* [PATCH v6 4/4] dt-bindings: i2c: pxa: Update the documentation for the Armada 3700
From: Romain Perier @ 2016-11-30 14:00 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <20161130140017.26307-1-romain.perier@free-electrons.com>
This commit documents the compatible string to have the compatibility for
the I2C unit found in the Armada 3700.
Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
---
Changes in v5:
- Added the tag 'Acked-by', by Rob Herring
Changes in v2:
- Fixed wrong compatible string, it should be "marvell,armada-3700-i2c"
and not "marvell,armada-3700".
Documentation/devicetree/bindings/i2c/i2c-pxa.txt | 1 +
1 file changed, 1 insertion(+)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-pxa.txt b/Documentation/devicetree/bindings/i2c/i2c-pxa.txt
index 12b78ac..d30f0b1 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-pxa.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-pxa.txt
@@ -7,6 +7,7 @@ Required properties :
compatible processor, e.g. pxa168, pxa910, mmp2, mmp3.
For the pxa2xx/pxa3xx, an additional node "mrvl,pxa-i2c" is required
as shown in the example below.
+ For the Armada 3700, the compatible should be "marvell,armada-3700-i2c".
Recommended properties :
--
2.9.3
^ permalink raw reply related
* [PATCH 06/10] iommu: of: Handle IOMMU lookup failure with deferred probing or error
From: Sricharan @ 2016-11-30 14:01 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <5043bd01-2fc3-851d-2d6f-ba5fea96c774@arm.com>
Hi Robin,
>On 30/11/16 07:54, Marek Szyprowski wrote:
>> Hi Sricharan and Robin,
>>
>>
>> On 2016-11-30 01:22, Sricharan R wrote:
>>> From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
>>>
>>> Failures to look up an IOMMU when parsing the DT iommus property need to
>>> be handled separately from the .of_xlate() failures to support deferred
>>> probing.
>>>
>>> The lack of a registered IOMMU can be caused by the lack of a driver for
>>> the IOMMU, the IOMMU device probe not having been performed yet, having
>>> been deferred, or having failed.
>>>
>>> The first case occurs when the device tree describes the bus master and
>>> IOMMU topology correctly but no device driver exists for the IOMMU yet
>>> or the device driver has not been compiled in. Return NULL, the caller
>>> will configure the device without an IOMMU.
>>>
>>> The second and third cases are handled by deferring the probe of the bus
>>> master device which will eventually get reprobed after the IOMMU.
>>>
>>> The last case is currently handled by deferring the probe of the bus
>>> master device as well. A mechanism to either configure the bus master
>>> device without an IOMMU or to fail the bus master device probe depending
>>> on whether the IOMMU is optional or mandatory would be a good
>>> enhancement.
>>>
>>> Signed-off-by: Laurent Pichart
>>> <laurent.pinchart+renesas@ideasonboard.com>
>>> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>>> [rm: massive PCI hacks]
>>> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
>>> ---
>>> drivers/base/dma-mapping.c | 4 ++--
>>> drivers/iommu/dma-iommu.c | 1 +
>>> drivers/iommu/of_iommu.c | 5 +++--
>>> drivers/of/device.c | 9 +++++++--
>>> drivers/pci/probe.c | 6 ++++--
>>> include/linux/of_device.h | 9 ++++++---
>>> include/linux/pci.h | 4 ++--
>>> 7 files changed, 25 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
>>> index b2a5629..576fdfb 100644
>>> --- a/drivers/base/dma-mapping.c
>>> +++ b/drivers/base/dma-mapping.c
>>> @@ -351,9 +351,9 @@ void dma_common_free_remap(void *cpu_addr, size_t
>>> size, unsigned long vm_flags)
>>> int dma_configure(struct device *dev)
>>> {
>>> if (dev_is_pci(dev))
>>> - pci_dma_configure(dev);
>>> + return pci_dma_configure(dev);
>>> else if (dev->of_node)
>>> - of_dma_configure(dev, dev->of_node);
>>> + return of_dma_configure(dev, dev->of_node);
>>> return 0;
>>> }
>>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>>> index c5ab866..d2a7a46 100644
>>> --- a/drivers/iommu/dma-iommu.c
>>> +++ b/drivers/iommu/dma-iommu.c
>>> @@ -148,6 +148,7 @@ int iommu_dma_init_domain(struct iommu_domain
>>> *domain, dma_addr_t base,
>>> base_pfn = max_t(unsigned long, 1, base >> order);
>>> end_pfn = (base + size - 1) >> order;
>>> + dev_info(dev, "0x%llx 0x%llx, 0x%llx 0x%llx, 0x%llx 0x%llx\n",
>>> base, size, domain->geometry.aperture_start,
>>> domain->geometry.aperture_end,
>>
>> This causes a NULL pointer dereference if caller passes NULL device
>> pointer.
>> There is such caller in drivers/gpu/drm/exynos/exynos_drm_iommu.h.
>> Trivial to fix as it looks like a leftover from developement or
>> debugging stage.
>
>Yes, this is some development crap which was never intended to go
>upstream. Hence "massive PCI hacks" ;)
>
>Other than the first two patches, the rest of the stuff from me here was
>just an experiment which I'm not entirely convinced by the outcome of -
>I don't particularly like the resulting fragmentation of having
>pci_dma_configure() awkwardly floating around on its own in pci.c.
Ha, sorry looks like that i have misunderstood that then. I thought that
the V3 changes that i had for pci was hacky and the reworked patches
in your latest branch were correct. So do you suggest that the
pci_dma_configure gets removed and the pci related changes gets handled
in of_iommu_configure /acpi_dma_configure itself ?
Regards,
Sricharan
^ permalink raw reply
* [PATCH v10 13/13] drm/mediatek: add support for Mediatek SoC MT2701
From: Matthias Brugger @ 2016-11-30 14:03 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <1480070076-6196-14-git-send-email-yt.shen@mediatek.com>
On 25/11/16 11:34, YT Shen wrote:
> static const struct of_device_id mtk_disp_rdma_driver_dt_match[] = {
> + { .compatible = "mediatek,mt2701-disp-rdma",
> + .data = &mt2701_rdma_driver_data},
> { .compatible = "mediatek,mt8173-disp-rdma",
> .data = &mt8173_rdma_driver_data},
> {},
[...]
> static const struct of_device_id ddp_driver_dt_match[] = {
> + { .compatible = "mediatek,mt2701-disp-mutex", .data = mt2701_mutex_mod},
> { .compatible = "mediatek,mt8173-disp-mutex", .data = mt8173_mutex_mod},
> {},
> };
[...]
>
> static const struct of_device_id mtk_disp_color_driver_dt_match[] = {
> + { .compatible = "mediatek,mt2701-disp-color",
> + .data = &mt2701_color_driver_data},
> { .compatible = "mediatek,mt8173-disp-color",
> .data = &mt8173_color_driver_data},
> {},
[...]
> static const struct of_device_id mtk_drm_of_ids[] = {
> + { .compatible = "mediatek,mt2701-mmsys",
> + .data = &mt2701_mmsys_driver_data},
> { .compatible = "mediatek,mt8173-mmsys",
> .data = &mt8173_mmsys_driver_data},
> { }
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 0569f2e..f63cc91 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -1203,6 +1203,7 @@ static int mtk_dsi_remove(struct platform_device *pdev)
> }
>
> static const struct of_device_id mtk_dsi_of_match[] = {
> + { .compatible = "mediatek,mt2701-dsi" },
> { .compatible = "mediatek,mt8173-dsi" },
> { },
> };
[...]
>
> static const struct of_device_id mtk_mipi_tx_match[] = {
> + { .compatible = "mediatek,mt2701-mipi-tx",
> + .data = &mt2701_mipitx_data },
> { .compatible = "mediatek,mt8173-mipi-tx",
> .data = &mt8173_mipitx_data },
> {},
I'm not sure if I missed some, but you should update the binding
description for newly added bindings.
Thanks a lot,
Matthias
^ permalink raw reply
* [PATCH 1/1] usb: return error code when platform_get_irq fails
From: Mathias Nyman @ 2016-11-30 14:05 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <52a774c0-9bca-6d1b-a470-f07caefa5d3a@gmail.com>
On 30.11.2016 15:41, Matthias Brugger wrote:
>
>
> On 29/11/16 13:57, Pan Bian wrote:
>> In function xhci_mtk_probe(), variable ret takes the return value. Its
>> value should be negative on failures. However, when the call to function
>> platform_get_irq() fails, it does not set the error code, and 0 will be
>> returned. 0 indicates no error. As a result, the callers of function
>> xhci_mtk_probe() will not be able to detect the error. This patch fixes
>> the bug by assigning the return value of platform_get_irq() to variable
>> ret if it fails.
