Chloe M.
134 lines
2.5 KiB
C
134 lines
2.5 KiB
C
/*
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* Copyright (c) 2026, Chloe M.
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* Provided under the BSD-3 clause.
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*
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* Description: Interrupt management
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* Author: Chloe M.
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*/
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#include <hal/intr.h>
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#include <machine/idt.h>
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#include <ke/knot.h>
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#include <stdef.h>
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/* Interrupt priority level shift */
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#define IPL_SHIFT 4
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/* Globals */
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static INTR_HANDLER Handlers[256];
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/*
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* Set a new IRQL
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*/
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static inline VOID
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SetIrql(IRQL Irql)
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{
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ASMV(
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"mov %0, %%cr8"
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:
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: "r" ((UQUAD)Irql)
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: "memory"
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);
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}
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ST_STATUS
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HalRegisterIntr(const INTR_HANDLER *Handler, BOOLEAN IsUser)
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{
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UCHAR Vector, Idx;
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INTR_HANDLER *HandlerSlot;
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if (Handler == NULL) {
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return STATUS_INVALID_PARAM;
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}
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/* Must have a valid handler */
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if (Handler->Handler == NULL) {
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return STATUS_INVALID_PARAM;
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}
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/* Ensure that the priority is valid */
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switch (Handler->Irql) {
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case IRQL_PASSIVE:
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case IRQL_APC:
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case IRQL_DEVICE:
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case IRQL_HIGH:
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break;
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default:
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return STATUS_INVALID_PARAM;
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}
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/*
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* We have 16 priorities at every band as 4-bits makes up
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* the interrupt priority level. Our job is to find a slot
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* that is free for our interrupt handler at its given IRQL.
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*/
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Vector = MAX(0x20, Handler->Irql << IPL_SHIFT);
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for (Idx = Vector; Idx < Vector + 16; ++Idx) {
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HandlerSlot = &Handlers[Idx];
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/* This entry is present, don't overwrite */
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if (HandlerSlot->Present) {
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continue;
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}
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/* Fill the slot */
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*HandlerSlot = *(INTR_HANDLER *)Handler;
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HandlerSlot->Present = 1;
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/* Register the interrupt */
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MdIdtSetEntry(
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Idx,
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(UPTR)Handler->Handler,
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(IsUser) ? IDT_USER_GATE : IDT_INT_GATE,
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0
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);
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return STATUS_SUCCESS;
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}
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/* No entry found */
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return STATUS_NOT_FOUND;
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}
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IRQL
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HalGetIrql(VOID)
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{
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UQUAD CurrentIrql;
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ASMV(
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"mov %%cr8, %0"
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: "=r" (CurrentIrql)
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:
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: "memory"
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);
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return (IRQL)CurrentIrql;
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}
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IRQL
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HalRaiseIrql(IRQL Irql)
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{
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IRQL CurrentIrql;
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CurrentIrql = HalGetIrql();
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if (Irql < CurrentIrql) {
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KeKnot(IRQL_NOT_GTE, "got bad irql\n");
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}
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SetIrql(Irql);
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return CurrentIrql;
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}
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IRQL
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HalLowerIrql(IRQL Irql)
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{
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IRQL CurrentIrql;
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CurrentIrql = HalGetIrql();
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if (Irql > CurrentIrql) {
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KeKnot(IRQL_NOT_LTE, "got bad irql\n");
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}
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return CurrentIrql;
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}
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