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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2008-12-25 12:38:36 (GMT)
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2008-12-25 12:38:55 (GMT)
commitb020632e40c3ed5e8c0c066d022672907e8401cf (patch)
treed7f805bd27e8378436fbba7e7457afbd10c22ed8 /arch/s390/kernel/vdso64
parentfc5243d98ac2575ad14a974b3c097e9ba874c03d (diff)
downloadlinux-b020632e40c3ed5e8c0c066d022672907e8401cf.tar.xz
[S390] introduce vdso on s390
Add a vdso to speed up gettimeofday and clock_getres/clock_gettime for CLOCK_REALTIME/CLOCK_MONOTONIC. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/vdso64')
-rw-r--r--arch/s390/kernel/vdso64/Makefile55
-rw-r--r--arch/s390/kernel/vdso64/clock_getres.S39
-rw-r--r--arch/s390/kernel/vdso64/clock_gettime.S89
-rw-r--r--arch/s390/kernel/vdso64/gettimeofday.S56
-rw-r--r--arch/s390/kernel/vdso64/note.S12
-rw-r--r--arch/s390/kernel/vdso64/vdso64.lds.S138
-rw-r--r--arch/s390/kernel/vdso64/vdso64_wrapper.S13
7 files changed, 402 insertions, 0 deletions
diff --git a/arch/s390/kernel/vdso64/Makefile b/arch/s390/kernel/vdso64/Makefile
new file mode 100644
index 0000000..6fc8e82
--- /dev/null
+++ b/arch/s390/kernel/vdso64/Makefile
@@ -0,0 +1,55 @@
+# List of files in the vdso, has to be asm only for now
+
+obj-vdso64 = gettimeofday.o clock_getres.o clock_gettime.o note.o
+
+# Build rules
+
+targets := $(obj-vdso64) vdso64.so vdso64.so.dbg
+obj-vdso64 := $(addprefix $(obj)/, $(obj-vdso64))
+
+KBUILD_AFLAGS_64 := $(filter-out -m64,$(KBUILD_AFLAGS))
+KBUILD_AFLAGS_64 += -m64 -s
+
+KBUILD_CFLAGS_64 := $(filter-out -m64,$(KBUILD_CFLAGS))
+KBUILD_CFLAGS_64 += -m64 -fPIC -shared -fno-common -fno-builtin
+KBUILD_CFLAGS_64 += -nostdlib -Wl,-soname=linux-vdso64.so.1 \
+ $(call ld-option, -Wl$(comma)--hash-style=sysv)
+
+$(targets:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_64)
+$(targets:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_64)
+
+obj-y += vdso64_wrapper.o
+extra-y += vdso64.lds
+CPPFLAGS_vdso64.lds += -P -C -U$(ARCH)
+
+# Force dependency (incbin is bad)
+$(obj)/vdso64_wrapper.o : $(obj)/vdso64.so
+
+# link rule for the .so file, .lds has to be first
+$(obj)/vdso64.so.dbg: $(src)/vdso64.lds $(obj-vdso64)
+ $(call if_changed,vdso64ld)
+
+# strip rule for the .so file
+$(obj)/%.so: OBJCOPYFLAGS := -S
+$(obj)/%.so: $(obj)/%.so.dbg FORCE
+ $(call if_changed,objcopy)
+
+# assembly rules for the .S files
+$(obj-vdso64): %.o: %.S
+ $(call if_changed_dep,vdso64as)
+
+# actual build commands
+quiet_cmd_vdso64ld = VDSO64L $@
+ cmd_vdso64ld = $(CC) $(c_flags) -Wl,-T $^ -o $@
+quiet_cmd_vdso64as = VDSO64A $@
+ cmd_vdso64as = $(CC) $(a_flags) -c -o $@ $<
+
+# install commands for the unstripped file
+quiet_cmd_vdso_install = INSTALL $@
+ cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
+
+vdso64.so: $(obj)/vdso64.so.dbg
+ @mkdir -p $(MODLIB)/vdso
+ $(call cmd,vdso_install)
+
+vdso_install: vdso64.so
diff --git a/arch/s390/kernel/vdso64/clock_getres.S b/arch/s390/kernel/vdso64/clock_getres.S
new file mode 100644
index 0000000..488e31a
--- /dev/null
+++ b/arch/s390/kernel/vdso64/clock_getres.S
@@ -0,0 +1,39 @@
+/*
+ * Userland implementation of clock_getres() for 64 bits processes in a
+ * s390 kernel for use in the vDSO
+ *
+ * Copyright IBM Corp. 2008
+ * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ */
+#include <asm/vdso.h>
+#include <asm/asm-offsets.h>
+#include <asm/unistd.h>
+
+ .text
+ .align 4
+ .globl __kernel_clock_getres
+ .type __kernel_clock_getres,@function
+__kernel_clock_getres:
+ .cfi_startproc
+ cghi %r2,CLOCK_REALTIME
+ je 0f
+ cghi %r2,CLOCK_MONOTONIC
+ jne 2f
+0: ltgr %r3,%r3
+ jz 1f /* res == NULL */
+ larl %r1,3f
+ lg %r0,0(%r1)
+ xc 0(8,%r3),0(%r3) /* set tp->tv_sec to zero */
+ stg %r0,8(%r3) /* store tp->tv_usec */
+1: lghi %r2,0
+ br %r14
+2: lghi %r1,__NR_clock_getres /* fallback to svc */
+ svc 0
+ br %r14
+3: .quad CLOCK_REALTIME_RES
+ .cfi_endproc
+ .size __kernel_clock_getres,.-__kernel_clock_getres
diff --git a/arch/s390/kernel/vdso64/clock_gettime.S b/arch/s390/kernel/vdso64/clock_gettime.S
new file mode 100644
index 0000000..738a410
--- /dev/null
+++ b/arch/s390/kernel/vdso64/clock_gettime.S
@@ -0,0 +1,89 @@
+/*
+ * Userland implementation of clock_gettime() for 64 bits processes in a
+ * s390 kernel for use in the vDSO
+ *
+ * Copyright IBM Corp. 2008
+ * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ */
+#include <asm/vdso.h>
+#include <asm/asm-offsets.h>
+#include <asm/unistd.h>
+
+ .text
+ .align 4
+ .globl __kernel_clock_gettime
+ .type __kernel_clock_gettime,@function
+__kernel_clock_gettime:
+ .cfi_startproc
+ larl %r5,_vdso_data
+ cghi %r2,CLOCK_REALTIME
+ je 4f
+ cghi %r2,CLOCK_MONOTONIC
+ jne 9f
+
+ /* CLOCK_MONOTONIC */
+ ltgr %r3,%r3
+ jz 3f /* tp == NULL */
+0: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
+ tmll %r4,0x0001 /* pending update ? loop */
+ jnz 0b
+ stck 48(%r15) /* Store TOD clock */
+ lg %r1,48(%r15)
+ sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
+ mghi %r1,1000
+ srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */
+ alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime */
+ lg %r0,__VDSO_XTIME_SEC(%r5)
+ alg %r1,__VDSO_WTOM_NSEC(%r5) /* + wall_to_monotonic */
+ alg %r0,__VDSO_WTOM_SEC(%r5)
+ clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */
+ jne 0b
+ larl %r5,10f
+1: clg %r1,0(%r5)
+ jl 2f
+ slg %r1,0(%r5)
+ aghi %r0,1
+ j 1b
+2: stg %r0,0(%r3) /* store tp->tv_sec */
+ stg %r1,8(%r3) /* store tp->tv_nsec */
+3: lghi %r2,0
+ br %r14
+
+ /* CLOCK_REALTIME */
+4: ltr %r3,%r3 /* tp == NULL */
+ jz 8f
+5: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
+ tmll %r4,0x0001 /* pending update ? loop */
+ jnz 5b
+ stck 48(%r15) /* Store TOD clock */
+ lg %r1,48(%r15)
+ sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
+ mghi %r1,1000
+ srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */
+ alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime */
+ lg %r0,__VDSO_XTIME_SEC(%r5)
+ clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */
+ jne 5b
+ larl %r5,10f
+6: clg %r1,0(%r5)
+ jl 7f
+ slg %r1,0(%r5)
+ aghi %r0,1
+ j 6b
+7: stg %r0,0(%r3) /* store tp->tv_sec */
+ stg %r1,8(%r3) /* store tp->tv_nsec */
+8: lghi %r2,0
+ br %r14
+
+ /* Fallback to system call */
+9: lghi %r1,__NR_clock_gettime
+ svc 0
+ br %r14
+
+10: .quad 1000000000
+ .cfi_endproc
+ .size __kernel_clock_gettime,.-__kernel_clock_gettime
diff --git a/arch/s390/kernel/vdso64/gettimeofday.S b/arch/s390/kernel/vdso64/gettimeofday.S
new file mode 100644
index 0000000..f873e75
--- /dev/null
+++ b/arch/s390/kernel/vdso64/gettimeofday.S
@@ -0,0 +1,56 @@
+/*