>>
>> Signed-off-by: Pan Bian <bianpan2016@163.com>
>> ---
>> drivers/usb/host/xhci-mtk.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
>> index 79959f1..f2365a4 100644
>> --- a/drivers/usb/host/xhci-mtk.c
>> +++ b/drivers/usb/host/xhci-mtk.c
>> @@ -560,8 +560,10 @@ static int xhci_mtk_probe(struct platform_device *pdev)
>> goto disable_ldos;
>>
>> irq = platform_get_irq(pdev, 0);
>> - if (irq < 0)
>> + if (irq < 0) {
>> + ret = irq;
>> goto disable_clk;
>> + }
>>
>> /* Initialize dma_mask and coherent_dma_mask to 32-bits */
>> ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
>>
>
>
> Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
>
Thanks, Added to queue
-Mathias
^ permalink raw reply
* [RFC PATCH 00/29] arm64: Scalable Vector Extension core support
From: Dave Martin @ 2016-11-30 14:06 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <583EB285.5050305@arm.com>
On Wed, Nov 30, 2016 at 11:05:41AM +0000, Szabolcs Nagy wrote:
> On 30/11/16 10:08, Florian Weimer wrote:
> > On 11/25/2016 08:38 PM, Dave Martin wrote:
[...]
> >> * Discussion is needed on how userspace should detect/negotiate signal
> >> frame size in order for this expansion mechanism to be workable.
> >
> > I'm leaning towards a simple increase in the glibc headers (despite the ABI risk), plus a personality flag to
> > disable really wide vector registers in case this causes problems with old binaries.
> >
>
> if the kernel does not increase the size and libc
> does not add size checks then old binaries would
> work with new libc just fine..
> but that's non-conforming, posix requires the check.
>
> if the kernel increases the size then it has to be
> changed in bionic and musl as well and old binaries
> may break.
Or we need a personality flag or similar to distinguish the two cases.
[...]
> > A more elaborate mechanism will likely introduce more bugs than it makes existing applications working, due to
> > its complexity.
> >
> >> The remaining patches implement initial SVE support for Linux, with the
> >> following limitations:
> >>
> >> * No KVM/virtualisation support for guests.
> >>
> >> * No independent SVE vector length configuration per thread. This is
> >> planned, but will follow as a separate add-on series.
> >
> > Per-thread register widths will likely make coroutine switching (setcontext) and C++ resumable
> > functions/executors quite challenging.
> >
>
> i'd assume it's undefined to context switch to a different
> thread or to resume a function on a different thread
> (because the implementation can cache thread local state
> on the stack: e.g. errno pointer).. of course this does
> not stop ppl from doing it, but the practice is questionable.
I don't have a view on this.
Cheers
---Dave
^ permalink raw reply
* [RFC v3 00/10] KVM PCIe/MSI passthrough on ARM/ARM64 and IOVA reserved regions
From: Auger Eric @ 2016-11-30 14:08 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <20161130103713.GB2724@arm.com>
Hi Will,
On 30/11/2016 11:37, Will Deacon wrote:
> On Wed, Nov 30, 2016 at 10:49:33AM +0100, Auger Eric wrote:
>> On 15/11/2016 14:09, Eric Auger wrote:
>>> Following LPC discussions, we now report reserved regions through
>>> iommu-group sysfs reserved_regions attribute file.
>>>
>>> Reserved regions are populated through the IOMMU get_resv_region callback
>>> (former get_dm_regions), now implemented by amd-iommu, intel-iommu and
>>> arm-smmu.
>>>
>>> The intel-iommu reports the [FEE0_0000h - FEF0_000h] MSI window as an
>>> IOMMU_RESV_NOMAP reserved region.
>>>
>>> arm-smmu reports the MSI window (arbitrarily located at 0x8000000 and
>>> 1MB large) and the PCI host bridge windows.
>>>
>>> The series integrates a not officially posted patch from Robin:
>>> "iommu/dma: Allow MSI-only cookies".
>>>
>>> This series currently does not address IRQ safety assessment.
>>
>> I will respin this series taking into account Joerg's comment. Does
>> anyone have additional comments or want to put forward some conceptual
>> issues with the current direction and with this implementation?
>>
>> As for the IRQ safety assessment, in a first step I would propose to
>> remove the IOMMU_CAP_INTR_REMAP from arm-smmus and consider the
>> assignment as unsafe. Any objection?
>
> Well, yeah, because it's perfectly safe with GICv3.
Well except if you have an MSI controller in-between the device and the
sMMU (typically embedded in the host bridge). Detecting this situation
is not straightforward; hence my proposal.
Thanks
Eric
>
> Will
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
^ permalink raw reply
* [RFC PATCH 00/29] arm64: Scalable Vector Extension core support
From: Dave Martin @ 2016-11-30 14:10 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <583EC488.9010906@arm.com>
On Wed, Nov 30, 2016 at 12:22:32PM +0000, Szabolcs Nagy wrote:
> On 30/11/16 12:06, Dave Martin wrote:
> > For setcontext/setjmp, we don't save/restore any SVE state due to the
> > caller-save status of SVE, and I would not consider it necessary to
> > save/restore VL itself because of the no-change-on-the-fly policy for
> > this.
>
> the problem is not changing VL within a thread,
> but that setcontext can resume a context of a
> different thread which had different VL and there
> might be SVE regs spilled on the stack according
> to that.
>
> (i consider this usage undefined, but at least
> the gccgo runtime does this)
Understood -- which is part of the reason for the argument that although
the kernel may permit different threads to have different VLs, whether
this actually works usefully also depends on your userspace runtime
environment.
This again leads me to the conclusion that the request to create threads
with different VLs within a single process should be explicit, in order
to avoid accidents.
Cheers
---Dave
^ permalink raw reply
* [PATCH 5/9] arm64: cpufeature: Define helpers for sys_reg id
From: Suzuki K Poulose @ 2016-11-30 14:16 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <20161130110455.GD2724@arm.com>
On 30/11/16 11:04, Will Deacon wrote:
> On Thu, Nov 24, 2016 at 01:40:05PM +0000, Suzuki K Poulose wrote:
>> Define helper macros to extract op0, op1, CRn, CRm & op2
>> for a given sys_reg id.
>>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Mark Rutland <mark.rutland@arm.com>
>> Cc: Will Deacon <will.deacon@arm.com>
>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>> ---
>> arch/arm64/include/asm/sysreg.h | 21 ++++++++++++++++++++-
>> 1 file changed, 20 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
>> index 6c80b36..488b939 100644
>> --- a/arch/arm64/include/asm/sysreg.h
>> +++ b/arch/arm64/include/asm/sysreg.h
>> @@ -34,8 +34,27 @@
>> * [11-8] : CRm
>> * [7-5] : Op2
>> */
>> +#define Op0_shift 19
>> +#define Op0_mask 0x3
>> +#define Op1_shift 16
>> +#define Op1_mask 0x7
>> +#define CRn_shift 12
>> +#define CRn_mask 0xf
>> +#define CRm_shift 8
>> +#define CRm_mask 0xf
>> +#define Op2_shift 5
>> +#define Op2_mask 0x7
>> +
>> #define sys_reg(op0, op1, crn, crm, op2) \
>> - ((((op0)&3)<<19)|((op1)<<16)|((crn)<<12)|((crm)<<8)|((op2)<<5))
>> + ((((op0) & Op0_mask) << Op0_shift) | \
>> + ((op1) << Op1_shift) | ((crn) << CRn_shift) | \
>> + ((crm) << CRm_shift) | ((op2) << Op2_shift))
>
> You're preserving the current behaviour here, but why do we care so much
> about masking op0 but then not bother masking any of the other fields?
I don't remember why it was there. But I do remember that there was some confusion
about using only the last bit (Op0 & 1), the other bit reserved as 1 in the mrs/msr
instructions. I think we changed it explicitly to use the 2 bits from the sys reg Op0,
which brought in support for using the mrs_s for things like PSTATE. We could take
out that mask and depend on the user to do the right thing, just like we do for
the rest of the fields.
Suzuki
>
> Will
>
^ permalink raw reply
* [GIT PULL 3/4] DaVinci DT updates for v4.10 (part 2)
From: Arnd Bergmann @ 2016-11-30 14:19 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <20161120134038.14998-3-nsekhar@ti.com>
On Sunday, November 20, 2016 7:10:37 PM CET Sekhar Nori wrote:
> DaVinci DT updates for v4.10 (part 2)
Pulled into next/dt, thanks!
