Re: [Qemu-devel] [PATCH 4/5] PPC: e500: Support platform devices

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

On 06/04/2014 02:28 PM, Alexander Graf wrote:
> For e500 our approach to supporting platform devices is to create a simple
> bus from the guest's point of view within which we map platform devices
> dynamically.
> 
> We allocate memory regions always within the "platform" hole in address
> space and map IRQs to predetermined IRQ lines that are reserved for platform
> device usage.
> 
> This maps really nicely into device tree logic, so we can just tell the
> guest about our virtual simple bus in device tree as well.
Hi Alex,

this "qemu_add_machine_init_done_notifier" was the qemu mechanism I
missed in my patch. You light my way ;-)

One first comment is it would make much sense to reuse your code in arm
virt.c too. I am currently doing the exercise. Do you think it would be
possible to share a common helper code, outside of e500 machine code?

Thank you in advance

Best Regards

Eric
> 
> Signed-off-by: Alexander Graf <agraf@suse.de>
> ---
>  default-configs/ppc-softmmu.mak   |   1 +
>  default-configs/ppc64-softmmu.mak |   1 +
>  hw/ppc/e500.c                     | 221 ++++++++++++++++++++++++++++++++++++++
>  hw/ppc/e500.h                     |   1 +
>  hw/ppc/e500plat.c                 |   1 +
>  5 files changed, 225 insertions(+)
> 
> diff --git a/default-configs/ppc-softmmu.mak b/default-configs/ppc-softmmu.mak
> index 33f8d84..d6ec8b9 100644
> --- a/default-configs/ppc-softmmu.mak
> +++ b/default-configs/ppc-softmmu.mak
> @@ -45,6 +45,7 @@ CONFIG_PREP=y
>  CONFIG_MAC=y
>  CONFIG_E500=y
>  CONFIG_OPENPIC_KVM=$(and $(CONFIG_E500),$(CONFIG_KVM))
> +CONFIG_PLATFORM=y
>  # For PReP
>  CONFIG_MC146818RTC=y
>  CONFIG_ETSEC=y
> diff --git a/default-configs/ppc64-softmmu.mak b/default-configs/ppc64-softmmu.mak
> index 37a15b7..06677bf 100644
> --- a/default-configs/ppc64-softmmu.mak
> +++ b/default-configs/ppc64-softmmu.mak
> @@ -45,6 +45,7 @@ CONFIG_PSERIES=y
>  CONFIG_PREP=y
>  CONFIG_MAC=y
>  CONFIG_E500=y
> +CONFIG_PLATFORM=y
>  CONFIG_OPENPIC_KVM=$(and $(CONFIG_E500),$(CONFIG_KVM))
>  # For pSeries
>  CONFIG_XICS=$(CONFIG_PSERIES)
> diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
> index 33d54b3..bc26215 100644
> --- a/hw/ppc/e500.c
> +++ b/hw/ppc/e500.c
> @@ -36,6 +36,7 @@
>  #include "exec/address-spaces.h"
>  #include "qemu/host-utils.h"
>  #include "hw/pci-host/ppce500.h"
> +#include "hw/platform/device.h"
>  
>  #define EPAPR_MAGIC                (0x45504150)
>  #define BINARY_DEVICE_TREE_FILE    "mpc8544ds.dtb"
> @@ -47,6 +48,14 @@
>  
>  #define RAM_SIZES_ALIGN            (64UL << 20)
>  
> +#define E500_PLATFORM_BASE         0xF0000000ULL
> +#define E500_PLATFORM_HOLE         (128ULL * 1024 * 1024) /* 128 MB */
> +#define E500_PLATFORM_PAGE_SHIFT   12
> +#define E500_PLATFORM_HOLE_PAGES   (E500_PLATFORM_HOLE >> \
> +                                    E500_PLATFORM_PAGE_SHIFT)
> +#define E500_PLATFORM_FIRST_IRQ    5
> +#define E500_PLATFORM_NUM_IRQS     10
> +
>  /* TODO: parameterize */
>  #define MPC8544_CCSRBAR_BASE       0xE0000000ULL
>  #define MPC8544_CCSRBAR_SIZE       0x00100000ULL
> @@ -122,6 +131,62 @@ static void dt_serial_create(void *fdt, unsigned long long offset,
>      }
>  }
>  
> +typedef struct PlatformDevtreeData {
> +    void *fdt;
> +    const char *mpic;
> +    int irq_start;
> +    const char *node;
> +} PlatformDevtreeData;
> +
> +static int platform_device_create_devtree(Object *obj, void *opaque)
> +{
> +    PlatformDevtreeData *data = opaque;
> +    Object *dev;
> +    PlatformDeviceState *pdev;
> +
> +    dev = object_dynamic_cast(obj, TYPE_PLATFORM_DEVICE);
> +    pdev = (PlatformDeviceState *)dev;
> +
> +    if (!pdev) {
> +        /* Container, traverse it for children */
> +        return object_child_foreach(obj, platform_device_create_devtree, data);
> +    }
> +
> +    return 0;
> +}
