hw/mips: implement Global Interrupt Controller

The Global Interrupt Controller (GIC) is responsible for mapping each
internal and external interrupt to the correct location for servicing.

The internal representation of registers is different from the specification
in order to consolidate information for each GIC Interrupt Sources and Virtual
Processors with same functionalities. For example SH_MAP00_VP00 registers are
defined like each bit represents a VP but in this implementation the equivalent
map_vp contains VP number in integer form for ease accesses. When it is being
accessed via read write functions an internal data is converted back into the
original format as the specification.

Limitations:
Level triggering only
GIC CounterHi not implemented (Countbits = 32bits)
DINT not implemented
Local WatchDog, Fast Debug Channel, Perf Counter not implemented

Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>

1 files changed, 216 insertions, 0 deletions

diff --git a/include/hw/intc/mips_gic.h b/include/hw/intc/mips_gic.h
new file mode 100644
index 0000000..dd6d44d
--- /dev/null
+++ b/include/hw/intc/mips_gic.h
@@ -0,0 +1,216 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2000, 07 MIPS Technologies, Inc.
+ * Copyright (C) 2016 Imagination Technologies
+ *
+ */
+
+#ifndef _MIPS_GIC_H
+#define _MIPS_GIC_H
+
+#include "hw/timer/mips_gictimer.h"
+#include "cpu.h"
+/*
+ * GIC Specific definitions
+ */
+
+/* The MIPS default location */
+#define GIC_BASE_ADDR           0x1bdc0000ULL
+#define GIC_ADDRSPACE_SZ        (128 * 1024)
+
+/* Constants */
+#define GIC_POL_POS     1
+#define GIC_POL_NEG     0
+#define GIC_TRIG_EDGE   1
+#define GIC_TRIG_LEVEL  0
+
+#define MSK(n)              ((1ULL << (n)) - 1)
+
+/* GIC Address Space */
+#define SHARED_SECTION_OFS          0x0000
+#define SHARED_SECTION_SIZE         0x8000
+#define VP_LOCAL_SECTION_OFS        0x8000
+#define VP_LOCAL_SECTION_SIZE       0x4000
+#define VP_OTHER_SECTION_OFS        0xc000
+#define VP_OTHER_SECTION_SIZE       0x4000
+#define USM_VISIBLE_SECTION_OFS     0x10000
+#define USM_VISIBLE_SECTION_SIZE    0x10000
+
+/* Register Map for Shared Section */
+
+#define GIC_SH_CONFIG_OFS           0x0000
+
+/* Shared Global Counter */
+#define GIC_SH_COUNTERLO_OFS        0x0010
+#define GIC_SH_COUNTERHI_OFS        0x0014
+#define GIC_SH_REVISIONID_OFS       0x0020
+
+/* Set/Clear corresponding bit in Edge Detect Register */
+#define GIC_SH_WEDGE_OFS            0x0280
+
+/* Reset Mask - Disables Interrupt */
+#define GIC_SH_RMASK_OFS            0x0300
+#define GIC_SH_RMASK_LAST_OFS       0x031c
+
+/* Set Mask (WO) - Enables Interrupt */
+#define GIC_SH_SMASK_OFS            0x0380
+#define GIC_SH_SMASK_LAST_OFS       0x039c
+
+/* Global Interrupt Mask Register (RO) - Bit Set == Interrupt enabled */
+#define GIC_SH_MASK_OFS             0x0400
+#define GIC_SH_MASK_LAST_OFS        0x041c
+