Arnd
^ permalink raw reply
* [GIT PULL 3/4] DaVinci DT updates for v4.10 (part 3)
From: Arnd Bergmann @ 2016-11-30 14:21 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <20161128114219.22325-4-nsekhar@ti.com>
On Monday, November 28, 2016 5:12:18 PM CET Sekhar Nori wrote:
> Some fixes for device-tree patches already queued.
> - Fix SD card detect polarity
> - Prevent Ethernet from picking a random mac address
> - Fix error messages on platforms which dont use
> bus master and emif priority settings.
>
Pulled into next/dt, thanks!
Arnd
^ permalink raw reply
* [PATCH v2 0/5] Add support for the Armada 3700 SPI controller
From: Gregory CLEMENT @ 2016-11-30 14:30 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <20161130094351.2748-1-romain.perier@free-electrons.com>
Hi Romain,
On mer., nov. 30 2016, Romain Perier <romain.perier@free-electrons.com> wrote:
> The Marvell Armada 3700 SoC includes an SPI controller. This controller
> supports up to 4 SPI slave devices, with dedicated chip selects, CPIO or
> FIFO mode with DMA or CPU transfers and different SPI transfer modes
> (Standard single, Dual or Quad).
>
> This set of patches adds a basic support for the CPIO mode, then it
> enables the FIFO mode (CPU-side only, DMA not supported yet). It also
> adds the required definitions of the spi nodes to the devicetree.
>
I tested the series on the Rev 1.1 and the Rev 2.0 Armada 3720 Db board
and it works on both of them: I managed at leat to read the spi
dataflash.
So for the series you can add my
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Thanks,
Gregory
> Romain Perier (5):
> spi: Add basic support for Armada 3700 SPI Controller
> spi: armada-3700: Add support for the FIFO mode
> dt-bindings: spi: Add documentation for the Armada 3700 SPI Controller
> arm64: dts: marvell: Add definition of SPI controller for Armada 3700
> arm64: dts: marvell: Enable spi0 on the board Armada-3720-db
>
> .../devicetree/bindings/spi/spi-armada-3700.txt | 25 +
> arch/arm64/boot/dts/marvell/armada-3720-db.dts | 30 +
> arch/arm64/boot/dts/marvell/armada-37xx.dtsi | 13 +
> drivers/spi/Kconfig | 7 +
> drivers/spi/Makefile | 1 +
> drivers/spi/spi-armada-3700.c | 1040 ++++++++++++++++++++
> 6 files changed, 1116 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/spi/spi-armada-3700.txt
> create mode 100644 drivers/spi/spi-armada-3700.c
>
> --
> 2.9.3
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
^ permalink raw reply
* [GIT PULL] iommu/arm-smmu: Updates for 4.10
From: Joerg Roedel @ 2016-11-30 14:40 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <20161129172822.GI30283@arm.com>
On Tue, Nov 29, 2016 at 05:28:22PM +0000, Will Deacon wrote:
> The following changes since commit a25f0944ba9b1d8a6813fd6f1a86f1bd59ac25a6:
>
> Linux 4.9-rc5 (2016-11-13 10:32:32 -0800)
>
> are available in the git repository at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git for-joerg/arm-smmu/updates
Pulled, thanks Will.
^ permalink raw reply
* [RFC v3 00/10] KVM PCIe/MSI passthrough on ARM/ARM64 and IOVA reserved regions
From: Robin Murphy @ 2016-11-30 14:41 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <1899e46c-7b06-01d6-6cff-eb0985a4f11d@redhat.com>
On 30/11/16 14:08, Auger Eric wrote:
> Hi Will,
>
> On 30/11/2016 11:37, Will Deacon wrote:
>> On Wed, Nov 30, 2016 at 10:49:33AM +0100, Auger Eric wrote:
>>> On 15/11/2016 14:09, Eric Auger wrote:
>>>> Following LPC discussions, we now report reserved regions through
>>>> iommu-group sysfs reserved_regions attribute file.
>>>>
>>>> Reserved regions are populated through the IOMMU get_resv_region callback
>>>> (former get_dm_regions), now implemented by amd-iommu, intel-iommu and
>>>> arm-smmu.
>>>>
>>>> The intel-iommu reports the [FEE0_0000h - FEF0_000h] MSI window as an
>>>> IOMMU_RESV_NOMAP reserved region.
>>>>
>>>> arm-smmu reports the MSI window (arbitrarily located at 0x8000000 and
>>>> 1MB large) and the PCI host bridge windows.
>>>>
>>>> The series integrates a not officially posted patch from Robin:
>>>> "iommu/dma: Allow MSI-only cookies".
>>>>
>>>> This series currently does not address IRQ safety assessment.
>>>
>>> I will respin this series taking into account Joerg's comment. Does
>>> anyone have additional comments or want to put forward some conceptual
>>> issues with the current direction and with this implementation?
>>>
>>> As for the IRQ safety assessment, in a first step I would propose to
>>> remove the IOMMU_CAP_INTR_REMAP from arm-smmus and consider the
>>> assignment as unsafe. Any objection?
>>
>> Well, yeah, because it's perfectly safe with GICv3.
>
> Well except if you have an MSI controller in-between the device and the
> sMMU (typically embedded in the host bridge). Detecting this situation
> is not straightforward; hence my proposal.
That's not the GICv3 (ITS) case, though, and either way it's irrelevant
to the "safety" aspect in question; the fact that writes to the ITS
carry sideband signals which disambiguate and isolate MSIs has nothing
to do with whether that write undergoes address translation along the way.
It's also not legacy INTx, and the fact that we have to pretend the SMMU
provides MSI isolation in order to make things work with INTx is an
entirely separate piece of brokenness I've raised several times before.
I more than anyone would love to remove IOMMU_CAP_INTR_REMAP from the
SMMU drivers yesterday, but doing so breaks the existing use-case on ARM
unless we actually fix that aspect of VFIO first (I did look into it
once, but it seemed way beyond my comprehension at the time).
Robin.
^ permalink raw reply
* [PATCH v2 4/5] arm64: dts: marvell: Add definition of SPI controller for Armada 3700
From: Gregory CLEMENT @ 2016-11-30 14:55 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <20161130094351.2748-5-romain.perier@free-electrons.com>
Hi Romain,
On mer., nov. 30 2016, Romain Perier <romain.perier@free-electrons.com> wrote:
> Armada 3700 SoC has an SPI Controller, this commit adds the definition
> of the SPI device node at the SoC level.
>
> Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
> ---
>
> Changes in v2:
> - Removed properties max-frequency and clock-frequency, it is no
> longer required and not used by the DT-bindings.
>
> arch/arm64/boot/dts/marvell/armada-37xx.dtsi | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
> index e9bd587..63c2002 100644
> --- a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
> +++ b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
> @@ -98,6 +98,17 @@
> /* 32M internal register @ 0xd000_0000 */
> ranges = <0x0 0x0 0xd0000000 0x2000000>;
>
> + spi0: spi at 10600 {
> + compatible = "marvell,armada-3700-spi";
> + #address-cells = <1>;
> + #size-cells = <0>;
> + reg = <0x10600 0x5d>;
The last register is at the offset 0x1065C but according tot he
datasheet the range address associated to this IP is from 0x10600 to
0x10FFF.
In the first case the size of the register set should be 0x60 (each
register is 32-bits). But I prefer that we register the full range so a
size of 0xA00.
Thanks,
Gregory
> + clocks = <&nb_periph_clk 7>;
> + interrupts = <GIC_SPI 0 IRQ_TYPE_LEVEL_HIGH>;
> + num-cs = <4>;
> + status = "disabled";
> + };
> +
> uart0: serial at 12000 {
> compatible = "marvell,armada-3700-uart";
> reg = <0x12000 0x400>;
> --
> 2.9.3
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
^ permalink raw reply
* [PATCH v2 0/9] arm64: Expose CPUID registers via emulation
From: Suzuki K Poulose @ 2016-11-30 15:14 UTC (permalink / raw)
To: linux-arm-kernel
This series adds a new ABI to expose the CPU feature registers
to the user space via emulation of MRS instruction. The system exposes
only a limited set of feature values (See the documentation patch)
from the cpufeature infrastructure. The feature bits that are not
exposed are set to the 'safe value' which implies 'not supported'.
Apart from the selected feature registers, we expose MIDR_EL1 (Main
ID Register). The user should be aware that, reading MIDR_EL1 can be
tricky on a heterogeneous system (just like getcpu()). We export the
value of the current CPU where 'MRS' is executed.