+ * Userland implementation of gettimeofday() for 64 bits processes in a
+ * s390 kernel for use in the vDSO
+ *
+ * Copyright IBM Corp. 2008
+ * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ */
+#include <asm/vdso.h>
+#include <asm/asm-offsets.h>
+#include <asm/unistd.h>
+
+ .text
+ .align 4
+ .globl __kernel_gettimeofday
+ .type __kernel_gettimeofday,@function
+__kernel_gettimeofday:
+ .cfi_startproc
+ larl %r5,_vdso_data
+0: ltgr %r3,%r3 /* check if tz is NULL */
+ je 1f
+ mvc 0(8,%r3),__VDSO_TIMEZONE(%r5)
+1: ltgr %r2,%r2 /* check if tv is NULL */
+ je 4f
+ lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */
+ tmll %r4,0x0001 /* pending update ? loop */
+ jnz 0b
+ stck 48(%r15) /* Store TOD clock */
+ lg %r1,48(%r15)
+ sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
+ mghi %r1,1000
+ srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */
+ alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime.tv_nsec */
+ lg %r0,__VDSO_XTIME_SEC(%r5) /* xtime.tv_sec */
+ clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */
+ jne 0b
+ larl %r5,5f
+2: clg %r1,0(%r5)
+ jl 3f
+ slg %r1,0(%r5)
+ aghi %r0,1
+ j 2b
+3: stg %r0,0(%r2) /* store tv->tv_sec */
+ slgr %r0,%r0 /* tv_nsec -> tv_usec */
+ ml %r0,8(%r5)
+ srlg %r0,%r0,6
+ stg %r0,8(%r2) /* store tv->tv_usec */
+4: lghi %r2,0
+ br %r14
+5: .quad 1000000000
+ .long 274877907
+ .cfi_endproc
+ .size __kernel_gettimeofday,.-__kernel_gettimeofday
diff --git a/arch/s390/kernel/vdso64/note.S b/arch/s390/kernel/vdso64/note.S
new file mode 100644
index 0000000..79a071e
--- /dev/null
+++ b/arch/s390/kernel/vdso64/note.S
@@ -0,0 +1,12 @@
+/*
+ * This supplies .note.* sections to go into the PT_NOTE inside the vDSO text.
+ * Here we can supply some information useful to userland.
+ */
+
+#include <linux/uts.h>
+#include <linux/version.h>
+#include <linux/elfnote.h>
+
+ELFNOTE_START(Linux, 0, "a")
+ .long LINUX_VERSION_CODE
+ELFNOTE_END
diff --git a/arch/s390/kernel/vdso64/vdso64.lds.S b/arch/s390/kernel/vdso64/vdso64.lds.S
new file mode 100644
index 0000000..9f5979d
--- /dev/null
+++ b/arch/s390/kernel/vdso64/vdso64.lds.S
@@ -0,0 +1,138 @@
+/*
+ * This is the infamous ld script for the 64 bits vdso
+ * library
+ */
+#include <asm/vdso.h>
+
+OUTPUT_FORMAT("elf64-s390", "elf64-s390", "elf64-s390")
+OUTPUT_ARCH(s390:64-bit)
+ENTRY(_start)
+
+SECTIONS
+{
+ . = VDSO64_LBASE + SIZEOF_HEADERS;
+
+ .hash : { *(.hash) } :text
+ .gnu.hash : { *(.gnu.hash) }
+ .dynsym : { *(.dynsym) }
+ .dynstr : { *(.dynstr) }
+ .gnu.version : { *(.gnu.version) }
+ .gnu.version_d : { *(.gnu.version_d) }
+ .gnu.version_r : { *(.gnu.version_r) }
+
+ .note : { *(.note.*) } :text :note
+
+ . = ALIGN(16);
+ .text : {
+ *(.text .stub .text.* .gnu.linkonce.t.*)
+ } :text
+ PROVIDE(__etext = .);
+ PROVIDE(_etext = .);
+ PROVIDE(etext = .);
+
+ /*
+ * Other stuff is appended to the text segment:
+ */
+ .rodata : { *(.rodata .rodata.* .gnu.linkonce.r.*) }
+ .rodata1 : { *(.rodata1) }
+
+ .dynamic : { *(.dynamic) } :text :dynamic
+
+ .eh_frame_hdr : { *(.eh_frame_hdr) } :text :eh_frame_hdr
+ .eh_frame : { KEEP (*(.eh_frame)) } :text
+ .gcc_except_table : { *(.gcc_except_table .gcc_except_table.*) }
+
+ .rela.dyn ALIGN(8) : { *(.rela.dyn) }
+ .got ALIGN(8) : { *(.got .toc) }
+
+ _end = .;
+ PROVIDE(end = .);
+
+ /*
+ * Stabs debugging sections are here too.
