Merge tag 'dlm-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm

[linux-2.6-microblaze.git] / include / linux / hmm.h

diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index f4a09ed..866a0fa 100644 (file)
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -37,16 +37,17 @@
  *                     will fail. Must be combined with HMM_PFN_REQ_FAULT.
  */
 enum hmm_pfn_flags {
-       /* Output flags */
+       /* Output fields and flags */
        HMM_PFN_VALID = 1UL << (BITS_PER_LONG - 1),
        HMM_PFN_WRITE = 1UL << (BITS_PER_LONG - 2),
        HMM_PFN_ERROR = 1UL << (BITS_PER_LONG - 3),
+       HMM_PFN_ORDER_SHIFT = (BITS_PER_LONG - 8),
 
        /* Input flags */
        HMM_PFN_REQ_FAULT = HMM_PFN_VALID,
        HMM_PFN_REQ_WRITE = HMM_PFN_WRITE,
 
-       HMM_PFN_FLAGS = HMM_PFN_VALID | HMM_PFN_WRITE | HMM_PFN_ERROR,
+       HMM_PFN_FLAGS = 0xFFUL << HMM_PFN_ORDER_SHIFT,
 };
 
 /*
@@ -61,6 +62,25 @@ static inline struct page *hmm_pfn_to_page(unsigned long hmm_pfn)
        return pfn_to_page(hmm_pfn & ~HMM_PFN_FLAGS);
 }
 
+/*
+ * hmm_pfn_to_map_order() - return the CPU mapping size order
+ *
+ * This is optionally useful to optimize processing of the pfn result
+ * array. It indicates that the page starts at the order aligned VA and is
+ * 1<<order bytes long.  Every pfn within an high order page will have the
+ * same pfn flags, both access protections and the map_order.  The caller must
+ * be careful with edge cases as the start and end VA of the given page may
+ * extend past the range used with hmm_range_fault().
+ *
+ * This must be called under the caller 'user_lock' after a successful
+ * mmu_interval_read_begin(). The caller must have tested for HMM_PFN_VALID
+ * already.
+ */
+static inline unsigned int hmm_pfn_to_map_order(unsigned long hmm_pfn)
+{
+       return (hmm_pfn >> HMM_PFN_ORDER_SHIFT) & 0x1F;
+}
+
 /*
  * struct hmm_range - track invalidation lock on virtual address range
  *