+/* Pending Global Interrupts (RO) */
+#define GIC_SH_PEND_OFS             0x0480
+#define GIC_SH_PEND_LAST_OFS        0x049c
+
+#define GIC_SH_MAP0_PIN_OFS         0x0500
+#define GIC_SH_MAP255_PIN_OFS       0x08fc
+
+#define GIC_SH_MAP0_VP_OFS          0x2000
+#define GIC_SH_MAP255_VP_LAST_OFS   0x3fe4
+
+/* Register Map for Local Section */
+#define GIC_VP_CTL_OFS              0x0000
+#define GIC_VP_PEND_OFS             0x0004
+#define GIC_VP_MASK_OFS             0x0008
+#define GIC_VP_RMASK_OFS            0x000c
+#define GIC_VP_SMASK_OFS            0x0010
+#define GIC_VP_WD_MAP_OFS           0x0040
+#define GIC_VP_COMPARE_MAP_OFS      0x0044
+#define GIC_VP_TIMER_MAP_OFS        0x0048
+#define GIC_VP_FDC_MAP_OFS          0x004c
+#define GIC_VP_PERFCTR_MAP_OFS      0x0050
+#define GIC_VP_SWINT0_MAP_OFS       0x0054
+#define GIC_VP_SWINT1_MAP_OFS       0x0058
+#define GIC_VP_OTHER_ADDR_OFS       0x0080
+#define GIC_VP_IDENT_OFS            0x0088
+#define GIC_VP_WD_CONFIG0_OFS       0x0090
+#define GIC_VP_WD_COUNT0_OFS        0x0094
+#define GIC_VP_WD_INITIAL0_OFS      0x0098
+#define GIC_VP_COMPARE_LO_OFS       0x00a0
+#define GIC_VP_COMPARE_HI_OFS       0x00a4
+#define GIC_VL_BRK_GROUP            0x3080
+
+/* User-Mode Visible Section Register */
+/* Read-only alias for GIC Shared CounterLo */
+#define GIC_USER_MODE_COUNTERLO     0x0000
+/* Read-only alias for GIC Shared CounterHi */
+#define GIC_USER_MODE_COUNTERHI     0x0004
+
+/* Masks */
+#define GIC_SH_CONFIG_COUNTSTOP_SHF     28
+#define GIC_SH_CONFIG_COUNTSTOP_MSK     (MSK(1) << GIC_SH_CONFIG_COUNTSTOP_SHF)
+#define GIC_SH_CONFIG_COUNTBITS_SHF     24
+#define GIC_SH_CONFIG_COUNTBITS_MSK     (MSK(4) << GIC_SH_CONFIG_COUNTBITS_SHF)
+#define GIC_SH_CONFIG_NUMINTRS_SHF      16
+#define GIC_SH_CONFIG_NUMINTRS_MSK      (MSK(8) << GIC_SH_CONFIG_NUMINTRS_SHF)
+#define GIC_SH_CONFIG_PVPS_SHF          0
+#define GIC_SH_CONFIG_PVPS_MSK          (MSK(8) << GIC_SH_CONFIG_NUMVPS_SHF)
+
+#define GIC_SH_WEDGE_RW_SHF             31
+#define GIC_SH_WEDGE_RW_MSK             (MSK(1) << GIC_SH_WEDGE_RW_SHF)
+
+#define GIC_MAP_TO_PIN_SHF              31
+#define GIC_MAP_TO_PIN_MSK              (MSK(1) << GIC_MAP_TO_PIN_SHF)
+#define GIC_MAP_TO_NMI_SHF              30
+#define GIC_MAP_TO_NMI_MSK              (MSK(1) << GIC_MAP_TO_NMI_SHF)
+#define GIC_MAP_TO_YQ_SHF               29
+#define GIC_MAP_TO_YQ_MSK               (MSK(1) << GIC_MAP_TO_YQ_SHF)
+#define GIC_MAP_SHF                     0
+#define GIC_MAP_MSK                     (MSK(6) << GIC_MAP_SHF)
+#define GIC_MAP_TO_PIN_REG_MSK          \
+    (GIC_MAP_TO_PIN_MSK | GIC_MAP_TO_NMI_MSK | GIC_MAP_TO_YQ_MSK | GIC_MAP_MSK)
+
+/* GIC_VP_CTL Masks */
+#define GIC_VP_CTL_FDC_RTBL_SHF         4
+#define GIC_VP_CTL_FDC_RTBL_MSK         (MSK(1) << GIC_VP_CTL_FDC_RTBL_SHF)
+#define GIC_VP_CTL_SWINT_RTBL_SHF       3
+#define GIC_VP_CTL_SWINT_RTBL_MSK       (MSK(1) << GIC_VP_CTL_SWINT_RTBL_SHF)
