Re: [PATCH v2 07/15] cxl: support type2 memdev creation

[fan <nifan.cxl@gmail.com>]

On Mon, Jul 15, 2024 at 06:28:27PM +0100, alejandro.lucero-palau@amd.com wrote:
> From: Alejandro Lucero <alucerop@amd.com>
> 
> Add memdev creation from sfc driver.
> 
> Current cxl core is relying on a CXL_DEVTYPE_CLASSMEM type device when
> creating a memdev leading to problems when obtaining cxl_memdev_state
> references from a CXL_DEVTYPE_DEVMEM type. This last device type is
> managed by a specific vendor driver and does not need same sysfs files
> since not userspace intervention is expected. This patch checks for the
> right device type in those functions using cxl_memdev_state.
> 
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
> ---
>  drivers/cxl/core/cdat.c            |  3 +++
>  drivers/cxl/core/memdev.c          |  9 +++++++++
>  drivers/cxl/mem.c                  | 17 +++++++++++------
>  drivers/net/ethernet/sfc/efx_cxl.c | 10 ++++++++--
>  include/linux/cxl_accel_mem.h      |  3 +++
>  5 files changed, 34 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/cxl/core/cdat.c b/drivers/cxl/core/cdat.c
> index bb83867d9fec..0d4679c137d4 100644
> --- a/drivers/cxl/core/cdat.c
> +++ b/drivers/cxl/core/cdat.c
> @@ -558,6 +558,9 @@ void cxl_region_perf_data_calculate(struct cxl_region *cxlr,
>  	};
>  	struct cxl_dpa_perf *perf;
>  
> +	if (!mds)
> +		return;
> +
>  	switch (cxlr->mode) {
>  	case CXL_DECODER_RAM:
>  		perf = &mds->ram_perf;
> diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
> index 58a51e7fd37f..b902948b121f 100644
> --- a/drivers/cxl/core/memdev.c
> +++ b/drivers/cxl/core/memdev.c
> @@ -468,6 +468,9 @@ static umode_t cxl_ram_visible(struct kobject *kobj, struct attribute *a, int n)
>  	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
>  	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds);
>  
> +	if (!mds)
> +		return 0;
> +
>  	if (a == &dev_attr_ram_qos_class.attr)
>  		if (mds->ram_perf.qos_class == CXL_QOS_CLASS_INVALID)
>  			return 0;
> @@ -487,6 +490,9 @@ static umode_t cxl_pmem_visible(struct kobject *kobj, struct attribute *a, int n
>  	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
>  	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds);
>  
> +	if (!mds)
> +		return 0;
> +
>  	if (a == &dev_attr_pmem_qos_class.attr)
>  		if (mds->pmem_perf.qos_class == CXL_QOS_CLASS_INVALID)
>  			return 0;
> @@ -507,6 +513,9 @@ static umode_t cxl_memdev_security_visible(struct kobject *kobj,
>  	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
>  	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds);
>  
> +	if (!mds)
> +		return 0;
> +
>  	if (a == &dev_attr_security_sanitize.attr &&
>  	    !test_bit(CXL_SEC_ENABLED_SANITIZE, mds->security.enabled_cmds))
>  		return 0;
> diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
> index 2f1b49bfe162..f76af75a87b7 100644
> --- a/drivers/cxl/mem.c
> +++ b/drivers/cxl/mem.c
> @@ -131,12 +131,14 @@ static int cxl_mem_probe(struct device *dev)
>  	dentry = cxl_debugfs_create_dir(dev_name(dev));
>  	debugfs_create_devm_seqfile(dev, "dpamem", dentry, cxl_mem_dpa_show);
>  
> -	if (test_bit(CXL_POISON_ENABLED_INJECT, mds->poison.enabled_cmds))
> -		debugfs_create_file("inject_poison", 0200, dentry, cxlmd,
> -				    &cxl_poison_inject_fops);
> -	if (test_bit(CXL_POISON_ENABLED_CLEAR, mds->poison.enabled_cmds))
> -		debugfs_create_file("clear_poison", 0200, dentry, cxlmd,
> -				    &cxl_poison_clear_fops);
> +	if (mds) {
> +		if (test_bit(CXL_POISON_ENABLED_INJECT, mds->poison.enabled_cmds))
> +			debugfs_create_file("inject_poison", 0200, dentry, cxlmd,
> +					    &cxl_poison_inject_fops);
> +		if (test_bit(CXL_POISON_ENABLED_CLEAR, mds->poison.enabled_cmds))
> +			debugfs_create_file("clear_poison", 0200, dentry, cxlmd,
> +					    &cxl_poison_clear_fops);
> +	}
>  
>  	rc = devm_add_action_or_reset(dev, remove_debugfs, dentry);
>  	if (rc)
> @@ -222,6 +224,9 @@ static umode_t cxl_mem_visible(struct kobject *kobj, struct attribute *a, int n)
>  	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
>  	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds);
>  
> +	if (!mds)
> +		return 0;
> +
>  	if (a == &dev_attr_trigger_poison_list.attr)
>  		if (!test_bit(CXL_POISON_ENABLED_LIST,
>  			      mds->poison.enabled_cmds))
> diff --git a/drivers/net/ethernet/sfc/efx_cxl.c b/drivers/net/ethernet/sfc/efx_cxl.c
> index a84fe7992c53..0abe66490ef5 100644
> --- a/drivers/net/ethernet/sfc/efx_cxl.c
> +++ b/drivers/net/ethernet/sfc/efx_cxl.c
> @@ -57,10 +57,16 @@ void efx_cxl_init(struct efx_nic *efx)
>  	if (cxl_accel_request_resource(cxl->cxlds, true))
>  		pci_info(pci_dev, "CXL accel resource request failed");
>  
> -	if (!cxl_await_media_ready(cxl->cxlds))
> +	if (!cxl_await_media_ready(cxl->cxlds)) {
>  		cxl_accel_set_media_ready(cxl->cxlds);
> -	else
> +	} else {
>  		pci_info(pci_dev, "CXL accel media not active");
pci_warning() ??
> +		return;
> +	}
> +
> +	cxl->cxlmd = devm_cxl_add_memdev(&pci_dev->dev, cxl->cxlds);
> +	if (IS_ERR(cxl->cxlmd))
> +		pci_info(pci_dev, "CXL accel memdev creation failed");
pci_err()

Fan
>  }
>  
>  
> diff --git a/include/linux/cxl_accel_mem.h b/include/linux/cxl_accel_mem.h
> index b883c438a132..442ed9862292 100644
> --- a/include/linux/cxl_accel_mem.h
> +++ b/include/linux/cxl_accel_mem.h
> @@ -26,4 +26,7 @@ int cxl_pci_accel_setup_regs(struct pci_dev *pdev, struct cxl_dev_state *cxlds);
>  int cxl_accel_request_resource(struct cxl_dev_state *cxlds, bool is_ram);
>  void cxl_accel_set_media_ready(struct cxl_dev_state *cxlds);
>  int cxl_await_media_ready(struct cxl_dev_state *cxlds);
> +
> +struct cxl_memdev *devm_cxl_add_memdev(struct device *host,
> +				       struct cxl_dev_state *cxlds);
>  #endif
> -- 
> 2.17.1
>