[Qemu-devel] [RFC v2 1/7] hw/misc/dyn_sysbus_binding: helpers for sysbus device dynamic binding

[Eric Auger <eric.auger@linaro.org>]

This new module implements routines which help in dynamic device
binding (mmio regions, irq). They are supposed to be used by machine
files that support dynamic sysbus instantiation.

---

v1 -> v2:
- platform_devices renamed into dyn_sysbus_binding
- PlatformParams renamed into DynSysbusParams
- PlatformBusNotifier renamed into DynSysbusNotifier
- platform_bus_map_irq, platform_bus_map_mmio, sysbus_device_check,
  platform_bus_init become static
- PlatformBusInitData becomes private to the module
- page_shift becomes a member of DynSysbusParams

v1: Dynamic sysbus device allocation fully written by Alex Graf.
Those functions were initially in ppc e500 machine file. Now moved to a
separate module.
PPCE500Params is replaced by a generic struct named PlatformParams

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Eric Auger <eric.auger@linaro.org>
---
 hw/misc/Makefile.objs                |   1 +
 hw/misc/dyn_sysbus_binding.c         | 163 +++++++++++++++++++++++++++++++++++
 include/hw/misc/dyn_sysbus_binding.h |  24 ++++++
 3 files changed, 188 insertions(+)
 create mode 100644 hw/misc/dyn_sysbus_binding.c
 create mode 100644 include/hw/misc/dyn_sysbus_binding.h

diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
index 979e532..86f6243 100644
--- a/hw/misc/Makefile.objs
+++ b/hw/misc/Makefile.objs
@@ -41,3 +41,4 @@ obj-$(CONFIG_SLAVIO) += slavio_misc.o
 obj-$(CONFIG_ZYNQ) += zynq_slcr.o
 
