struct hmm;
/*
- * hmm_pfn_t - HMM uses its own pfn type to keep several flags per page
+ * hmm_pfn_flag_e - HMM flag enums
*
* Flags:
- * HMM_PFN_VALID: pfn is valid
- * HMM_PFN_READ: CPU page table has read permission set
+ * HMM_PFN_VALID: pfn is valid. It has, at least, read permission.
* HMM_PFN_WRITE: CPU page table has write permission set
+ * HMM_PFN_DEVICE_PRIVATE: private device memory (ZONE_DEVICE)
+ *
+ * The driver provide a flags array, if driver valid bit for an entry is bit
+ * 3 ie (entry & (1 << 3)) is true if entry is valid then driver must provide
+ * an array in hmm_range.flags with hmm_range.flags[HMM_PFN_VALID] == 1 << 3.
+ * Same logic apply to all flags. This is same idea as vm_page_prot in vma
+ * except that this is per device driver rather than per architecture.
+ */
+enum hmm_pfn_flag_e {
+ HMM_PFN_VALID = 0,
+ HMM_PFN_WRITE,
+ HMM_PFN_DEVICE_PRIVATE,
+ HMM_PFN_FLAG_MAX
+};
+
+/*
+ * hmm_pfn_value_e - HMM pfn special value
+ *
+ * Flags:
* HMM_PFN_ERROR: corresponding CPU page table entry points to poisoned memory
- * HMM_PFN_EMPTY: corresponding CPU page table entry is pte_none()
+ * 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 vm_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.
- * HMM_PFN_DEVICE_UNADDRESSABLE: unaddressable device memory (ZONE_DEVICE)
+ *
+ * Driver provide entry value for none entry, error entry and special entry,
+ * driver can alias (ie use same value for error and special for instance). It
+ * should not alias none and error or special.
+ *
+ * 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
+ * hmm_range.values[HMM_PFN_SPECIAL] if CPU page table entry is a special one
*/
-typedef unsigned long hmm_pfn_t;
+enum hmm_pfn_value_e {
+ HMM_PFN_ERROR,
+ HMM_PFN_NONE,
+ HMM_PFN_SPECIAL,
+ HMM_PFN_VALUE_MAX
+};
-#define HMM_PFN_VALID (1 << 0)
-#define HMM_PFN_READ (1 << 1)
-#define HMM_PFN_WRITE (1 << 2)
-#define HMM_PFN_ERROR (1 << 3)
-#define HMM_PFN_EMPTY (1 << 4)
-#define HMM_PFN_SPECIAL (1 << 5)
-#define HMM_PFN_DEVICE_UNADDRESSABLE (1 << 6)
-#define HMM_PFN_SHIFT 7
+/*
+ * struct hmm_range - track invalidation lock on virtual address range
+ *
+ * @vma: the vm area struct for the range
+ * @list: all range lock are on a list
+ * @start: range virtual start address (inclusive)
+ * @end: range virtual end address (exclusive)
+ * @pfns: array of pfns (big enough for the range)
+ * @flags: pfn flags to match device driver page table
+ * @values: pfn value for some special case (none, special, error, ...)
+ * @pfn_shifts: pfn shift value (should be <= PAGE_SHIFT)
+ * @valid: pfns array did not change since it has been fill by an HMM function
+ */
+struct hmm_range {
+ struct vm_area_struct *vma;
+ struct list_head list;
+ unsigned long start;
+ unsigned long end;
+ uint64_t *pfns;
+ const uint64_t *flags;
+ const uint64_t *values;
+ uint8_t pfn_shift;
+ bool valid;
+};
/*
- * hmm_pfn_t_to_page() - return struct page pointed to by a valid hmm_pfn_t
- * @pfn: hmm_pfn_t to convert to struct page
- * Returns: struct page pointer if pfn is a valid hmm_pfn_t, NULL otherwise
+ * hmm_pfn_to_page() - return struct page pointed to by a valid HMM pfn
+ * @range: range use to decode HMM pfn value
+ * @pfn: HMM pfn value to get corresponding struct page from
+ * Returns: struct page pointer if pfn is a valid HMM pfn, NULL otherwise
*
- * If the hmm_pfn_t is valid (ie valid flag set) then return the struct page
- * matching the pfn value stored in the hmm_pfn_t. Otherwise return NULL.
