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.sie...@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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