[PATCH v2 0/4] Add system mmu support for Armada-806

[PATCH v2 0/4] Add system mmu support for Armada-806

[Gregory CLEMENT]

Hello,

last year a first version of this series was submitted to add support
for IOMMU for AP806, including workaround for accessing ARM SMMU 64bit
registers[1].

For the record, AP-806 can't access SMMU registers with 64bit width,
this patches split the readq/writeq for 32bit access, due to erratanum
#582743.

Based on the feedback from Robin Murphy, I also add code ensuring that
we won't try to use AArch64 format with 32 bits acces.

It was also discussed to not use compatible but propertu to support
this workaround. I agree to make this change if needed, but for now I
would like to have a feedback on the current code to know if it is
acceptable if there is still potential issue.

The series was tested on a vanilla v5.1 kernel, and without the
series, an USB stick was not detected under QEMU whereas with this
series it worked as expected.

Greogry

[1]: https://lkml.org/lkml/2018/10/15/373

Gregory CLEMENT (1):
  arm64: dts: marvell: armada-ap806: add smmu support

Hanna Hawa (3):
  iommu/arm-smmu: Introduce wrapper for writeq/readq
  iommu/arm-smmu: Workaround for Marvell Armada-AP806 SoC erratum
    #582743
  dt-bindings: iommu/arm,smmu: add compatible string for Marvell

 Documentation/arm64/silicon-errata.txt        |  2 +
 .../devicetree/bindings/iommu/arm,smmu.txt    |  1 +
 arch/arm64/boot/dts/marvell/armada-ap806.dtsi | 17 +++++
 drivers/iommu/arm-smmu.c                      | 74 ++++++++++++++++---
 4 files changed, 83 insertions(+), 11 deletions(-)

-- 
2.20.1

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[PATCH v2 1/4] iommu/arm-smmu: Introduce wrapper for writeq/readq

[Gregory CLEMENT]

From: Hanna Hawa <hannah@marvell.com>

This patch introduces the smmu_writeq_relaxed/smmu_readq_relaxed
helpers, as preparation to add specific Marvell work-around for
accessing 64 bits width registers of ARM SMMU.

Signed-off-by: Hanna Hawa <hannah@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
 drivers/iommu/arm-smmu.c | 36 +++++++++++++++++++++++++++---------
 1 file changed, 27 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 045d93884164..ac0784b5b675 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -91,9 +91,11 @@
  * therefore this actually makes more sense than it might first appear.
  */
 #ifdef CONFIG_64BIT
-#define smmu_write_atomic_lq		writeq_relaxed
+#define smmu_write_atomic_lq(smmu, val, reg)	\
+					smmu_writeq_relaxed(smmu, val, reg)
 #else
-#define smmu_write_atomic_lq		writel_relaxed
+#define smmu_write_atomic_lq(smmu, val, reg)	\
+					writel_relaxed(val, reg)
 #endif
 
 /* Translation context bank */
@@ -295,6 +297,19 @@ static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
 	return container_of(dom, struct arm_smmu_domain, domain);
 }
 
+static inline void smmu_writeq_relaxed(struct arm_smmu_device *smmu,
+				       u64 val,
+				       void __iomem *addr)
+{
+	writeq_relaxed(val, addr);
+}
+
+static inline u64 smmu_readq_relaxed(struct arm_smmu_device *smmu,
+				     void __iomem *addr)
+{
+	return readq_relaxed(addr);
+}
+
 static void parse_driver_options(struct arm_smmu_device *smmu)
 {
 	int i = 0;
@@ -495,6 +510,7 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size,
 					  size_t granule, bool leaf, void *cookie)
 {
 	struct arm_smmu_domain *smmu_domain = cookie;
+	struct arm_smmu_device *smmu = smmu_domain->smmu;
 	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
 	bool stage1 = cfg->cbar != CBAR_TYPE_S2_TRANS;
 	void __iomem *reg = ARM_SMMU_CB(smmu_domain->smmu, cfg->cbndx);
@@ -516,7 +532,7 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size,
 			iova >>= 12;
 			iova |= (u64)cfg->asid << 48;
 			do {
-				writeq_relaxed(iova, reg);
+				smmu_writeq_relaxed(smmu, iova, reg);
 				iova += granule >> 12;
 			} while (size -= granule);
 		}
@@ -525,7 +541,7 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size,
 			      ARM_SMMU_CB_S2_TLBIIPAS2;
 		iova >>= 12;
 		do {
-			smmu_write_atomic_lq(iova, reg);
+			smmu_write_atomic_lq(smmu, iova, reg);
 			iova += granule >> 12;
 		} while (size -= granule);
 	}
@@ -584,7 +600,7 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
 		return IRQ_NONE;
 