+ * If the HMM pfn is valid (ie valid flag set) then return the struct page
+ * matching the pfn value stored in the HMM pfn. Otherwise return NULL.
*/
-static inline struct page *hmm_pfn_t_to_page(hmm_pfn_t pfn)
+static inline struct page *hmm_pfn_to_page(const struct hmm_range *range,
+ uint64_t pfn)
{
- if (!(pfn & HMM_PFN_VALID))
+ if (pfn == range->values[HMM_PFN_NONE])
+ return NULL;
+ if (pfn == range->values[HMM_PFN_ERROR])
return NULL;
- return pfn_to_page(pfn >> HMM_PFN_SHIFT);
+ if (pfn == range->values[HMM_PFN_SPECIAL])
+ return NULL;
+ if (!(pfn & range->flags[HMM_PFN_VALID]))
+ return NULL;
+ return pfn_to_page(pfn >> range->pfn_shift);
}
/*
- * hmm_pfn_t_to_pfn() - return pfn value store in a hmm_pfn_t
- * @pfn: hmm_pfn_t to extract pfn from
- * Returns: pfn value if hmm_pfn_t is valid, -1UL otherwise
+ * hmm_pfn_to_pfn() - return pfn value store in a HMM pfn
+ * @range: range use to decode HMM pfn value
+ * @pfn: HMM pfn value to extract pfn from
+ * Returns: pfn value if HMM pfn is valid, -1UL otherwise
*/
-static inline unsigned long hmm_pfn_t_to_pfn(hmm_pfn_t pfn)
+static inline unsigned long hmm_pfn_to_pfn(const struct hmm_range *range,
+ uint64_t pfn)
{
- if (!(pfn & HMM_PFN_VALID))
+ if (pfn == range->values[HMM_PFN_NONE])
+ return -1UL;
+ if (pfn == range->values[HMM_PFN_ERROR])
+ return -1UL;
+ if (pfn == range->values[HMM_PFN_SPECIAL])
+ return -1UL;
+ if (!(pfn & range->flags[HMM_PFN_VALID]))
return -1UL;
- return (pfn >> HMM_PFN_SHIFT);
+ return (pfn >> range->pfn_shift);
}
/*
- * hmm_pfn_t_from_page() - create a valid hmm_pfn_t value from struct page
- * @page: struct page pointer for which to create the hmm_pfn_t
- * Returns: valid hmm_pfn_t for the page
+ * hmm_pfn_from_page() - create a valid HMM pfn value from struct page
+ * @range: range use to encode HMM pfn value
+ * @page: struct page pointer for which to create the HMM pfn
+ * Returns: valid HMM pfn for the page
*/
-static inline hmm_pfn_t hmm_pfn_t_from_page(struct page *page)
+static inline uint64_t hmm_pfn_from_page(const struct hmm_range *range,
+ struct page *page)
{
- return (page_to_pfn(page) << HMM_PFN_SHIFT) | HMM_PFN_VALID;
+ return (page_to_pfn(page) << range->pfn_shift) |
+ range->flags[HMM_PFN_VALID];
}
/*
- * hmm_pfn_t_from_pfn() - create a valid hmm_pfn_t value from pfn
- * @pfn: pfn value for which to create the hmm_pfn_t
- * Returns: valid hmm_pfn_t for the pfn
+ * hmm_pfn_from_pfn() - create a valid HMM pfn value from pfn
+ * @range: range use to encode HMM pfn value
+ * @pfn: pfn value for which to create the HMM pfn
+ * Returns: valid HMM pfn for the pfn
*/
-static inline hmm_pfn_t hmm_pfn_t_from_pfn(unsigned long pfn)
+static inline uint64_t hmm_pfn_from_pfn(const struct hmm_range *range,
+ unsigned long pfn)
{
- return (pfn << HMM_PFN_SHIFT) | HMM_PFN_VALID;
+ return (pfn << range->pfn_shift) |
+ range->flags[HMM_PFN_VALID];
}
* @update: callback to update range on a device
*/
struct hmm_mirror_ops {
+ /* release() - release hmm_mirror
+ *
+ * @mirror: pointer to struct hmm_mirror
+ *
+ * This is called when the mm_struct is being released.
+ * The callback should make sure no references to the mirror occur
+ * after the callback returns.
