[PATCH v2 0/2] arm64: Fix CMA/crashkernel reservation

[PATCH v2 0/2] arm64: Fix CMA/crashkernel reservation

[Nicolas Saenz Julienne]

As pointed out by Qian Cai[1] the series enabling ZONE_DMA in arm64
breaks CMA/crashkernel reservations on large devices, as it changed its
default placement. After discussing it with Catalin Marinas we're
restoring the old behavior.

The Raspberry Pi 4, being the only device that needs CMA and crashkernel
in ZONE_DMA will explicitly do so trough it's device tree.

[1] https://lkml.org/lkml/2019/10/21/725

---

Changes since v1:
  - Move CMA area registration into bcm2711.dtsi

Nicolas Saenz Julienne (2):
  ARM: dts: bcm2711: force CMA into first GB of memory
  arm64: mm: reserve CMA and crashkernel in ZONE_DMA32

 arch/arm/boot/dts/bcm2711.dtsi | 20 ++++++++++++++++++++
 arch/arm64/mm/init.c           |  4 ++--
 2 files changed, 22 insertions(+), 2 deletions(-)

-- 
2.23.0

[PATCH v2 0/2] arm64: Fix CMA/crashkernel reservation

[Nicolas Saenz Julienne]

As pointed out by Qian Cai[1] the series enabling ZONE_DMA in arm64
breaks CMA/crashkernel reservations on large devices, as it changed its
default placement. After discussing it with Catalin Marinas we're
restoring the old behavior.

The Raspberry Pi 4, being the only device that needs CMA and crashkernel
in ZONE_DMA will explicitly do so trough it's device tree.

[1] https://lkml.org/lkml/2019/10/21/725

---

Changes since v1:
  - Move CMA area registration into bcm2711.dtsi

Nicolas Saenz Julienne (2):
  ARM: dts: bcm2711: force CMA into first GB of memory
  arm64: mm: reserve CMA and crashkernel in ZONE_DMA32

 arch/arm/boot/dts/bcm2711.dtsi | 20 ++++++++++++++++++++
 arch/arm64/mm/init.c           |  4 ++--
 2 files changed, 22 insertions(+), 2 deletions(-)

-- 
2.23.0


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[PATCH v2 1/2] ARM: dts: bcm2711: force CMA into first GB of memory

[Nicolas Saenz Julienne]

arm64 places the CMA in ZONE_DMA32, which is not good enough for the
Raspberry Pi 4 since it contains peripherals that can only address the
first GB of memory. Explicitly place the CMA into that area.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

---

Changes since v1:
  - Move into bcm2711.dtsi

 arch/arm/boot/dts/bcm2711.dtsi | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
index 1f3acd3363ea..6000a01652fa 100644
--- a/arch/arm/boot/dts/bcm2711.dtsi
+++ b/arch/arm/boot/dts/bcm2711.dtsi
@@ -12,6 +12,26 @@
 
 	interrupt-parent = <&gicv2>;
 
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <1>;
+		ranges;
+
+		/*
+		 * arm64 reserves the CMA by default somewhere in ZONE_DMA32,
+		 * that's not good enough for the Raspberry Pi 4 as some
+		 * devices can only address the lower 1G of memory (ZONE_DMA).
+		 */
+		linux,cma {
+			compatible = "shared-dma-pool";
+			size = <0x2000000>; /* 32MB */
+			alloc-ranges = <0x0 0x00000000 0x40000000>;
+			reusable;
+			linux,cma-default;
+		};
+	};
+
+
 	soc {
 		/*
 		 * Defined ranges:
-- 
2.23.0

[PATCH v2 1/2] ARM: dts: bcm2711: force CMA into first GB of memory

[Nicolas Saenz Julienne]

arm64 places the CMA in ZONE_DMA32, which is not good enough for the
Raspberry Pi 4 since it contains peripherals that can only address the
first GB of memory. Explicitly place the CMA into that area.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

---

Changes since v1:
  - Move into bcm2711.dtsi

 arch/arm/boot/dts/bcm2711.dtsi | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
index 1f3acd3363ea..6000a01652fa 100644
--- a/arch/arm/boot/dts/bcm2711.dtsi
+++ b/arch/arm/boot/dts/bcm2711.dtsi
@@ -12,6 +12,26 @@
 
 	interrupt-parent = <&gicv2>;
 