+#define GIC_VP_CTL_PERFCNT_RTBL_SHF     2
+#define GIC_VP_CTL_PERFCNT_RTBL_MSK     (MSK(1) << GIC_VP_CTL_PERFCNT_RTBL_SHF)
+#define GIC_VP_CTL_TIMER_RTBL_SHF       1
+#define GIC_VP_CTL_TIMER_RTBL_MSK       (MSK(1) << GIC_VP_CTL_TIMER_RTBL_SHF)
+#define GIC_VP_CTL_EIC_MODE_SHF         0
+#define GIC_VP_CTL_EIC_MODE_MSK         (MSK(1) << GIC_VP_CTL_EIC_MODE_SHF)
+
+/* GIC_VP_MASK Masks */
+#define GIC_VP_MASK_FDC_SHF         6
+#define GIC_VP_MASK_FDC_MSK         (MSK(1) << GIC_VP_MASK_FDC_SHF)
+#define GIC_VP_MASK_SWINT1_SHF      5
+#define GIC_VP_MASK_SWINT1_MSK      (MSK(1) << GIC_VP_MASK_SWINT1_SHF)
+#define GIC_VP_MASK_SWINT0_SHF      4
+#define GIC_VP_MASK_SWINT0_MSK      (MSK(1) << GIC_VP_MASK_SWINT0_SHF)
+#define GIC_VP_MASK_PERFCNT_SHF     3
+#define GIC_VP_MASK_PERFCNT_MSK     (MSK(1) << GIC_VP_MASK_PERFCNT_SHF)
+#define GIC_VP_MASK_TIMER_SHF       2
+#define GIC_VP_MASK_TIMER_MSK       (MSK(1) << GIC_VP_MASK_TIMER_SHF)
+#define GIC_VP_MASK_CMP_SHF         1
+#define GIC_VP_MASK_CMP_MSK         (MSK(1) << GIC_VP_MASK_CMP_SHF)
+#define GIC_VP_MASK_WD_SHF          0
+#define GIC_VP_MASK_WD_MSK          (MSK(1) << GIC_VP_MASK_WD_SHF)
+#define GIC_VP_SET_RESET_MSK        (MSK(7) << GIC_VP_MASK_WD_SHF)
+
+#define GIC_CPU_INT_MAX             5 /* Core Interrupt 7 */
+#define GIC_CPU_PIN_OFFSET          2
+
+/* Local GIC interrupts. */
+#define GIC_NUM_LOCAL_INTRS     7
+#define GIC_LOCAL_INT_FDC       6 /* CPU fast debug channel */
+#define GIC_LOCAL_INT_SWINT1    5 /* CPU software interrupt 1 */
+#define GIC_LOCAL_INT_SWINT0    4 /* CPU software interrupt 0 */
+#define GIC_LOCAL_INT_PERFCTR   3 /* CPU performance counter */
+#define GIC_LOCAL_INT_TIMER     2 /* CPU timer interrupt */
+#define GIC_LOCAL_INT_COMPARE   1 /* GIC count and compare timer */
+#define GIC_LOCAL_INT_WD        0 /* GIC watchdog */
+
+#define TYPE_MIPS_GIC "mips-gic"
+#define MIPS_GIC(obj) OBJECT_CHECK(MIPSGICState, (obj), TYPE_MIPS_GIC)
+
+/* Support up to 32 VPs and 256 IRQs */
+#define GIC_MAX_VPS             32
+#define GIC_MAX_INTRS           256
+
+typedef struct MIPSGICState MIPSGICState;
+typedef struct MIPSGICIRQState MIPSGICIRQState;
+typedef struct MIPSGICVPState MIPSGICVPState;
+
+struct MIPSGICIRQState {
+    uint8_t enabled;
+    uint8_t pending;
+    uint32_t map_pin;
+    int32_t map_vp;
+    qemu_irq irq;
+};
+
+struct MIPSGICVPState {
+    uint32_t ctl;
+    uint32_t pend;
+    uint32_t mask;
+    uint32_t compare_map;
+    uint32_t other_addr;
+    CPUMIPSState *env;
+};
+
+struct MIPSGICState {
+    SysBusDevice parent_obj;
+    MemoryRegion mr;
+
+    /* Shared Section Registers */
+    uint32_t sh_config;
+    MIPSGICIRQState *irq_state;
+
+    /* VP Local/Other Section Registers */
+    MIPSGICVPState *vps;
+
+    /* GIC VP Timer */
+    MIPSGICTimerState *gic_timer;
+
+    int32_t num_vps;
+    int32_t num_irq;
+};
+
+#endif /* _MIPS_GIC_H */