Implement SwitchContext() and SwitchThreadStack() routines

2026-05-06 22:25:39 +02:00
parent 100b58312f
commit 9761569e06
4 changed files with 318 additions and 2 deletions
--- a/xtoskrnl/CMakeLists.txt
+++ b/xtoskrnl/CMakeLists.txt
@@ -34,6 +34,7 @@ list(APPEND XTOSKRNL_SOURCE
    ${XTOSKRNL_SOURCE_DIR}/kd/data.cc
    ${XTOSKRNL_SOURCE_DIR}/kd/dbgio.cc
    ${XTOSKRNL_SOURCE_DIR}/kd/exports.cc
+    ${XTOSKRNL_SOURCE_DIR}/ke/${ARCH}/dispatch.cc
    ${XTOSKRNL_SOURCE_DIR}/ke/${ARCH}/krnlinit.cc
    ${XTOSKRNL_SOURCE_DIR}/ke/${ARCH}/kthread.cc
    ${XTOSKRNL_SOURCE_DIR}/ke/${ARCH}/proc.cc
--- a/xtoskrnl/ke/amd64/dispatch.cc
+++ b/xtoskrnl/ke/amd64/dispatch.cc
@@ -0,0 +1,177 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtoskrnl/ke/amd64/dispatch.cc
+ * DESCRIPTION:     Kernel Thread Dispatcher
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ */
+
+#include <xtos.hh>
+
+
+/**
+ * Entry point for thread context switching.
+ *
+ * @param CurrentThread
+ *        Pointer to the KTHREAD structure of the current thread being suspended.
+ *
+ * @param RunLevel
+ *        Supplies the running level at which the wait was initiated.
+ *
+ * @return This routine returns TRUE if a kernel APC is pending and can be delivered, or FALSE otherwise.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+BOOLEAN
+KE::Dispatcher::SwitchContext(IN PKTHREAD CurrentThread,
+                              IN KRUNLEVEL RunLevel)
+{
+    BOOLEAN PendingApc;
+
+    /* Save non-volatile and XMM registers to the exception frame, align the stack and invoke the switch routine */
+    __asm__ volatile("subq %[ExFrameSize], %%rsp\n"
+                     "movq %%rbp, %c[ExRbp](%%rsp)\n"
+                     "movq %%rbx, %c[ExRbx](%%rsp)\n"
+                     "movq %%rdi, %c[ExRdi](%%rsp)\n"
+                     "movq %%rsi, %c[ExRsi](%%rsp)\n"
+                     "movq %%r12, %c[ExR12](%%rsp)\n"
+                     "movq %%r13, %c[ExR13](%%rsp)\n"
+                     "movq %%r14, %c[ExR14](%%rsp)\n"
+                     "movq %%r15, %c[ExR15](%%rsp)\n"
+                     "movdqa %%xmm6, %c[ExXmm6](%%rsp)\n"
+                     "movdqa %%xmm7, %c[ExXmm7](%%rsp)\n"
+                     "movdqa %%xmm8, %c[ExXmm8](%%rsp)\n"
+                     "movdqa %%xmm9, %c[ExXmm9](%%rsp)\n"
+                     "movdqa %%xmm10, %c[ExXmm10](%%rsp)\n"
+                     "movdqa %%xmm11, %c[ExXmm11](%%rsp)\n"
+                     "movdqa %%xmm12, %c[ExXmm12](%%rsp)\n"
+                     "movdqa %%xmm13, %c[ExXmm13](%%rsp)\n"
+                     "movdqa %%xmm14, %c[ExXmm14](%%rsp)\n"
+                     "movdqa %%xmm15, %c[ExXmm15](%%rsp)\n"
+                     "callq %P[SwitchRoutine]\n"
+                     "movq %c[ExRbp](%%rsp), %%rbp\n"
+                     "movq %c[ExRbx](%%rsp), %%rbx\n"
+                     "movq %c[ExRdi](%%rsp), %%rdi\n"
+                     "movq %c[ExRsi](%%rsp), %%rsi\n"
+                     "movq %c[ExR12](%%rsp), %%r12\n"
+                     "movq %c[ExR13](%%rsp), %%r13\n"
+                     "movq %c[ExR14](%%rsp), %%r14\n"
+                     "movq %c[ExR15](%%rsp), %%r15\n"
+                     "movdqa %c[ExXmm6](%%rsp), %%xmm6\n"
+                     "movdqa %c[ExXmm7](%%rsp), %%xmm7\n"
+                     "movdqa %c[ExXmm8](%%rsp), %%xmm8\n"
+                     "movdqa %c[ExXmm9](%%rsp), %%xmm9\n"
