powerpc: Add hwcap/hwcap2/platform data to TCB.

This patch adds a new feature for powerpc.  In order to get faster access to
the HWCAP/HWCAP2 bits and platform number (i.e. for implementing
__builtin_cpu_is () / __builtin_cpu_supports () in GCC) without the overhead of
reading from the auxiliary vector, we now reserve space for them in the TCB.
This is an ABI change for GLIBC 2.23.

A new versioned symbol '__parse_hwcap_and_convert_at_platform' is available to
get the data from the auxiliary vector and parse it, and store it for later use
in the TLS initialization code.  This function is called very early
(in _dl_sysdep_start () via DL_PLATFORM_INFO for the dynamic linking case, and
in __libc_start_main () for the static linking case) to make sure the data is
available at the time of TLS initialization.

	* sysdeps/powerpc/Makefile (sysdep-dl-routines): Add hwcapinfo.
	(sysdep_routines): Likewise.
	(sysdep-rtld-routines): Likewise.
	[$(subdir) = nptl](tests): Add test-get_hwcap and test-get_hwcap-static
	[$(subdir) = nptl](tests-static): test-get_hwcap-static
	* sysdeps/powerpc/Versions: Added new
	__parse_hwcap_and_convert_at_platform symbol to GLIBC-2.23.
	* sysdeps/powerpc/hwcapinfo.c: New file.
	(__tcb_parse_hwcap_and_convert_at_platform): New function to initialize
	and parse hwcap, hwcap2 and platform number information.
	* sysdeps/powerpc/hwcapinfo.h: New file.  Creates global variables
	to store HWCAP+HWCAP2 and platform number.
	* sysdeps/powerpc/nptl/tcb-offsets.sym: Added new offsets
	for HWCAP+HWCAP2 and platform number in the TCB.
	* sysdeps/powerpc/nptl/tls.h: New functionality.  Stores
	the HWCAP, HWCAP2 and platform number in the TCB.
	(dtv): Added new fields for HWCAP+HWCAP2 and platform number.
	(TLS_INIT_TP): Included calls to add the hwcap and
	at_platform values in the TCB in TP initialization.
	(TLS_DEFINE_INIT_TP): Likewise.
	(THREAD_GET_HWCAP): New macro.
	(THREAD_SET_HWCAP): Likewise.
	(THREAD_GET_AT_PLATFORM): Likewise.
	(THREAD_SET_AT_PLATFORM): Likewise.
	* sysdeps/powerpc/powerpc32/dl-machine.h:
	(dl_platform_init): New function that calls
	__parse_hwcap_and_convert_at_platform for the dymanic linking case for
	powerpc32.
	* sysdeps/powerpc/powerpc64/dl-machine.h: Likewise, for powerpc64.
	* sysdeps/powerpc/test-get_hwcap-static.c: New file.  Testcase for
	this functionality, static linking case.
	* sysdeps/powerpc/test-get_hwcap.c: New file.  Likewise, dynamic
	linking case.
	* sysdeps/unix/sysv/linux/powerpc/libc-start.c: Added call to
	__parse_hwcap_and_convert_at_platform for the static linking case.
	* sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist:
	Included the new __parse_hwcap_and_convert_at_platform symbol in the
	ABI list for GLIBC 2.23.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/ld-le.abilist:
	Likewise.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/ld.abilist:
	Likewise.

2 files changed, 49 insertions, 3 deletions

diff --git a/sysdeps/powerpc/nptl/tcb-offsets.sym b/sysdeps/powerpc/nptl/tcb-offsets.sym
index d955142aff..f580e69555 100644
--- a/sysdeps/powerpc/nptl/tcb-offsets.sym
+++ b/sysdeps/powerpc/nptl/tcb-offsets.sym
@@ -19,7 +19,15 @@ POINTER_GUARD			(offsetof (tcbhead_t, pointer_guard) - TLS_TCB_OFFSET - sizeof (
 TAR_SAVE			(offsetof (tcbhead_t, tar_save) - TLS_TCB_OFFSET - sizeof (tcbhead_t))
 DSO_SLOT1			(offsetof (tcbhead_t, dso_slot1) - TLS_TCB_OFFSET - sizeof (tcbhead_t))
 DSO_SLOT2			(offsetof (tcbhead_t, dso_slot2) - TLS_TCB_OFFSET - sizeof (tcbhead_t))
+#ifdef __powerpc64__
+TCB_AT_PLATFORM			(offsetof (tcbhead_t, at_platform) - TLS_TCB_OFFSET - sizeof(tcbhead_t))
+#endif
 TM_CAPABLE			(offsetof (tcbhead_t, tm_capable) - TLS_TCB_OFFSET - sizeof (tcbhead_t))
+#ifndef __powerpc64__
+TCB_AT_PLATFORM			(offsetof (tcbhead_t, at_platform) - TLS_TCB_OFFSET - sizeof(tcbhead_t))
+PADDING				(offsetof (tcbhead_t, padding) - TLS_TCB_OFFSET - sizeof(tcbhead_t))
+#endif
+TCB_HWCAP			(offsetof (tcbhead_t, hwcap) - TLS_TCB_OFFSET - sizeof (tcbhead_t))
 #ifndef __ASSUME_PRIVATE_FUTEX
 PRIVATE_FUTEX_OFFSET		thread_offsetof (header.private_futex)
 #endif
diff --git a/sysdeps/powerpc/nptl/tls.h b/sysdeps/powerpc/nptl/tls.h
index 1f3d97a995..7b6682c8e0 100644
--- a/sysdeps/powerpc/nptl/tls.h
+++ b/sysdeps/powerpc/nptl/tls.h
@@ -44,6 +44,8 @@ typedef union dtv
 