 	fsynr = readl_relaxed(cb_base + ARM_SMMU_CB_FSYNR0);
-	iova = readq_relaxed(cb_base + ARM_SMMU_CB_FAR);
+	iova = smmu_readq_relaxed(smmu, cb_base + ARM_SMMU_CB_FAR);
 
 	dev_err_ratelimited(smmu->dev,
 	"Unhandled context fault: fsr=0x%x, iova=0x%08lx, fsynr=0x%x, cb=%d\n",
@@ -734,9 +750,11 @@ static void arm_smmu_write_context_bank(struct arm_smmu_device *smmu, int idx)
 		writel_relaxed(cb->ttbr[0], cb_base + ARM_SMMU_CB_TTBR0);
 		writel_relaxed(cb->ttbr[1], cb_base + ARM_SMMU_CB_TTBR1);
 	} else {
-		writeq_relaxed(cb->ttbr[0], cb_base + ARM_SMMU_CB_TTBR0);
+		smmu_writeq_relaxed(smmu, cb->ttbr[0],
+				    cb_base + ARM_SMMU_CB_TTBR0);
 		if (stage1)
-			writeq_relaxed(cb->ttbr[1], cb_base + ARM_SMMU_CB_TTBR1);
+			smmu_writeq_relaxed(smmu, cb->ttbr[1],
+					    cb_base + ARM_SMMU_CB_TTBR1);
 	}
 
 	/* MAIRs (stage-1 only) */
@@ -1367,7 +1385,7 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain,
 	/* ATS1 registers can only be written atomically */
 	va = iova & ~0xfffUL;
 	if (smmu->version == ARM_SMMU_V2)
-		smmu_write_atomic_lq(va, cb_base + ARM_SMMU_CB_ATS1PR);
+		smmu_write_atomic_lq(smmu, va, cb_base + ARM_SMMU_CB_ATS1PR);
 	else /* Register is only 32-bit in v1 */
 		writel_relaxed(va, cb_base + ARM_SMMU_CB_ATS1PR);
 
@@ -1380,7 +1398,7 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain,
 		return ops->iova_to_phys(ops, iova);
 	}
 
-	phys = readq_relaxed(cb_base + ARM_SMMU_CB_PAR);
+	phys = smmu_readq_relaxed(smmu, cb_base + ARM_SMMU_CB_PAR);
 	spin_unlock_irqrestore(&smmu_domain->cb_lock, flags);
 	if (phys & CB_PAR_F) {
 		dev_err(dev, "translation fault!\n");
-- 
2.20.1

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[PATCH v2 2/4] iommu/arm-smmu: Workaround for Marvell Armada-AP806 SoC erratum #582743

[Gregory CLEMENT]

From: Hanna Hawa <hannah@marvell.com>

Due to erratum #582743, the Marvell Armada-AP806 can't access 64bit to
ARM SMMUv2 registers.

This patch split the writeq/readq to two accesses of writel/readl.

We also mask the MMU_IDR2.PTFSv8 fields to not use AArch64 format but
only AARCH32_L. Indeed with AArch64 format 32 bits acces is not
supported.

Note that separate writes/reads to 2 is not problem regards to
atomicity, because the driver use the readq/writeq while initialize
the SMMU, report for SMMU fault, and use spinlock in one
case (iova_to_phys).

