Re: [PATCH] hw/ppc/ppc4xx_pci: Fix ppc4xx_pci_map_irq() for recent Linux kernels

[Cédric Le Goater]

On 10/19/21 11:18, Thomas Huth wrote:
> Recent Linux kernels are accessing the PCI device in slot 0 that
> represents the PCI host bridge. This causes ppc4xx_pci_map_irq()
> to return -1 which causes an assert() later:
>
>   hw/pci/pci.c:262: pci_bus_change_irq_level: Assertion `irq_num >= 0' failed.
>
> Thus we should allocate an IRQ line for the device in slot 0, too.
> To avoid changes to the outside of ppc4xx_pci.c, we map it to
> the internal IRQ number 4 which will then happily be ignored since
> ppc440_bamboo.c does not wire it up.
>
> With these changes it is now possible again to use recent Linux
> kernels for the bamboo board.
>
> Signed-off-by: Thomas Huth <thuth@redhat.com>

Reviewed-by: Cédric Le Goater <clg@kaod.org>

and

Tested-by: Cédric Le Goater <clg@kaod.org>

with kernel 5.15.0-rc6, ppc44x_defconfig + rtl8139. See below.

Thanks,

C.

Activating Kernel Userspace Execution Prevention
Linux version 5.15.0-rc6-dirty (legoater@yukon) (powerpc64-linux-gnu-gcc (GCC) 
11.2.1 20210728 (Red Hat Cross 11.2.1-1), GNU ld version 2.35.2-1.fc34) #3 Tue 
Oct 19 16:39:39 CEST 2021
random: fast init done
Found initrd at 0xc1900000:0xc19a6be7
Using PowerPC 44x Platform machine description
Found legacy serial port 0 for /plb/opb/serial@ef600300
  mem=ef600300, taddr=ef600300, irq=0, clk=11059200, speed=115200
Found legacy serial port 1 for /plb/opb/serial@ef600400
  mem=ef600400, taddr=ef600400, irq=0, clk=11059200, speed=0
printk: bootconsole [udbg0] enabled
-----------------------------------------------------
phys_mem_size     = 0x8000000
dcache_bsize      = 0x20
icache_bsize      = 0x20
cpu_features      = 0x0000000000000100
  possible        = 0x0000000040000100
  always          = 0x0000000000000100
cpu_user_features = 0x8c008000 0x00000000
mmu_features      = 0x00000008
-----------------------------------------------------
Top of RAM: 0x8000000, Total RAM: 0x8000000
Memory hole size: 0MB
Zone ranges:
  Normal   [mem 0x0000000000000000-0x0000000007ffffff]
Movable zone start for each node
Early memory node ranges
  node   0: [mem 0x0000000000000000-0x0000000007ffffff]
Initmem setup node 0 [mem 0x0000000000000000-0x0000000007ffffff]
MMU: Allocated 1088 bytes of context maps for 255 contexts
pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768
pcpu-alloc: [0] 0
Built 1 zonelists, mobility grouping on.  Total pages: 32512
Kernel command line: console=ttyS0 HOST=powerpc-440fp
Unknown command line parameters: HOST=powerpc-440fp
Dentry cache hash table entries: 16384 (order: 4, 65536 bytes, linear)
Inode-cache hash table entries: 8192 (order: 3, 32768 bytes, linear)
mem auto-init: stack:off, heap alloc:off, heap free:off
Kernel virtual memory layout:
  * 0xffbdf000..0xfffff000  : fixmap
  * 0xd1000000..0xffbdf000  : vmalloc & ioremap
Memory: 122100K/131072K available (5180K kernel code, 220K rwdata, 1312K 
rodata, 208K init, 147K bss, 8972K reserved, 0K cma-reserved)
SLUB: HWalign=32, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
NR_IRQS: 512, nr_irqs: 512, preallocated irqs: 16
UIC0 (32 IRQ sources) at DCR 0xc0
random: get_random_u32 called from start_kernel+0x4cc/0x640 with crng_init=0
time_init: decrementer frequency = 400.000000 MHz
time_init: processor frequency   = 400.000000 MHz
clocksource: timebase: mask: 0xffffffffffffffff max_cycles: 0x5c4093a7d1, 
max_idle_ns: 440795210635 ns
clocksource: timebase mult[2800000] shift[24] registered
clockevent: decrementer mult[66666666] shift[32] cpu[0]
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear)
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 
7645041785100000 ns
