NVDIMM Device and Persistent Memory development
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From: Dave Jiang <dave.jiang@intel.com>
To: Anisa Su <anisa.su887@gmail.com>,
	linux-cxl@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: nvdimm@lists.linux.dev, Dan Williams <djbw@kernel.org>,
	Jonathan Cameron <jic23@kernel.org>,
	Davidlohr Bueso <dave@stgolabs.net>,
	Ira Weiny <iweiny@kernel.org>,
	Alison Schofield <alison.schofield@intel.com>,
	John Groves <John@Groves.net>, Gregory Price <gourry@gourry.net>,
	Ira Weiny <ira.weiny@intel.com>
Subject: Re: [PATCH v6 2/7] libcxl: Add Dynamic RAM A partition mode support
Date: Mon, 8 Jun 2026 16:19:47 -0700	[thread overview]
Message-ID: <06747633-ed22-48a2-b8d0-c9b544a682f8@intel.com> (raw)
In-Reply-To: <20260523095043.471098-3-anisa.su@samsung.com>



On 5/23/26 2:50 AM, Anisa Su wrote:
> From: Ira Weiny <ira.weiny@intel.com>
> 
> Dynamic capacity partitions are exposed as a singular dynamic ram
> partition.
> 
> Add CXL library support to read this partition information.
> 
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Missing Anisa sign off.

Can probably squash this and the next commit so the usage is shown for the reviewer.

DJ

> ---
>  Documentation/cxl/lib/libcxl.txt |  6 +++--
>  cxl/lib/libcxl.c                 | 43 ++++++++++++++++++++++++++++++++
>  cxl/lib/libcxl.sym               |  4 +++
>  cxl/lib/private.h                |  3 +++
>  cxl/libcxl.h                     | 10 +++++++-
>  5 files changed, 63 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/cxl/lib/libcxl.txt b/Documentation/cxl/lib/libcxl.txt
> index 5c3ebd4..9921ac1 100644
> --- a/Documentation/cxl/lib/libcxl.txt
> +++ b/Documentation/cxl/lib/libcxl.txt
> @@ -74,6 +74,7 @@ int cxl_memdev_get_major(struct cxl_memdev *memdev);
>  int cxl_memdev_get_minor(struct cxl_memdev *memdev);
>  unsigned long long cxl_memdev_get_pmem_size(struct cxl_memdev *memdev);
>  unsigned long long cxl_memdev_get_ram_size(struct cxl_memdev *memdev);
> +unsigned long long cxl_memdev_get_dynamic_ram_a_size(struct cxl_memdev *memdev);
>  const char *cxl_memdev_get_firmware_version(struct cxl_memdev *memdev);
>  size_t cxl_memdev_get_label_size(struct cxl_memdev *memdev);
>  int cxl_memdev_nvdimm_bridge_active(struct cxl_memdev *memdev);
> @@ -93,8 +94,8 @@ The character device node for command submission can be found by default
>  at /dev/cxl/mem%d, or created with a major / minor returned from
>  cxl_memdev_get_{major,minor}().
>  
> -The 'pmem_size' and 'ram_size' attributes return the current
> -provisioning of DPA (Device Physical Address / local capacity) in the
> +The 'pmem_size', 'ram_size', and 'dynamic_ram_a_size' attributes return the
> +current provisioning of DPA (Device Physical Address / local capacity) in the
>  device.
