intc/gic: Extract some reusable vGIC code

Some functions previously used only by vGICv2 are useful also for vGICv3
implementation. Untie them from GICState and make accessible from within
other modules:
- kvm_arm_gic_set_irq()
- kvm_gic_supports_attr() - moved to common code and renamed to
  kvm_device_check_attr()
- kvm_gic_access() - turned into GIC-independent kvm_device_access().
  Data pointer changed to void * because some GICv3 registers are
  64-bit wide

Some of these changes are not used right now, but they will be helpful for
implementing live migration.

Actually kvm_dist_get() and kvm_dist_put() could also be made reusable, but
they would require two extra parameters (s->dev_fd and s->num_cpu) as well as
lots of typecasts of 's' to DeviceState * and back to GICState *. This makes
the code very ugly so i decided to stop at this point. I tried also an
approach with making a base class for all possible GICs, but it would contain
only three variables (dev_fd, cpu_num and irq_num), and accessing them through
the rest of the code would be again tedious (either ugly casts or qemu-style
separate object pointer). So i disliked it too.

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Tested-by: Ashok kumar <ashoks@broadcom.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 2ef56d1dd64ffb75ed02a10dcdaf605e5b8ff4f8.1441784344.git.p.fedin@samsung.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 35 insertions, 0 deletions

diff --git a/hw/intc/vgic_common.h b/hw/intc/vgic_common.h
new file mode 100644
index 0000000..80d919e
--- /dev/null
+++ b/hw/intc/vgic_common.h
@@ -0,0 +1,35 @@
+/*
+ * ARM KVM vGIC utility functions
+ *
+ * Copyright (c) 2015 Samsung Electronics
+ * Written by Pavel Fedin
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef QEMU_ARM_VGIC_COMMON_H
+#define QEMU_ARM_VGIC_COMMON_H
+
+/**
+ * kvm_arm_gic_set_irq - Send an IRQ to the in-kernel vGIC
+ * @num_irq: Total number of IRQs configured for the GIC instance
+ * @irq: qemu internal IRQ line number:
+ *  [0..N-1] : external interrupts
+ *  [N..N+31] : PPI (internal) interrupts for CPU 0
+ *  [N+32..N+63] : PPI (internal interrupts for CPU 1
+ * @level: level of the IRQ line.
+ */
+void kvm_arm_gic_set_irq(uint32_t num_irq, int irq, int level);
+
+#endif