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[v5,0/4] arm64 SMMUv3 PMU driver with IORT support

Message ID 20181130154751.28580-1-shameerali.kolothum.thodi@huawei.com
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Series arm64 SMMUv3 PMU driver with IORT support | expand

Message

Shameerali Kolothum Thodi Nov. 30, 2018, 3:47 p.m. UTC
This adds a driver for the SMMUv3 PMU into the perf framework.
It includes an IORT update to support PM Counter Groups.

This is based on the initial work done by Neil Leeder[1]

SMMUv3 PMCG devices are named as smmuv3_pmcg_<phys_addr_page>
where <phys_addr_page> is the physical page address of the SMMU PMCG.
For example, the PMCG at 0xff88840000 is named smmuv3_pmcg_ff88840

Usage example:
For common arch supported events:
perf stat -e smmuv3_pmcg_ff88840/transaction,filter_enable=1,
 filter_span=1,filter_stream_id=0x42/ -a netperf

For IMP DEF events:
perf stat -e smmuv3_pmcg_ff88840/event=id/ -a netperf

This is sanity tested on a HiSilicon platform that requires
a quirk to run  it properly. As per HiSilicon erratum  #162001800,
PMCG event counter registers (SMMU_PMCG_EVCNTRn) on HiSilicon Hip08
platforms are read only and this prevents the software from setting
the initial period on event start. Unfortunately we were a bit late
in the cycle to detect this issue and now require software workaround
for this. Patch #4 is added to this series to provide a workaround
for this issue.

Further testing on supported platforms are very much welcome.

v4 ---> v5
-IORT code is modified to pass the option/quirk flags to the driver
 through platform_data (patch #4), based on Robin's comments.
-Removed COMPILE_TEST (patch #2).

v3 --> v4

-Addressed comments from Jean and Robin.
-Merged dma config callbacks as per Lorenzo's comments(patch #1).
-Added handling of Global(Counter0) filter settings mode(patch #2).
-Added patch #4 to address HiSilicon erratum  #162001800
-
v2 --> v3

-Addressed comments from Robin.
-Removed iort helper function to retrieve the PMCG reference smmu.
-PMCG devices are now named using the base address

v1 --> v2

- Addressed comments from Robin.
- Added an helper to retrieve the associated smmu dev and named PMUs
  to make the association visible to user.
- Added MSI support  for overflow irq

[1]https://www.spinics.net/lists/arm-kernel/msg598591.html

Neil Leeder (2):
  acpi: arm64: add iort support for PMCG
  perf: add arm64 smmuv3 pmu driver

Shameer Kolothum (2):
  perf/smmuv3: Add MSI irq support
  perf/smmuv3_pmu: Enable HiSilicon Erratum 162001800 quirk

 drivers/acpi/arm64/iort.c     | 127 +++++--
 drivers/perf/Kconfig          |   9 +
 drivers/perf/Makefile         |   1 +
 drivers/perf/arm_smmuv3_pmu.c | 859 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/acpi_iort.h     |   3 +
 5 files changed, 975 insertions(+), 24 deletions(-)
 create mode 100644 drivers/perf/arm_smmuv3_pmu.c

-- 
2.7.4

Comments

Shameerali Kolothum Thodi Jan. 22, 2019, 2:38 p.m. UTC | #1
Hi Robin/Lorenzo,

A gentle reminder on this series. Please take a look.

Thanks,
Shameer

> -----Original Message-----

> From: Linuxarm [mailto:linuxarm-bounces@huawei.com] On Behalf Of Shameer

> Kolothum

> Sent: 30 November 2018 15:48

> To: lorenzo.pieralisi@arm.com; robin.murphy@arm.com

> Cc: mark.rutland@arm.com; vkilari@codeaurora.org;

> neil.m.leeder@gmail.com; jean-philippe.brucker@arm.com;

> pabba@codeaurora.org; will.deacon@arm.com; rruigrok@codeaurora.org;

> Linuxarm <linuxarm@huawei.com>; linux-kernel@vger.kernel.org;

> linux-acpi@vger.kernel.org; linux-arm-kernel@lists.infradead.org

> Subject: [PATCH v5 0/4] arm64 SMMUv3 PMU driver with IORT support

> 

> This adds a driver for the SMMUv3 PMU into the perf framework.

> It includes an IORT update to support PM Counter Groups.

> 

> This is based on the initial work done by Neil Leeder[1]

> 

> SMMUv3 PMCG devices are named as smmuv3_pmcg_<phys_addr_page>

> where <phys_addr_page> is the physical page address of the SMMU PMCG.

