[PATCH v2 09/12] lib: test_hmm add module param for zone device type

Alistair Popple apopple at nvidia.com
Mon Sep 20 08:53:55 UTC 2021


On Tuesday, 14 September 2021 2:16:01 AM AEST Alex Sierra wrote:
> In order to configure device public in test_hmm, two module parameters
> should be passed, which correspond to the SP start address of each
> device (2) spm_addr_dev0 & spm_addr_dev1. If no parameters are passed,
> private device type is configured.

It's a pity that testing this seems to require some amount of special setup to
test. Is there a way this could be made to work on a more standard setup
similar to how DEVICE_PRIVATE is tested?

> Signed-off-by: Alex Sierra <alex.sierra at amd.com>
> ---
> v5:
> Remove devmem->pagemap.type = MEMORY_DEVICE_PRIVATE at
> dmirror_allocate_chunk that was forcing to configure pagemap.type
> to MEMORY_DEVICE_PRIVATE
> 
> v6:
> Check for null pointers for resource and memremap references
> at dmirror_allocate_chunk
> 
> v7:
> Due to patch dropped from these patch series "kernel: resource:
> lookup_resource as exported symbol", lookup_resource was not longer a
> callable function. This was used in public device configuration, to
> get start and end addresses, to create pgmap->range struct. This
> information is now taken directly from the spm_addr_devX parameters and
> the fixed size DEVMEM_CHUNK_SIZE.
> ---
>  lib/test_hmm.c      | 66 +++++++++++++++++++++++++++++++--------------
>  lib/test_hmm_uapi.h |  1 +
>  2 files changed, 47 insertions(+), 20 deletions(-)
> 
> diff --git a/lib/test_hmm.c b/lib/test_hmm.c
> index 3cd91ca31dd7..ef27e355738a 100644
> --- a/lib/test_hmm.c
> +++ b/lib/test_hmm.c
> @@ -33,6 +33,16 @@
>  #define DEVMEM_CHUNK_SIZE		(256 * 1024 * 1024U)
>  #define DEVMEM_CHUNKS_RESERVE		16
>  
> +static unsigned long spm_addr_dev0;
> +module_param(spm_addr_dev0, long, 0644);
> +MODULE_PARM_DESC(spm_addr_dev0,
> +		"Specify start address for SPM (special purpose memory) used for device 0. By setting this Generic device type will be used. Make sure spm_addr_dev1 is set too");
> +
> +static unsigned long spm_addr_dev1;
> +module_param(spm_addr_dev1, long, 0644);
> +MODULE_PARM_DESC(spm_addr_dev1,
> +		"Specify start address for SPM (special purpose memory) used for device 1. By setting this Generic device type will be used. Make sure spm_addr_dev0 is set too");
> +
>  static const struct dev_pagemap_ops dmirror_devmem_ops;
>  static const struct mmu_interval_notifier_ops dmirror_min_ops;
>  static dev_t dmirror_dev;
> @@ -450,11 +460,11 @@ static int dmirror_write(struct dmirror *dmirror, struct hmm_dmirror_cmd *cmd)
>  	return ret;
>  }
>  
> -static bool dmirror_allocate_chunk(struct dmirror_device *mdevice,
> +static int dmirror_allocate_chunk(struct dmirror_device *mdevice,
>  				   struct page **ppage)
>  {
>  	struct dmirror_chunk *devmem;
> -	struct resource *res;
> +	struct resource *res = NULL;
>  	unsigned long pfn;
>  	unsigned long pfn_first;
>  	unsigned long pfn_last;
> @@ -462,17 +472,29 @@ static bool dmirror_allocate_chunk(struct dmirror_device *mdevice,
>  
>  	devmem = kzalloc(sizeof(*devmem), GFP_KERNEL);
>  	if (!devmem)
> -		return false;
> +		return -ENOMEM;
>  
> -	res = request_free_mem_region(&iomem_resource, DEVMEM_CHUNK_SIZE,
> -				      "hmm_dmirror");
> -	if (IS_ERR(res))
> -		goto err_devmem;
> +	if (!spm_addr_dev0 && !spm_addr_dev1) {