>  
>  cxl_memdev_get_numa_node() returns the affinitized CPU node number if
> @@ -453,6 +454,7 @@ enum cxl_decoder_mode {
>  	CXL_DECODER_MODE_MIXED,
>  	CXL_DECODER_MODE_PMEM,
>  	CXL_DECODER_MODE_RAM,
> +	CXL_DECODER_MODE_DYNAMIC_RAM_A,
>  };
>  enum cxl_decoder_mode cxl_decoder_get_mode(struct cxl_decoder *decoder);
>  int cxl_decoder_set_mode(struct cxl_decoder *decoder, enum cxl_decoder_mode mode);
> diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
> index e55a7b4..be0bc03 100644
> --- a/cxl/lib/libcxl.c
> +++ b/cxl/lib/libcxl.c
> @@ -501,6 +501,9 @@ CXL_EXPORT bool cxl_region_qos_class_mismatch(struct cxl_region *region)
>  		} else if (region->mode == CXL_DECODER_MODE_PMEM) {
>  			if (root_decoder->qos_class != memdev->pmem_qos_class)
>  				return true;
> +		} else if (region->mode == CXL_DECODER_MODE_DYNAMIC_RAM_A) {
> +			if (root_decoder->qos_class != memdev->dynamic_ram_a_qos_class)
> +				return true;
>  		}
>  	}
>  
> @@ -1426,6 +1429,10 @@ static void *add_cxl_memdev(void *parent, int id, const char *cxlmem_base)
>  	if (sysfs_read_attr(ctx, path, buf) == 0)
>  		memdev->ram_size = strtoull(buf, NULL, 0);
>  
> +	sprintf(path, "%s/dynamic_ram_a/size", cxlmem_base);
> +	if (sysfs_read_attr(ctx, path, buf) == 0)
> +		memdev->dynamic_ram_a_size = strtoull(buf, NULL, 0);
> +
>  	sprintf(path, "%s/pmem/qos_class", cxlmem_base);
>  	if (sysfs_read_attr(ctx, path, buf) < 0)
>  		memdev->pmem_qos_class = CXL_QOS_CLASS_NONE;
> @@ -1438,6 +1445,12 @@ static void *add_cxl_memdev(void *parent, int id, const char *cxlmem_base)
>  	else
>  		memdev->ram_qos_class = atoi(buf);
>  
> +	sprintf(path, "%s/dynamic_ram_a/qos_class", cxlmem_base);
> +	if (sysfs_read_attr(ctx, path, buf) < 0)
> +		memdev->dynamic_ram_a_qos_class = CXL_QOS_CLASS_NONE;
> +	else
> +		memdev->dynamic_ram_a_qos_class = atoi(buf);
> +
>  	sprintf(path, "%s/payload_max", cxlmem_base);
>  	if (sysfs_read_attr(ctx, path, buf) == 0) {
>  		memdev->payload_max = strtoull(buf, NULL, 0);
> @@ -1685,6 +1698,11 @@ CXL_EXPORT unsigned long long cxl_memdev_get_ram_size(struct cxl_memdev *memdev)
>  	return memdev->ram_size;
>  }
>  
> +CXL_EXPORT unsigned long long cxl_memdev_get_dynamic_ram_a_size(struct cxl_memdev *memdev)
> +{
> +	return memdev->dynamic_ram_a_size;
> +}
> +
>  CXL_EXPORT int cxl_memdev_get_pmem_qos_class(struct cxl_memdev *memdev)
>  {
>  	return memdev->pmem_qos_class;
> @@ -1695,6 +1713,11 @@ CXL_EXPORT int cxl_memdev_get_ram_qos_class(struct cxl_memdev *memdev)
>  	return memdev->ram_qos_class;
>  }
>  
> +CXL_EXPORT int cxl_memdev_get_dynamic_ram_a_qos_class(struct cxl_memdev *memdev)
> +{
> +	return memdev->dynamic_ram_a_qos_class;
> +}
> +
>  CXL_EXPORT const char *cxl_memdev_get_firmware_verison(struct cxl_memdev *memdev)
>  {
>  	return memdev->firmware_version;
> @@ -2465,6 +2488,8 @@ static void *add_cxl_decoder(void *parent, int id, const char *cxldecoder_base)