Signed-off-by: Hanna Hawa <hannah@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
 Documentation/arm64/silicon-errata.txt |  2 ++
 drivers/iommu/arm-smmu.c               | 42 +++++++++++++++++++++++---
 2 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
index d1e2bb801e1b..3f78ae7a7690 100644
--- a/Documentation/arm64/silicon-errata.txt
+++ b/Documentation/arm64/silicon-errata.txt
@@ -72,6 +72,8 @@ stable kernels.
 | Cavium         | ThunderX2 SMMUv3| #74             | N/A                         |
 | Cavium         | ThunderX2 SMMUv3| #126            | N/A                         |
 |                |                 |                 |                             |
+| Marvell        | ARM-MMU-500     | #582743         | N/A                         |
+|                |                 |                 |                             |
 | Freescale/NXP  | LS2080A/LS1043A | A-008585        | FSL_ERRATUM_A008585         |
 |                |                 |                 |                             |
 | Hisilicon      | Hip0{5,6,7}     | #161010101      | HISILICON_ERRATUM_161010101 |
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index ac0784b5b675..32536ccae22d 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -126,6 +126,7 @@ enum arm_smmu_arch_version {
 enum arm_smmu_implementation {
 	GENERIC_SMMU,
 	ARM_MMU500,
+	MRVL_MMU500,
 	CAVIUM_SMMUV2,
 	QCOM_SMMUV2,
 };
@@ -301,13 +302,35 @@ static inline void smmu_writeq_relaxed(struct arm_smmu_device *smmu,
 				       u64 val,
 				       void __iomem *addr)
 {
-	writeq_relaxed(val, addr);
+	/*
+	 * Marvell Armada-AP806 erratum #582743.
+	 * Split all the writeq to double writel
+	 */
+	if (smmu->model != MRVL_MMU500) {
+		writeq_relaxed(val, addr);
+		return;
+	}
+
+	writel_relaxed(upper_32_bits(val), addr + 4);
+	writel_relaxed(lower_32_bits(val), addr);
 }
 
 static inline u64 smmu_readq_relaxed(struct arm_smmu_device *smmu,
 				     void __iomem *addr)
 {
-	return readq_relaxed(addr);
+	u64 val;
+
+	/*
+	 * Marvell Armada-AP806 erratum #582743.
+	 * Split all the readq to double readl
+	 */
+	if (smmu->model != MRVL_MMU500)
+		return readq_relaxed(addr);
+
+	val = (u64)readl_relaxed(addr + 4) << 32;
+	val |= readl_relaxed(addr);
+
+	return val;
 }
 
 static void parse_driver_options(struct arm_smmu_device *smmu)
@@ -1741,7 +1764,7 @@ static void arm_smmu_device_reset(struct arm_smmu_device *smmu)
 	for (i = 0; i < smmu->num_mapping_groups; ++i)
 		arm_smmu_write_sme(smmu, i);
 
-	if (smmu->model == ARM_MMU500) {
+	if (smmu->model == ARM_MMU500 || smmu->model == MRVL_MMU500) {
 		/*
 		 * Before clearing ARM_MMU500_ACTLR_CPRE, need to
 		 * clear CACHE_LOCK bit of ACR first. And, CACHE_LOCK
@@ -1770,7 +1793,7 @@ static void arm_smmu_device_reset(struct arm_smmu_device *smmu)
 		 * Disable MMU-500's not-particularly-beneficial next-page
 		 * prefetcher for the sake of errata #841119 and #826419.
 		 */
-		if (smmu->model == ARM_MMU500) {
+		if (smmu->model == ARM_MMU500 || smmu->model == MRVL_MMU500) {
 			reg = readl_relaxed(cb_base + ARM_SMMU_CB_ACTLR);
 			reg &= ~ARM_MMU500_ACTLR_CPRE;
 			writel_relaxed(reg, cb_base + ARM_SMMU_CB_ACTLR);
@@ -1987,6 +2010,15 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
 	if (id & ID2_VMID16)
 		smmu->features |= ARM_SMMU_FEAT_VMID16;
 
+	/*
+	 * Armada-AP806 erratum #582743.
+	 * Hide the SMMU_IDR2.PTFSv8 fields to sidestep the AArch64
+	 * formats altogether and allow using 32 bits access on the
+	 * interconnect.
+	 */
+	if (smmu->model == MRVL_MMU500)
+		id &= ~(ID2_PTFS_4K | ID2_PTFS_16K | ID2_PTFS_64K);
+
 	/*
 	 * What the page table walker can address actually depends on which
 	 * descriptor format is in use, but since a) we don't know that yet,
@@ -2053,6 +2085,7 @@ ARM_SMMU_MATCH_DATA(smmu_generic_v1, ARM_SMMU_V1, GENERIC_SMMU);
 ARM_SMMU_MATCH_DATA(smmu_generic_v2, ARM_SMMU_V2, GENERIC_SMMU);
 ARM_SMMU_MATCH_DATA(arm_mmu401, ARM_SMMU_V1_64K, GENERIC_SMMU);
 ARM_SMMU_MATCH_DATA(arm_mmu500, ARM_SMMU_V2, ARM_MMU500);
+ARM_SMMU_MATCH_DATA(mrvl_mmu500, ARM_SMMU_V2, MRVL_MMU500);
 ARM_SMMU_MATCH_DATA(cavium_smmuv2, ARM_SMMU_V2, CAVIUM_SMMUV2);
 ARM_SMMU_MATCH_DATA(qcom_smmuv2, ARM_SMMU_V2, QCOM_SMMUV2);
 