> For example, the PMCG at 0xff88840000 is named smmuv3_pmcg_ff88840

> 

> Usage example:

> For common arch supported events:

> perf stat -e smmuv3_pmcg_ff88840/transaction,filter_enable=1,

>  filter_span=1,filter_stream_id=0x42/ -a netperf

> 

> For IMP DEF events:

> perf stat -e smmuv3_pmcg_ff88840/event=id/ -a netperf

> 

> This is sanity tested on a HiSilicon platform that requires

> a quirk to run  it properly. As per HiSilicon erratum  #162001800,

> PMCG event counter registers (SMMU_PMCG_EVCNTRn) on HiSilicon Hip08

> platforms are read only and this prevents the software from setting

> the initial period on event start. Unfortunately we were a bit late

> in the cycle to detect this issue and now require software workaround

> for this. Patch #4 is added to this series to provide a workaround

> for this issue.

> 

> Further testing on supported platforms are very much welcome.

> 

> v4 ---> v5

> -IORT code is modified to pass the option/quirk flags to the driver

>  through platform_data (patch #4), based on Robin's comments.

> -Removed COMPILE_TEST (patch #2).

> 

> v3 --> v4

> 

> -Addressed comments from Jean and Robin.

> -Merged dma config callbacks as per Lorenzo's comments(patch #1).

> -Added handling of Global(Counter0) filter settings mode(patch #2).

> -Added patch #4 to address HiSilicon erratum  #162001800

> -

> v2 --> v3

> 

> -Addressed comments from Robin.

> -Removed iort helper function to retrieve the PMCG reference smmu.

> -PMCG devices are now named using the base address

> 

> v1 --> v2

> 

> - Addressed comments from Robin.

> - Added an helper to retrieve the associated smmu dev and named PMUs

>   to make the association visible to user.

> - Added MSI support  for overflow irq

> 

> [1]https://www.spinics.net/lists/arm-kernel/msg598591.html

> 

> Neil Leeder (2):

>   acpi: arm64: add iort support for PMCG

>   perf: add arm64 smmuv3 pmu driver

> 

> Shameer Kolothum (2):

>   perf/smmuv3: Add MSI irq support

>   perf/smmuv3_pmu: Enable HiSilicon Erratum 162001800 quirk

> 

>  drivers/acpi/arm64/iort.c     | 127 +++++--

>  drivers/perf/Kconfig          |   9 +

>  drivers/perf/Makefile         |   1 +

>  drivers/perf/arm_smmuv3_pmu.c | 859

> ++++++++++++++++++++++++++++++++++++++++++

>  include/linux/acpi_iort.h     |   3 +

>  5 files changed, 975 insertions(+), 24 deletions(-)

>  create mode 100644 drivers/perf/arm_smmuv3_pmu.c

> 

> --

> 2.7.4

> 

> 

> _______________________________________________

> Linuxarm mailing list

> Linuxarm@huawei.com

> http://hulk.huawei.com/mailman/listinfo/linuxarm
Robin Murphy Jan. 24, 2019, 5:31 p.m. UTC | #2
On 30/11/2018 15:47, Shameer Kolothum wrote:
> From: Neil Leeder <nleeder@codeaurora.org>

> 

> Add support for the SMMU Performance Monitor Counter Group

> information from ACPI. This is in preparation for its use

> in the SMMUv3 PMU driver.

> 

> Signed-off-by: Neil Leeder <nleeder@codeaurora.org>

> Signed-off-by: Hanjun Guo <guohanjun@huawei.com>

> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

> ---

>   drivers/acpi/arm64/iort.c | 97 +++++++++++++++++++++++++++++++++++++----------

>   1 file changed, 76 insertions(+), 21 deletions(-)

> 

> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c

> index 2a361e2..2da08e1 100644

> --- a/drivers/acpi/arm64/iort.c

> +++ b/drivers/acpi/arm64/iort.c

> @@ -356,7 +356,8 @@ static struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,

>   	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {

>   		if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||

>   		    node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX ||

> -		    node->type == ACPI_IORT_NODE_SMMU_V3) {

> +		    node->type == ACPI_IORT_NODE_SMMU_V3 ||

> +		    node->type == ACPI_IORT_NODE_PMCG) {

>   			*id_out = map->output_base;

>   			return parent;

>   		}

> @@ -394,6 +395,8 @@ static int iort_get_id_mapping_index(struct acpi_iort_node *node)

>   		}

>   

>   		return smmu->id_mapping_index;

> +	case ACPI_IORT_NODE_PMCG:

> +		return 0;

>   	default:

>   		return -EINVAL;