>  			decoder->mode = CXL_DECODER_MODE_MIXED;
>  		else if (strcmp(buf, "none") == 0)
>  			decoder->mode = CXL_DECODER_MODE_NONE;
> +		else if (strcmp(buf, "dynamic_ram_a") == 0)
> +			decoder->mode = CXL_DECODER_MODE_DYNAMIC_RAM_A;
>  		else
>  			decoder->mode = CXL_DECODER_MODE_MIXED;
>  	} else
> @@ -2504,6 +2529,7 @@ static void *add_cxl_decoder(void *parent, int id, const char *cxldecoder_base)
>  	case CXL_PORT_SWITCH:
>  		decoder->pmem_capable = true;
>  		decoder->volatile_capable = true;
> +		decoder->dynamic_ram_a_capable = true;
>  		decoder->mem_capable = true;
>  		decoder->accelmem_capable = true;
>  		sprintf(path, "%s/locked", cxldecoder_base);
> @@ -2528,6 +2554,7 @@ static void *add_cxl_decoder(void *parent, int id, const char *cxldecoder_base)
>  			{ "cap_type3", &decoder->mem_capable },
>  			{ "cap_ram", &decoder->volatile_capable },
>  			{ "cap_pmem", &decoder->pmem_capable },
> +			{ "cap_dynamic_ram_a", &decoder->dynamic_ram_a_capable },
>  			{ "locked", &decoder->locked },
>  		};
>  
> @@ -2778,6 +2805,9 @@ CXL_EXPORT int cxl_decoder_set_mode(struct cxl_decoder *decoder,
>  	case CXL_DECODER_MODE_RAM:
>  		sprintf(buf, "ram");
>  		break;
> +	case CXL_DECODER_MODE_DYNAMIC_RAM_A:
> +		sprintf(buf, "dynamic_ram_a");
> +		break;
>  	default:
>  		err(ctx, "%s: unsupported mode: %d\n",
>  		    cxl_decoder_get_devname(decoder), mode);
> @@ -2829,6 +2859,11 @@ CXL_EXPORT bool cxl_decoder_is_volatile_capable(struct cxl_decoder *decoder)
>  	return decoder->volatile_capable;
>  }
>  
> +CXL_EXPORT bool cxl_decoder_is_dynamic_ram_a_capable(struct cxl_decoder *decoder)
> +{
> +	return decoder->dynamic_ram_a_capable;
> +}
> +
>  CXL_EXPORT bool cxl_decoder_is_mem_capable(struct cxl_decoder *decoder)
>  {
>  	return decoder->mem_capable;
> @@ -2903,6 +2938,8 @@ static struct cxl_region *cxl_decoder_create_region(struct cxl_decoder *decoder,
>  		sprintf(path, "%s/create_pmem_region", decoder->dev_path);
>  	else if (mode == CXL_DECODER_MODE_RAM)
>  		sprintf(path, "%s/create_ram_region", decoder->dev_path);
> +	else if (mode == CXL_DECODER_MODE_DYNAMIC_RAM_A)
> +		sprintf(path, "%s/create_dynamic_ram_a_region", decoder->dev_path);
>  
>  	rc = sysfs_read_attr(ctx, path, buf);
>  	if (rc < 0) {
> @@ -2954,6 +2991,12 @@ cxl_decoder_create_ram_region(struct cxl_decoder *decoder)
>  	return cxl_decoder_create_region(decoder, CXL_DECODER_MODE_RAM);
>  }
>  
> +CXL_EXPORT struct cxl_region *
> +cxl_decoder_create_dynamic_ram_a_region(struct cxl_decoder *decoder)
> +{
> +	return cxl_decoder_create_region(decoder, CXL_DECODER_MODE_DYNAMIC_RAM_A);
> +}
> +
>  CXL_EXPORT int cxl_decoder_get_nr_targets(struct cxl_decoder *decoder)
>  {
>  	return decoder->nr_targets;
> diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym
> index ed4429f..258bdd3 100644
> --- a/cxl/lib/libcxl.sym
> +++ b/cxl/lib/libcxl.sym
