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| author | Alex Sierra <alex.sierra@amd.com> | 2022-07-15 10:05:17 -0500 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-07-17 17:14:29 -0700 |
| commit | 4c2e0f764eb4444272cfd2fa4afeb84c453a1a34 (patch) | |
| tree | b3c5ec1b5a3739048420261920e0b09b2cb113a6 /lib/test_hmm_uapi.h | |
| parent | 25b80162d550408058b2d8fff2e63807bceda64c (diff) | |
| download | lwn-4c2e0f764eb4444272cfd2fa4afeb84c453a1a34.tar.gz lwn-4c2e0f764eb4444272cfd2fa4afeb84c453a1a34.zip | |
lib: add support for device coherent type in test_hmm
Device Coherent type uses device memory that is coherently accesible by
the CPU. This could be shown as SP (special purpose) memory range at the
BIOS-e820 memory enumeration. If no SP memory is supported in system,
this could be faked by setting CONFIG_EFI_FAKE_MEMMAP.
Currently, test_hmm only supports two different SP ranges of at least
256MB size. This could be specified in the kernel parameter variable
efi_fake_mem. Ex. Two SP ranges of 1GB starting at 0x100000000 &
0x140000000 physical address. Ex.
efi_fake_mem=1G@0x100000000:0x40000,1G@0x140000000:0x40000
Private and coherent device mirror instances can be created in the same
probed. This is done by passing the module parameters spm_addr_dev0 &
spm_addr_dev1. In this case, it will create four instances of
device_mirror. The first two correspond to private device type, the last
two to coherent type. Then, they can be easily accessed from user space
through /dev/hmm_mirror<num_device>. Usually num_device 0 and 1 are for
private, and 2 and 3 for coherent types. If no module parameters are
passed, two instances of private type device_mirror will be created only.
Link: https://lkml.kernel.org/r/20220715150521.18165-11-alex.sierra@amd.com
Signed-off-by: Alex Sierra <alex.sierra@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Alistair Poppple <apopple@nvidia.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib/test_hmm_uapi.h')
| -rw-r--r-- | lib/test_hmm_uapi.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/test_hmm_uapi.h b/lib/test_hmm_uapi.h index f700da7807c1..e31d58c9034a 100644 --- a/lib/test_hmm_uapi.h +++ b/lib/test_hmm_uapi.h @@ -50,6 +50,8 @@ struct hmm_dmirror_cmd { * device the ioctl() is made * HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE: Migrated device private page on some * other device + * HMM_DMIRROR_PROT_DEV_COHERENT: Migrate device coherent page on the device + * the ioctl() is made */ enum { HMM_DMIRROR_PROT_ERROR = 0xFF, @@ -61,6 +63,8 @@ enum { HMM_DMIRROR_PROT_ZERO = 0x10, HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL = 0x20, HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE = 0x30, + HMM_DMIRROR_PROT_DEV_COHERENT_LOCAL = 0x40, + HMM_DMIRROR_PROT_DEV_COHERENT_REMOTE = 0x50, }; enum { |