arm/mem_access: Add defines supporting PTs with varying page sizes

AArch64 supports pages with different (4K, 16K, and 64K) sizes.  To
enable guest page table walks for various configurations, this commit
extends the defines and helpers of the current implementation.

Signed-off-by: Sergej Proskurin <proskurin@sec.in.tum.de>
Reviewed-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>

diff --git a/xen/include/asm-arm/lpae.h b/xen/include/asm-arm/lpae.h
index a62b118630f69efebfa324dd92cce36b3440e198..efec4933135e08c7a17ae7c5ea46353828314583 100644 (file)
--- a/xen/include/asm-arm/lpae.h
+++ b/xen/include/asm-arm/lpae.h
@@ -3,6 +3,8 @@
 
 #ifndef __ASSEMBLY__
 
+#include <xen/page-defs.h>
+
 /*
  * WARNING!  Unlike the x86 pagetable code, where l1 is the lowest level and
  * l4 is the root of the trie, the ARM pagetables follow ARM's documentation:
@@ -151,6 +153,65 @@ static inline bool lpae_is_superpage(lpae_t pte, unsigned int level)
     return (level < 3) && lpae_mapping(pte);
 }
 
+/*
+ * AArch64 supports pages with different sizes (4K, 16K, and 64K). To enable
+ * page table walks for various configurations, the following helpers enable
+ * walking the translation table with varying page size granularities.
+ */
+
+#define LPAE_SHIFT_4K           (9)
+#define LPAE_SHIFT_16K          (11)
+#define LPAE_SHIFT_64K          (13)
+
+#define lpae_entries(gran)      (_AC(1,U) << LPAE_SHIFT_##gran)
+#define lpae_entry_mask(gran)   (lpae_entries(gran) - 1)
+
+#define third_shift(gran)       (PAGE_SHIFT_##gran)
+#define third_size(gran)        ((paddr_t)1 << third_shift(gran))
+
+#define second_shift(gran)      (third_shift(gran) + LPAE_SHIFT_##gran)
+#define second_size(gran)       ((paddr_t)1 << second_shift(gran))
+
+#define first_shift(gran)       (second_shift(gran) + LPAE_SHIFT_##gran)
+#define first_size(gran)        ((paddr_t)1 << first_shift(gran))
+
+/* Note that there is no zeroeth lookup level with a 64K granule size. */
+#define zeroeth_shift(gran)     (first_shift(gran) + LPAE_SHIFT_##gran)
+#define zeroeth_size(gran)      ((paddr_t)1 << zeroeth_shift(gran))
+
+#define TABLE_OFFSET(offs, gran)      (offs & lpae_entry_mask(gran))
+#define TABLE_OFFSET_HELPERS(gran)                                          \
+static inline paddr_t third_table_offset_##gran##K(paddr_t va)              \
+{                                                                           \
+    return TABLE_OFFSET((va >> third_shift(gran##K)), gran##K);             \
+}                                                                           \
+                                                                            \
+static inline paddr_t second_table_offset_##gran##K(paddr_t va)             \
+{                                                                           \
+    return TABLE_OFFSET((va >> second_shift(gran##K)), gran##K);            \
+}                                                                           \
+                                                                            \
+static inline paddr_t first_table_offset_##gran##K(paddr_t va)              \
+{                                                                           \
+    return TABLE_OFFSET((va >> first_shift(gran##K)), gran##K);             \
+}                                                                           \
+                                                                            \
+static inline paddr_t zeroeth_table_offset_##gran##K(paddr_t va)            \
+{                                                                           \
+    /* Note that there is no zeroeth lookup level with 64K granule sizes. */\
+    if ( gran == 64 )                                                       \
+        return 0;                                                           \
+    else                                                                    \
+        return TABLE_OFFSET((va >> zeroeth_shift(gran##K)), gran##K);       \
+}                                                                           \
+
+TABLE_OFFSET_HELPERS(4);
+TABLE_OFFSET_HELPERS(16);
+TABLE_OFFSET_HELPERS(64);
+
+#undef TABLE_OFFSET
+#undef TABLE_OFFSET_HELPERS
+
 #endif /* __ASSEMBLY__ */
 
 /*