> @@ -294,6 +294,10 @@ global:
>  	cxl_memdev_get_fwctl;
>  	cxl_fwctl_get_major;
>  	cxl_fwctl_get_minor;
> +	cxl_memdev_get_dynamic_ram_a_size;
> +	cxl_memdev_get_dynamic_ram_a_qos_class;
> +	cxl_decoder_is_dynamic_ram_a_capable;
> +	cxl_decoder_create_dynamic_ram_a_region;
>  } LIBECXL_8;
>  
>  LIBCXL_10 {
> diff --git a/cxl/lib/private.h b/cxl/lib/private.h
> index d2d71fc..37b7b06 100644
> --- a/cxl/lib/private.h
> +++ b/cxl/lib/private.h
> @@ -52,8 +52,10 @@ struct cxl_memdev {
>  	struct list_node list;
>  	unsigned long long pmem_size;
>  	unsigned long long ram_size;
> +	unsigned long long dynamic_ram_a_size;
>  	int ram_qos_class;
>  	int pmem_qos_class;
> +	int dynamic_ram_a_qos_class;
>  	int payload_max;
>  	size_t lsa_size;
>  	struct kmod_module *module;
> @@ -159,6 +161,7 @@ struct cxl_decoder {
>  	unsigned int interleave_granularity;
>  	bool pmem_capable;
>  	bool volatile_capable;
> +	bool dynamic_ram_a_capable;
>  	bool mem_capable;
>  	bool accelmem_capable;
>  	bool locked;
> diff --git a/cxl/libcxl.h b/cxl/libcxl.h
> index e91af90..fd41122 100644
> --- a/cxl/libcxl.h
> +++ b/cxl/libcxl.h
> @@ -75,8 +75,10 @@ struct cxl_fwctl *cxl_memdev_get_fwctl(struct cxl_memdev *memdev);
>  struct cxl_ctx *cxl_memdev_get_ctx(struct cxl_memdev *memdev);
>  unsigned long long cxl_memdev_get_pmem_size(struct cxl_memdev *memdev);
>  unsigned long long cxl_memdev_get_ram_size(struct cxl_memdev *memdev);
> +unsigned long long cxl_memdev_get_dynamic_ram_a_size(struct cxl_memdev *memdev);
>  int cxl_memdev_get_pmem_qos_class(struct cxl_memdev *memdev);
>  int cxl_memdev_get_ram_qos_class(struct cxl_memdev *memdev);
> +int cxl_memdev_get_dynamic_ram_a_qos_class(struct cxl_memdev *memdev);
>  const char *cxl_memdev_get_firmware_verison(struct cxl_memdev *memdev);
>  bool cxl_memdev_fw_update_in_progress(struct cxl_memdev *memdev);
>  size_t cxl_memdev_fw_update_get_remaining(struct cxl_memdev *memdev);
> @@ -210,6 +212,7 @@ enum cxl_decoder_mode {
>  	CXL_DECODER_MODE_MIXED,
>  	CXL_DECODER_MODE_PMEM,
>  	CXL_DECODER_MODE_RAM,
> +	CXL_DECODER_MODE_DYNAMIC_RAM_A,
>  };
>  
>  static inline const char *cxl_decoder_mode_name(enum cxl_decoder_mode mode)
> @@ -219,9 +222,10 @@ static inline const char *cxl_decoder_mode_name(enum cxl_decoder_mode mode)
>  		[CXL_DECODER_MODE_MIXED] = "mixed",
>  		[CXL_DECODER_MODE_PMEM] = "pmem",
>  		[CXL_DECODER_MODE_RAM] = "ram",
> +		[CXL_DECODER_MODE_DYNAMIC_RAM_A] = "dynamic_ram_a",
>  	};
>  
> -	if (mode < CXL_DECODER_MODE_NONE || mode > CXL_DECODER_MODE_RAM)
> +	if (mode < CXL_DECODER_MODE_NONE || mode > CXL_DECODER_MODE_DYNAMIC_RAM_A)
>  		mode = CXL_DECODER_MODE_NONE;
>  	return names[mode];
>  }
> @@ -235,6 +239,8 @@ cxl_decoder_mode_from_ident(const char *ident)
>  		return CXL_DECODER_MODE_RAM;
>  	else if (strcmp(ident, "pmem") == 0)
>  		return CXL_DECODER_MODE_PMEM;
> +	else if (strcmp(ident, "dynamic_ram_a") == 0)