@@ -2062,6 +2095,7 @@ static const struct of_device_id arm_smmu_of_match[] = {
 	{ .compatible = "arm,mmu-400", .data = &smmu_generic_v1 },
 	{ .compatible = "arm,mmu-401", .data = &arm_mmu401 },
 	{ .compatible = "arm,mmu-500", .data = &arm_mmu500 },
+	{ .compatible = "marvell,mmu-500", .data = &mrvl_mmu500 },
 	{ .compatible = "cavium,smmu-v2", .data = &cavium_smmuv2 },
 	{ .compatible = "qcom,smmu-v2", .data = &qcom_smmuv2 },
 	{ },
-- 
2.20.1

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[PATCH v2 3/4] dt-bindings: iommu/arm, smmu: add compatible string for Marvell

[Gregory CLEMENT]

From: Hanna Hawa <hannah@marvell.com>

Add specific compatible string for Marvell usage due errata of
accessing 64bits registers of ARM SMMU, in AP806.

AP806 SoC uses the generic ARM-MMU500, and there's no specific
implementation of Marvell, this compatible is used for errata only.

Signed-off-by: Hanna Hawa <hannah@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
 Documentation/devicetree/bindings/iommu/arm,smmu.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
index 3133f3ba7567..7ed58d51846e 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
@@ -16,6 +16,7 @@ conditions.
                         "arm,mmu-400"
                         "arm,mmu-401"
                         "arm,mmu-500"
+                        "marvell,mmu-500"
                         "cavium,smmu-v2"
                         "qcom,smmu-v2"
 
-- 
2.20.1

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[PATCH v2 4/4] arm64: dts: marvell: armada-ap806: add smmu support

[Gregory CLEMENT]

Add IOMMU node for Marvell AP806 based SoCs.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
 arch/arm64/boot/dts/marvell/armada-ap806.dtsi | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/arch/arm64/boot/dts/marvell/armada-ap806.dtsi b/arch/arm64/boot/dts/marvell/armada-ap806.dtsi
index 91dad7e4ee59..8e29d593970a 100644
--- a/arch/arm64/boot/dts/marvell/armada-ap806.dtsi
+++ b/arch/arm64/boot/dts/marvell/armada-ap806.dtsi
@@ -115,6 +115,23 @@
 				interrupts = <17>;
 			};
 
+			smmu: iommu@5000000 {
+				compatible = "marvell,mmu-500";
+				reg = <0x100000 0x100000>;
+				dma-coherent;
+				#iommu-cells = <1>;
+				#global-interrupts = <1>;
+				interrupts = <GIC_SPI 6 IRQ_TYPE_LEVEL_HIGH>,
+					    <GIC_SPI 6 IRQ_TYPE_LEVEL_HIGH>,
+					    <GIC_SPI 6 IRQ_TYPE_LEVEL_HIGH>,
+					    <GIC_SPI 6 IRQ_TYPE_LEVEL_HIGH>,
+					    <GIC_SPI 6 IRQ_TYPE_LEVEL_HIGH>,
+					    <GIC_SPI 6 IRQ_TYPE_LEVEL_HIGH>,
+					    <GIC_SPI 6 IRQ_TYPE_LEVEL_HIGH>,
+					    <GIC_SPI 6 IRQ_TYPE_LEVEL_HIGH>,
+					    <GIC_SPI 6 IRQ_TYPE_LEVEL_HIGH>;
+			};
+
 			odmi: odmi@300000 {
 				compatible = "marvell,odmi-controller";
 				interrupt-controller;
-- 
2.20.1

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Re: [PATCH v2 3/4] dt-bindings: iommu/arm,smmu: add compatible string for Marvell

[Rob Herring]

On Thu, 11 Jul 2019 17:02:41 +0200, Gregory CLEMENT wrote:
> From: Hanna Hawa <hannah@marvell.com>
> 
> Add specific compatible string for Marvell usage due errata of
> accessing 64bits registers of ARM SMMU, in AP806.
> 
> AP806 SoC uses the generic ARM-MMU500, and there's no specific
> implementation of Marvell, this compatible is used for errata only.
> 
> Signed-off-by: Hanna Hawa <hannah@marvell.com>
> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
> ---
>  Documentation/devicetree/bindings/iommu/arm,smmu.txt | 1 +
>  1 file changed, 1 insertion(+)
> 