+	reserved-memory {
+		#address-cells = <2>;
+		#size-cells = <1>;
+		ranges;
+
+		/*
+		 * arm64 reserves the CMA by default somewhere in ZONE_DMA32,
+		 * that's not good enough for the Raspberry Pi 4 as some
+		 * devices can only address the lower 1G of memory (ZONE_DMA).
+		 */
+		linux,cma {
+			compatible = "shared-dma-pool";
+			size = <0x2000000>; /* 32MB */
+			alloc-ranges = <0x0 0x00000000 0x40000000>;
+			reusable;
+			linux,cma-default;
+		};
+	};
+
+
 	soc {
 		/*
 		 * Defined ranges:
-- 
2.23.0


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[PATCH v2 2/2] arm64: mm: reserve CMA and crashkernel in ZONE_DMA32

[Nicolas Saenz Julienne]

With the introduction of ZONE_DMA in arm64 we moved the default CMA and
crashkernel reservation into that area. This caused a regression on big
machines that need big CMA and crashkernel reservations. Note that
ZONE_DMA is only 1GB big.

Restore the previous behavior as the wide majority of devices are OK
with reserving these in ZONE_DMA32. The ones that need them in ZONE_DMA
will configure it explicitly.

Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
 arch/arm64/mm/init.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 580d1052ac34..8385d3c0733f 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -88,7 +88,7 @@ static void __init reserve_crashkernel(void)
 
 	if (crash_base == 0) {
 		/* Current arm64 boot protocol requires 2MB alignment */
-		crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT,
+		crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit,
 				crash_size, SZ_2M);
 		if (crash_base == 0) {
 			pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
@@ -454,7 +454,7 @@ void __init arm64_memblock_init(void)
 
 	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
 
-	dma_contiguous_reserve(arm64_dma_phys_limit ? : arm64_dma32_phys_limit);
+	dma_contiguous_reserve(arm64_dma32_phys_limit);
 }
 
 void __init bootmem_init(void)
-- 
2.23.0

[PATCH v2 2/2] arm64: mm: reserve CMA and crashkernel in ZONE_DMA32

[Nicolas Saenz Julienne]

With the introduction of ZONE_DMA in arm64 we moved the default CMA and
crashkernel reservation into that area. This caused a regression on big
machines that need big CMA and crashkernel reservations. Note that
ZONE_DMA is only 1GB big.

Restore the previous behavior as the wide majority of devices are OK
with reserving these in ZONE_DMA32. The ones that need them in ZONE_DMA
will configure it explicitly.

Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
 arch/arm64/mm/init.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 580d1052ac34..8385d3c0733f 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -88,7 +88,7 @@ static void __init reserve_crashkernel(void)
 
 	if (crash_base == 0) {
 		/* Current arm64 boot protocol requires 2MB alignment */
-		crash_base = memblock_find_in_range(0, ARCH_LOW_ADDRESS_LIMIT,
+		crash_base = memblock_find_in_range(0, arm64_dma32_phys_limit,
 				crash_size, SZ_2M);
 		if (crash_base == 0) {
 			pr_warn("cannot allocate crashkernel (size:0x%llx)\n",
@@ -454,7 +454,7 @@ void __init arm64_memblock_init(void)
 
 	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
 
-	dma_contiguous_reserve(arm64_dma_phys_limit ? : arm64_dma32_phys_limit);
+	dma_contiguous_reserve(arm64_dma32_phys_limit);
 }
 
 void __init bootmem_init(void)
-- 
2.23.0


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Re: [PATCH v2 1/2] ARM: dts: bcm2711: force CMA into first GB of memory

[Stefan Wahren]

Hi Nicolas,

Am 06.11.19 um 10:59 schrieb Nicolas Saenz Julienne:
> arm64 places the CMA in ZONE_DMA32, which is not good enough for the
> Raspberry Pi 4 since it contains peripherals that can only address the
> first GB of memory. Explicitly place the CMA into that area.
>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
>
> ---
>
> Changes since v1:
>   - Move into bcm2711.dtsi
>
>  arch/arm/boot/dts/bcm2711.dtsi | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>
> diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
> index 1f3acd3363ea..6000a01652fa 100644
> --- a/arch/arm/boot/dts/bcm2711.dtsi
> +++ b/arch/arm/boot/dts/bcm2711.dtsi
> @@ -12,6 +12,26 @@
>
>  	interrupt-parent = <&gicv2>;
>
> +	reserved-memory {
> +		#address-cells = <2>;
> +		#size-cells = <1>;
> +		ranges;
> +
> +		/*
> +		 * arm64 reserves the CMA by default somewhere in ZONE_DMA32,
> +		 * that's not good enough for the Raspberry Pi 4 as some

sorry for the nitpicking but i hope the Raspberry Pi 4 B wont be the
only user of BCM2711.