+ */
+ void (*release)(struct hmm_mirror *mirror);
+
/* sync_cpu_device_pagetables() - synchronize page tables
*
* @mirror: pointer to struct hmm_mirror
void hmm_mirror_unregister(struct hmm_mirror *mirror);
-/*
- * struct hmm_range - track invalidation lock on virtual address range
- *
- * @list: all range lock are on a list
- * @start: range virtual start address (inclusive)
- * @end: range virtual end address (exclusive)
- * @pfns: array of pfns (big enough for the range)
- * @valid: pfns array did not change since it has been fill by an HMM function
- */
-struct hmm_range {
- struct list_head list;
- unsigned long start;
- unsigned long end;
- hmm_pfn_t *pfns;
- bool valid;
-};
-
/*
* To snapshot the CPU page table, call hmm_vma_get_pfns(), then take a device
* driver lock that serializes device page table updates, then call
*
* IF YOU DO NOT FOLLOW THE ABOVE RULE THE SNAPSHOT CONTENT MIGHT BE INVALID !
*/
-int hmm_vma_get_pfns(struct vm_area_struct *vma,
- struct hmm_range *range,
- unsigned long start,
- unsigned long end,
- hmm_pfn_t *pfns);
-bool hmm_vma_range_done(struct vm_area_struct *vma, struct hmm_range *range);
+int hmm_vma_get_pfns(struct hmm_range *range);
+bool hmm_vma_range_done(struct hmm_range *range);
/*
* Fault memory on behalf of device driver. Unlike handle_mm_fault(), this will
- * not migrate any device memory back to system memory. The hmm_pfn_t array will
+ * not migrate any device memory back to system memory. The HMM pfn array will
* be updated with the fault result and current snapshot of the CPU page table
* for the range.
*
* function returns -EAGAIN.
*
* Return value does not reflect if the fault was successful for every single
- * address or not. Therefore, the caller must to inspect the hmm_pfn_t array to
+ * address or not. Therefore, the caller must to inspect the HMM pfn array to
* determine fault status for each address.
*
* Trying to fault inside an invalid vma will result in -EINVAL.
*
* See the function description in mm/hmm.c for further documentation.
*/
-int hmm_vma_fault(struct vm_area_struct *vma,
- struct hmm_range *range,
- unsigned long start,
- unsigned long end,
- hmm_pfn_t *pfns,
- bool write,
- bool block);
-#endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */
+int hmm_vma_fault(struct hmm_range *range, bool block);
+/* Below are for HMM internal use only! Not to be used by device driver! */
+void hmm_mm_destroy(struct mm_struct *mm);
+
+static inline void hmm_mm_init(struct mm_struct *mm)
+{
+ mm->hmm = NULL;
+}
+#else /* IS_ENABLED(CONFIG_HMM_MIRROR) */
+static inline void hmm_mm_destroy(struct mm_struct *mm) {}
+static inline void hmm_mm_init(struct mm_struct *mm) {}
+#endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */
#if IS_ENABLED(CONFIG_DEVICE_PRIVATE) || IS_ENABLED(CONFIG_DEVICE_PUBLIC)
struct hmm_devmem;
struct hmm_device *hmm_device_new(void *drvdata);
void hmm_device_put(struct hmm_device *hmm_device);
#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */
-#endif /* IS_ENABLED(CONFIG_HMM) */
-
-/* Below are for HMM internal use only! Not to be used by device driver! */
-#if IS_ENABLED(CONFIG_HMM_MIRROR)
-void hmm_mm_destroy(struct mm_struct *mm);
-
-static inline void hmm_mm_init(struct mm_struct *mm)
-{
- mm->hmm = NULL;
-}
-#else /* IS_ENABLED(CONFIG_HMM_MIRROR) */
-static inline void hmm_mm_destroy(struct mm_struct *mm) {}
-static inline void hmm_mm_init(struct mm_struct *mm) {}
-#endif /* IS_ENABLED(CONFIG_HMM_MIRROR) */
-
-
#else /* IS_ENABLED(CONFIG_HMM) */
static inline void hmm_mm_destroy(struct mm_struct *mm) {}
static inline void hmm_mm_init(struct mm_struct *mm) {}
+#endif /* IS_ENABLED(CONFIG_HMM) */
+
#endif /* LINUX_HMM_H */
git.samba.org / sfrench / cifs-2.6.git / blobdiff