[Xen-devel] [PATCH v6 08/14] arm/mem_access: Introduce GENMASK_ULL bit operation

[Sergej Proskurin <proskurin@xxxxxxxxxxxxx>]

The current implementation of GENMASK is capable of creating bitmasks of
32-bit values on AArch32 and 64-bit values on AArch64. As we need to
create masks for 64-bit values on AArch32 as well, in this commit we
introduce the GENMASK_ULL bit operation. Please note that the
GENMASK_ULL implementation has been lifted from the linux kernel source
code.

Signed-off-by: Sergej Proskurin <proskurin@xxxxxxxxxxxxx>
---
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Julien Grall <julien.grall@xxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Tim Deegan <tim@xxxxxxx>
Cc: Wei Liu <wei.liu2@xxxxxxxxxx>
---
v6: As similar patches have been already submitted and NACKED in the
    past, we resubmit this patch with 'THE REST' maintainers in Cc to
    discuss whether this patch shall be applied into common or put into
    ARM related code.
---
 xen/include/asm-arm/config.h | 2 ++
 xen/include/xen/bitops.h     | 5 ++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/xen/include/asm-arm/config.h b/xen/include/asm-arm/config.h
index 5b6f3c985d..7fa412f1b1 100644
--- a/xen/include/asm-arm/config.h
+++ b/xen/include/asm-arm/config.h
@@ -19,6 +19,8 @@
 #define BITS_PER_LONG (BYTES_PER_LONG << 3)
 #define POINTER_ALIGN BYTES_PER_LONG
 
+#define BITS_PER_LONG_LONG 64
+
 /* xen_ulong_t is always 64 bits */
 #define BITS_PER_XEN_ULONG 64
 
diff --git a/xen/include/xen/bitops.h b/xen/include/xen/bitops.h
index bd0883ab22..3d85164bba 100644
--- a/xen/include/xen/bitops.h
+++ b/xen/include/xen/bitops.h
@@ -10,6 +10,9 @@
 #define GENMASK(h, l) \
     (((~0UL) << (l)) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
 
+#define GENMASK_ULL(h, l) \
+    (((~0ULL) << (l)) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
+
 /*
  * ffs: find first bit set. This is defined the same way as
  * the libc and compiler builtin ffs routines, therefore
@@ -128,7 +131,7 @@ static inline int generic_fls64(__u64 x)
 static __inline__ int get_bitmask_order(unsigned int count)
 {
     int order;
-    
+
     order = fls(count);
     return order;   /* We could be slightly more clever with -1 here... */
 }
-- 
2.13.2


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