Index: kernel/arch/amd64/src/asm_utils.S =================================================================== --- kernel/arch/amd64/src/asm_utils.S (revision 49ace2326d8ef34bd12cb31fe46d0f0a0e7f08ac) +++ kernel/arch/amd64/src/asm_utils.S (revision 54171e826878d11de7fc97f4a3b8a288755db3dc) @@ -1,29 +1,29 @@ -# -# Copyright (c) 2005 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. -# +/* + * Copyright (c) 2005 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. + */ #define IREGISTER_SPACE 80 @@ -40,7 +40,9 @@ #define IOFFSET_RBP 0x48 -# Mask for interrupts 0 - 31 (bits 0 - 31) where 0 means that int -# has no error word and 1 means interrupt with error word - +/** + * Mask for interrupts 0 - 31 (bits 0 - 31) where 0 means that int + * has no error word and 1 means interrupt with error word + * + */ #define ERROR_WORD_INTERRUPT_LIST 0x00027D00 @@ -63,9 +65,9 @@ .global memcpy_to_uspace_failover_address -# Wrapper for generic memsetb +/* Wrapper for generic memsetb */ memsetb: jmp _memsetb -# Wrapper for generic memsetw +/* Wrapper for generic memsetw */ memsetw: jmp _memsetw @@ -115,26 +117,38 @@ ret -## Determine CPUID support -# -# Return 0 in EAX if CPUID is not support, 1 if supported. -# +/** Determine CPUID support +* +* @return 0 in EAX if CPUID is not support, 1 if supported. +* +*/ has_cpuid: - pushfq # store flags - popq %rax # read flags - movq %rax, %rdx # copy flags - btcl $21, %edx # swap the ID bit + /* Load RFLAGS */ + pushfq + popq %rax + movq %rax, %rdx + + /* Flip the ID bit */ + btcl $21, %edx + + /* Store RFLAGS */ pushq %rdx - popfq # propagate the change into flags + popfq pushfq - popq %rdx # read flags - andl $(1 << 21), %eax # interested only in ID bit + + /* Get the ID bit again */ + popq %rdx + andl $(1 << 21), %eax andl $(1 << 21), %edx - xorl %edx, %eax # 0 if not supported, 1 if supported + + /* 0 if not supported, 1 if supported */ + xorl %edx, %eax ret cpuid: - movq %rbx, %r10 # we have to preserve rbx across function calls - - movl %edi,%eax # load the command into %eax + /* Preserve %rbx across function calls */ + movq %rbx, %r10 + + /* Load the command into %eax */ + movl %edi, %eax cpuid @@ -154,10 +168,12 @@ ret -read_efer_flag: +read_efer_flag: movq $0xc0000080, %rcx rdmsr ret -# Push all volatile general purpose registers on stack +/** Push all volatile general purpose registers on stack + * + */ .macro save_all_gpr movq %rax, IOFFSET_RAX(%rsp) @@ -188,11 +204,12 @@ #define INTERRUPT_ALIGN 128 -## Declare interrupt handlers -# -# Declare interrupt handlers for n interrupt -# vectors starting at vector i. -# -# The handlers call exc_dispatch(). -# +/** Declare interrupt handlers + * + * Declare interrupt handlers for n interrupt + * vectors starting at vector i. + * + * The handlers call exc_dispatch(). + * + */ .macro handler i n @@ -227,8 +244,8 @@ save_all_gpr cld - - # - # Stop stack traces here if we came from userspace. - # + + /* + * Stop stack traces here if we came from userspace. + */ movq %cs, %rax xorq %rdx, %rdx @@ -236,10 +253,13 @@ cmovneq %rdx, %rbp - movq $(\i), %rdi # %rdi - first parameter - movq %rsp, %rsi # %rsi - pointer to istate - call exc_dispatch # exc_dispatch(i, istate) + movq $(\i), %rdi /* %rdi - first argument */ + movq %rsp, %rsi /* %rsi - pointer to istate */ + + /* Call exc_dispatch(i, istate) */ + call exc_dispatch restore_all_gpr - # $8 = Skip error word + + /* $8 = Skip error word */ addq $(IREGISTER_SPACE + 8), %rsp iretq @@ -257,31 +277,37 @@ h_end: -## Low-level syscall handler -# -# Registers on entry: -# -# @param rcx Userspace return address. -# @param r11 Userspace RLFAGS. -# -# @param rax Syscall number. -# @param rdi 1st syscall argument. -# @param rsi 2nd syscall argument. -# @param rdx 3rd syscall argument. -# @param r10 4th syscall argument. Used instead of RCX because -# the SYSCALL instruction clobbers it. -# @param r8 5th syscall argument. -# @param r9 6th syscall argument. -# -# @return Return value is in rax. -# +/** Low-level syscall handler + * + * Registers on entry: + * + * @param %rcx Userspace return address. + * @param %r11 Userspace RLFAGS. + * + * @param %rax Syscall number. + * @param %rdi 1st syscall argument. + * @param %rsi 2nd syscall argument. + * @param %rdx 3rd syscall argument. + * @param %r10 4th syscall argument. Used instead of RCX because + * the SYSCALL instruction clobbers it. + * @param %r8 5th syscall argument. + * @param %r9 6th syscall argument. + * + * @return Return value is in %rax. + * + */ syscall_entry: - swapgs # Switch to hidden gs - # - # %gs:0 Scratch space for this thread's user RSP - # %gs:8 Address to be used as this thread's kernel RSP - # - movq %rsp, %gs:0 # Save this thread's user RSP - movq %gs:8, %rsp # Set this thread's kernel RSP - swapgs # Switch back to remain consistent + /* Switch to hidden %gs */ + swapgs + + /* + * %gs:0 Scratch space for this thread's user RSP + * %gs:8 Address to be used as this thread's kernel RSP + */ + + movq %rsp, %gs:0 /* save this thread's user RSP */ + movq %gs:8, %rsp /* set this thread's kernel RSP */ + + /* Switch back to remain consistent */ + swapgs sti @@ -289,12 +315,15 @@ pushq %r11 pushq %rbp - - xorq %rbp, %rbp # stop the stack traces here - - movq %r10, %rcx # Copy the 4th argument where it is expected + + xorq %rbp, %rbp /* stop the stack traces here */ + + /* Copy the 4th argument where it is expected */ + movq %r10, %rcx pushq %rax + call syscall_handler + addq $8, %rsp - + popq %rbp popq %r11 @@ -303,5 +332,7 @@ cli swapgs - movq %gs:0, %rsp # Restore the user RSP + + /* Restore the user RSP */ + movq %gs:0, %rsp swapgs