> +		return CXL_DECODER_MODE_DYNAMIC_RAM_A;
>  	return CXL_DECODER_MODE_NONE;
>  }
>  
> @@ -264,6 +270,7 @@ cxl_decoder_get_target_type(struct cxl_decoder *decoder);
>  bool cxl_decoder_is_pmem_capable(struct cxl_decoder *decoder);
>  bool cxl_decoder_is_volatile_capable(struct cxl_decoder *decoder);
>  bool cxl_decoder_is_mem_capable(struct cxl_decoder *decoder);
> +bool cxl_decoder_is_dynamic_ram_a_capable(struct cxl_decoder *decoder);
>  bool cxl_decoder_is_accelmem_capable(struct cxl_decoder *decoder);
>  bool cxl_decoder_is_locked(struct cxl_decoder *decoder);
>  unsigned int
> @@ -272,6 +279,7 @@ unsigned int cxl_decoder_get_interleave_ways(struct cxl_decoder *decoder);
>  struct cxl_region *cxl_decoder_get_region(struct cxl_decoder *decoder);
>  struct cxl_region *cxl_decoder_create_pmem_region(struct cxl_decoder *decoder);
>  struct cxl_region *cxl_decoder_create_ram_region(struct cxl_decoder *decoder);
> +struct cxl_region *cxl_decoder_create_dynamic_ram_a_region(struct cxl_decoder *decoder);
>  struct cxl_decoder *cxl_decoder_get_by_name(struct cxl_ctx *ctx,
>  					    const char *ident);
>  struct cxl_memdev *cxl_decoder_get_memdev(struct cxl_decoder *decoder);


  reply	other threads:[~2026-06-08 23:19 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-23  9:50 [PATCH v6 0/7] ndctl: Dynamic Capacity additions for cxl-cli Anisa Su
2026-05-23  9:50 ` [PATCH v6 1/7] " Anisa Su
2026-06-08 23:18   ` Dave Jiang
2026-05-23  9:50 ` [PATCH v6 2/7] libcxl: Add Dynamic RAM A partition mode support Anisa Su
2026-06-08 23:19   ` Dave Jiang [this message]
2026-06-10  3:51     ` Richard Cheng
2026-06-10 16:55       ` Dave Jiang
2026-06-25  9:08         ` Anisa Su
2026-06-25  9:07     ` Anisa Su
2026-05-23  9:50 ` [PATCH v6 3/7] cxl/region: Add cxl-cli support for dynamic RAM A Anisa Su
2026-06-08 23:58   ` Dave Jiang
2026-05-23  9:50 ` [PATCH v6 4/7] libcxl: Add extent functionality to DC regions Anisa Su
2026-06-09  0:05   ` Dave Jiang
2026-06-25  9:18     ` Anisa Su
2026-05-23  9:50 ` [PATCH v6 5/7] cxl/region: Add extent output to region query Anisa Su
2026-06-09  0:08   ` Dave Jiang
2026-06-10  3:55     ` Richard Cheng
2026-06-16 10:47       ` Anisa Su
2026-06-16 10:45     ` Anisa Su
2026-05-23  9:50 ` [PATCH v6 6/7] daxctl: Add --uuid option to create-device for sparse regions Anisa Su
2026-06-09  0:12   ` Dave Jiang
2026-06-25  9:30     ` Anisa Su
2026-05-23  9:50 ` [PATCH v6 7/7] cxl/test: Add Dynamic Capacity tests Anisa Su
2026-06-09  0:24   ` Dave Jiang
2026-06-25  9:34     ` Anisa Su
2026-06-05  5:43 ` [PATCH v6 0/7] ndctl: Dynamic Capacity additions for cxl-cli Alison Schofield
2026-06-08  8:11   ` Anisa Su
2026-06-17  7:10   ` Alison Schofield
2026-06-18  5:52     ` Anisa Su
2026-06-19  0:38       ` Alison Schofield
2026-06-24  4:51         ` Anisa Su

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