 obj-$(CONFIG_PVPANIC) += pvpanic.o
+obj-y += dyn_sysbus_binding.o
diff --git a/hw/misc/dyn_sysbus_binding.c b/hw/misc/dyn_sysbus_binding.c
new file mode 100644
index 0000000..0f34f0b
--- /dev/null
+++ b/hw/misc/dyn_sysbus_binding.c
@@ -0,0 +1,163 @@
+#include "hw/misc/dyn_sysbus_binding.h"
+#include "qemu/error-report.h"
+
+typedef struct PlatformBusInitData {
+    unsigned long *used_irqs;
+    unsigned long *used_mem;
+    MemoryRegion *mem;
+    qemu_irq *irqs;
+    int device_count;
+    DynSysbusParams *params;
+} PlatformBusInitData;
+
+
+static int platform_bus_map_irq(DynSysbusParams *params,
+                                SysBusDevice *sbdev,
+                                int n, unsigned long *used_irqs,
+                                qemu_irq *platform_irqs)
+{
+    int max_irqs = params->platform_bus_num_irqs;
+    char *prop = g_strdup_printf("irq[%d]", n);
+    int irqn = object_property_get_int(OBJECT(sbdev), prop, NULL);
+
+    if (irqn == SYSBUS_DYNAMIC) {
+        /* Find the first available IRQ */
+        irqn = find_first_zero_bit(used_irqs, max_irqs);
+    }
+
+    if ((irqn >= max_irqs) || test_and_set_bit(irqn, used_irqs)) {
+        hw_error("IRQ %d is already allocated or no free IRQ left", irqn);
+    }
+
+    sysbus_connect_irq(sbdev, n, platform_irqs[irqn]);
+    object_property_set_int(OBJECT(sbdev), irqn, prop, NULL);
+
+    g_free(prop);
+    return 0;
+}
+
+static int platform_bus_map_mmio(DynSysbusParams *params,
+                                 SysBusDevice *sbdev,
+                                 int n, unsigned long *used_mem,
+                                 MemoryRegion *pmem)
+{
+    MemoryRegion *device_mem = sbdev->mmio[n].memory;
+    uint64_t size = memory_region_size(device_mem);
+    uint64_t page_size = (1 << params->page_shift);
+    uint64_t page_mask = page_size - 1;
+    uint64_t size_pages = (size + page_mask) >> params->page_shift;
+    uint64_t max_size = params->platform_bus_size;
+    uint64_t max_pages = max_size >> params->page_shift;
+    char *prop = g_strdup_printf("mmio[%d]", n);
+    hwaddr addr = object_property_get_int(OBJECT(sbdev), prop, NULL);
+    int page;
+    int i;
+
+    page = addr >> params->page_shift;
+    if (addr == SYSBUS_DYNAMIC) {
+        uint64_t size_pages_align;
+
+        /* Align the region to at least its own size granularity */
+        if (is_power_of_2(size_pages)) {
+            size_pages_align = size_pages;
+        } else {
+            size_pages_align = pow2floor(size_pages) << 1;
+        }
+
+        /* Find the first available region that fits */
+        page = bitmap_find_next_zero_area(used_mem, max_pages, 0, size_pages,
+                                          size_pages_align);
+
+        addr = (uint64_t)page << params->page_shift;
+    }
+
+    if (page >= max_pages || test_bit(page, used_mem) ||
+        (find_next_bit(used_mem, max_pages, page) < size_pages)) {
+        hw_error("Memory [%"PRIx64":%"PRIx64" is already allocated or "
+                 "no slot left", addr, size);
+    }
+
+    for (i = page; i < (page + size_pages); i++) {
+        set_bit(i, used_mem);
+    }
+
+    memory_region_add_subregion(pmem, addr, device_mem);
+    sbdev->mmio[n].addr = addr;
+    object_property_set_int(OBJECT(sbdev), addr, prop, NULL);
+
+    g_free(prop);
+    return 0;
+}
+
+static int sysbus_device_check(Object *obj, void *opaque)
+{
+    PlatformBusInitData *init = opaque;
+    Object *dev;
+    SysBusDevice *sbdev;
+    int i;
+
+    dev = object_dynamic_cast(obj, TYPE_SYS_BUS_DEVICE);
+    sbdev = (SysBusDevice *)dev;
+
+    if (!sbdev) {
+        /* Container, traverse it for children */
+        return object_child_foreach(obj, sysbus_device_check, opaque);
+    }
+
+    /* Connect sysbus device to virtual platform bus */
+    for (i = 0; i < sbdev->num_irq; i++) {
+        if (!sbdev->irqp[i]) {
+            /* This IRQ is an incoming IRQ, we can't wire those here */
+            continue;
+        }
+        platform_bus_map_irq(init->params, sbdev, i,
+                             init->used_irqs, init->irqs);
+    }
+
+    for (i = 0; i < sbdev->num_mmio; i++) {
+        platform_bus_map_mmio(init->params, sbdev, i,
+                              init->used_mem, init->mem);
+    }
+
+    return 0;
+}
+
+static void platform_bus_init(DynSysbusParams *params,
+                       MemoryRegion *address_space_mem,
+                       qemu_irq *mpic)
+{
+    uint64_t max_size = params->platform_bus_size;
+    uint64_t max_pages = max_size >> params->page_shift;
+    DECLARE_BITMAP(used_irqs, params->platform_bus_num_irqs);
+    DECLARE_BITMAP(used_mem, max_pages);
+    MemoryRegion *platform_region = g_new(MemoryRegion, 1);
+    Object *container;
+    PlatformBusInitData init = {
+        .used_irqs = used_irqs,
+        .used_mem = used_mem,
+        .mem = platform_region,
+        .irqs = &mpic[params->platform_bus_first_irq],
+        .params = params,
+    };
+
+    memory_region_init(platform_region, NULL, "platform devices",
+                       params->platform_bus_size);
+
+    bitmap_clear(used_irqs, 0, params->platform_bus_num_irqs);
+    bitmap_clear(used_mem, 0, max_pages);
+
+    /* Loop through all sysbus devices that were spawened outside the machine */
+    container = container_get(qdev_get_machine(), "/peripheral");
+    sysbus_device_check(container, &init);
+    container = container_get(qdev_get_machine(), "/peripheral-anon");
+    sysbus_device_check(container, &init);
+
+    memory_region_add_subregion(address_space_mem, params->platform_bus_base,
+                                platform_region);
+}
+
+void platform_bus_init_notify(Notifier *notifier, void *data)
+{
+    DynSysbusNotifier *pn = (DynSysbusNotifier *)notifier;
+    platform_bus_init(&pn->params, pn->address_space_mem, pn->mpic);
+}
diff --git a/include/hw/misc/dyn_sysbus_binding.h b/include/hw/misc/dyn_sysbus_binding.h
new file mode 100644
index 0000000..961c9c7
--- /dev/null
+++ b/include/hw/misc/dyn_sysbus_binding.h
@@ -0,0 +1,24 @@
+#ifndef HW_MISC_PLATFORM_DEVICES_H
+#define HW_MISC_PLATFORM_DEVICES_H
+
+#include "qemu-common.h"
+#include "hw/sysbus.h"
+
+typedef struct {
+    bool has_platform_bus;
+    hwaddr platform_bus_base;
+    hwaddr platform_bus_size;
+    int platform_bus_first_irq;
+    int platform_bus_num_irqs;
+    int page_shift;
+} DynSysbusParams;
+
+typedef struct DynSysbusNotifier {
+    Notifier notifier;
+    MemoryRegion *address_space_mem;
+    qemu_irq *mpic;
+    DynSysbusParams params;
+} DynSysbusNotifier;
+
+void platform_bus_init_notify(Notifier *notifier, void *data);
+#endif
-- 
1.8.3.2