>   	}

> @@ -1216,14 +1219,23 @@ static void __init arm_smmu_v3_init_resources(struct resource *res,

>   	}

>   }

>   

> -static bool __init arm_smmu_v3_is_coherent(struct acpi_iort_node *node)

> +static void __init arm_smmu_v3_dma_configure(struct device *dev,

> +					     struct acpi_iort_node *node)

>   {

>   	struct acpi_iort_smmu_v3 *smmu;

> +	enum dev_dma_attr attr;

>   

>   	/* Retrieve SMMUv3 specific data */

>   	smmu = (struct acpi_iort_smmu_v3 *)node->node_data;

>   

> -	return smmu->flags & ACPI_IORT_SMMU_V3_COHACC_OVERRIDE;

> +	attr = (smmu->flags & ACPI_IORT_SMMU_V3_COHACC_OVERRIDE) ?

> +			DEV_DMA_COHERENT : DEV_DMA_NON_COHERENT;

> +

> +	/* We expect the dma masks to be equivalent for all SMMUv3 set-ups */

> +	dev->dma_mask = &dev->coherent_dma_mask;

> +

> +	/* Configure DMA for the page table walker */

> +	acpi_dma_configure(dev, attr);

>   }

>   

>   #if defined(CONFIG_ACPI_NUMA)

> @@ -1299,20 +1311,64 @@ static void __init arm_smmu_init_resources(struct resource *res,

>   	}

>   }

>   

> -static bool __init arm_smmu_is_coherent(struct acpi_iort_node *node)

> +static void __init arm_smmu_dma_configure(struct device *dev,

> +					  struct acpi_iort_node *node)

>   {

>   	struct acpi_iort_smmu *smmu;

> +	enum dev_dma_attr attr;

>   

>   	/* Retrieve SMMU specific data */

>   	smmu = (struct acpi_iort_smmu *)node->node_data;

>   

> -	return smmu->flags & ACPI_IORT_SMMU_COHERENT_WALK;

> +	attr = (smmu->flags & ACPI_IORT_SMMU_COHERENT_WALK) ?

> +			DEV_DMA_COHERENT : DEV_DMA_NON_COHERENT;

> +

> +	/* We expect the dma masks to be equivalent for SMMU set-ups */

> +	dev->dma_mask = &dev->coherent_dma_mask;

> +

> +	/* Configure DMA for the page table walker */

> +	acpi_dma_configure(dev, attr);

> +}

> +

> +static int __init arm_smmu_v3_pmcg_count_resources(struct acpi_iort_node *node)

> +{

> +	struct acpi_iort_pmcg *pmcg;

> +

> +	/* Retrieve PMCG specific data */

> +	pmcg = (struct acpi_iort_pmcg *)node->node_data;

> +

> +	/*

> +	 * There are always 2 memory resources.

> +	 * If the overflow_gsiv is present then add that for a total of 3.

> +	 */

> +	return pmcg->overflow_gsiv ? 3 : 2;

> +}

> +

> +static void __init arm_smmu_v3_pmcg_init_resources(struct resource *res,

> +					       struct acpi_iort_node *node)

> +{

> +	struct acpi_iort_pmcg *pmcg;

> +

> +	/* Retrieve PMCG specific data */

> +	pmcg = (struct acpi_iort_pmcg *)node->node_data;

> +

> +	res[0].start = pmcg->page0_base_address;

> +	res[0].end = pmcg->page0_base_address + SZ_4K - 1;

> +	res[0].flags = IORESOURCE_MEM;

> +	res[1].start = pmcg->page1_base_address;

> +	res[1].end = pmcg->page1_base_address + SZ_4K - 1;

> +	res[1].flags = IORESOURCE_MEM;

> +

> +	if (pmcg->overflow_gsiv)

> +		acpi_iort_register_irq(pmcg->overflow_gsiv, "overflow",

> +				       ACPI_EDGE_SENSITIVE, &res[2]);

>   }

>   

>   struct iort_dev_config {

>   	const char *name;

>   	int (*dev_init)(struct acpi_iort_node *node);

> -	bool (*dev_is_coherent)(struct acpi_iort_node *node);

> +	void (*dev_dma_configure)(struct device *dev,

> +				    struct acpi_iort_node *node);

>   	int (*dev_count_resources)(struct acpi_iort_node *node);

>   	void (*dev_init_resources)(struct resource *res,

>   				     struct acpi_iort_node *node);