Changes since V1:
- Drop mask for Op0 in sys_reg()
- Fix documentation
- Change safe value of MPIDR to drop MT support
- Do not emulate AArch32 ID registers
Mark Rutland (2):
arm64: cpufeature: treat unknown fields as RES0
arm64: cpufeature: remove explicit RAZ fields
Suzuki K Poulose (7):
arm64: cpufeature: Cleanup feature bit tables
arm64: cpufeature: Document the rules of safe value for features
arm64: cpufeature: Define helpers for sys_reg id
arm64: Add helper to decode register from instruction
arm64: cpufeature: Track user visible fields
arm64: cpufeature: Expose CPUID registers by emulation
arm64: Documentation - Expose CPU feature registers
Documentation/arm64/cpu-feature-registers.txt | 196 +++++++++++++++
arch/arm64/include/asm/cpufeature.h | 27 +-
arch/arm64/include/asm/insn.h | 2 +
arch/arm64/include/asm/sysreg.h | 25 +-
arch/arm64/include/uapi/asm/hwcap.h | 1 +
arch/arm64/kernel/cpufeature.c | 340 +++++++++++++++++---------
arch/arm64/kernel/cpuinfo.c | 1 +
arch/arm64/kernel/insn.c | 29 +++
arch/arm64/kernel/traps.c | 2 +-
9 files changed, 502 insertions(+), 121 deletions(-)
create mode 100644 Documentation/arm64/cpu-feature-registers.txt
--
2.7.4
^ permalink raw reply
* [PATCH v2 1/9] arm64: cpufeature: treat unknown fields as RES0
From: Suzuki K Poulose @ 2016-11-30 15:14 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <1480518901-18544-1-git-send-email-suzuki.poulose@arm.com>
From: Mark Rutland <mark.rutland@arm.com>
Any fields not defined in an arm64_ftr_bits entry are propagated to the
system-wide register value in init_cpu_ftr_reg(), and while we require
that these strictly match for the sanity checks, we don't update them in
update_cpu_ftr_reg().
Generally, the lack of an arm64_ftr_bits entry indicates that the bits
are currently RES0 (as is the case for the upper 32 bits of all
supposedly 32-bit registers).
A better default would be to use zero for the system-wide value of
unallocated bits, making all register checking consistent, and allowing
for subsequent simplifications to the arm64_ftr_bits arrays.
This patch updates init_cpu_ftr_reg() to treat unallocated bits as RES0
for the purpose of the system-wide safe value. These bits will still be
sanity checked with strict match requirements, as is currently the case.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
arch/arm64/kernel/cpufeature.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index c02504e..a6ecf51 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -409,23 +409,33 @@ static void __init sort_ftr_regs(void)
/*
* Initialise the CPU feature register from Boot CPU values.
* Also initiliases the strict_mask for the register.
+ * Any bits that are not covered by an arm64_ftr_bits entry are considered
+ * RES0 for the system-wide value, and must strictly match.
*/
static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
{
u64 val = 0;
u64 strict_mask = ~0x0ULL;
+ u64 valid_mask = 0;
+
const struct arm64_ftr_bits *ftrp;
struct arm64_ftr_reg *reg = get_arm64_ftr_reg(sys_reg);
BUG_ON(!reg);
for (ftrp = reg->ftr_bits; ftrp->width; ftrp++) {
+ u64 ftr_mask = arm64_ftr_mask(ftrp);
s64 ftr_new = arm64_ftr_value(ftrp, new);
val = arm64_ftr_set_value(ftrp, val, ftr_new);
+
+ valid_mask |= ftr_mask;
if (!ftrp->strict)
- strict_mask &= ~arm64_ftr_mask(ftrp);
+ strict_mask &= ~ftr_mask;
}
+
+ val &= valid_mask;
+
reg->sys_val = val;
reg->strict_mask = strict_mask;
}
--
2.7.4
^ permalink raw reply related
* [PATCH v2 2/9] arm64: cpufeature: remove explicit RAZ fields
From: Suzuki K Poulose @ 2016-11-30 15:14 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <1480518901-18544-1-git-send-email-suzuki.poulose@arm.com>
From: Mark Rutland <mark.rutland@arm.com>
We currently have some RAZ fields described explicitly in our
arm64_ftr_bits arrays. These are inconsistently commented, grouped,
and/or applied, and maintaining these is error-prone.
Luckily, we don't need these at all. We'll never need to inspect RAZ
fields to determine feature support, and init_cpu_ftr_reg() will ensure
that any bits without a corresponding arm64_ftr_bits entry are treated
as RES0 with strict matching requirements. In check_update_ftr_reg()
we'll then compare these bits from the relevant cpuinfo_arm64
structures, and need not store them in a arm64_ftr_reg.
This patch removes the unnecessary arm64_ftr_bits entries for RES0 bits.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
arch/arm64/kernel/cpufeature.c | 15 ---------------
1 file changed, 15 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index a6ecf51..aaf3cba 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -80,21 +80,16 @@ cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused)
static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 24, 4, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0), /* RAZ */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 4, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_GIC_SHIFT, 4, 0),
S_ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
S_ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
@@ -107,7 +102,6 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
};
static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
S_ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
S_ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
@@ -125,7 +119,6 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
};
static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
@@ -146,7 +139,6 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = {
static const struct arm64_ftr_bits ftr_ctr[] = {
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RAO */
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 3, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_HIGHER_SAFE, 24, 4, 0), /* CWG */
ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0), /* ERG */
ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 1), /* DminLine */
@@ -156,7 +148,6 @@ static const struct arm64_ftr_bits ftr_ctr[] = {
* If we have differing I-cache policies, report it as the weakest - AIVIVT.
*/
ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, 14, 2, ICACHE_POLICY_AIVIVT), /* L1Ip */
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 10, 0), /* RAZ */
ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* IminLine */
ARM64_FTR_END,
};
@@ -190,14 +181,12 @@ static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
};
static const struct arm64_ftr_bits ftr_mvfr2[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 24, 0), /* RAZ */
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0), /* FPMisc */
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0), /* SIMDMisc */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_dczid[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 5, 27, 0), /* RAZ */
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 1, 1), /* DZP */
ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* BS */
ARM64_FTR_END,
@@ -206,7 +195,6 @@ static const struct arm64_ftr_bits ftr_dczid[] = {
static const struct arm64_ftr_bits ftr_id_isar5[] = {
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_RDM_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 20, 4, 0), /* RAZ */
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_CRC32_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SHA2_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SHA1_SHIFT, 4, 0),
@@ -216,14 +204,11 @@ static const struct arm64_ftr_bits ftr_id_isar5[] = {
};
static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 24, 0), /* RAZ */
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0), /* ac2 */
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0), /* RAZ */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_pfr0[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 16, 16, 0), /* RAZ */
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 12, 4, 0), /* State3 */
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 4, 0), /* State2 */
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0), /* State1 */
--
2.7.4
^ permalink raw reply related
* [PATCH v2 3/9] arm64: cpufeature: Cleanup feature bit tables
From: Suzuki K Poulose @ 2016-11-30 15:14 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <1480518901-18544-1-git-send-email-suzuki.poulose@arm.com>
This patch does the following clean ups :
1) All undescribed fields of a register are now treated as "strict"
with a safe value of 0. Hence we could leave an empty table for
describing registers which are RAZ.
2) ID_AA64DFR1_EL1 is RAZ and should use the table for RAZ register.
3) ftr_generic32 is used to represent a register with a 32bit feature
value. Rename this to ftr_singl32 to make it more obvious. Since
we don't have a 64bit singe feature register, kill ftr_generic.
