Re: [PATCH v4 5/7] hw/ppc/e500: Implement pflash handling

[B]

Am 28. Oktober 2022 15:09:50 UTC schrieb Daniel Henrique Barboza 
<danielhb413@gmail.com>:
>Bernhard,

Hi Daniel,

>
>The 32 builds aren't fancying this patch. The issue is down there:
>
>On 10/18/22 18:01, Bernhard Beschow wrote:
>> Allows e500 boards to have their root file system reside on flash using
>> only builtin devices located in the eLBC memory region.
>> 
>> Note that the flash memory area is only created when a -pflash argument is
>> given, and that the size is determined by the given file. The idea is to
>> put users into control.
>> 
>> Signed-off-by: Bernhard Beschow <shentey@gmail.com>
>> ---
>>   docs/system/ppc/ppce500.rst | 16 ++++++++
>>   hw/ppc/Kconfig              |  1 +
>>   hw/ppc/e500.c               | 79 +++++++++++++++++++++++++++++++++++++
>>   3 files changed, 96 insertions(+)
>> 
>> diff --git a/docs/system/ppc/ppce500.rst b/docs/system/ppc/ppce500.rst
>> index 7b5eb3c4ee..38f8ceb0cf 100644
>> --- a/docs/system/ppc/ppce500.rst
>> +++ b/docs/system/ppc/ppce500.rst
>> @@ -165,3 +165,19 @@ if “-device eTSEC” is given to QEMU:
>>   .. code-block:: bash
>>       -netdev tap,ifname=tap0,script=no,downscript=no,id=net0 -device 
>> eTSEC,netdev=net0
>> +
>> +Root file system on flash drive
>> +-------------------------------
>> +
>> +Rather than using a root file system on ram disk, it is possible to have it 
>> on
>> +CFI flash. Given an ext2 image whose size must be a power of two, it can be 
>> used
>> +as follows:
>> +
>> +.. code-block:: bash
>> +
>> +  $ qemu-system-ppc64 -M ppce500 -cpu e500mc -smp 4 -m 2G \
>> +      -display none -serial stdio \
>> +      -kernel vmlinux \
>> +      -drive if=pflash,file=/path/to/rootfs.ext2,format=raw \
>> +      -append "rootwait root=/dev/mtdblock0"
>> +
>> diff --git a/hw/ppc/Kconfig b/hw/ppc/Kconfig
>> index 791fe78a50..769a1ead1c 100644
>> --- a/hw/ppc/Kconfig
>> +++ b/hw/ppc/Kconfig
>> @@ -126,6 +126,7 @@ config E500
>>       select ETSEC
>>       select GPIO_MPC8XXX
>>       select OPENPIC
>> +    select PFLASH_CFI01
>>       select PLATFORM_BUS
>>       select PPCE500_PCI
>>       select SERIAL
>> diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
>> index 3e950ea3ba..73198adac8 100644
>> --- a/hw/ppc/e500.c
>> +++ b/hw/ppc/e500.c
>> @@ -23,8 +23,10 @@
>>   #include "e500-ccsr.h"
>>   #include "net/net.h"
>>   #include "qemu/config-file.h"
>> +#include "hw/block/flash.h"
>>   #include "hw/char/serial.h"
>>   #include "hw/pci/pci.h"
>> +#include "sysemu/block-backend-io.h"
>>   #include "sysemu/sysemu.h"
>>   #include "sysemu/kvm.h"
>>   #include "sysemu/reset.h"
>> @@ -267,6 +269,31 @@ static void sysbus_device_create_devtree(SysBusDevice 
>> *sbdev, void *opaque)
>>       }
>>   }
>>   +static void create_devtree_flash(SysBusDevice *sbdev,
>> +                                 PlatformDevtreeData *data)
>> +{
>> +    g_autofree char *name = NULL;
>> +    uint64_t num_blocks = object_property_get_uint(OBJECT(sbdev),
>> +                                                   "num-blocks",
>> +                                                   &error_fatal);
>> +    uint64_t sector_length = object_property_get_uint(OBJECT(sbdev),
>> +                                                      "sector-length",
>> +                                                      &error_fatal);
>> +    uint64_t bank_width = object_property_get_uint(OBJECT(sbdev),
>> +                                                   "width",
>> +                                                   &error_fatal);
>> +    hwaddr flashbase = 0;
>> +    hwaddr flashsize = num_blocks * sector_length;
>> +    void *fdt = data->fdt;
>> +
>> +    name = g_strdup_printf("%s/nor@%" PRIx64, data->node, flashbase);
>> +    qemu_fdt_add_subnode(fdt, name);
>> +    qemu_fdt_setprop_string(fdt, name, "compatible", "cfi-flash");
>> +    qemu_fdt_setprop_sized_cells(fdt, name, "reg",