> @@ -1322,7 +1378,7 @@ struct iort_dev_config {

>   

>   static const struct iort_dev_config iort_arm_smmu_v3_cfg __initconst = {

>   	.name = "arm-smmu-v3",

> -	.dev_is_coherent = arm_smmu_v3_is_coherent,

> +	.dev_dma_configure = arm_smmu_v3_dma_configure,

>   	.dev_count_resources = arm_smmu_v3_count_resources,

>   	.dev_init_resources = arm_smmu_v3_init_resources,

>   	.dev_set_proximity = arm_smmu_v3_set_proximity,

> @@ -1330,19 +1386,28 @@ static const struct iort_dev_config iort_arm_smmu_v3_cfg __initconst = {

>   

>   static const struct iort_dev_config iort_arm_smmu_cfg __initconst = {

>   	.name = "arm-smmu",

> -	.dev_is_coherent = arm_smmu_is_coherent,

> +	.dev_dma_configure = arm_smmu_dma_configure,

>   	.dev_count_resources = arm_smmu_count_resources,

> -	.dev_init_resources = arm_smmu_init_resources

> +	.dev_init_resources = arm_smmu_init_resources,

> +};

> +

> +static const struct iort_dev_config iort_arm_smmu_v3_pmcg_cfg __initconst = {

> +	.name = "arm-smmu-v3-pmu",


Nit: s/pmu/pmcg/ for consistency, I think.

> +	.dev_count_resources = arm_smmu_v3_pmcg_count_resources,

> +	.dev_init_resources = arm_smmu_v3_pmcg_init_resources,

>   };

>   

>   static __init const struct iort_dev_config *iort_get_dev_cfg(

>   			struct acpi_iort_node *node)

>   {

> +


Nit: spurious newline.

Otherwise,

Reviewed-by: Robin Murphy <robin.murphy@arm.com>


>   	switch (node->type) {

>   	case ACPI_IORT_NODE_SMMU_V3:

>   		return &iort_arm_smmu_v3_cfg;

>   	case ACPI_IORT_NODE_SMMU:

>   		return &iort_arm_smmu_cfg;

> +	case ACPI_IORT_NODE_PMCG:

> +		return &iort_arm_smmu_v3_pmcg_cfg;

>   	default:

>   		return NULL;

>   	}

> @@ -1360,7 +1425,6 @@ static int __init iort_add_platform_device(struct acpi_iort_node *node,

>   	struct fwnode_handle *fwnode;

>   	struct platform_device *pdev;

>   	struct resource *r;

> -	enum dev_dma_attr attr;

>   	int ret, count;

>   

>   	pdev = platform_device_alloc(ops->name, PLATFORM_DEVID_AUTO);

> @@ -1398,12 +1462,6 @@ static int __init iort_add_platform_device(struct acpi_iort_node *node,

>   	if (ret)

>   		goto dev_put;

>   

> -	/*

> -	 * We expect the dma masks to be equivalent for

> -	 * all SMMUs set-ups

> -	 */

> -	pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;

> -

>   	fwnode = iort_get_fwnode(node);

>   

>   	if (!fwnode) {

> @@ -1413,11 +1471,8 @@ static int __init iort_add_platform_device(struct acpi_iort_node *node,

>   

>   	pdev->dev.fwnode = fwnode;

>   

> -	attr = ops->dev_is_coherent && ops->dev_is_coherent(node) ?

> -			DEV_DMA_COHERENT : DEV_DMA_NON_COHERENT;

> -

> -	/* Configure DMA for the page table walker */

> -	acpi_dma_configure(&pdev->dev, attr);

> +	if (ops->dev_dma_configure)

> +		ops->dev_dma_configure(&pdev->dev, node);

>   

>   	iort_set_device_domain(&pdev->dev, node);

>   

>
Robin Murphy Jan. 25, 2019, 6:32 p.m. UTC | #3
On 30/11/2018 15:47, Shameer Kolothum wrote:
> HiSilicon erratum 162001800 describes the limitation of

> SMMUv3 PMCG implementation on HiSilicon Hip08 platforms.

> 

> On these platforms, the PMCG event counter registers

> (SMMU_PMCG_EVCNTRn) are read only and as a result it

> is not possible to set the initial counter period value

> on event monitor start.

> 

> To work around this, the current value of the counter

> is read and used for delta calculations. OEM information

> from ACPI header is used to identify the affected hardware

> platforms.