Reviewed-by: Rob Herring <robh@kernel.org>
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Re: [PATCH v2 1/4] iommu/arm-smmu: Introduce wrapper for writeq/readq

[Will Deacon]

Hi Gregory, Hanna,

On Thu, Jul 11, 2019 at 05:02:39PM +0200, Gregory CLEMENT wrote:
> From: Hanna Hawa <hannah@marvell.com>
> 
> This patch introduces the smmu_writeq_relaxed/smmu_readq_relaxed
> helpers, as preparation to add specific Marvell work-around for
> accessing 64 bits width registers of ARM SMMU.
> 
> Signed-off-by: Hanna Hawa <hannah@marvell.com>
> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
> ---
>  drivers/iommu/arm-smmu.c | 36 +++++++++++++++++++++++++++---------
>  1 file changed, 27 insertions(+), 9 deletions(-)

Sorry for the delay in replying to this -- Robin's been reworking the driver
so that implementation quirks can be specified more cleanly. Please can you
take a look at:

https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=for-joerg/arm-smmu/refactoring

and try to respin your patches on top of that?

Thanks,

Will
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Re: [PATCH v2 3/4] dt-bindings: iommu/arm, smmu: add compatible string for Marvell

[Robin Murphy]

On 11/07/2019 16:02, Gregory CLEMENT wrote:
> From: Hanna Hawa <hannah@marvell.com>
> 
> Add specific compatible string for Marvell usage due errata of
> accessing 64bits registers of ARM SMMU, in AP806.
> 
> AP806 SoC uses the generic ARM-MMU500, and there's no specific
> implementation of Marvell, this compatible is used for errata only.

Forgive me for repeating myself[1], but:

"Given that, I think something more specific like:

	"marvell,ap806-smmu", "arm,mmu-500";

would be most appropriate. Otherwise, if some future Marvell SoC were to
ever come out with a *different* MMU-500 integration problem, you'd
already have painted yourself into a corner."

Robin.

[1] 
https://lore.kernel.org/linux-arm-kernel/3ce1d67a-4e3c-e8d8-f7fc-79649f1def68@arm.com/

> Signed-off-by: Hanna Hawa <hannah@marvell.com>
> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
> ---
>   Documentation/devicetree/bindings/iommu/arm,smmu.txt | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
> index 3133f3ba7567..7ed58d51846e 100644
> --- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
> +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
> @@ -16,6 +16,7 @@ conditions.
>                           "arm,mmu-400"
>                           "arm,mmu-401"
>                           "arm,mmu-500"
> +                        "marvell,mmu-500"
>                           "cavium,smmu-v2"
>                           "qcom,smmu-v2"
>   
> 
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Re: [PATCH v2 1/4] iommu/arm-smmu: Introduce wrapper for writeq/readq

[Robin Murphy]

On 20/08/2019 13:08, Will Deacon wrote:
> Hi Gregory, Hanna,
> 
> On Thu, Jul 11, 2019 at 05:02:39PM +0200, Gregory CLEMENT wrote:
>> From: Hanna Hawa <hannah@marvell.com>
>>
>> This patch introduces the smmu_writeq_relaxed/smmu_readq_relaxed
>> helpers, as preparation to add specific Marvell work-around for
>> accessing 64 bits width registers of ARM SMMU.
>>
>> Signed-off-by: Hanna Hawa <hannah@marvell.com>
>> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
>> ---
>>   drivers/iommu/arm-smmu.c | 36 +++++++++++++++++++++++++++---------
>>   1 file changed, 27 insertions(+), 9 deletions(-)
> 
> Sorry for the delay in replying to this -- Robin's been reworking the driver
> so that implementation quirks can be specified more cleanly. Please can you
> take a look at:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=for-joerg/arm-smmu/refactoring
> 
> and try to respin your patches on top of that?

Right, the arm_smmu_impl design was specifically anticipating this quirk 
as well - it should just be a case of a cfg_probe hook to hide the 
features which can't work, plus {read,write}_reg64 hooks to override any 
remaining 64-bit accesses with the explicit hi_lo_* variants, munged 
together (either statically or dynamically) with the standard MMU-500 hooks.

Robin.
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