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authorRoland McGrath <roland@gnu.org>2003-02-16 03:02:08 +0000
committerRoland McGrath <roland@gnu.org>2003-02-16 03:02:08 +0000
commit8321ef15ae777fc7e7a0716e2e931adb099f310a (patch)
tree988277507d116a9ea2316678c37972c7086387ae /sysdeps/mach/hurd/i386
parent7125d3cf1a4820c8e98147160673565427bc57ff (diff)
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* sysdeps/mach/hurd/tls.h: New file.
* sysdeps/mach/hurd/i386/tls.h: New file.
Diffstat (limited to 'sysdeps/mach/hurd/i386')
-rw-r--r--sysdeps/mach/hurd/i386/tls.h122
1 files changed, 122 insertions, 0 deletions
diff --git a/sysdeps/mach/hurd/i386/tls.h b/sysdeps/mach/hurd/i386/tls.h
new file mode 100644
index 0000000000..454d16472a
--- /dev/null
+++ b/sysdeps/mach/hurd/i386/tls.h
@@ -0,0 +1,122 @@
+/* Definitions for thread-local data handling. Hurd/i386 version.
+ Copyright (C) 2003 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#ifndef _I386_TLS_H
+#define _I386_TLS_H
+
+#if defined HAVE_TLS_SUPPORT
+
+/* Some things really need not be machine-dependent. */
+# include <sysdeps/mach/hurd/tls.h>
+
+/* Indiciate that TLS support is available. */
+# define USE_TLS 1
+
+/* Use i386-specific RPCs to arrange that %gs segment register prefix
+ addresses the TCB in each thread. */
+# include <mach/i386/mach_i386.h>
+
+#ifndef HAVE_I386_SET_GDT
+# define __i386_set_gdt(thr, sel, desc) ((thr), (sel), (desc), MIG_BAD_ID)
+#endif
+
+static inline int _hurd_tls_init (tcbhead_t *, int secondcall)
+ __attribute__ ((unused));
+
+static inline const char *
+_hurd_tls_init (tcbhead_t *tcb, int secondcall)
+{
+ const unsigned int base = (unsigned int) tcb;
+ const struct descriptor desc =
+ { /* low word: */
+ 0xffff /* limit 0..15 */
+ | (base << 16) /* base 0..15 */
+ , /* high word: */
+ ((base >> 16) & 0xff) /* base 16..23 */
+ | ((0x12 | 0x60 | 0x80) << 8) /* access = ACC_DATA_W|ACC_PL_U|ACC_P */
+ | (0xf << 16) /* limit 16..19 */
+ | ((4 | 8) << 20) /* granularity = SZ_32|SZ_G */
+ | (base & 0xff000000) /* base 24..31 */
+ };
+
+ if (!secondcall)
+ {
+ /* Cache our thread port. */
+ tcb->self = __mach_thread_self ();
+
+ /* Get the first available selector. */
+ int sel = -1;
+ error_t err = __i386_set_gdt (tcb->self, &sel, &desc);
+ if (err == MIG_BAD_ID)
+ {
+ /* Old kernel, use a per-thread LDT. */
+ sel = 0x27;
+ err = __i386_set_ldt (tcb->self, sel, &desc, 1);
+ assert_perror (err);
+ return "i386_set_ldt failed";
+ }
+ else
+ {
+ assert_perror (err); /* Separate from above with different line #. */
+ return "i386_set_gdt failed";
+ }
+
+ /* Now install the new selector. */
+ asm volatile ("mov %w0, %%gs" :: "q" (sel));
+ }
+ else
+ {
+ /* Fetch the selector set by the first call. */
+ int sel;
+ asm ("mov %%gs, %w0" : "=q" (sel));
+ if (__builtin_expect (sel, 0x50) & 4) /* LDT selector */
+ {
+ error_t err = __i386_set_ldt (tcb->self, sel, &desc, 1);
+ assert_perror (err);
+ return "i386_set_ldt failed";
+ }
+ else
+ {
+ error_t err = __i386_set_gdt (tcb->self, &sel, &desc);
+ assert_perror (err);
+ return "i386_set_gdt failed";
+ }
+ }
+
+ return 0;
+}
+
+/* Code to initially initialize the thread pointer. This might need
+ special attention since 'errno' is not yet available and if the
+ operation can cause a failure 'errno' must not be touched. */
+# define TLS_INIT_TP(descr, secondcall) \
+ _hurd_tls_init ((tcbhead_t *) (descr), (secondcall))
+
+/* Install new dtv for current thread. */
+# define INSTALL_NEW_DTV(dtv) \
+ ({ __asm__ ("movl %0, %%gs:0" : : "r" (dtv)); })
+
+/* Return the address of the dtv for the current thread. */
+# define THREAD_DTV() \
+ ({ void *_dtv; __asm__ ("movl %%gs:0, %0" : "=r" (_dtv)); _dtv; })
+
+
+#endif /* HAVE_TLS_SUPPORT */
+
+#endif /* i386/tls.h */