> 

> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

> ---

>   drivers/acpi/arm64/iort.c     | 30 +++++++++++++++++++++++++++---

>   drivers/perf/arm_smmuv3_pmu.c | 35 +++++++++++++++++++++++++++++------

>   include/linux/acpi_iort.h     |  3 +++

>   3 files changed, 59 insertions(+), 9 deletions(-)

> 

> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c

> index 2da08e1..d174379 100644

> --- a/drivers/acpi/arm64/iort.c

> +++ b/drivers/acpi/arm64/iort.c

> @@ -1364,6 +1364,22 @@ static void __init arm_smmu_v3_pmcg_init_resources(struct resource *res,

>   				       ACPI_EDGE_SENSITIVE, &res[2]);

>   }

>   

> +static struct acpi_platform_list pmcg_evcntr_rdonly_list[] __initdata = {

> +	/* HiSilicon Erratum 162001800 */

> +	{"HISI  ", "HIP08   ", 0, ACPI_SIG_IORT, greater_than_or_equal},

> +	{ }

> +};

> +

> +static int __init arm_smmu_v3_pmcg_add_platdata(struct platform_device *pdev)

> +{

> +	u32 options = 0;

> +

> +	if (acpi_match_platform_list(pmcg_evcntr_rdonly_list) >= 0)

> +		options |= IORT_PMCG_EVCNTR_RDONLY;


Hmm, do we want IORT code to have to understand a (potential) whole load 
of PMCG-specific quirks directly, or do we really only need to pass some 
unambiguous identifier for the PMCG implementation, and let the driver 
handle the details in private - much like the SMMU model field, only 
without an external spec to constrain us :)

If we ever want to have named imp-def events, we'd need to do something 
like that anyway, so perhaps we might be better off taking that approach 
to begin with (and if so, I'd be inclined to push the basic platdata 
initialisation for "generic PMCG" into patch #1).

> +

> +	return platform_device_add_data(pdev, &options, sizeof(options));

> +}

> +

>   struct iort_dev_config {

>   	const char *name;

>   	int (*dev_init)(struct acpi_iort_node *node);

> @@ -1374,6 +1390,7 @@ struct iort_dev_config {

>   				     struct acpi_iort_node *node);

>   	void (*dev_set_proximity)(struct device *dev,

>   				    struct acpi_iort_node *node);

> +	int (*dev_add_platdata)(struct platform_device *pdev);

>   };

>   

>   static const struct iort_dev_config iort_arm_smmu_v3_cfg __initconst = {

> @@ -1395,6 +1412,7 @@ static const struct iort_dev_config iort_arm_smmu_v3_pmcg_cfg __initconst = {

>   	.name = "arm-smmu-v3-pmu",

>   	.dev_count_resources = arm_smmu_v3_pmcg_count_resources,

>   	.dev_init_resources = arm_smmu_v3_pmcg_init_resources,

> +	.dev_add_platdata	= arm_smmu_v3_pmcg_add_platdata,

>   };

>   

>   static __init const struct iort_dev_config *iort_get_dev_cfg(

> @@ -1455,10 +1473,16 @@ static int __init iort_add_platform_device(struct acpi_iort_node *node,

>   		goto dev_put;

>   

>   	/*

> -	 * Add a copy of IORT node pointer to platform_data to

> -	 * be used to retrieve IORT data information.

> +	 * Platform devices based on PMCG nodes uses platform_data to

> +	 * pass quirk flags to the driver. For others, add a copy of

> +	 * IORT node pointer to platform_data to be used to retrieve

> +	 * IORT data information.

>   	 */

> -	ret = platform_device_add_data(pdev, &node, sizeof(node));

> +	if (ops->dev_add_platdata)

> +		ret = ops->dev_add_platdata(pdev);

> +	else

> +		ret = platform_device_add_data(pdev, &node, sizeof(node));

> +

>   	if (ret)

>   		goto dev_put;

>   

> diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c

> index 71d10a0..02107a1 100644

> --- a/drivers/perf/arm_smmuv3_pmu.c

> +++ b/drivers/perf/arm_smmuv3_pmu.c

> @@ -35,6 +35,7 @@

>    */

>   

>   #include <linux/acpi.h>

> +#include <linux/acpi_iort.h>

>   #include <linux/bitfield.h>

>   #include <linux/bitops.h>

>   #include <linux/cpuhotplug.h>

> @@ -111,6 +112,7 @@ struct smmu_pmu {

>   	struct device *dev;

>   	void __iomem *reg_base;

>   	void __iomem *reloc_base;

> +	u32 options;

>   	u64 counter_present_mask;

>   	u64 counter_mask;

>   };

> @@ -224,12 +226,25 @@ static void smmu_pmu_set_period(struct smmu_pmu *smmu_pmu,

>   	u32 idx = hwc->idx;

>   	u64 new;

>   

> -	/*

> -	 * We limit the max period to half the max counter value of the counter

> -	 * size, so that even in the case of extreme interrupt latency the

> -	 * counter will (hopefully) not wrap past its initial value.

