xen/pdx: Reorder pdx.[ch]

The next patch compiles out compression-related chunks, and it's helpful to
have them grouped together beforehand.

No functional change.

Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

xen/common/pdx.c

@@ -20,6 +20,35 @@
 #include <xen/bitops.h>
 #include <xen/nospec.h>
 
+/**
+ * Maximum (non-inclusive) usable pdx. Must be
+ * modifiable after init due to memory hotplug
+ */
+unsigned long __read_mostly max_pdx;
+
+unsigned long __read_mostly pdx_group_valid[BITS_TO_LONGS(
+    (FRAMETABLE_NR + PDX_GROUP_COUNT - 1) / PDX_GROUP_COUNT)] = { [0] = 1 };
+
+bool __mfn_valid(unsigned long mfn)
+{
+    if ( unlikely(evaluate_nospec(mfn >= max_page)) )
+        return false;
+    return likely(!(mfn & pfn_hole_mask)) &&
+           likely(test_bit(pfn_to_pdx(mfn) / PDX_GROUP_COUNT,
+                           pdx_group_valid));
+}
+
+void set_pdx_range(unsigned long smfn, unsigned long emfn)
+{
+    unsigned long idx, eidx;
+
+    idx = pfn_to_pdx(smfn) / PDX_GROUP_COUNT;
+    eidx = (pfn_to_pdx(emfn - 1) + PDX_GROUP_COUNT) / PDX_GROUP_COUNT;
+
+    for ( ; idx < eidx; ++idx )
+        __set_bit(idx, pdx_group_valid);
+}
+
 /*
  * Diagram to make sense of the following variables. The masks and shifts
  * are done on mfn values in order to convert to/from pdx:
@@ -47,12 +76,6 @@
  * ones.
  */
 
-/**
- * Maximum (non-inclusive) usable pdx. Must be
- * modifiable after init due to memory hotplug
- */
-unsigned long __read_mostly max_pdx;
-
 /** Mask for the lower non-compressible bits of an mfn */
 unsigned long __ro_after_init pfn_pdx_bottom_mask = ~0UL;
 
@@ -75,18 +98,6 @@ unsigned long __ro_after_init pfn_hole_mask = 0;
 /** Number of bits of the "compressible" bit slice of an mfn */
 unsigned int __ro_after_init pfn_pdx_hole_shift = 0;
 
-unsigned long __read_mostly pdx_group_valid[BITS_TO_LONGS(
-    (FRAMETABLE_NR + PDX_GROUP_COUNT - 1) / PDX_GROUP_COUNT)] = { [0] = 1 };
-
-bool __mfn_valid(unsigned long mfn)
-{
-    if ( unlikely(evaluate_nospec(mfn >= max_page)) )
-        return false;
-    return likely(!(mfn & pfn_hole_mask)) &&
-           likely(test_bit(pfn_to_pdx(mfn) / PDX_GROUP_COUNT,
-                           pdx_group_valid));
-}
-
 /* Sets all bits from the most-significant 1-bit down to the LSB */
 static uint64_t fill_mask(uint64_t mask)
 {
@@ -124,17 +135,6 @@ uint64_t pdx_region_mask(uint64_t base, uint64_t len)
     return fill_mask(base ^ (base + len - 1));
 }
 
-void set_pdx_range(unsigned long smfn, unsigned long emfn)
-{
-    unsigned long idx, eidx;
-
-    idx = pfn_to_pdx(smfn) / PDX_GROUP_COUNT;
-    eidx = (pfn_to_pdx(emfn - 1) + PDX_GROUP_COUNT) / PDX_GROUP_COUNT;
-
-    for ( ; idx < eidx; ++idx )
-        __set_bit(idx, pdx_group_valid);
-}
-
 void __init pfn_pdx_hole_setup(unsigned long mask)
 {
     unsigned int i, j, bottom_shift = 0, hole_shift = 0;

xen/include/xen/pdx.h

@@ -70,15 +70,41 @@
 #ifdef CONFIG_HAS_PDX
 
 extern unsigned long max_pdx;
-extern unsigned long pfn_pdx_bottom_mask, ma_va_bottom_mask;
-extern unsigned int pfn_pdx_hole_shift;
-extern unsigned long pfn_hole_mask;
-extern unsigned long pfn_top_mask, ma_top_mask;
 
 #define PDX_GROUP_COUNT ((1 << PDX_GROUP_SHIFT) / \
                          (sizeof(*frame_table) & -sizeof(*frame_table)))
 extern unsigned long pdx_group_valid[];
 
+/**
+ * Mark [smfn, emfn) as allocatable in the frame table
+ *
+ * @param smfn Start mfn
+ * @param emfn End mfn
+ */
+void set_pdx_range(unsigned long smfn, unsigned long emfn);
+
+/**
+ * Invoked to determine if an mfn has an associated valid frame table entry
+ *
+ * In order for it to be legal it must pass bounds, grouping and
+ * compression sanity checks.
+ *
+ * @param mfn To-be-checked mfn
+ * @return True iff all checks pass
+ */
+bool __mfn_valid(unsigned long mfn);
+
+#define page_to_pdx(pg)  ((pg) - frame_table)
+#define pdx_to_page(pdx) gcc11_wrap(frame_table + (pdx))
+
+#define mfn_to_pdx(mfn) pfn_to_pdx(mfn_x(mfn))
+#define pdx_to_mfn(pdx) _mfn(pdx_to_pfn(pdx))
+
+extern unsigned long pfn_pdx_bottom_mask, ma_va_bottom_mask;
+extern unsigned int pfn_pdx_hole_shift;
+extern unsigned long pfn_hole_mask;
+extern unsigned long pfn_top_mask, ma_top_mask;
+
 /**
  * Validate a region's compatibility with the current compression runtime
  *
@@ -120,28 +146,6 @@ uint64_t pdx_region_mask(uint64_t base, uint64_t len);
  */
 uint64_t pdx_init_mask(uint64_t base_addr);
 
-/**
- * Mark [smfn, emfn) as accesible in the frame table
- *
- * @param smfn Start mfn
- * @param emfn End mfn
- */
-void set_pdx_range(unsigned long smfn, unsigned long emfn);
-
-#define page_to_pdx(pg)  ((pg) - frame_table)
-#define pdx_to_page(pdx) gcc11_wrap(frame_table + (pdx))
-
-/**
- * Invoked to determine if an mfn has an associated valid frame table entry
- *
- * In order for it to be legal it must pass bounds, grouping and
- * compression sanity checks.
- *
- * @param mfn To-be-checked mfn
- * @return True iff all checks pass
- */
-bool __mfn_valid(unsigned long mfn);
-
 /**
  * Map pfn to its corresponding pdx
  *
@@ -166,9 +170,6 @@ static inline unsigned long pdx_to_pfn(unsigned long pdx)
            ((pdx << pfn_pdx_hole_shift) & pfn_top_mask);
 }
 
-#define mfn_to_pdx(mfn) pfn_to_pdx(mfn_x(mfn))
-#define pdx_to_mfn(pdx) _mfn(pdx_to_pfn(pdx))
-
 /**
  * Computes the offset into the direct map of an maddr
  *