Index: arch/amd64/Makefile.inc =================================================================== --- arch/amd64/Makefile.inc (revision 40ca40239dd13e9208afb2d4d3539ec93d198a9c) +++ arch/amd64/Makefile.inc (revision dd4d6b00d0c3e88b7dd79f5e3fcc541f04c5289e) @@ -100,5 +100,6 @@ arch/$(ARCH)/src/cpu/cpu.c \ arch/$(ARCH)/src/proc/scheduler.c \ - arch/$(ARCH)/src/userspace.c + arch/$(ARCH)/src/userspace.c \ + arch/$(ARCH)/src/syscall.c ifeq ($(CONFIG_SMP),y) Index: arch/amd64/include/asm.h =================================================================== --- arch/amd64/include/asm.h (revision 40ca40239dd13e9208afb2d4d3539ec93d198a9c) +++ arch/amd64/include/asm.h (revision dd4d6b00d0c3e88b7dd79f5e3fcc541f04c5289e) @@ -189,4 +189,24 @@ } +/** Write to MSR */ +static inline void write_msr(__u32 msr, __u64 value) +{ + __asm__ volatile ( + "wrmsr;" : : "c" (msr), + "a" ((__u32)(value)), + "d" ((__u32)(value >> 32)) + ); +} + +static inline __native read_msr(__u32 msr) +{ + __u32 ax, dx; + + __asm__ volatile ( + "rdmsr;" : "=a"(ax), "=d"(dx) : "c" (msr) + ); + return ((__u64)dx << 32) | ax; +} + /** Enable local APIC Index: arch/amd64/include/cpu.h =================================================================== --- arch/amd64/include/cpu.h (revision 40ca40239dd13e9208afb2d4d3539ec93d198a9c) +++ arch/amd64/include/cpu.h (revision dd4d6b00d0c3e88b7dd79f5e3fcc541f04c5289e) @@ -38,4 +38,9 @@ #define AMD_NXE_FLAG 11 +/* MSR registers */ +#define AMD_MSR_STAR 0xc0000081 +#define AMD_MSR_LSTAR 0xc0000082 +#define AMD_MSR_SFMASK 0xc0000084 + #ifndef __ASM__ Index: arch/amd64/include/pm.h =================================================================== --- arch/amd64/include/pm.h (revision 40ca40239dd13e9208afb2d4d3539ec93d198a9c) +++ arch/amd64/include/pm.h (revision dd4d6b00d0c3e88b7dd79f5e3fcc541f04c5289e) @@ -40,9 +40,11 @@ #define NULL_DES 0 +/* Warning: Do not reorder next items, unless you look into syscall.c!!! */ #define KTEXT_DES 1 #define KDATA_DES 2 -#define UTEXT_DES 3 -#define UDATA_DES 4 +#define UDATA_DES 3 +#define UTEXT_DES 4 #define KTEXT32_DES 5 +/* EndOfWarning */ #define TSS_DES 6 Index: arch/amd64/include/syscall.h =================================================================== --- arch/amd64/include/syscall.h (revision dd4d6b00d0c3e88b7dd79f5e3fcc541f04c5289e) +++ arch/amd64/include/syscall.h (revision dd4d6b00d0c3e88b7dd79f5e3fcc541f04c5289e) @@ -0,0 +1,37 @@ +/* + * Copyright (C) 2006 Ondrej Palkovsky + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * - Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * - The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef __amd64_SYSCALL_H__ +#define __amd64_SYSCALL_H__ + +#include + +extern __native syscall_handler(__native id, __native a1, __native a2, __native a3); +extern void syscall_setup_cpu(void); + +#endif Index: arch/amd64/src/amd64.c =================================================================== --- arch/amd64/src/amd64.c (revision 40ca40239dd13e9208afb2d4d3539ec93d198a9c) +++ arch/amd64/src/amd64.c (revision dd4d6b00d0c3e88b7dd79f5e3fcc541f04c5289e) @@ -46,4 +46,5 @@ #include #include +#include /** Disable I/O on non-privileged levels @@ -100,8 +101,7 @@ /* Enable No-execute pages */ set_efer_flag(AMD_NXE_FLAG); - /* Enable