So please s/Raspberry Pi 4/BCM2711/

Beside that:

Acked-by: Stefan Wahren <wahrenst@gmx.net>

> +		 * devices can only address the lower 1G of memory (ZONE_DMA).
> +		 */
> +		linux,cma {
> +			compatible = "shared-dma-pool";
> +			size = <0x2000000>; /* 32MB */
> +			alloc-ranges = <0x0 0x00000000 0x40000000>;
> +			reusable;
> +			linux,cma-default;
> +		};
> +	};
> +
> +
>  	soc {
>  		/*
>  		 * Defined ranges:

Re: [PATCH v2 1/2] ARM: dts: bcm2711: force CMA into first GB of memory

[Stefan Wahren]

Hi Nicolas,

Am 06.11.19 um 10:59 schrieb Nicolas Saenz Julienne:
> arm64 places the CMA in ZONE_DMA32, which is not good enough for the
> Raspberry Pi 4 since it contains peripherals that can only address the
> first GB of memory. Explicitly place the CMA into that area.
>
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
>
> ---
>
> Changes since v1:
>   - Move into bcm2711.dtsi
>
>  arch/arm/boot/dts/bcm2711.dtsi | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>
> diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
> index 1f3acd3363ea..6000a01652fa 100644
> --- a/arch/arm/boot/dts/bcm2711.dtsi
> +++ b/arch/arm/boot/dts/bcm2711.dtsi
> @@ -12,6 +12,26 @@
>
>  	interrupt-parent = <&gicv2>;
>
> +	reserved-memory {
> +		#address-cells = <2>;
> +		#size-cells = <1>;
> +		ranges;
> +
> +		/*
> +		 * arm64 reserves the CMA by default somewhere in ZONE_DMA32,
> +		 * that's not good enough for the Raspberry Pi 4 as some

sorry for the nitpicking but i hope the Raspberry Pi 4 B wont be the
only user of BCM2711.

So please s/Raspberry Pi 4/BCM2711/

Beside that:

Acked-by: Stefan Wahren <wahrenst@gmx.net>

> +		 * devices can only address the lower 1G of memory (ZONE_DMA).
> +		 */
> +		linux,cma {
> +			compatible = "shared-dma-pool";
> +			size = <0x2000000>; /* 32MB */
> +			alloc-ranges = <0x0 0x00000000 0x40000000>;
> +			reusable;
> +			linux,cma-default;
> +		};
> +	};
> +
> +
>  	soc {
>  		/*
>  		 * Defined ranges:

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Re: [PATCH v2 1/2] ARM: dts: bcm2711: force CMA into first GB of memory

[Nicolas Saenz Julienne]

[-- Attachment #1: Type: text/plain, Size: 1992 bytes --]

On Thu, 2019-11-07 at 07:23 +0100, Stefan Wahren wrote:
> Hi Nicolas,
> 
> Am 06.11.19 um 10:59 schrieb Nicolas Saenz Julienne:
> > arm64 places the CMA in ZONE_DMA32, which is not good enough for the
> > Raspberry Pi 4 since it contains peripherals that can only address the
> > first GB of memory. Explicitly place the CMA into that area.
> > 
> > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > 
> > ---
> > 
> > Changes since v1:
> >   - Move into bcm2711.dtsi
> > 
> >  arch/arm/boot/dts/bcm2711.dtsi | 20 ++++++++++++++++++++
> >  1 file changed, 20 insertions(+)
> > 
> > diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
> > index 1f3acd3363ea..6000a01652fa 100644
> > --- a/arch/arm/boot/dts/bcm2711.dtsi
> > +++ b/arch/arm/boot/dts/bcm2711.dtsi
> > @@ -12,6 +12,26 @@
> > 
> >  	interrupt-parent = <&gicv2>;
> > 
> > +	reserved-memory {
> > +		#address-cells = <2>;
> > +		#size-cells = <1>;
> > +		ranges;
> > +
> > +		/*
> > +		 * arm64 reserves the CMA by default somewhere in ZONE_DMA32,
> > +		 * that's not good enough for the Raspberry Pi 4 as some
> 
> sorry for the nitpicking but i hope the Raspberry Pi 4 B wont be the
> only user of BCM2711.