> -	 */

> -	new = smmu_pmu->counter_mask >> 1;

> +	if (smmu_pmu->options & IORT_PMCG_EVCNTR_RDONLY) {

> +		/*

> +		 * On platforms that require this quirk, if the counter starts

> +		 * at < half_counter value and wraps, the current logic of

> +		 * handling the overflow may not work. It is expected that,

> +		 * those platforms will have full 64 counter bits implemented

> +		 * so that such a possibility is remote(eg: HiSilicon HIP08).

> +		 */

> +		new = smmu_pmu_counter_get_value(smmu_pmu, idx);

> +	} else {

> +		/*

> +		 * We limit the max period to half the max counter value

> +		 * of the counter size, so that even in the case of extreme

> +		 * interrupt latency the counter will (hopefully) not wrap

> +		 * past its initial value.

> +		 */

> +		new = smmu_pmu->counter_mask >> 1;

> +		smmu_pmu_counter_set_value(smmu_pmu, idx, new);

> +	}

>   

>   	local64_set(&hwc->prev_count, new);

>   	smmu_pmu_counter_set_value(smmu_pmu, idx, new);


Either we've just done this already, or it's not going to have any 
effect anyway, so it can definitely go.

Robin.

> @@ -670,6 +685,12 @@ static void smmu_pmu_reset(struct smmu_pmu *smmu_pmu)

>   		       smmu_pmu->reloc_base + SMMU_PMCG_OVSCLR0);

>   }

>   

> +static void smmu_pmu_get_acpi_options(struct smmu_pmu *smmu_pmu)

> +{

> +	smmu_pmu->options = *(u32 *)dev_get_platdata(smmu_pmu->dev);

> +	dev_notice(smmu_pmu->dev, "option mask 0x%x\n", smmu_pmu->options);

> +}

> +

>   static int smmu_pmu_probe(struct platform_device *pdev)

>   {

>   	struct smmu_pmu *smmu_pmu;

> @@ -749,6 +770,8 @@ static int smmu_pmu_probe(struct platform_device *pdev)

>   		return -EINVAL;

>   	}

>   

> +	smmu_pmu_get_acpi_options(smmu_pmu);

> +

>   	/* Pick one CPU to be the preferred one to use */

>   	smmu_pmu->on_cpu = get_cpu();

>   	WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(smmu_pmu->on_cpu)));

> diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h

> index 38cd77b..4a7ae69 100644

> --- a/include/linux/acpi_iort.h

> +++ b/include/linux/acpi_iort.h

> @@ -26,6 +26,9 @@

>   #define IORT_IRQ_MASK(irq)		(irq & 0xffffffffULL)

>   #define IORT_IRQ_TRIGGER_MASK(irq)	((irq >> 32) & 0xffffffffULL)

>   

> +/* PMCG node option or quirk flags */

> +#define IORT_PMCG_EVCNTR_RDONLY		(1 << 0)

> +

>   int iort_register_domain_token(int trans_id, phys_addr_t base,

>   			       struct fwnode_handle *fw_node);

>   void iort_deregister_domain_token(int trans_id);

>
Shameerali Kolothum Thodi Jan. 28, 2019, 9:24 a.m. UTC | #4
> -----Original Message-----

> From: Robin Murphy [mailto:robin.murphy@arm.com]

> Sent: 25 January 2019 18:33

> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>;

> lorenzo.pieralisi@arm.com

> Cc: jean-philippe.brucker@arm.com; will.deacon@arm.com;

> mark.rutland@arm.com; Guohanjun (Hanjun Guo) <guohanjun@huawei.com>;

> John Garry <john.garry@huawei.com>; pabba@codeaurora.org;

> vkilari@codeaurora.org; rruigrok@codeaurora.org; linux-acpi@vger.kernel.org;

> linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org; Linuxarm

> <linuxarm@huawei.com>; neil.m.leeder@gmail.com

> Subject: Re: [PATCH v5 4/4] perf/smmuv3_pmu: Enable HiSilicon Erratum

> 162001800 quirk

> 

> On 30/11/2018 15:47, Shameer Kolothum wrote:

> > HiSilicon erratum 162001800 describes the limitation of

> > SMMUv3 PMCG implementation on HiSilicon Hip08 platforms.

> >

> > On these platforms, the PMCG event counter registers

> > (SMMU_PMCG_EVCNTRn) are read only and as a result it

> > is not possible to set the initial counter period value

> > on event monitor start.

> >

> > To work around this, the current value of the counter

> > is read and used for delta calculations. OEM information

> > from ACPI header is used to identify the affected hardware

> > platforms.