> +
> +static void platform_create_devtree(void *fdt, const char *node, uint64_t addr,
> +                                    const char *mpic, int irq_start,
> +                                    int nr_irqs)
> +{
> +    const char platcomp[] = "qemu,platform\0simple-bus";
> +    PlatformDevtreeData data;
> +
> +    /* Create a /platform node that we can put all devices into */
> +
> +    qemu_fdt_add_subnode(fdt, node);
> +    qemu_fdt_setprop(fdt, node, "compatible", platcomp, sizeof(platcomp));
> +    qemu_fdt_setprop_string(fdt, node, "device_type", "platform");
> +
> +    /* Our platform hole is less than 32bit big, so 1 cell is enough for address
> +       and size */
> +    qemu_fdt_setprop_cells(fdt, node, "#size-cells", 1);
> +    qemu_fdt_setprop_cells(fdt, node, "#address-cells", 1);
> +    qemu_fdt_setprop_cells(fdt, node, "ranges", 0, addr >> 32, addr,
> +                           E500_PLATFORM_HOLE);
> +
> +    qemu_fdt_setprop_phandle(fdt, node, "interrupt-parent", mpic);
> +
> +    /* Loop through all devices and create nodes for known ones */
> +
> +    data.fdt = fdt;
> +    data.mpic = mpic;
> +    data.irq_start = irq_start;
> +    data.node = node;
> +
> +    platform_device_create_devtree(qdev_get_machine(), &data);
> +}
> +
>  static int ppce500_load_device_tree(MachineState *machine,
>                                      PPCE500Params *params,
>                                      hwaddr addr,
> @@ -379,6 +444,12 @@ static int ppce500_load_device_tree(MachineState *machine,
>      qemu_fdt_setprop_cell(fdt, pci, "#address-cells", 3);
>      qemu_fdt_setprop_string(fdt, "/aliases", "pci0", pci);
>  
> +    if (params->has_platform) {
> +        platform_create_devtree(fdt, "/platform", E500_PLATFORM_BASE,
> +                               mpic, E500_PLATFORM_FIRST_IRQ,
> +                               E500_PLATFORM_NUM_IRQS);
> +    }
> +
>      params->fixup_devtree(params, fdt);
>  
>      if (toplevel_compat) {
> @@ -618,6 +689,147 @@ static qemu_irq *ppce500_init_mpic(PPCE500Params *params, MemoryRegion *ccsr,
>      return mpic;
>  }
>  
> +typedef struct PlatformNotifier {
> +    Notifier notifier;
> +    MemoryRegion *address_space_mem;
> +    qemu_irq *mpic;
> +} PlatformNotifier;
> +
> +typedef struct PlatformInitData {
> +    unsigned long *used_irqs;
> +    unsigned long *used_mem;
> +    MemoryRegion *mem;
> +    qemu_irq *irqs;
> +    int device_count;
> +} PlatformInitData;
> +
> +static int platform_map_irq(unsigned long *used_irqs, qemu_irq *platform_irqs,
> +                            uint32_t *device_irqn, qemu_irq *device_irq)
> +{
> +    int max_irqs = E500_PLATFORM_NUM_IRQS;
> +    int irqn = *device_irqn;
> +
> +    if (irqn == (uint32_t)PLATFORM_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("e500: IRQ %d is already allocated or no free IRQ left", irqn);
> +    }
> +
> +    *device_irq = platform_irqs[irqn];
> +    *device_irqn = irqn;
> +
> +    return 0;
> +}
> +
> +static int platform_map_region(unsigned long *used_mem, MemoryRegion *pmem,
> +                               uint64_t *device_addr, MemoryRegion *device_mem)
> +{
> +    uint64_t size = memory_region_size(device_mem);
> +    uint64_t page_size = (1 << E500_PLATFORM_PAGE_SHIFT);
> +    uint64_t page_mask = page_size - 1;
> +    uint64_t size_pages = (size + page_mask) >> E500_PLATFORM_PAGE_SHIFT;
> +    hwaddr addr = *device_addr;
> +    int page;
> +    int i;
> +
> +    page = addr >> E500_PLATFORM_PAGE_SHIFT;
> +    if (addr == (uint64_t)PLATFORM_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, E500_PLATFORM_HOLE_PAGES, 0,
> +                                          size_pages, size_pages_align);
> +
> +        addr = (uint64_t)page << E500_PLATFORM_PAGE_SHIFT;
> +    }
> +
> +    if (page >= E500_PLATFORM_HOLE_PAGES || test_bit(page, used_mem) ||
> +        (find_next_bit(used_mem, E500_PLATFORM_HOLE_PAGES, page) < size_pages)) {