Based on a patch by Mark Rutland.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
arch/arm64/kernel/cpufeature.c | 19 +++++++------------
1 file changed, 7 insertions(+), 12 deletions(-)
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index aaf3cba..67e6935 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -246,18 +246,13 @@ static const struct arm64_ftr_bits ftr_generic_32bits[] = {
ARM64_FTR_END,
};
-static const struct arm64_ftr_bits ftr_generic[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 64, 0),
- ARM64_FTR_END,
-};
-
-static const struct arm64_ftr_bits ftr_generic32[] = {
+/* Table for a single 32bit feature value */
+static const struct arm64_ftr_bits ftr_single32[] = {
ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 32, 0),
ARM64_FTR_END,
};
-static const struct arm64_ftr_bits ftr_aa64raz[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 64, 0),
+static const struct arm64_ftr_bits ftr_raz[] = {
ARM64_FTR_END,
};
@@ -298,15 +293,15 @@ static const struct __ftr_reg_entry {
/* Op1 = 0, CRn = 0, CRm = 4 */
ARM64_FTR_REG(SYS_ID_AA64PFR0_EL1, ftr_id_aa64pfr0),
- ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_aa64raz),
+ ARM64_FTR_REG(SYS_ID_AA64PFR1_EL1, ftr_raz),
/* Op1 = 0, CRn = 0, CRm = 5 */
ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
- ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_generic),
+ ARM64_FTR_REG(SYS_ID_AA64DFR1_EL1, ftr_raz),
/* Op1 = 0, CRn = 0, CRm = 6 */
ARM64_FTR_REG(SYS_ID_AA64ISAR0_EL1, ftr_id_aa64isar0),
- ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_aa64raz),
+ ARM64_FTR_REG(SYS_ID_AA64ISAR1_EL1, ftr_raz),
/* Op1 = 0, CRn = 0, CRm = 7 */
ARM64_FTR_REG(SYS_ID_AA64MMFR0_EL1, ftr_id_aa64mmfr0),
@@ -318,7 +313,7 @@ static const struct __ftr_reg_entry {
ARM64_FTR_REG(SYS_DCZID_EL0, ftr_dczid),
/* Op1 = 3, CRn = 14, CRm = 0 */
- ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_generic32),
+ ARM64_FTR_REG(SYS_CNTFRQ_EL0, ftr_single32),
};
static int search_cmp_ftr_reg(const void *id, const void *regp)
--
2.7.4
^ permalink raw reply related
* [PATCH v2 4/9] arm64: cpufeature: Document the rules of safe value for features
From: Suzuki K Poulose @ 2016-11-30 15:14 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <1480518901-18544-1-git-send-email-suzuki.poulose@arm.com>
Document the rules for choosing the safe value for different types
of features.
Cc: Dave Martin <dave.martin@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
arch/arm64/include/asm/cpufeature.h | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 0bc0b1d..59508a9 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -29,7 +29,21 @@
#include <linux/kernel.h>
-/* CPU feature register tracking */
+/*
+ * CPU feature register tracking
+ *
+ * The safe value of a CPUID feature field is dependent on the implications
+ * of the values assigned to it by the architecture. Based on the relationship
+ * between the values, the features are classified into 3 types.
+ *
+ * a) LOWER_SAFE - The value 'n+1' indicates, value 'n' and some
+ * additional features. (where n >= 0). The smaller value (n) is
+ * considered safer in this case.
+ * b) HIGHER_SAFE - The value 'n+1' is safer than 'n' (for n>= 0).
+ * c) EXACT - If the values of the feature don't have any relationship,
+ * a predefined safe value is used.
+ */
+
enum ftr_type {
FTR_EXACT, /* Use a predefined safe value */
FTR_LOWER_SAFE, /* Smaller value is safe */
--
2.7.4
^ permalink raw reply related
* [PATCH v2 5/9] arm64: cpufeature: Define helpers for sys_reg id
From: Suzuki K Poulose @ 2016-11-30 15:14 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <1480518901-18544-1-git-send-email-suzuki.poulose@arm.com>
Define helper macros to extract op0, op1, CRn, CRm & op2
for a given sys_reg id. While at it remove the explicit
masking only used for Op0.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
arch/arm64/include/asm/sysreg.h | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 6c80b36..c94a56f 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -34,8 +34,27 @@
* [11-8] : CRm
* [7-5] : Op2
*/
+#define Op0_shift 19
+#define Op0_mask 0x3
+#define Op1_shift 16
+#define Op1_mask 0x7
+#define CRn_shift 12
+#define CRn_mask 0xf
+#define CRm_shift 8
+#define CRm_mask 0xf
+#define Op2_shift 5
+#define Op2_mask 0x7
+
#define sys_reg(op0, op1, crn, crm, op2) \
- ((((op0)&3)<<19)|((op1)<<16)|((crn)<<12)|((crm)<<8)|((op2)<<5))
+ (((op0) << Op0_shift) | ((op1) << Op1_shift) | \
+ ((crn) << CRn_shift) | ((crm) << CRm_shift) | \
+ ((op2) << Op2_shift))
+
+#define sys_reg_Op0(id) (((id) >> Op0_shift) & Op0_mask)
+#define sys_reg_Op1(id) (((id) >> Op1_shift) & Op1_mask)
+#define sys_reg_CRn(id) (((id) >> CRn_shift) & CRn_mask)
+#define sys_reg_CRm(id) (((id) >> CRm_shift) & CRm_mask)
+#define sys_reg_Op2(id) (((id) >> Op2_shift) & Op2_mask)
#define SYS_MIDR_EL1 sys_reg(3, 0, 0, 0, 0)
#define SYS_MPIDR_EL1 sys_reg(3, 0, 0, 0, 5)
--
2.7.4
^ permalink raw reply related
* [PATCH v2 6/9] arm64: Add helper to decode register from instruction
From: Suzuki K Poulose @ 2016-11-30 15:14 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <1480518901-18544-1-git-send-email-suzuki.poulose@arm.com>
Add a helper to extract the register field from a given
instruction.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
arch/arm64/include/asm/insn.h | 2 ++
arch/arm64/kernel/insn.c | 29 +++++++++++++++++++++++++++++
2 files changed, 31 insertions(+)
diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h
index bc85366..aecc07e 100644
--- a/arch/arm64/include/asm/insn.h
+++ b/arch/arm64/include/asm/insn.h
@@ -332,6 +332,8 @@ bool aarch64_insn_is_branch(u32 insn);
u64 aarch64_insn_decode_immediate(enum aarch64_insn_imm_type type, u32 insn);
u32 aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
u32 insn, u64 imm);
+u32 aarch64_insn_decode_register(enum aarch64_insn_register_type type,
+ u32 insn);
u32 aarch64_insn_gen_branch_imm(unsigned long pc, unsigned long addr,
enum aarch64_insn_branch_type type);
u32 aarch64_insn_gen_comp_branch_imm(unsigned long pc, unsigned long addr,
diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
index 6f2ac4f..755b3dd 100644
--- a/arch/arm64/kernel/insn.c
+++ b/arch/arm64/kernel/insn.c
@@ -418,6 +418,35 @@ u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
return insn;
}
+u32 aarch64_insn_decode_register(enum aarch64_insn_register_type type,
+ u32 insn)
+{
+ int shift;
+
+ switch (type) {
+ case AARCH64_INSN_REGTYPE_RT:
+ case AARCH64_INSN_REGTYPE_RD:
+ shift = 0;
+ break;
+ case AARCH64_INSN_REGTYPE_RN:
+ shift = 5;
+ break;
+ case AARCH64_INSN_REGTYPE_RT2:
+ case AARCH64_INSN_REGTYPE_RA:
+ shift = 10;
+ break;
+ case AARCH64_INSN_REGTYPE_RM:
+ shift = 16;
+ break;
+ default:
+ pr_err("%s: unknown register type encoding %d\n", __func__,
+ type);
+ return 0;
+ }
+
+ return (insn >> shift) & GENMASK(4, 0);
+}
+
static u32 aarch64_insn_encode_register(enum aarch64_insn_register_type type,
u32 insn,
enum aarch64_insn_register reg)
--
2.7.4
^ permalink raw reply related
* [PATCH v2 7/9] arm64: cpufeature: Track user visible fields
From: Suzuki K Poulose @ 2016-11-30 15:14 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <1480518901-18544-1-git-send-email-suzuki.poulose@arm.com>
Track the user visible fields of a CPU feature register. This will be
used for exposing the value to the userspace. All the user visible
fields of a feature register will be passed on as it is, while the
others would be filled with their respective safe value.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
arch/arm64/include/asm/cpufeature.h | 11 +++
arch/arm64/kernel/cpufeature.c | 189 +++++++++++++++++++-----------------
arch/arm64/kernel/traps.c | 2 +-
3 files changed, 111 insertions(+), 91 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index 59508a9..10d478e 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -56,8 +56,12 @@ enum ftr_type {
#define FTR_SIGNED true /* Value should be treated as signed */
#define FTR_UNSIGNED false /* Value should be treated as unsigned */
+#define FTR_VISIBLE true /* Feature visible to the user space */
+#define FTR_HIDDEN false /* Featured is hidden from the user */
+
struct arm64_ftr_bits {
bool sign; /* Value is signed ? */
+ bool visible;
bool strict; /* CPU Sanity check: strict matching required ? */
enum ftr_type type;
u8 shift;
@@ -73,7 +77,9 @@ struct arm64_ftr_bits {
struct arm64_ftr_reg {
const char *name;
u64 strict_mask;
+ u64 user_mask;
u64 sys_val;
+ u64 user_val;
const struct arm64_ftr_bits *ftr_bits;
};
@@ -168,6 +174,11 @@ static inline u64 arm64_ftr_mask(const struct arm64_ftr_bits *ftrp)
return (u64)GENMASK(ftrp->shift + ftrp->width - 1, ftrp->shift);
}
+static inline u64 arm64_ftr_reg_user_value(const struct arm64_ftr_reg *reg)
+{
+ return (reg->user_val | (reg->sys_val & reg->user_mask));
+}
+
static inline int __attribute_const__
cpuid_feature_extract_field(u64 features, int field, bool sign)
{
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 67e6935..a7532dd 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -51,9 +51,10 @@ DECLARE_BITMAP(cpu_hwcaps, ARM64_NCAPS);
DEFINE_STATIC_KEY_ARRAY_FALSE(cpu_hwcap_keys, ARM64_NCAPS);
EXPORT_SYMBOL(cpu_hwcap_keys);
-#define __ARM64_FTR_BITS(SIGNED, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
+#define __ARM64_FTR_BITS(SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
{ \
.sign = SIGNED, \
+ .visible = VISIBLE, \
.strict = STRICT, \
.type = TYPE, \
.shift = SHIFT, \
@@ -62,12 +63,12 @@ EXPORT_SYMBOL(cpu_hwcap_keys);
}
/* Define a feature with unsigned values */
-#define ARM64_FTR_BITS(STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
- __ARM64_FTR_BITS(FTR_UNSIGNED, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
+#define ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
+ __ARM64_FTR_BITS(FTR_UNSIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
/* Define a feature with a signed value */
-#define S_ARM64_FTR_BITS(STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
- __ARM64_FTR_BITS(FTR_SIGNED, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
+#define S_ARM64_FTR_BITS(VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL) \
+ __ARM64_FTR_BITS(FTR_SIGNED, VISIBLE, STRICT, TYPE, SHIFT, WIDTH, SAFE_VAL)
#define ARM64_FTR_END \
{ \
@@ -80,75 +81,75 @@ cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused)
static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_CRC32_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA2_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_SHA1_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_AES_SHIFT, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_GIC_SHIFT, 4, 0),
- S_ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
- S_ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64PFR0_GIC_SHIFT, 4, 0),
+ S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_ASIMD_SHIFT, 4, ID_AA64PFR0_ASIMD_NI),