+ */
+ .stab 0 : { *(.stab) }
+ .stabstr 0 : { *(.stabstr) }
+ .stab.excl 0 : { *(.stab.excl) }
+ .stab.exclstr 0 : { *(.stab.exclstr) }
+ .stab.index 0 : { *(.stab.index) }
+ .stab.indexstr 0 : { *(.stab.indexstr) }
+ .comment 0 : { *(.comment) }
+
+ /*
+ * DWARF debug sections.
+ * Symbols in the DWARF debugging sections are relative to the
+ * beginning of the section so we begin them at 0.
+ */
+ /* DWARF 1 */
+ .debug 0 : { *(.debug) }
+ .line 0 : { *(.line) }
+ /* GNU DWARF 1 extensions */
+ .debug_srcinfo 0 : { *(.debug_srcinfo) }
+ .debug_sfnames 0 : { *(.debug_sfnames) }
+ /* DWARF 1.1 and DWARF 2 */
+ .debug_aranges 0 : { *(.debug_aranges) }
+ .debug_pubnames 0 : { *(.debug_pubnames) }
+ /* DWARF 2 */
+ .debug_info 0 : { *(.debug_info .gnu.linkonce.wi.*) }
+ .debug_abbrev 0 : { *(.debug_abbrev) }
+ .debug_line 0 : { *(.debug_line) }
+ .debug_frame 0 : { *(.debug_frame) }
+ .debug_str 0 : { *(.debug_str) }
+ .debug_loc 0 : { *(.debug_loc) }
+ .debug_macinfo 0 : { *(.debug_macinfo) }
+ /* SGI/MIPS DWARF 2 extensions */
+ .debug_weaknames 0 : { *(.debug_weaknames) }
+ .debug_funcnames 0 : { *(.debug_funcnames) }
+ .debug_typenames 0 : { *(.debug_typenames) }
+ .debug_varnames 0 : { *(.debug_varnames) }
+ /* DWARF 3 */
+ .debug_pubtypes 0 : { *(.debug_pubtypes) }
+ .debug_ranges 0 : { *(.debug_ranges) }
+ .gnu.attributes 0 : { KEEP (*(.gnu.attributes)) }
+
+ . = ALIGN(4096);
+ PROVIDE(_vdso_data = .);
+
+ /DISCARD/ : {
+ *(.note.GNU-stack)
+ *(.branch_lt)
+ *(.data .data.* .gnu.linkonce.d.* .sdata*)
+ *(.bss .sbss .dynbss .dynsbss)
+ }
+}
+
+/*
+ * Very old versions of ld do not recognize this name token; use the constant.
+ */
+#define PT_GNU_EH_FRAME 0x6474e550
+
+/*
+ * We must supply the ELF program headers explicitly to get just one
+ * PT_LOAD segment, and set the flags explicitly to make segments read-only.
+ */
+PHDRS
+{
+ text PT_LOAD FILEHDR PHDRS FLAGS(5); /* PF_R|PF_X */
+ dynamic PT_DYNAMIC FLAGS(4); /* PF_R */
+ note PT_NOTE FLAGS(4); /* PF_R */
+ eh_frame_hdr PT_GNU_EH_FRAME;
+}
+
+/*
+ * This controls what symbols we export from the DSO.
+ */
+VERSION
+{
+ VDSO_VERSION_STRING {
+ global:
+ /*
+ * Has to be there for the kernel to find
+ */
+ __kernel_gettimeofday;
+ __kernel_clock_gettime;
+ __kernel_clock_getres;
+
+ local: *;
+ };
+}
diff --git a/arch/s390/kernel/vdso64/vdso64_wrapper.S b/arch/s390/kernel/vdso64/vdso64_wrapper.S
new file mode 100644
index 0000000..d8e2ac1
--- /dev/null
+++ b/arch/s390/kernel/vdso64/vdso64_wrapper.S
@@ -0,0 +1,13 @@
+#include <linux/init.h>
+#include <asm/page.h>
+
+ .section ".data.page_aligned"
+
+ .globl vdso64_start, vdso64_end
+ .balign PAGE_SIZE
+vdso64_start:
+ .incbin "arch/s390/kernel/vdso64/vdso64.so"
+ .balign PAGE_SIZE
+vdso64_end:
+
+ .previous