>> +                                 1, flashbase, 1, flashsize);
>> +    qemu_fdt_setprop_cell(fdt, name, "bank-width", bank_width);
>> +}
>> +
>>   static void platform_bus_create_devtree(PPCE500MachineState *pms,
>>                                           void *fdt, const char *mpic)
>>   {
>> @@ -276,6 +303,8 @@ static void 
>> platform_bus_create_devtree(PPCE500MachineState *pms,
>>       uint64_t addr = pmc->platform_bus_base;
>>       uint64_t size = pmc->platform_bus_size;
>>       int irq_start = pmc->platform_bus_first_irq;
>> +    SysBusDevice *sbdev;
>> +    bool ambiguous;
>>         /* Create a /platform node that we can put all devices into */
>>   @@ -302,6 +331,13 @@ static void 
>> platform_bus_create_devtree(PPCE500MachineState *pms,
>>       /* Loop through all dynamic sysbus devices and create nodes for them */
>>       foreach_dynamic_sysbus_device(sysbus_device_create_devtree, &data);
>>   +    sbdev = SYS_BUS_DEVICE(object_resolve_path_type("", TYPE_PFLASH_CFI01,
>> +                                                    &ambiguous));
>> +    if (sbdev) {
>> +        assert(!ambiguous);
>> +        create_devtree_flash(sbdev, &data);
>> +    }
>> +
>>       g_free(node);
>>   }
>>   @@ -856,6 +892,7 @@ void ppce500_init(MachineState *machine)
>>       unsigned int pci_irq_nrs[PCI_NUM_PINS] = {1, 2, 3, 4};
>>       IrqLines *irqs;
>>       DeviceState *dev, *mpicdev;
>> +    DriveInfo *dinfo;
>>       CPUPPCState *firstenv = NULL;
>>       MemoryRegion *ccsr_addr_space;
>>       SysBusDevice *s;
>> @@ -1024,6 +1061,48 @@ void ppce500_init(MachineState *machine)
>>                                   pmc->platform_bus_base,
>>                                   &pms->pbus_dev->mmio);
>>   +    dinfo = drive_get(IF_PFLASH, 0, 0);
>> +    if (dinfo) {
>> +        BlockBackend *blk = blk_by_legacy_dinfo(dinfo);
>> +        BlockDriverState *bs = blk_bs(blk);
>> +        uint64_t size = bdrv_getlength(bs);
>> +        uint64_t mmio_size = pms->pbus_dev->mmio.size;
>
>^ here. The issue is that on a 32 bit system it is not possible to cast the
>Int128 type to uint64_t:
>
>FAILED: libqemu-ppc64-softmmu.fa.p/hw_ppc_e500.c.o
>3746cc -m32 -Ilibqemu-ppc64-softmmu.fa.p -I. -I.. -Itarget/ppc -I../target/ppc 
>-I../dtc/libfdt -Iqapi -Itrace -Iui -Iui/shader -I/usr/include/pixman-1 
>-I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/sysprof-4 
>-fdiagnostics-color=auto -Wall -Winvalid-pch -Werror -std=gnu11 -O2 -g 
>-isystem /builds/danielhb/qemu/linux-headers -isystem linux-headers -iquote . 
>-iquote /builds/danielhb/qemu -iquote /builds/danielhb/qemu/include -iquote 
>/builds/danielhb/qemu/tcg/i386 -pthread -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 
>-D_GNU_SOURCE -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -Wstrict-prototypes 
>-Wredundant-decls -Wundef -Wwrite-strings -Wmissing-prototypes 
>-fno-strict-aliasing -fno-common -fwrapv -Wold-style-declaration 
>-Wold-style-definition -Wtype-limits -Wformat-security -Wformat-y2k 
>-Winit-self -Wignored-qualifiers -Wempty-body -Wnested-externs -Wendif-labels 
>-Wexpansion-to-defined -Wimplicit-fallthrough=2 -Wno-missing-include-dirs 
>-Wno-shift-negative-value -Wno-psabi -fstack-protector-strong -fPIE 
>-isystem../linux-headers -isystemlinux-headers -DNEED_CPU_H 
>'-DCONFIG_TARGET="ppc64-softmmu-config-target.h"' 
>'-DCONFIG_DEVICES="ppc64-softmmu-config-devices.h"' -MD -MQ 
>libqemu-ppc64-softmmu.fa.p/hw_ppc_e500.c.o -MF 
>libqemu-ppc64-softmmu.fa.p/hw_ppc_e500.c.o.d -o 
>libqemu-ppc64-softmmu.fa.p/hw_ppc_e500.c.o -c ../hw/ppc/e500.c
>3747../hw/ppc/e500.c: In function 'ppce500_init':
>3748../hw/ppc/e500.c:1069:30: error: incompatible types when initializing type 
>'uint64_t' {aka 'long long unsigned int'} using type 'Int128'
>3749 1069 |         uint64_t mmio_size = pms->pbus_dev->mmio.size;
>3750      |                              ^~~
>3751[3207/5331] Compiling C object 
>libqemu-ppc64-softmmu.fa.p/hw_ppc_mpc8544_guts.c.o