+ S_ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_FP_SHIFT, 4, ID_AA64PFR0_FP_NI),
/* Linux doesn't care about the EL3 */
- ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, ID_AA64PFR0_EL3_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL2_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64PFR0_EL3_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL2_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL1_SHIFT, 4, ID_AA64PFR0_EL1_64BIT_ONLY),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64PFR0_EL0_SHIFT, 4, ID_AA64PFR0_EL0_64BIT_ONLY),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
- S_ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
- S_ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
+ S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN4_SHIFT, 4, ID_AA64MMFR0_TGRAN4_NI),
+ S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN64_SHIFT, 4, ID_AA64MMFR0_TGRAN64_NI),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_TGRAN16_SHIFT, 4, ID_AA64MMFR0_TGRAN16_NI),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_BIGENDEL0_SHIFT, 4, 0),
/* Linux shouldn't care about secure memory */
- ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_EXACT, ID_AA64MMFR0_SNSMEM_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_BIGENDEL_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR0_ASID_SHIFT, 4, 0),
/*
* Differing PARange is fine as long as all peripherals and memory are mapped
* within the minimum PARange of all CPUs
*/
- ARM64_FTR_BITS(FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_PARANGE_SHIFT, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_PAN_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_LOR_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_HPD_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_VHE_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_VMIDBITS_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR1_HADBS_SHIFT, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR2_LVA_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR2_IESB_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR2_LSM_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR2_UAO_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64MMFR2_CNP_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR2_LVA_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR2_IESB_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR2_LSM_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR2_UAO_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64MMFR2_CNP_SHIFT, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_ctr[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RAO */
- ARM64_FTR_BITS(FTR_STRICT, FTR_HIGHER_SAFE, 24, 4, 0), /* CWG */
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0), /* ERG */
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 1), /* DminLine */
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_EXACT, 31, 1, 1), /* RAO */
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_HIGHER_SAFE, 24, 4, 0), /* CWG */
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0), /* ERG */
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 1), /* DminLine */
/*
* Linux can handle differing I-cache policies. Userspace JITs will
* make use of *minLine.
* If we have differing I-cache policies, report it as the weakest - AIVIVT.
*/
- ARM64_FTR_BITS(FTR_NONSTRICT, FTR_EXACT, 14, 2, ICACHE_POLICY_AIVIVT), /* L1Ip */
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* IminLine */
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_EXACT, 14, 2, ICACHE_POLICY_AIVIVT), /* L1Ip */
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* IminLine */
ARM64_FTR_END,
};
@@ -158,73 +159,73 @@ struct arm64_ftr_reg arm64_ftr_reg_ctrel0 = {
};
static const struct arm64_ftr_bits ftr_id_mmfr0[] = {
- S_ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 28, 4, 0xf), /* InnerShr */
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 24, 4, 0), /* FCSE */
- ARM64_FTR_BITS(FTR_NONSTRICT, FTR_LOWER_SAFE, 20, 4, 0), /* AuxReg */
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 16, 4, 0), /* TCM */
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 12, 4, 0), /* ShareLvl */
- S_ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 4, 0xf), /* OuterShr */
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0), /* PMSA */
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0), /* VMSA */
+ S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 28, 4, 0xf), /* InnerShr */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 24, 4, 0), /* FCSE */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, 20, 4, 0), /* AuxReg */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 16, 4, 0), /* TCM */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 12, 4, 0), /* ShareLvl */
+ S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 8, 4, 0xf), /* OuterShr */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 4, 4, 0), /* PMSA */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 4, 0), /* VMSA */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_aa64dfr0[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 32, 32, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
- S_ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 32, 32, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_CTX_CMPS_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_WRPS_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64DFR0_BRPS_SHIFT, 4, 0),
+ S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_PMUVER_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_TRACEVER_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64DFR0_DEBUGVER_SHIFT, 4, 0x6),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_mvfr2[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0), /* FPMisc */
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0), /* SIMDMisc */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 4, 4, 0), /* FPMisc */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 4, 0), /* SIMDMisc */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_dczid[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 1, 1), /* DZP */
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* BS */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 4, 1, 1), /* DZP */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0), /* BS */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_isar5[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_RDM_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_CRC32_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SHA2_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SHA1_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_AES_SHIFT, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, ID_ISAR5_SEVL_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_ISAR5_RDM_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_ISAR5_CRC32_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_ISAR5_SHA2_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_ISAR5_SHA1_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_ISAR5_AES_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_ISAR5_SEVL_SHIFT, 4, 0),
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_mmfr4[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0), /* ac2 */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 4, 4, 0), /* ac2 */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_pfr0[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 12, 4, 0), /* State3 */
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 8, 4, 0), /* State2 */
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 4, 4, 0), /* State1 */
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 4, 0), /* State0 */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 12, 4, 0), /* State3 */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 8, 4, 0), /* State2 */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 4, 4, 0), /* State1 */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 4, 0), /* State0 */
ARM64_FTR_END,
};
static const struct arm64_ftr_bits ftr_id_dfr0[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
- S_ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0xf), /* PerfMon */
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
+ S_ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0xf), /* PerfMon */
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
ARM64_FTR_END,
};
@@ -235,20 +236,20 @@ static const struct arm64_ftr_bits ftr_id_dfr0[] = {
* id_isar[0-4], id_mmfr[1-3], id_pfr1, mvfr[0-1]
*/
static const struct arm64_ftr_bits ftr_generic_32bits[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
- ARM64_FTR_BITS(FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 28, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 24, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 20, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 16, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 12, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 8, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 4, 4, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, 0, 4, 0),
ARM64_FTR_END,
};
/* Table for a single 32bit feature value */
static const struct arm64_ftr_bits ftr_single32[] = {
- ARM64_FTR_BITS(FTR_STRICT, FTR_EXACT, 0, 32, 0),
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, 0, 32, 0),
ARM64_FTR_END,
};
@@ -396,6 +397,7 @@ static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
{
u64 val = 0;
u64 strict_mask = ~0x0ULL;
+ u64 user_mask = 0;
u64 valid_mask = 0;
const struct arm64_ftr_bits *ftrp;
@@ -412,12 +414,19 @@ static void __init init_cpu_ftr_reg(u32 sys_reg, u64 new)
valid_mask |= ftr_mask;
if (!ftrp->strict)
strict_mask &= ~ftr_mask;
+ if (ftrp->visible)
+ user_mask |= ftr_mask;
+ else
+ reg->user_val = arm64_ftr_set_value(ftrp,
+ reg->user_val,
+ ftrp->safe_val);
}
val &= valid_mask;
reg->sys_val = val;
reg->strict_mask = strict_mask;
+ reg->user_mask = user_mask;
}
void __init init_cpu_features(struct cpuinfo_arm64 *info)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index c9986b3..1f4b6df 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -488,7 +488,7 @@ static void ctr_read_handler(unsigned int esr, struct pt_regs *regs)
{
int rt = (esr & ESR_ELx_SYS64_ISS_RT_MASK) >> ESR_ELx_SYS64_ISS_RT_SHIFT;
- regs->regs[rt] = arm64_ftr_reg_ctrel0.sys_val;
+ regs->regs[rt] = arm64_ftr_reg_user_value(&arm64_ftr_reg_ctrel0);
regs->pc += 4;
}
--
2.7.4
^ permalink raw reply related
* [PATCH v2 8/9] arm64: cpufeature: Expose CPUID registers by emulation
From: Suzuki K Poulose @ 2016-11-30 15:14 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <1480518901-18544-1-git-send-email-suzuki.poulose@arm.com>
This patch adds the hook for emulating MRS instruction to
export the 'user visible' value of supported system registers.
