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[Qemu-devel] [PULL 12/43] hw/core/or-irq: Support more than 16 inputs to
From: |
Peter Maydell |
Subject: |
[Qemu-devel] [PULL 12/43] hw/core/or-irq: Support more than 16 inputs to an OR gate |
Date: |
Fri, 15 Jun 2018 15:24:50 +0100 |
For the IoTKit MPC support, we need to wire together the
interrupt outputs of 17 MPCs; this exceeds the current
value of MAX_OR_LINES. Increase MAX_OR_LINES to 32 (which
should be enough for anyone).
The tricky part is retaining the migration compatibility for
existing OR gates; we add a subsection which is only used
for larger OR gates, and define it such that we can freely
increase MAX_OR_LINES in future (or even move to a dynamically
allocated levels[] array without an upper size limit) without
breaking compatibility.
Signed-off-by: Peter Maydell <address@hidden>
Reviewed-by: Alex Bennée <address@hidden>
Message-id: address@hidden
---
include/hw/or-irq.h | 5 ++++-
hw/core/or-irq.c | 39 +++++++++++++++++++++++++++++++++++++--
2 files changed, 41 insertions(+), 3 deletions(-)
diff --git a/include/hw/or-irq.h b/include/hw/or-irq.h
index 3f6fc1b58a4..5a31e5a1881 100644
--- a/include/hw/or-irq.h
+++ b/include/hw/or-irq.h
@@ -31,7 +31,10 @@
#define TYPE_OR_IRQ "or-irq"
-#define MAX_OR_LINES 16
+/* This can safely be increased if necessary without breaking
+ * migration compatibility (as long as it remains greater than 15).
+ */
+#define MAX_OR_LINES 32
typedef struct OrIRQState qemu_or_irq;
diff --git a/hw/core/or-irq.c b/hw/core/or-irq.c
index f9d76c46415..a86901b673c 100644
--- a/hw/core/or-irq.c
+++ b/hw/core/or-irq.c
@@ -66,14 +66,49 @@ static void or_irq_init(Object *obj)
qdev_init_gpio_out(DEVICE(obj), &s->out_irq, 1);
}
+/* The original version of this device had a fixed 16 entries in its
+ * VMState array; devices with more inputs than this need to
+ * migrate the extra lines via a subsection.
+ * The subsection migrates as much of the levels[] array as is needed
+ * (including repeating the first 16 elements), to avoid the awkwardness
+ * of splitting it in two to meet the requirements of VMSTATE_VARRAY_UINT16.
+ */
+#define OLD_MAX_OR_LINES 16
+#if MAX_OR_LINES < OLD_MAX_OR_LINES
+#error MAX_OR_LINES must be at least 16 for migration compatibility
+#endif
+
+static bool vmstate_extras_needed(void *opaque)
+{
+ qemu_or_irq *s = OR_IRQ(opaque);
+
+ return s->num_lines >= OLD_MAX_OR_LINES;
+}
+
+static const VMStateDescription vmstate_or_irq_extras = {
+ .name = "or-irq-extras",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = vmstate_extras_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_VARRAY_UINT16_UNSAFE(levels, qemu_or_irq, num_lines, 0,
+ vmstate_info_bool, bool),
+ VMSTATE_END_OF_LIST(),
+ },
+};
+
static const VMStateDescription vmstate_or_irq = {
.name = TYPE_OR_IRQ,
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
- VMSTATE_BOOL_ARRAY(levels, qemu_or_irq, MAX_OR_LINES),
+ VMSTATE_BOOL_SUB_ARRAY(levels, qemu_or_irq, 0, OLD_MAX_OR_LINES),
VMSTATE_END_OF_LIST(),
- }
+ },
+ .subsections = (const VMStateDescription*[]) {
+ &vmstate_or_irq_extras,
+ NULL
+ },
};
static Property or_irq_properties[] = {
--
2.17.1
- [Qemu-devel] [PULL 08/43] hw/char/parallel: Convert away from old_mmio, (continued)
- [Qemu-devel] [PULL 08/43] hw/char/parallel: Convert away from old_mmio, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 07/43] hw/input/pckbd: Convert away from old_mmio, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 05/43] hw/block/pflash_cfi02: Convert away from old_mmio, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 17/43] exec.c: Don't accidentally sign-extend 4-byte loads in subpage_read(), Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 16/43] bswap: Add new stn_*_p() and ldn_*_p() memory access functions, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 04/43] hw/m68k/mcf5206: Convert away from old_mmio, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 15/43] CODING_STYLE: Define our preferred form for multiline comments, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 09/43] stellaris: Stop using armv7m_init(), Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 23/43] target/arm: Implement SVE compress active elements, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 06/43] hw/watchdog/wdt_i6300esb: Convert away from old_mmio, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 12/43] hw/core/or-irq: Support more than 16 inputs to an OR gate,
Peter Maydell <=
- [Qemu-devel] [PULL 01/43] arm_gicv3_kvm: kvm_dist_get/put_priority: skip the registers banked by GICR_IPRIORITYR, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 14/43] cputlb: Pass cpu_transaction_failed() the correct physaddr, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 21/43] target/arm: Implement SVE Permute - Predicates Group, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 18/43] exec.c: Use stn_p() and ldn_p() instead of explicit switches, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 19/43] target/arm: Extend vec_reg_offset to larger sizes, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 03/43] hw/sh/sh7750: Convert away from old_mmio, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 20/43] target/arm: Implement SVE Permute - Unpredicated Group, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 25/43] target/arm: Implement SVE copy to vector (predicated), Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 24/43] target/arm: Implement SVE conditionally broadcast/extract element, Peter Maydell, 2018/06/15
- [Qemu-devel] [PULL 02/43] hw/arm/mps2-tz: Put ethernet controller behind PPC, Peter Maydell, 2018/06/15