellini@kernel.org>,
	"linux@armlinux.org.uk" <linux@armlinux.org.uk>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	dl-linux-imx <linux-imx@nxp.com>,
	"van.freenix@gmail.com" <van.freenix@gmail.com>,
	"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
	Robin Murphy <robin.murphy@arm.com>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [Xen-devel] [PATCH] arm: xen: mm: use __GPF_DMA32 for arm64
Date: Wed, 28 Aug 2019 11:09:46 -0700 (PDT)	[thread overview]
Message-ID: <alpine.DEB.2.21.1908281103290.25361@sstabellini-ThinkPad-T480s> (raw)
In-Reply-To: <AM0PR04MB4481386D2C54AEA6987E1B1588A30@AM0PR04MB4481.eurprd04.prod.outlook.com>

On Wed, 28 Aug 2019, Peng Fan wrote:
> Hi Robin,
> 
> > Subject: Re: [PATCH] arm: xen: mm: use __GPF_DMA32 for arm64
> > 
> > On 09/07/2019 09:22, Peng Fan wrote:
> > > arm64 shares some code under arch/arm/xen, including mm.c.
> > > However ZONE_DMA is removed by commit
> > > ad67f5a6545("arm64: replace ZONE_DMA with ZONE_DMA32").
> > > So to ARM64, need use __GFP_DMA32.

Hi Peng,

Sorry for being so late in replying, this email got lost in the noise.


> > > Signed-off-by: Peng Fan <peng.fan@nxp.com>
> > > ---
> > >   arch/arm/xen/mm.c | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index
> > > e1d44b903dfc..a95e76d18bf9 100644
> > > --- a/arch/arm/xen/mm.c
> > > +++ b/arch/arm/xen/mm.c
> > > @@ -27,7 +27,7 @@ unsigned long xen_get_swiotlb_free_pages(unsigned
> > > int order)
> > >
> > >   	for_each_memblock(memory, reg) {
> > >   		if (reg->base < (phys_addr_t)0xffffffff) {
> > > -			flags |= __GFP_DMA;
> > > +			flags |= __GFP_DMA | __GFP_DMA32;
> > 
> > Given the definition of GFP_ZONE_BAD, I'm not sure this combination of flags
> > is strictly valid, but rather is implicitly reliant on only one of those zones ever
> > actually existing. As such, it seems liable to blow up if the plans to add
> > ZONE_DMA to arm64[1] go ahead.
> 
> How about this, or do you have any suggestions?
> diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
> index d33b77e9add3..f61c29a4430f 100644
> --- a/arch/arm/xen/mm.c
> +++ b/arch/arm/xen/mm.c
> @@ -28,7 +28,11 @@ unsigned long xen_get_swiotlb_free_pages(unsigned int order)
> 
>         for_each_memblock(memory, reg) {
>                 if (reg->base < (phys_addr_t)0xffffffff) {
> +#ifdef CONFIG_ARM64
> +                       flags |= __GFP_DMA32;
> +#else
>                         flags |= __GFP_DMA;
> +#endif
>                         break;
>                 }
>         }

Yes I think this is the way to go, but we are trying not to add any
#ifdef CONFIG_ARM64 under arch/arm. Maybe you could introduce a static
inline function to set GFP_DMA:

  static inline void xen_set_gfp_dma(gfp_t *flags)

it could be implemented under arch/arm/include/asm/xen/page.h for arm
and under arch/arm64/include/asm/xen/page.h for arm64 using __GFP_DMA
for the former and __GFP_DMA32 for the latter.

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

  reply	other threads:[~2019-08-28 18:09 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-09  8:22 Peng Fan
2019-07-09  8:22 ` [Xen-devel] " Peng Fan
2019-07-09  8:22 ` Peng Fan
2019-07-23  3:21 ` Peng Fan
2019-07-23  3:21   ` [Xen-devel] " Peng Fan
2019-07-23  3:21   ` Peng Fan
2019-08-27  9:27   ` Peng Fan
2019-08-27  9:27     ` [Xen-devel] " Peng Fan
2019-08-27  9:27     ` Peng Fan
2019-08-27  9:45     ` Russell King - ARM Linux admin
2019-08-27  9:45       ` [Xen-devel] " Russell King - ARM Linux admin
2019-08-27  9:45       ` Russell King - ARM Linux admin
2019-08-27 12:23 ` Robin Murphy
2019-08-27 12:23   ` [Xen-devel] " Robin Murphy
2019-08-27 12:23   ` Robin Murphy
2019-08-28  1:48   ` Peng Fan
2019-08-28  1:48     ` [Xen-devel] " Peng Fan
2019-08-28  1:48     ` Peng Fan
2019-08-28 18:09     ` Stefano Stabellini [this message]
2019-08-28 18:09       ` [Xen-devel] " Stefano Stabellini
2019-08-28 18:09       ` Stefano Stabellini
2019-08-29  2:46       ` Peng Fan
2019-08-29  2:46         ` [Xen-devel] " Peng Fan
2019-08-29  2:46         ` Peng Fan

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=alpine.DEB.2.21.1908281103290.25361@sstabellini-ThinkPad-T480s \
    --to=sstabellini@kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-imx@nxp.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=peng.fan@nxp.com \
    --cc=robin.murphy@arm.com \
    --cc=van.freenix@gmail.com \
    --cc=xen-devel@lists.xenproject.org \
    --subject='RE: [PATCH] arm: xen: mm: use __GPF_DMA32 for arm64' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.