> +        hw_error("e500: 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);
> +    *device_addr = addr;
> +
> +    return 0;
> +}
> +
> +static int platform_device_check(Object *obj, void *opaque)
> +{
> +    PlatformInitData *init = opaque;
> +    Object *dev;
> +    PlatformDeviceState *pdev;
> +    int i;
> +
> +    dev = object_dynamic_cast(obj, TYPE_PLATFORM_DEVICE);
> +    pdev = (PlatformDeviceState *)dev;
> +
> +    if (!pdev) {
> +        /* Container, traverse it for children */
> +        return object_child_foreach(obj, platform_device_check, opaque);
> +    }
> +
> +    /* Connect platform device to machine */
> +    for (i = 0; i < pdev->num_irqs; i++) {
> +        platform_map_irq(init->used_irqs, init->irqs, &pdev->plat_irqs[i],
> +                         pdev->irqs[i]);
> +    }
> +
> +    for (i = 0; i < pdev->num_regions; i++) {
> +        platform_map_region(init->used_mem, init->mem,
> +                            &pdev->plat_region_addrs[i], pdev->regions[i]);
> +    }
> +
> +    return 0;
> +}
> +
> +static void platform_devices_init(MemoryRegion *address_space_mem,
> +                                  qemu_irq *mpic)
> +{
> +    DECLARE_BITMAP(used_irqs, E500_PLATFORM_NUM_IRQS);
> +    DECLARE_BITMAP(used_mem, E500_PLATFORM_HOLE_PAGES);
> +    MemoryRegion *platform_region = g_new(MemoryRegion, 1);
> +    PlatformInitData init = {
> +        .used_irqs = used_irqs,
> +        .used_mem = used_mem,
> +        .mem = platform_region,
> +        .irqs = &mpic[E500_PLATFORM_FIRST_IRQ],
> +    };
> +
> +    memory_region_init(platform_region, NULL, "platform devices",
> +                       E500_PLATFORM_HOLE);
> +
> +    bitmap_clear(used_irqs, 0, E500_PLATFORM_NUM_IRQS);
> +    bitmap_clear(used_mem, 0, E500_PLATFORM_HOLE_PAGES);
> +
> +    /* Loop through our internal device tree and attach any dangling device */
> +    platform_device_check(qdev_get_machine(), &init);
> +
> +    memory_region_add_subregion(address_space_mem, E500_PLATFORM_BASE,
> +                                platform_region);
> +}
> +
> +static void platform_devices_init_notify(Notifier *notifier, void *data)
> +{
> +    PlatformNotifier *pn = (PlatformNotifier *)notifier;
> +    platform_devices_init(pn->address_space_mem, pn->mpic);
> +}
> +
>  void ppce500_init(MachineState *machine, PPCE500Params *params)
>  {
>      MemoryRegion *address_space_mem = get_system_memory();
> @@ -770,6 +982,15 @@ void ppce500_init(MachineState *machine, PPCE500Params *params)
>          cur_base = (32 * 1024 * 1024);
>      }
>  
> +    /* Platform Devices */
> +    if (params->has_platform) {
> +        PlatformNotifier *notifier = g_new(PlatformNotifier, 1);
> +        notifier->notifier.notify = platform_devices_init_notify;
> +        notifier->address_space_mem = address_space_mem;
> +        notifier->mpic = mpic;
> +        qemu_add_machine_init_done_notifier(&notifier->notifier);
> +    }
> +
>      /* Load kernel. */
>      if (machine->kernel_filename) {
>          kernel_base = cur_base;
> diff --git a/hw/ppc/e500.h b/hw/ppc/e500.h
> index 08b25fa..3a588ed 100644
> --- a/hw/ppc/e500.h
> +++ b/hw/ppc/e500.h
> @@ -11,6 +11,7 @@ typedef struct PPCE500Params {
>      void (*fixup_devtree)(struct PPCE500Params *params, void *fdt);
>  
>      int mpic_version;
> +    bool has_platform;
>  } PPCE500Params;
>  
>  void ppce500_init(MachineState *machine, PPCE500Params *params);
> diff --git a/hw/ppc/e500plat.c b/hw/ppc/e500plat.c
> index 27df31d..bb84283 100644
> --- a/hw/ppc/e500plat.c
> +++ b/hw/ppc/e500plat.c
> @@ -35,6 +35,7 @@ static void e500plat_init(MachineState *machine)
>          .pci_nr_slots = PCI_SLOT_MAX - 1,
>          .fixup_devtree = e500plat_fixup_devtree,
>          .mpic_version = OPENPIC_MODEL_FSL_MPIC_42,
> +        .has_platform = true,
>      };
>  
>      /* Older KVM versions don't support EPR which breaks guests when we announce
>