Whoops.
>
>
>What I did to solve the problem is this:
>
>
>+         uint64_t mmio_size = int128_get64(pms->pbus_dev->mmio.size);
>
>
>This will get the lower 64 bits and return an uint64_t.
>
>Note that this function will assert if mmio.size is bigger than UINT64_MAX, but
>since you're doing an error(1) on the "if size > mmio_size" conditional, this
>assert() is not introducing a new side effect. We'll just fail earlier with
>a different error message.

Yes, sounds reasonable.
>
>
>Let me know if this is acceptable for you.

Yes, that's fine with me. Thanks for the fix!

Best regards,
Bernhard
>
>
>Daniel
>
>
>
>> +        uint32_t sector_len = 64 * KiB;
>> +
>> +        if (!is_power_of_2(size)) {
>> +            error_report("Size of pflash file must be a power of two.");
>> +            exit(1);
>> +        }
>> +
>> +        if (size > mmio_size) {
>> +            error_report("Size of pflash file must not be bigger than %" 
>> PRIu64
>> +                         " bytes.", mmio_size);
>> +            exit(1);
>> +        }
>> +
>> +        if (!QEMU_IS_ALIGNED(size, sector_len)) {
>> +            error_report("Size of pflash file must be a multiple of %" 
>> PRIu32
>> +                         ".", sector_len);
>> +            exit(1);
>> +        }
>> +
>> +        dev = qdev_new(TYPE_PFLASH_CFI01);
>> +        qdev_prop_set_drive(dev, "drive", blk);
>> +        qdev_prop_set_uint32(dev, "num-blocks", size / sector_len);
>> +        qdev_prop_set_uint64(dev, "sector-length", sector_len);
>> +        qdev_prop_set_uint8(dev, "width", 2);
>> +        qdev_prop_set_bit(dev, "big-endian", true);
>> +        qdev_prop_set_uint16(dev, "id0", 0x89);
>> +        qdev_prop_set_uint16(dev, "id1", 0x18);
>> +        qdev_prop_set_uint16(dev, "id2", 0x0000);
>> +        qdev_prop_set_uint16(dev, "id3", 0x0);
>> +        qdev_prop_set_string(dev, "name", "e500.flash");
>> +        sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
>> +
>> +        memory_region_add_subregion(&pms->pbus_dev->mmio, 0,
>> +                                    
>> pflash_cfi01_get_memory(PFLASH_CFI01(dev)));
>> +    }
>> +
>>       /*
>>        * Smart firmware defaults ahead!
>>        *