 #ifndef __ASSEMBLER__
 
+# include <hwcapinfo.h>
+
 /* Get system call information.  */
 # include <sysdep.h>
 
@@ -63,8 +65,24 @@ typedef union dtv
    are private.  */
 typedef struct
 {
+  /* Reservation for HWCAP data.  To be accessed by GCC in
+     __builtin_cpu_supports(), so it is a part of public ABI.  */
+  uint64_t hwcap;
+  /* Reservation for AT_PLATFORM data.  To be accessed by GCC in
+     __builtin_cpu_is(), so it is a part of public ABI.  Since there
+     are different ABIs for 32 and 64 bit, we put this field in a
+     previously empty padding space for powerpc64.  */
+#ifndef __powerpc64__
+  /* Padding to maintain alignment.  */
+  uint32_t padding;
+  uint32_t at_platform;
+#endif
   /* Indicate if HTM capable (ISA 2.07).  */
-  int tm_capable;
+  uint32_t tm_capable;
+  /* Reservation for AT_PLATFORM data - powerpc64.  */
+#ifdef __powerpc64__
+  uint32_t at_platform;
+#endif
   /* Reservation for Dynamic System Optimizer ABI.  */
   uintptr_t dso_slot2;
   uintptr_t dso_slot1;
@@ -134,7 +152,9 @@ register void *__thread_register __asm__ ("r13");
 # define TLS_INIT_TP(tcbp) \
   ({ 									      \
     __thread_register = (void *) (tcbp) + TLS_TCB_OFFSET;		      \
-    THREAD_SET_TM_CAPABLE (GLRO (dl_hwcap2) & PPC_FEATURE2_HAS_HTM ? 1 : 0);  \
+    THREAD_SET_TM_CAPABLE (__tcb_hwcap & PPC_FEATURE2_HAS_HTM ? 1 : 0);	      \
+    THREAD_SET_HWCAP (__tcb_hwcap);					      \
+    THREAD_SET_AT_PLATFORM (__tcb_platform);				      \
     NULL;								      \
   })
 
@@ -142,7 +162,11 @@ register void *__thread_register __asm__ ("r13");
 # define TLS_DEFINE_INIT_TP(tp, pd) \
     void *tp = (void *) (pd) + TLS_TCB_OFFSET + TLS_PRE_TCB_SIZE;	      \
     (((tcbhead_t *) ((char *) tp - TLS_TCB_OFFSET))[-1].tm_capable) =	      \
-      THREAD_GET_TM_CAPABLE ();
+      THREAD_GET_TM_CAPABLE ();						      \
+    (((tcbhead_t *) ((char *) tp - TLS_TCB_OFFSET))[-1].hwcap) =	      \
+      THREAD_GET_HWCAP ();						      \
+    (((tcbhead_t *) ((char *) tp - TLS_TCB_OFFSET))[-1].at_platform) =	      \
+      THREAD_GET_AT_PLATFORM ();
 
 /* Return the address of the dtv for the current thread.  */
 # define THREAD_DTV() \
@@ -203,6 +227,20 @@ register void *__thread_register __asm__ ("r13");
 # define THREAD_SET_TM_CAPABLE(value) \
     (THREAD_GET_TM_CAPABLE () = (value))
 
+/* hwcap field in TCB head.  */
+# define THREAD_GET_HWCAP() \
+    (((tcbhead_t *) ((char *) __thread_register				      \
+		     - TLS_TCB_OFFSET))[-1].hwcap)
+# define THREAD_SET_HWCAP(value) \
+    (THREAD_GET_HWCAP () = (value))
+
+/* at_platform field in TCB head.  */
+# define THREAD_GET_AT_PLATFORM() \
+    (((tcbhead_t *) ((char *) __thread_register				      \
+		     - TLS_TCB_OFFSET))[-1].at_platform)
+# define THREAD_SET_AT_PLATFORM(value) \
+    (THREAD_GET_AT_PLATFORM () = (value))
+
 /* l_tls_offset == 0 is perfectly valid on PPC, so we have to use some
    different value to mean unset l_tls_offset.  */
 # define NO_TLS_OFFSET		-1