> >

> > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

> > ---

> >   drivers/acpi/arm64/iort.c     | 30 +++++++++++++++++++++++++++---

> >   drivers/perf/arm_smmuv3_pmu.c | 35

> +++++++++++++++++++++++++++++------

> >   include/linux/acpi_iort.h     |  3 +++

> >   3 files changed, 59 insertions(+), 9 deletions(-)

> >

> > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c

> > index 2da08e1..d174379 100644

> > --- a/drivers/acpi/arm64/iort.c

> > +++ b/drivers/acpi/arm64/iort.c

> > @@ -1364,6 +1364,22 @@ static void __init

> arm_smmu_v3_pmcg_init_resources(struct resource *res,

> >   				       ACPI_EDGE_SENSITIVE, &res[2]);

> >   }

> >

> > +static struct acpi_platform_list pmcg_evcntr_rdonly_list[] __initdata = {

> > +	/* HiSilicon Erratum 162001800 */

> > +	{"HISI  ", "HIP08   ", 0, ACPI_SIG_IORT, greater_than_or_equal},

> > +	{ }

> > +};

> > +

> > +static int __init arm_smmu_v3_pmcg_add_platdata(struct platform_device

> *pdev)

> > +{

> > +	u32 options = 0;

> > +

> > +	if (acpi_match_platform_list(pmcg_evcntr_rdonly_list) >= 0)

> > +		options |= IORT_PMCG_EVCNTR_RDONLY;

> 

> Hmm, do we want IORT code to have to understand a (potential) whole load

> of PMCG-specific quirks directly, or do we really only need to pass some

> unambiguous identifier for the PMCG implementation, and let the driver

> handle the details in private - much like the SMMU model field, only

> without an external spec to constrain us :)


Could do that, but was not sure about coming up with an identifier which is not
really part of the spec and placing that in IORT code. Personally I prefer having
all this private to driver rather than in IORT code. But I see your point that this
will be more like smmu if we can pass identifiers here. 

> If we ever want to have named imp-def events, we'd need to do something

> like that anyway, so perhaps we might be better off taking that approach

> to begin with (and if so, I'd be inclined to push the basic platdata

> initialisation for "generic PMCG" into patch #1).


Ok. I will give that a try in next respin.

> > +

> > +	return platform_device_add_data(pdev, &options, sizeof(options));

> > +}

> > +

> >   struct iort_dev_config {

> >   	const char *name;

> >   	int (*dev_init)(struct acpi_iort_node *node);

> > @@ -1374,6 +1390,7 @@ struct iort_dev_config {

> >   				     struct acpi_iort_node *node);

> >   	void (*dev_set_proximity)(struct device *dev,

> >   				    struct acpi_iort_node *node);

> > +	int (*dev_add_platdata)(struct platform_device *pdev);

> >   };

> >

> >   static const struct iort_dev_config iort_arm_smmu_v3_cfg __initconst = {

> > @@ -1395,6 +1412,7 @@ static const struct iort_dev_config

> iort_arm_smmu_v3_pmcg_cfg __initconst = {

> >   	.name = "arm-smmu-v3-pmu",

> >   	.dev_count_resources = arm_smmu_v3_pmcg_count_resources,

> >   	.dev_init_resources = arm_smmu_v3_pmcg_init_resources,

> > +	.dev_add_platdata	= arm_smmu_v3_pmcg_add_platdata,

> >   };

> >

> >   static __init const struct iort_dev_config *iort_get_dev_cfg(

> > @@ -1455,10 +1473,16 @@ static int __init

> iort_add_platform_device(struct acpi_iort_node *node,

> >   		goto dev_put;

> >

> >   	/*

> > -	 * Add a copy of IORT node pointer to platform_data to

> > -	 * be used to retrieve IORT data information.

> > +	 * Platform devices based on PMCG nodes uses platform_data to

> > +	 * pass quirk flags to the driver. For others, add a copy of

> > +	 * IORT node pointer to platform_data to be used to retrieve

> > +	 * IORT data information.