No worries :)

It's better that way anyway.

> 
> So please s/Raspberry Pi 4/BCM2711/
> 
> Beside that:
> 
> Acked-by: Stefan Wahren <wahrenst@gmx.net>

Thanks!

> 
> > +		 * devices can only address the lower 1G of memory (ZONE_DMA).
> > +		 */
> > +		linux,cma {
> > +			compatible = "shared-dma-pool";
> > +			size = <0x2000000>; /* 32MB */
> > +			alloc-ranges = <0x0 0x00000000 0x40000000>;
> > +			reusable;
> > +			linux,cma-default;
> > +		};
> > +	};
> > +
> > +
> >  	soc {
> >  		/*
> >  		 * Defined ranges:
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel


[-- Attachment #2: This is a digitally signed message part --]
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Re: [PATCH v2 1/2] ARM: dts: bcm2711: force CMA into first GB of memory

[Nicolas Saenz Julienne]

[-- Attachment #1.1: Type: text/plain, Size: 1992 bytes --]

On Thu, 2019-11-07 at 07:23 +0100, Stefan Wahren wrote:
> Hi Nicolas,
> 
> Am 06.11.19 um 10:59 schrieb Nicolas Saenz Julienne:
> > arm64 places the CMA in ZONE_DMA32, which is not good enough for the
> > Raspberry Pi 4 since it contains peripherals that can only address the
> > first GB of memory. Explicitly place the CMA into that area.
> > 
> > Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> > 
> > ---
> > 
> > Changes since v1:
> >   - Move into bcm2711.dtsi
> > 
> >  arch/arm/boot/dts/bcm2711.dtsi | 20 ++++++++++++++++++++
> >  1 file changed, 20 insertions(+)
> > 
> > diff --git a/arch/arm/boot/dts/bcm2711.dtsi b/arch/arm/boot/dts/bcm2711.dtsi
> > index 1f3acd3363ea..6000a01652fa 100644
> > --- a/arch/arm/boot/dts/bcm2711.dtsi
> > +++ b/arch/arm/boot/dts/bcm2711.dtsi
> > @@ -12,6 +12,26 @@
> > 
> >  	interrupt-parent = <&gicv2>;
> > 
> > +	reserved-memory {
> > +		#address-cells = <2>;
> > +		#size-cells = <1>;
> > +		ranges;
> > +
> > +		/*
> > +		 * arm64 reserves the CMA by default somewhere in ZONE_DMA32,
> > +		 * that's not good enough for the Raspberry Pi 4 as some
> 
> sorry for the nitpicking but i hope the Raspberry Pi 4 B wont be the
> only user of BCM2711.

No worries :)

It's better that way anyway.

> 
> So please s/Raspberry Pi 4/BCM2711/
> 
> Beside that:
> 
> Acked-by: Stefan Wahren <wahrenst@gmx.net>

Thanks!

> 
> > +		 * devices can only address the lower 1G of memory (ZONE_DMA).
> > +		 */
> > +		linux,cma {
> > +			compatible = "shared-dma-pool";
> > +			size = <0x2000000>; /* 32MB */
> > +			alloc-ranges = <0x0 0x00000000 0x40000000>;
> > +			reusable;
> > +			linux,cma-default;
> > +		};
> > +	};
> > +
> > +
> >  	soc {
> >  		/*
> >  		 * Defined ranges:
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel


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Re: [PATCH v2 1/2] ARM: dts: bcm2711: force CMA into first GB of memory

[Florian Fainelli]

On Wed,  6 Nov 2019 10:59:44 +0100, Nicolas Saenz Julienne <nsaenzjulienne@suse.de> wrote:
> arm64 places the CMA in ZONE_DMA32, which is not good enough for the
> Raspberry Pi 4 since it contains peripherals that can only address the
> first GB of memory. Explicitly place the CMA into that area.
> 
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> 
> ---

Applied to devicetree/next, thanks!
--
Florian

Re: [PATCH v2 1/2] ARM: dts: bcm2711: force CMA into first GB of memory

[Florian Fainelli]

On Wed,  6 Nov 2019 10:59:44 +0100, Nicolas Saenz Julienne <nsaenzjulienne@suse.de> wrote:
> arm64 places the CMA in ZONE_DMA32, which is not good enough for the
> Raspberry Pi 4 since it contains peripherals that can only address the
> first GB of memory. Explicitly place the CMA into that area.
> 
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> 
> ---

Applied to devicetree/next, thanks!
--
Florian

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