> +		res = request_free_mem_region(&iomem_resource, DEVMEM_CHUNK_SIZE,
> +					      "hmm_dmirror");
> +		if (IS_ERR_OR_NULL(res))
> +			goto err_devmem;
> +		devmem->pagemap.range.start = res->start;
> +		devmem->pagemap.range.end = res->end;
> +		devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
> +		mdevice->zone_device_type = HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
> +	} else if (spm_addr_dev0 && spm_addr_dev1) {
> +		devmem->pagemap.range.start = MINOR(mdevice->cdevice.dev) ?
> +							spm_addr_dev0 :
> +							spm_addr_dev1;
> +		devmem->pagemap.range.end = devmem->pagemap.range.start +
> +					    DEVMEM_CHUNK_SIZE - 1;
> +		devmem->pagemap.type = MEMORY_DEVICE_PUBLIC;
> +		mdevice->zone_device_type = HMM_DMIRROR_MEMORY_DEVICE_PUBLIC;
> +	} else {
> +		pr_err("Both spm_addr_dev parameters should be set\n");
> +	}
>  
> -	mdevice->zone_device_type = HMM_DMIRROR_MEMORY_DEVICE_PRIVATE;
> -	devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
> -	devmem->pagemap.range.start = res->start;
> -	devmem->pagemap.range.end = res->end;
>  	devmem->pagemap.nr_range = 1;
>  	devmem->pagemap.ops = &dmirror_devmem_ops;
>  	devmem->pagemap.owner = mdevice;
> @@ -493,10 +515,14 @@ static bool dmirror_allocate_chunk(struct dmirror_device *mdevice,
>  		mdevice->devmem_capacity = new_capacity;
>  		mdevice->devmem_chunks = new_chunks;
>  	}
> -
>  	ptr = memremap_pages(&devmem->pagemap, numa_node_id());
> -	if (IS_ERR(ptr))
> +	if (IS_ERR_OR_NULL(ptr)) {
> +		if (ptr)
> +			ret = PTR_ERR(ptr);
> +		else
> +			ret = -EFAULT;
>  		goto err_release;
> +	}
>  
>  	devmem->mdevice = mdevice;
>  	pfn_first = devmem->pagemap.range.start >> PAGE_SHIFT;
> @@ -529,7 +555,8 @@ static bool dmirror_allocate_chunk(struct dmirror_device *mdevice,
>  
>  err_release:
>  	mutex_unlock(&mdevice->devmem_lock);
> -	release_mem_region(devmem->pagemap.range.start, range_len(&devmem->pagemap.range));
> +	if (res)
> +		release_mem_region(devmem->pagemap.range.start, range_len(&devmem->pagemap.range));
>  err_devmem:
>  	kfree(devmem);
>  
> @@ -1097,10 +1124,8 @@ static int dmirror_device_init(struct dmirror_device *mdevice, int id)
>  	if (ret)
>  		return ret;
>  
> -	/* Build a list of free ZONE_DEVICE private struct pages */
> -	dmirror_allocate_chunk(mdevice, NULL);
> -
> -	return 0;
> +	/* Build a list of free ZONE_DEVICE struct pages */
> +	return dmirror_allocate_chunk(mdevice, NULL);
>  }
>  
>  static void dmirror_device_remove(struct dmirror_device *mdevice)
> @@ -1113,8 +1138,9 @@ static void dmirror_device_remove(struct dmirror_device *mdevice)
>  				mdevice->devmem_chunks[i];
>  
>  			memunmap_pages(&devmem->pagemap);
> -			release_mem_region(devmem->pagemap.range.start,
> -					   range_len(&devmem->pagemap.range));
> +			if (devmem->pagemap.type == MEMORY_DEVICE_PRIVATE)
> +				release_mem_region(devmem->pagemap.range.start,
> +						   range_len(&devmem->pagemap.range));
>  			kfree(devmem);
>  		}
>  		kfree(mdevice->devmem_chunks);
> diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h
> index ee88701793d5..00259d994410 100644
> --- a/lib/test_hmm_uapi.h
> +++ b/lib/test_hmm_uapi.h
> @@ -65,6 +65,7 @@ enum {
>  enum {
>  	/* 0 is reserved to catch uninitialized type fields */
>  	HMM_DMIRROR_MEMORY_DEVICE_PRIVATE = 1,
> +	HMM_DMIRROR_MEMORY_DEVICE_PUBLIC,
>  };
>  
>  #endif /* _LIB_TEST_HMM_UAPI_H */
> 






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