[PATCH hmm 4/5] mm/hmm: remove HMM_PFN_SPECIAL

Jason Gunthorpe
2020-04-22T00:22:03Z

From: Jason Gunthorpe <jgg@mellanox.com>

This is just an alias for HMM_PFN_ERROR, nothing cares that the error was
because of a special page vs any other error case.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 1 -
drivers/gpu/drm/nouveau/nouveau_svm.c | 1 -
include/linux/hmm.h | 8 --------
mm/hmm.c | 2 +-
4 files changed, 1 insertion(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index bff8e64701a547..449083f9f8a2bf 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -775,7 +775,6 @@ static const uint64_t hmm_range_flags[HMM_PFN_FLAG_MAX] = {
static const uint64_t hmm_range_values[HMM_PFN_VALUE_MAX] = {
0xfffffffffffffffeUL, /* HMM_PFN_ERROR */
0, /* HMM_PFN_NONE */
- 0xfffffffffffffffcUL /* HMM_PFN_SPECIAL */
};

/**
diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c
index c68e9317cf0740..cf0d9bd61bebf9 100644
--- a/drivers/gpu/drm/nouveau/nouveau_svm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_svm.c
@@ -379,7 +379,6 @@ static const u64
nouveau_svm_pfn_values[HMM_PFN_VALUE_MAX] = {
[HMM_PFN_ERROR ] = ~NVIF_VMM_PFNMAP_V0_V,
[HMM_PFN_NONE ] = NVIF_VMM_PFNMAP_V0_NONE,
- [HMM_PFN_SPECIAL] = ~NVIF_VMM_PFNMAP_V0_V,
};

/* Issue fault replay for GPU to retry accesses that faulted previously. */
diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index 0df27dd03d53d7..81c302c884c0e3 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -44,10 +44,6 @@ enum hmm_pfn_flag_e {
* Flags:
* HMM_PFN_ERROR: corresponding CPU page table entry points to poisoned memory
* HMM_PFN_NONE: corresponding CPU page table entry is pte_none()
- * HMM_PFN_SPECIAL: corresponding CPU page table entry is special; i.e., the
- * result of vmf_insert_pfn() or vm_insert_page(). Therefore, it should not
- * be mirrored by a device, because the entry will never have HMM_PFN_VALID
- * set and the pfn value is undefined.
*
* Driver provides values for none entry, error entry, and special entry.
* Driver can alias (i.e., use same value) error and special, but
@@ -56,12 +52,10 @@ enum hmm_pfn_flag_e {
* HMM pfn value returned by hmm_vma_get_pfns() or hmm_vma_fault() will be:
* hmm_range.values[HMM_PFN_ERROR] if CPU page table entry is poisonous,
* hmm_range.values[HMM_PFN_NONE] if there is no CPU page table entry,
- * hmm_range.values[HMM_PFN_SPECIAL] if CPU page table entry is a special one
*/
enum hmm_pfn_value_e {
HMM_PFN_ERROR,
HMM_PFN_NONE,
- HMM_PFN_SPECIAL,
HMM_PFN_VALUE_MAX
};

@@ -110,8 +104,6 @@ static inline struct page *hmm_device_entry_to_page(const struct hmm_range *rang
return NULL;
if (entry == range->values[HMM_PFN_ERROR])
return NULL;
- if (entry == range->values[HMM_PFN_SPECIAL])
- return NULL;
if (!(entry & range->flags[HMM_PFN_VALID]))
return NULL;
return pfn_to_page(entry >> range->pfn_shift);
diff --git a/mm/hmm.c b/mm/hmm.c
index 4c7c396655b528..2693393dc14b30 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -301,7 +301,7 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr,
pte_unmap(ptep);
return -EFAULT;
}
- *pfn = range->values[HMM_PFN_SPECIAL];
+ *pfn = range->values[HMM_PFN_ERROR];
return 0;
}

--
2.26.0