We emulate only the following id space for system registers:
Op0=3, Op1=0, CRn=0, CRm=[0, 4-7]
The rest will fall back to SIGILL. This capability is also
advertised via a new HWCAP_CPUID.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
arch/arm64/include/asm/sysreg.h | 4 ++
arch/arm64/include/uapi/asm/hwcap.h | 1 +
arch/arm64/kernel/cpufeature.c | 101 ++++++++++++++++++++++++++++++++++++
arch/arm64/kernel/cpuinfo.c | 1 +
4 files changed, 107 insertions(+)
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index c94a56f..7d00ce21 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -239,6 +239,10 @@
#define ID_AA64MMFR0_TGRAN_SUPPORTED ID_AA64MMFR0_TGRAN64_SUPPORTED
#endif
+
+/* Safe value for MPIDR_EL1: Bit31:RES1, Bit30:U:0, Bit24:MT:0 */
+#define SYS_MPIDR_SAFE_VAL ((1UL<<31))
+
#ifdef __ASSEMBLY__
.irp num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30
diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h
index a739287..773c90b 100644
--- a/arch/arm64/include/uapi/asm/hwcap.h
+++ b/arch/arm64/include/uapi/asm/hwcap.h
@@ -30,5 +30,6 @@
#define HWCAP_ATOMICS (1 << 8)
#define HWCAP_FPHP (1 << 9)
#define HWCAP_ASIMDHP (1 << 10)
+#define HWCAP_CPUID (1 << 11)
#endif /* _UAPI__ASM_HWCAP_H */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index a7532dd..fa52042 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -29,6 +29,7 @@
#include <asm/mmu_context.h>
#include <asm/processor.h>
#include <asm/sysreg.h>
+#include <asm/traps.h>
#include <asm/virt.h>
unsigned long elf_hwcap __read_mostly;
@@ -916,6 +917,8 @@ static bool cpus_have_elf_hwcap(const struct arm64_cpu_capabilities *cap)
static void __init setup_elf_hwcaps(const struct arm64_cpu_capabilities *hwcaps)
{
+ /* We support emulation of accesses to CPU ID feature registers */
+ elf_hwcap |= HWCAP_CPUID;
for (; hwcaps->matches; hwcaps++)
if (hwcaps->matches(hwcaps, hwcaps->def_scope))
cap_set_elf_hwcap(hwcaps);
@@ -1103,3 +1106,101 @@ cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused)
{
return (cpus_have_cap(ARM64_HAS_PAN) && !cpus_have_cap(ARM64_HAS_UAO));
}
+
+/*
+ * We emulate only the following system register space.
+ * Op0 = 0x3, CRn = 0x0, Op1 = 0x0, CRm = [0, 4 - 7]
+ * See Table C5-6 System instruction encodings for System register accesses,
+ * ARMv8 ARM(ARM DDI 0487A.f) for more details.
+ */
+static inline bool __attribute_const__ is_emulated(u32 id)
+{
+ return (sys_reg_Op0(id) == 0x3 &&
+ sys_reg_CRn(id) == 0x0 &&
+ sys_reg_Op1(id) == 0x0 &&
+ (sys_reg_CRm(id) == 0 ||
+ ((sys_reg_CRm(id) >= 4) && (sys_reg_CRm(id) <= 7))));
+}
+
+/*
+ * With CRm == 0, reg should be one of :
+ * MIDR_EL1, MPIDR_EL1 or REVIDR_EL1.
+ */
+static inline int emulate_id_reg(u32 id, u64 *valp)
+{
+ switch(id) {
+ case SYS_MIDR_EL1:
+ *valp = read_cpuid_id();
+ break;
+ case SYS_MPIDR_EL1:
+ *valp = SYS_MPIDR_SAFE_VAL;
+ break;
+ case SYS_REVIDR_EL1:
+ /* IMPLEMENTATION DEFINED values are emulated with 0 */
+ *valp = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int emulate_sys_reg(u32 id, u64 *valp)
+{
+ struct arm64_ftr_reg *regp;
+
+ if (!is_emulated(id))
+ return -EINVAL;
+
+ if (sys_reg_CRm(id) == 0)
+ return emulate_id_reg(id, valp);
+
+ regp = get_arm64_ftr_reg(id);
+ if (regp)
+ *valp = arm64_ftr_reg_user_value(regp);
+ else
+ /*
+ * The untracked registers are either IMPLEMENTATION DEFINED
+ * (e.g, ID_AFR0_EL1) or reserved RAZ.
+ */
+ *valp = 0;
+ return 0;
+}
+
+static int emulate_mrs(struct pt_regs *regs, u32 insn)
+{
+ int rc;
+ u32 sys_reg, dst;
+ u64 val;
+
+ /*
+ * sys_reg values are defined as used in mrs/msr instruction.
+ * shift the imm value to get the encoding.
+ */
+ sys_reg = (u32)aarch64_insn_decode_immediate(AARCH64_INSN_IMM_16, insn) << 5;
+ rc = emulate_sys_reg(sys_reg, &val);
+ if (!rc) {
+ dst = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn);
+ regs->user_regs.regs[dst] = val;
+ regs->pc += 4;
+ }
+
+ return rc;
+}
+
+static struct undef_hook mrs_hook = {
+ .instr_mask = 0xfff00000,
+ .instr_val = 0xd5300000,
+ .pstate_mask = COMPAT_PSR_MODE_MASK,
+ .pstate_val = PSR_MODE_EL0t,
+ .fn = emulate_mrs,
+};
+
+int __init enable_mrs_emulation(void)
+{
+ register_undef_hook(&mrs_hook);
+ return 0;
+}
+
+late_initcall(enable_mrs_emulation);
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index b3d5b3e..ef8406f 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -63,6 +63,7 @@ static const char *const hwcap_str[] = {
"atomics",
"fphp",
"asimdhp",
+ "cpuid",
NULL
};
--
2.7.4
^ permalink raw reply related
* [PATCH v2 9/9] arm64: Documentation - Expose CPU feature registers
From: Suzuki K Poulose @ 2016-11-30 15:15 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <1480518901-18544-1-git-send-email-suzuki.poulose@arm.com>
Documentation for the infrastructure to expose CPU feature
register by emulating MRS.
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Dave Martin <dave.martin@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
Documentation/arm64/cpu-feature-registers.txt | 196 ++++++++++++++++++++++++++
arch/arm64/kernel/cpufeature.c | 4 +
2 files changed, 200 insertions(+)
create mode 100644 Documentation/arm64/cpu-feature-registers.txt
diff --git a/Documentation/arm64/cpu-feature-registers.txt b/Documentation/arm64/cpu-feature-registers.txt
new file mode 100644
index 0000000..a7b73cb
--- /dev/null
+++ b/Documentation/arm64/cpu-feature-registers.txt
@@ -0,0 +1,196 @@
+ ARM64 CPU Feature Registers
+ ===========================
+
+Author: Suzuki K Poulose <suzuki.poulose@arm.com>
+
+
+This file describes the ABI for exporting the AArch64 CPU ID/feature
+registers to userspace. The availability of this ABI is advertised
+via the HWCAP_CPUID in HWCAPs.
+
+1. Motivation
+---------------
+
+The ARM architecture defines a set of feature registers, which describe
+the capabilities of the CPU/system. Access to these system registers is
+restricted from EL0 and there is no reliable way for an application to
+extract this information to make better decisions at runtime. There is
+limited information available to the application via HWCAPs, however
+there are some issues with their usage.
+
+ a) Any change to the HWCAPs requires an update to userspace (e.g libc)
+ to detect the new changes, which can take a long time to appear in
+ distributions. Exposing the registers allows applications to get the
+ information without requiring updates to the toolchains.