> >   	 */

> > -	ret = platform_device_add_data(pdev, &node, sizeof(node));

> > +	if (ops->dev_add_platdata)

> > +		ret = ops->dev_add_platdata(pdev);

> > +	else

> > +		ret = platform_device_add_data(pdev, &node, sizeof(node));

> > +

> >   	if (ret)

> >   		goto dev_put;

> >

> > diff --git a/drivers/perf/arm_smmuv3_pmu.c

> b/drivers/perf/arm_smmuv3_pmu.c

> > index 71d10a0..02107a1 100644

> > --- a/drivers/perf/arm_smmuv3_pmu.c

> > +++ b/drivers/perf/arm_smmuv3_pmu.c

> > @@ -35,6 +35,7 @@

> >    */

> >

> >   #include <linux/acpi.h>

> > +#include <linux/acpi_iort.h>

> >   #include <linux/bitfield.h>

> >   #include <linux/bitops.h>

> >   #include <linux/cpuhotplug.h>

> > @@ -111,6 +112,7 @@ struct smmu_pmu {

> >   	struct device *dev;

> >   	void __iomem *reg_base;

> >   	void __iomem *reloc_base;

> > +	u32 options;

> >   	u64 counter_present_mask;

> >   	u64 counter_mask;

> >   };

> > @@ -224,12 +226,25 @@ static void smmu_pmu_set_period(struct

> smmu_pmu *smmu_pmu,

> >   	u32 idx = hwc->idx;

> >   	u64 new;

> >

> > -	/*

> > -	 * We limit the max period to half the max counter value of the counter

> > -	 * size, so that even in the case of extreme interrupt latency the

> > -	 * counter will (hopefully) not wrap past its initial value.

> > -	 */

> > -	new = smmu_pmu->counter_mask >> 1;

> > +	if (smmu_pmu->options & IORT_PMCG_EVCNTR_RDONLY) {

> > +		/*

> > +		 * On platforms that require this quirk, if the counter starts

> > +		 * at < half_counter value and wraps, the current logic of

> > +		 * handling the overflow may not work. It is expected that,

> > +		 * those platforms will have full 64 counter bits implemented

> > +		 * so that such a possibility is remote(eg: HiSilicon HIP08).

> > +		 */

> > +		new = smmu_pmu_counter_get_value(smmu_pmu, idx);

> > +	} else {

> > +		/*

> > +		 * We limit the max period to half the max counter value

> > +		 * of the counter size, so that even in the case of extreme

> > +		 * interrupt latency the counter will (hopefully) not wrap

> > +		 * past its initial value.

> > +		 */

> > +		new = smmu_pmu->counter_mask >> 1;

> > +		smmu_pmu_counter_set_value(smmu_pmu, idx, new);

> > +	}

> >

> >   	local64_set(&hwc->prev_count, new);

> >   	smmu_pmu_counter_set_value(smmu_pmu, idx, new);

> 

> Either we've just done this already, or it's not going to have any

> effect anyway, so it can definitely go.


My bad. Forgot to remove that. v4 didn’t have this here.

Thanks,
Shameer

> Robin.

> 

> > @@ -670,6 +685,12 @@ static void smmu_pmu_reset(struct smmu_pmu

> *smmu_pmu)

> >   		       smmu_pmu->reloc_base + SMMU_PMCG_OVSCLR0);

> >   }

> >

> > +static void smmu_pmu_get_acpi_options(struct smmu_pmu *smmu_pmu)

> > +{

> > +	smmu_pmu->options = *(u32 *)dev_get_platdata(smmu_pmu->dev);

> > +	dev_notice(smmu_pmu->dev, "option mask 0x%x\n",

> smmu_pmu->options);

> > +}

> > +

> >   static int smmu_pmu_probe(struct platform_device *pdev)

> >   {

> >   	struct smmu_pmu *smmu_pmu;

> > @@ -749,6 +770,8 @@ static int smmu_pmu_probe(struct platform_device

> *pdev)

> >   		return -EINVAL;

> >   	}

> >

> > +	smmu_pmu_get_acpi_options(smmu_pmu);

> > +

> >   	/* Pick one CPU to be the preferred one to use */

> >   	smmu_pmu->on_cpu = get_cpu();

> >   	WARN_ON(irq_set_affinity(smmu_pmu->irq,

> cpumask_of(smmu_pmu->on_cpu)));

> > diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h

> > index 38cd77b..4a7ae69 100644

> > --- a/include/linux/acpi_iort.h

> > +++ b/include/linux/acpi_iort.h

> > @@ -26,6 +26,9 @@

> >   #define IORT_IRQ_MASK(irq)		(irq & 0xffffffffULL)

> >   #define IORT_IRQ_TRIGGER_MASK(irq)	((irq >> 32) & 0xffffffffULL)

> >

> > +/* PMCG node option or quirk flags */

> > +#define IORT_PMCG_EVCNTR_RDONLY		(1 << 0)

> > +

> >   int iort_register_domain_token(int trans_id, phys_addr_t base,

> >   			       struct fwnode_handle *fw_node);

> >   void iort_deregister_domain_token(int trans_id);

> >