+                     "movdqa %c[ExXmm10](%%rsp), %%xmm10\n"
+                     "movdqa %c[ExXmm11](%%rsp), %%xmm11\n"
+                     "movdqa %c[ExXmm12](%%rsp), %%xmm12\n"
+                     "movdqa %c[ExXmm13](%%rsp), %%xmm13\n"
+                     "movdqa %c[ExXmm14](%%rsp), %%xmm14\n"
+                     "movdqa %c[ExXmm15](%%rsp), %%xmm15\n"
+                     "addq %[ExFrameSize], %%rsp\n"
+                     : "=a" (PendingApc)
+                     : "c" (CurrentThread),
+                       "d" (RunLevel),
+                       [ExFrameSize] "i" (sizeof(KEXCEPTION_FRAME) - 8),
+                       [ExR12] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, R12)),
+                       [ExR13] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, R13)),
+                       [ExR14] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, R14)),
+                       [ExR15] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, R15)),
+                       [ExRbp] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Rbp)),
+                       [ExRbx] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Rbx)),
+                       [ExRdi] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Rdi)),
+                       [ExRsi] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Rsi)),
+                       [ExXmm6] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Xmm6)),
+                       [ExXmm7] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Xmm7)),
+                       [ExXmm8] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Xmm8)),
+                       [ExXmm9] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Xmm9)),
+                       [ExXmm10] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Xmm10)),
+                       [ExXmm11] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Xmm11)),
+                       [ExXmm12] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Xmm12)),
+                       [ExXmm13] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Xmm13)),
+                       [ExXmm14] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Xmm14)),
+                       [ExXmm15] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Xmm15)),
+                       [SwitchRoutine] "i" (SwitchThreadStack)
+                     : "cc", "memory", "r8", "r9", "r10", "r11");
+
+    /* Return the APC status */
+    return PendingApc;
+}
+
+/**
+ * Switches context from current thread to the new thread.
+ *
+ * @param CurrentThread
+ *        Pointer to the KTHREAD structure of the current thread being suspended.
+ *
+ * @param ApcBypass
+ *        Indicates whether the APC delivery should be bypassed.
+ *
+ * @return This routine returns TRUE if a kernel APC is pending and can be delivered, or FALSE otherwise.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+BOOLEAN
+KE::Dispatcher::SwitchThreadContext(IN PKTHREAD CurrentThread,
+                                    IN BOOLEAN ApcBypass)
+{
+    UNIMPLEMENTED;
+
+    return FALSE;
+}
+
+/**
+ * Switches the thread stack and performs necessary operations to prepare for context switching.
+ *
+ * @param CurrentThread
+ *        Pointer to the KTHREAD structure of the current thread being suspended.
+ *
+ * @param RunLevel
+ *        Supplies the running level at which the wait was initiated.