+
+ b) Access to HWCAPs is sometimes limited (e.g prior to libc, or
+ when ld is initialised at startup time).
+
+ c) HWCAPs cannot represent non-boolean information effectively. The
+ architecture defines a canonical format for representing features
+ in the ID registers; this is well defined and is capable of
+ representing all valid architecture variations.
+
+
+2. Requirements
+-----------------
+
+ a) Safety :
+ Applications should be able to use the information provided by the
+ infrastructure to run safely across the system. This has greater
+ implications on a system with heterogeneous CPUs.
+ The infrastructure exports a value that is safe across all the
+ available CPU on the system.
+
+ e.g, If at least one CPU doesn't implement CRC32 instructions, while
+ others do, we should report that the CRC32 is not implemented.
+ Otherwise an application could crash when scheduled on the CPU
+ which doesn't support CRC32.
+
+ b) Security :
+ Applications should only be able to receive information that is
+ relevant to the normal operation in userspace. Hence, some of the
+ fields are masked out and the values of the fields are set to
+ indicate the feature is 'not supported' (See the 'visible' field in
+ the table in Section 4). Also, the kernel may manipulate the fields
+ based on what it supports. e.g, If FP is not supported by the
+ kernel, the values could indicate that the FP is not available
+ (even when the CPU provides it).
+
+ c) Implementation Defined Features
+ The infrastructure doesn't expose any register which is
+ IMPLEMENTATION DEFINED as per ARMv8-A Architecture.
+
+ d) CPU Identification :
+ MIDR_EL1 is exposed to help identify the processor. On a
+ heterogeneous system, this could be racy (just like getcpu()). The
+ process could be migrated to another CPU by the time it uses the
+ register value, unless the CPU affinity is set. Hence, there is no
+ guarantee that the value reflects the processor that it is
+ currently executing on. The REVIDR is not exposed due to this
+ constraint, as REVIDR makes sense only in conjunction with the
+ MIDR. Alternately, MIDR_EL1 and REVIDR_EL1 are exposed via sysfs
+ at:
+
+ /sys/devices/system/cpu/cpu$ID/regs/identification/
+ \- midr
+ \- revidr
+
+The list of supported registers and the attributes of individual
+feature bits are listed in section 4. Unless there is absolute
+necessity, we don't encourage the addition of new feature registers to
+the list. In any case, it should comply to the requirements listed
+above.
+
+3. Implementation
+--------------------
+
+The infrastructure is built on the emulation of the 'MRS' instruction.
+Accessing a restricted system register from an application generates an
+exception and ends up in SIGILL being delivered to the process.
+The infrastructure hooks into the exception handler and emulates the
+operation if the source belongs to the supported system register space.
+
+The infrastructure emulates only the following system register space:
+ Op0=3, Op1=0, CRn=0, CRm=0,4,5,6,7
+
+(See Table C5-6 'System instruction encodings for non-Debug System
+register accesses' in ARMv8 ARM DDI 0487A.h, for the list of
+registers).
+
+
+The following rules are applied to the value returned by the
+infrastructure:
+
+ a) The value of an 'IMPLEMENTATION DEFINED' field is set to 0.
+ b) The value of a reserved field is populated with the reserved
+ value as defined by the architecture.
+ c) The value of a field marked as not 'visible', is set to indicate
+ the feature is missing (as defined by the architecture).
+ d) The value of a 'visible' field holds the system wide safe value
+ for the particular feature(except for MIDR_EL1, see section 4).
+ See Appendix I for more information on safe value.
+
+There are only a few registers visible to the userspace. See Section 4,
+for the list of 'visible' registers.
+
+All others are emulated as having 'invisible' features.
+
+4. List of exposed registers
+-----------------------------
+
+ 1) ID_AA64ISAR0_EL1 - Instruction Set Attribute Register 0
+ x--------------------------------------------------x
+ | Name | bits | visible |
+ |--------------------------------------------------|
+ | RES0 | [63-24] | y |
+ |--------------------------------------------------|
+ | ATOMICS | [20-23] | y |
+ |--------------------------------------------------|
+ | CRC32 | [19-16] | y |
+ |--------------------------------------------------|
+ | SHA2 | [15-12] | y |
+ |--------------------------------------------------|
+ | SHA1 | [11-8] | y |
+ |--------------------------------------------------|
+ | AES | [7-4] | y |
+ |--------------------------------------------------|
+ | RES0 | [3-0] | y |
+ x--------------------------------------------------x
+
+ 2) ID_AA64ISAR1_EL1 - Instruction Set Attribute Register 1
+ x--------------------------------------------------x
+ | Name | bits | visible |
+ |--------------------------------------------------|
+ | RES0 | [63-0] | y |
+ x--------------------------------------------------x
+
+ 3) ID_AA64PFR0_EL1 - Processor Feature Register 0
+ x--------------------------------------------------x
+ | Name | bits | visible |
+ |--------------------------------------------------|
+ | RES0 | [63-28] | y |
+ |--------------------------------------------------|
+ | GIC | [27-24] | n |
+ |--------------------------------------------------|
+ | AdvSIMD | [23-20] | y |
+ |--------------------------------------------------|
+ | FP | [19-16] | y |
+ |--------------------------------------------------|
+ | EL3 | [15-12] | n |
+ |--------------------------------------------------|
+ | EL2 | [11-8] | n |
+ |--------------------------------------------------|
+ | EL1 | [7-4] | n |
+ |--------------------------------------------------|
+ | EL0 | [3-0] | n |
+ x--------------------------------------------------x
+
+ 4) ID_AA64PFR1_EL1 - Processor Feature Register 1
+ x--------------------------------------------------x
+ | Name | bits | visible |
+ |--------------------------------------------------|
+ | RES0 | [63-0] | y |
+ x--------------------------------------------------x
+
+ 5) MIDR_EL1 - Main ID Register
+ x--------------------------------------------------x
+ | Name | bits | visible |
+ |--------------------------------------------------|
+ | RES0 | [63-32] | y |
+ |--------------------------------------------------|
+ | Implementer | [31-24] | y |
+ |--------------------------------------------------|
+ | Variant | [23-20] | y |
+ |--------------------------------------------------|
+ | Architecture | [19-16] | y |
+ |--------------------------------------------------|
+ | PartNum | [15-4] | y |
+ |--------------------------------------------------|
+ | Revision | [3-0] | y |
+ x--------------------------------------------------x
+
+ NOTE: The 'visible' fields of MIDR_EL1 will contain the value
+ as available on the CPU where it is fetched and is not a system
+ wide safe value.
+
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index fa52042..524848f 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -81,6 +81,10 @@ static bool __maybe_unused
cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused);
+/*
+ * NOTE: Any changes to the visibility of features should be kept in
+ * sync with the documentation of the CPU feature register ABI.
+ */
static const struct arm64_ftr_bits ftr_id_aa64isar0[] = {
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_EXACT, ID_AA64ISAR0_RDM_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR0_ATOMICS_SHIFT, 4, 0),
--
2.7.4
^ permalink raw reply related
* [sample] A sample program for MRS emulation
From: Suzuki K Poulose @ 2016-11-30 15:15 UTC (permalink / raw)
To: linux-arm-kernel
In-Reply-To: <1480518901-18544-1-git-send-email-suzuki.poulose@arm.com>
Here is a sample program which demonstrates how to use mrs
emulation to fetch the ID registers.
----8>----
/*
* Sample program to demonstrate the MRS emulation
* ABI.
* Copyright (C) 2015-2016, ARM Ltd
*
* Author: Suzuki K Poulose <suzuki.poulose@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <stdio.h>
#define get_cpu_ftr(id) ({ \
unsigned long long __val; \
asm("mrs %0, "#id : "=r" (__val)); \
printf("%-20s: 0x%016lx\n", #id, __val); \
})
int main()
{
get_cpu_ftr(ID_AA64ISAR0_EL1);
get_cpu_ftr(ID_AA64ISAR1_EL1);
get_cpu_ftr(ID_AA64MMFR0_EL1);
get_cpu_ftr(ID_AA64MMFR1_EL1);
get_cpu_ftr(ID_AA64PFR0_EL1);
get_cpu_ftr(ID_AA64PFR1_EL1);
get_cpu_ftr(ID_AA64DFR0_EL1);
get_cpu_ftr(ID_AA64DFR1_EL1);
get_cpu_ftr(MIDR_EL1);
get_cpu_ftr(MPIDR_EL1);
get_cpu_ftr(REVIDR_EL1);
return 0;
}
^ permalink raw reply
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