X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=blobdiff_plain;f=geekos%2Fsrc%2Fgeekos%2Firq.c;fp=geekos%2Fsrc%2Fgeekos%2Firq.c;h=07543ba111a596d8d94a18f7bda62dab8e706210;hp=0000000000000000000000000000000000000000;hb=ddc16b0737cf58f7aa90a69c6652cdf4090aec51;hpb=626595465a2c6987606a6bc697df65130ad8c2d3

diff --git a/geekos/src/geekos/irq.c b/geekos/src/geekos/irq.c
new file mode 100644
index 0000000..07543ba
--- /dev/null
+++ b/geekos/src/geekos/irq.c
@@ -0,0 +1,141 @@
+/*
+ * This is the device-driver interface to the interrupt system.
+ * Copyright (c) 2001,2003 David H. Hovemeyer <daveho@cs.umd.edu>
+ * $Revision: 1.4 $
+ * 
+ * This is free software.  You are permitted to use,
+ * redistribute, and modify it as specified in the file "COPYING".
+ */
+
+#include <geekos/kassert.h>
+#include <geekos/idt.h>
+#include <geekos/io.h>
+#include <geekos/irq.h>
+
+#include <geekos/debug.h>
+
+/* ----------------------------------------------------------------------
+ * Private functions and data
+ * ---------------------------------------------------------------------- */
+
+/*
+ * Current IRQ mask.
+ * This should be kept up to date with setup.asm
+ * (which does the initial programming of the PICs).
+ */
+static ushort_t s_irqMask = 0xfffb;
+
+/*
+ * Get the master and slave parts of an IRQ mask.
+ */
+#define MASTER(mask) ((mask) & 0xff)
+#define SLAVE(mask) (((mask)>>8) & 0xff)
+
+
+/* ----------------------------------------------------------------------
+ * Public functions
+ * ---------------------------------------------------------------------- */
+
+/*
+ * Install a handler for given IRQ.
+ * Note that we don't unmask the IRQ.
+ */
+void Install_IRQ(int irq, Interrupt_Handler handler)
+{
+    Install_Interrupt_Handler(irq + FIRST_EXTERNAL_INT, handler);
+}
+
+/*
+ * Get current IRQ mask.  Each bit position represents
+ * one of the 16 IRQ lines.
+ */
+ushort_t Get_IRQ_Mask(void)
+{
+    return s_irqMask;
+}
+
+/*
+ * Set the IRQ mask.
+ */
+void Set_IRQ_Mask(ushort_t mask)
+{
+    uchar_t oldMask, newMask;
+
+    oldMask = MASTER(s_irqMask);
+    newMask = MASTER(mask);
+    if (newMask != oldMask) {
+	Out_Byte(0x21, newMask);
+    }
+
+    oldMask = SLAVE(s_irqMask);
+    newMask = SLAVE(mask);
+    if (newMask != oldMask) {
+	Out_Byte(0xA1, newMask);
+    }
+
+    s_irqMask = mask;
+}
+
+/*
+ * Enable given IRQ.
+ */
+void Enable_IRQ(int irq)
+{
+    bool iflag = Begin_Int_Atomic();
+
+    KASSERT(irq >= 0 && irq < 16);
+    ushort_t mask = Get_IRQ_Mask();
+    mask &= ~(1 << irq);
+    Set_IRQ_Mask(mask);
+
+    End_Int_Atomic(iflag);
+}
+
+/*
+ * Disable given IRQ.
+ */
+void Disable_IRQ(int irq)
+{
+    bool iflag = Begin_Int_Atomic();
+
+    KASSERT(irq >= 0 && irq < 16);
+    ushort_t mask = Get_IRQ_Mask();
+    mask |= (1 << irq);
+    Set_IRQ_Mask(mask);
+
+    End_Int_Atomic(iflag);
+}
+
+/*
+ * Called by an IRQ handler to begin the interrupt.
+ * Currently a no-op.
+ */
+void Begin_IRQ(struct Interrupt_State* state)
+{
+  //   SerialPrint("Begin_IRQ for interrupt 0x%x\n",state->intNum);
+}
+
+/*
+ * Called by an IRQ handler to end the interrupt.
+ * Sends an EOI command to the appropriate PIC(s).
+ */
+void End_IRQ(struct Interrupt_State* state)
+{
+    int irq = state->intNum - FIRST_EXTERNAL_INT;
+    End_IRQ_num(irq);
+}
+
+
+void End_IRQ_num(int irq) {
+    uchar_t command = 0x60 | (irq & 0x7);
+
+    if (irq < 8) {
+	/* Specific EOI to master PIC */
+	Out_Byte(0x20, command);
+    }
+    else {
+	/* Specific EOI to slave PIC, then to master (cascade line) */
+	Out_Byte(0xA0, command);
+	Out_Byte(0x20, 0x62);
+    }
+}