SYSCALL/SYSRET */ - set_efer_flag(AMD_SCE_FLAG); /* Enable FPU */ cpu_setup_fpu(); + /* Initialize segmentation */ pm_init(); @@ -113,5 +113,4 @@ /* Disable alignment check */ clean_AM_flag(); - if (config.cpu_active == 1) { @@ -133,4 +132,7 @@ ega_init(); /* video */ } + /* Setup fast SYSCALL/SYSRET */ + syscall_setup_cpu(); + } Index: arch/amd64/src/asm_utils.S =================================================================== --- arch/amd64/src/asm_utils.S (revision 40ca40239dd13e9208afb2d4d3539ec93d198a9c) +++ arch/amd64/src/asm_utils.S (revision dd4d6b00d0c3e88b7dd79f5e3fcc541f04c5289e) @@ -39,4 +39,5 @@ .text .global interrupt_handlers +.global syscall_entry .global panic_printf @@ -189,5 +190,12 @@ handler 0 IDT_ITEMS h_end: - + + +syscall_entry: + # TODO: Switch to kernel stack + call syscall_handler + # Switch back + sysret + .data .global interrupt_handler_size Index: arch/amd64/src/pm.c =================================================================== --- arch/amd64/src/pm.c (revision 40ca40239dd13e9208afb2d4d3539ec93d198a9c) +++ arch/amd64/src/pm.c (revision dd4d6b00d0c3e88b7dd79f5e3fcc541f04c5289e) @@ -72,4 +72,15 @@ .granularity = 1, .base_24_31 = 0 }, + /* UDATA descriptor */ + { .limit_0_15 = 0xffff, + .base_0_15 = 0, + .base_16_23 = 0, + .access = AR_PRESENT | AR_DATA | AR_WRITABLE | DPL_USER, + .limit_16_19 = 0xf, + .available = 0, + .longmode = 0, + .special = 1, + .granularity = 1, + .base_24_31 = 0 }, /* UTEXT descriptor */ { .limit_0_15 = 0xffff, @@ -81,15 +92,4 @@ .longmode = 1, .special = 0, - .granularity = 1, - .base_24_31 = 0 }, - /* UDATA descriptor */ - { .limit_0_15 = 0xffff, - .base_0_15 = 0, - .base_16_23 = 0, - .access = AR_PRESENT | AR_DATA | AR_WRITABLE | DPL_USER, - .limit_16_19 = 0xf, - .available = 0, - .longmode = 0, - .special = 1, .granularity = 1, .base_24_31 = 0 }, Index: arch/amd64/src/syscall.c =================================================================== --- arch/amd64/src/syscall.c (revision dd4d6b00d0c3e88b7dd79f5e3fcc541f04c5289e) +++ arch/amd64/src/syscall.c (revision dd4d6b00d0c3e88b7dd79f5e3fcc541f04c5289e) @@ -0,0 +1,70 @@ +/* + * Copyright (C) 2006 Ondrej Palkovsky + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * - Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * - The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include +#include +#include +#include +#include + +#include + +extern void syscall_entry(void); + +/** Enable & setup support for SYSCALL/SYSRET */ +void syscall_setup_cpu(void) +{ + /* Enable SYSCALL/SYSRET */ + set_efer_flag(AMD_SCE_FLAG); + + /* Setup syscall entry address */ + + /* This is _mess_ - the 64-bit CS is argument+16, + * the SS is argument+8. The order is: + * +0(KDATA_DES), +8(UDATA_DES), +16(UTEXT_DES) + */ + write_msr(AMD_MSR_STAR, + ((__u64)(gdtselector(KDATA_DES) | PL_USER)<<48) \ + | ((__u64)(gdtselector(KTEXT_DES) | PL_KERNEL)<<32)); + write_msr(AMD_MSR_LSTAR, (__u64)syscall_entry); + /* Mask RFLAGS on syscall + * - we do not care what is in the flags field + */ + write_msr(AMD_MSR_SFMASK, 0); +} + +/** Dispatch system call */ +__native syscall_handler(__native id, __native a1, __native a2, __native a3) +{ + if (id < SYSCALL_END) + return syscall_table[id](a1,a2,a3); + else + panic("Undefined syscall %d", id); + +}