+ *
+ * @return This routine returns TRUE if a kernel APC is pending and can be delivered, or FALSE otherwise.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+BOOLEAN
+KE::Dispatcher::SwitchThreadStack(IN PKTHREAD CurrentThread,
+                                  IN KRUNLEVEL RunLevel)
+{
+    BOOLEAN PendingApc;
+
+    /* Preserve MXCSR, synchronize with CPUs, switch stack and call the switch routine */
+    __asm__ volatile("pushq %%rbp\n"
+                     "subq %[FrameSize], %%rsp\n"
+                     "stmxcsr %c[SwMxCsr](%%rsp)\n"
+                     "movq %%gs:%c[PrcbcCurrentThread], %%r8\n"
+                     "BusyLoop:\n"
+                     "cmpb $0, %c[ThrdSwapBusy](%%r8)\n"
+                     "je ExitLoop\n"
+                     "pause\n"
+                     "jmp BusyLoop\n"
+                     "ExitLoop:\n"
+                     "movb %%dl, %c[SwApcBypass](%%rsp)\n"
+                     "movq %%rsp, %c[ThrdStack](%%rcx)\n"
+                     "movq %c[ThrdStack](%%r8), %%rsp\n"
+                     "movzbl %c[SwApcBypass](%%rsp), %%edx\n"
+                     "callq %P[SwitchRoutine]\n"
+                     "ldmxcsr %c[SwMxCsr](%%rsp)\n"
+                     "addq %[FrameSize], %%rsp\n"
+                     "popq %%rbp\n"
+                     : "=a" (PendingApc)
+                     : "c" (CurrentThread),
+                       "d" (RunLevel),
+                       [FrameSize] "i" (FIELD_OFFSET(KSWITCH_FRAME, Rbp)),
+                       [PrcbcCurrentThread] "i" (FIELD_OFFSET(KPROCESSOR_BLOCK, Prcb.CurrentThread)),
+                       [SwApcBypass] "i" (FIELD_OFFSET(KSWITCH_FRAME, ApcBypass)),
+                       [SwMxCsr] "i" (FIELD_OFFSET(KSWITCH_FRAME, MxCsr)),
+                       [SwitchRoutine] "i" (SwitchThreadContext),
+                       [ThrdStack] "i" (FIELD_OFFSET(KTHREAD, KernelStack)),
+                       [ThrdSwapBusy] "i" (FIELD_OFFSET(KTHREAD, SwapBusy))
+                     : "cc", "memory", "r8", "r9", "r10", "r11");
+
+    /* Return the APC status */
+    return PendingApc;
+}
--- a/xtoskrnl/ke/i686/dispatch.cc
+++ b/xtoskrnl/ke/i686/dispatch.cc
@@ -0,0 +1,134 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtoskrnl/ke/i686/dispatch.cc
+ * DESCRIPTION:     Kernel Thread Dispatcher
+ * DEVELOPERS:      Rafal Kupiec <belliash@codingworkshop.eu.org>
+ */
+
+#include <xtos.hh>
+
+
+/**
+ * Entry point for thread context switching.
+ *
+ * @param CurrentThread
+ *        Pointer to the KTHREAD structure of the current thread being suspended.
+ *
+ * @param RunLevel
+ *        Supplies the running level at which the wait was initiated.
+ *
+ * @return This routine returns TRUE if a kernel APC is pending and can be delivered, or FALSE otherwise.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+BOOLEAN
+KE::Dispatcher::SwitchContext(IN PKTHREAD CurrentThread,
+                              IN KRUNLEVEL RunLevel)
+{
+    BOOLEAN PendingApc;
+
+    /* Save registers to the exception frame and invoke the stack switch routine */
+    __asm__ volatile("subl %[ExFrameSize], %%esp\n"
+                     "movl %%esi, %c[ExEsi](%%esp)\n"
+                     "movl %%edi, %c[ExEdi](%%esp)\n"
+                     "movl %%ebx, %c[ExEbx](%%esp)\n"
+                     "movl %%ebp, %c[ExEbp](%%esp)\n"
+                     "call %P[SwitchRoutine]\n"
+                     "movl %c[ExEbp](%%esp), %%ebp\n"
+                     "movl %c[ExEbx](%%esp), %%ebx\n"
+                     "movl %c[ExEdi](%%esp), %%edi\n"
+                     "movl %c[ExEsi](%%esp), %%esi\n"
+                     "addl %[ExFrameSize], %%esp\n"
+                     : "=a" (PendingApc)
+                     : "c" (CurrentThread),
+                       "d" (RunLevel),
+                       [ExFrameSize] "i" (sizeof(KEXCEPTION_FRAME) - 4),
+                       [ExEbp] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Ebp)),
+                       [ExEbx] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Ebx)),
+                       [ExEdi] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Edi)),
+                       [ExEsi] "i" (FIELD_OFFSET(KEXCEPTION_FRAME, Esi)),
+                       [SwitchRoutine] "i" (SwitchThreadStack)
+                     : "cc", "memory");
+
+    /* Return the APC status */
+    return PendingApc;
+}
+
+/**
+ * Switches context from current thread to the new thread.
+ *
+ * @param CurrentThread
+ *        Pointer to the KTHREAD structure of the current thread being suspended.
+ *
+ * @param ApcBypass
+ *        Indicates whether the APC delivery should be bypassed.
+ *
+ * @return This routine returns TRUE if a kernel APC is pending and can be delivered, or FALSE otherwise.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+BOOLEAN
+KE::Dispatcher::SwitchThreadContext(IN PKTHREAD CurrentThread,
+                                    IN BOOLEAN ApcBypass)
+{
+    UNIMPLEMENTED;
+
+    return FALSE;
+}
+
+/**
+ * Switches the thread stack and performs necessary operations to prepare for context switching.
+ *
+ * @param CurrentThread
+ *        Pointer to the KTHREAD structure of the current thread being suspended.
+ *
+ * @param RunLevel
+ *        Supplies the running level at which the wait was initiated.
+ *
+ * @return This routine returns TRUE if a kernel APC is pending and can be delivered, or FALSE otherwise.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+BOOLEAN
+KE::Dispatcher::SwitchThreadStack(IN PKTHREAD CurrentThread,
+                                  IN KRUNLEVEL RunLevel)
+{
+    BOOLEAN PendingApc;
+
+    /* Save old state, synchronize with CPUs, switch stack and call the switch routine */
+    __asm__ volatile("subl %[FrameSize], %%esp\n"
+                     "movl %%fs:%c[PrcbcCurrentThread], %%ebx\n"
+                     "BusyLoop:\n"
+                     "cmpb $0, %c[ThrdSwapBusy](%%ebx)\n"
+                     "je ExitLoop\n"
+                     "pause\n"
+                     "jmp BusyLoop\n"
+                     "ExitLoop:\n"
+                     "movl %%fs:%c[ThrdInfoExceptions], %%eax\n"
+                     "movl %%eax, %c[SwExceptionList](%%esp)\n"
+                     "movb %%dl, %c[SwApcBypass](%%esp)\n"
+                     "movl %%esp, %c[ThrdStack](%%ecx)\n"
+                     "movl %c[ThrdStack](%%ebx), %%esp\n"
+                     "movzbl %c[SwApcBypass](%%esp), %%edx\n"
+                     "call %P[SwitchRoutine]\n"
+                     "addl %[FrameSize], %%esp\n"
+                     : "=a" (PendingApc)
+                     : "c" (CurrentThread),
+                       "d" (RunLevel),
+                       [FrameSize] "i" (sizeof(KSWITCH_FRAME) - 4),
+                       [PrcbcCurrentThread] "i" (FIELD_OFFSET(KPROCESSOR_BLOCK, Prcb.CurrentThread)),
+                       [SwApcBypass] "i" (FIELD_OFFSET(KSWITCH_FRAME, ApcBypassDisabled)),
+                       [SwExceptionList] "i" (FIELD_OFFSET(KSWITCH_FRAME, ExceptionList)),
+                       [SwitchRoutine] "i" (SwitchThreadContext),
+                       [ThrdInfoExceptions] "i" (FIELD_OFFSET(THREAD_INFORMATION_BLOCK, ExceptionList)),
+                       [ThrdStack] "i" (FIELD_OFFSET(KTHREAD, KernelStack)),
+                       [ThrdSwapBusy] "i" (FIELD_OFFSET(KTHREAD, SwapBusy))
+                     : "cc", "memory");
+
+    /* Return the APC status */
+    return PendingApc;
+}