futex hash table entries: 256 (order: -1, 3072 bytes, linear)
NET: Registered PF_NETLINK/PF_ROUTE protocol family
DMA: preallocated 128 KiB GFP_KERNEL pool for atomic allocations
PCI host bridge /plb/pci@ec000000 (primary) ranges:
 MEM 0x00000000a0000000..0x00000000bfffffff -> 0x00000000a0000000
  IO 0x00000000e8000000..0x00000000e800ffff -> 0x0000000000000000
4xx PCI DMA offset set to 0x00000000
4xx PCI DMA window base to 0x0000000000000000
DMA window size 0x0000000080000000
PCI: Probing PCI hardware
PCI host bridge to bus 0000:00
pci_bus 0000:00: root bus resource [io  0x0000-0xffff]
pci_bus 0000:00: root bus resource [mem 0xa0000000-0xbfffffff]
pci_bus 0000:00: root bus resource [bus 00-ff]
pci_bus 0000:00: busn_res: [bus 00-ff] end is updated to ff
pci 0000:00:00.0: [1014:027f] type 00 class 0x068000
PCI: Hiding 4xx host bridge resources 0000:00:00.0
pci 0000:00:01.0: [10ec:8139] type 00 class 0x020000
pci 0000:00:01.0: reg 0x10: [io  0x0000-0x00ff]
pci 0000:00:01.0: reg 0x14: [mem 0x00000000-0x000000ff]
pci 0000:00:01.0: reg 0x30: [mem 0x00000000-0x0003ffff pref]
pci_bus 0000:00: busn_res: [bus 00-ff] end is updated to 00
pci 0000:00:01.0: BAR 6: assigned [mem 0xa0000000-0xa003ffff pref]
pci 0000:00:01.0: BAR 0: assigned [io  0x1000-0x10ff]
pci 0000:00:01.0: BAR 1: assigned [mem 0xa0040000-0xa00400ff]
pci_bus 0000:00: resource 4 [io  0x0000-0xffff]
pci_bus 0000:00: resource 5 [mem 0xa0000000-0xbfffffff]
vgaarb: loaded
pps_core: LinuxPPS API ver. 1 registered
pps_core: Software ver. 5.3.6 - Copyright 2005-2007 Rodolfo Giometti 
<giometti@linux.it>
PTP clock support registered
clocksource: Switched to clocksource timebase
NET: Registered PF_INET protocol family
IP idents hash table entries: 2048 (order: 2, 16384 bytes, linear)
tcp_listen_portaddr_hash hash table entries: 512 (order: 0, 4096 bytes, linear)
TCP established hash table entries: 1024 (order: 0, 4096 bytes, linear)
TCP bind hash table entries: 1024 (order: 0, 4096 bytes, linear)
TCP: Hash tables configured (established 1024 bind 1024)
UDP hash table entries: 256 (order: 0, 4096 bytes, linear)
UDP-Lite hash table entries: 256 (order: 0, 4096 bytes, linear)
NET: Registered PF_UNIX/PF_LOCAL protocol family
RPC: Registered named UNIX socket transport module.
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
RPC: Registered tcp NFSv4.1 backchannel transport module.
PCI: CLS 0 bytes, default 32
Trying to unpack rootfs image as initramfs...
workingset: timestamp_bits=30 max_order=15 bucket_order=0
jffs2: version 2.2. (NAND) © 2001-2006 Red Hat, Inc.
io scheduler mq-deadline registered
io scheduler kyber registered
Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
printk: console [ttyS0] disabled
serial8250.0: ttyS0 at MMIO 0xef600300 (irq = 16, base_baud = 691200) is a 
16550A
printk: console [ttyS0] enabled
printk: bootconsole [udbg0] disabled
printk: console [ttyS0] disabled
ef600300.serial: ttyS0 at MMIO 0xef600300 (irq = 16, base_baud = 691200) is a 
16550
printk: console [ttyS0] enabled
ef600400.serial: ttyS1 at MMIO 0xef600400 (irq = 17, base_baud = 691200) is a 
16550
Freeing initrd memory: 664K
brd: module loaded
libphy: Fixed MDIO Bus: probed
PPC 4xx OCP EMAC driver, version 3.54
ZMII /plb/opb/emac-zmii@ef600d00 initialized
8139cp: 8139cp: 10/100 PCI Ethernet driver v1.3 (Mar 22, 2004)
8139cp 0000:00:01.0: enabling device (0000 -> 0003)
8139cp 0000:00:01.0 eth0: RTL-8139C+ at 0x(ptrval), 52:54:00:12:34:56, IRQ 28
NET: Registered PF_INET6 protocol family
Segment Routing with IPv6
In-situ OAM (IOAM) with IPv6
sit: IPv6, IPv4 and MPLS over IPv4 tunneling driver
NET: Registered PF_PACKET protocol family
drmem: No dynamic reconfiguration memory found
Freeing unused kernel image (initmem) memory: 208K
Kernel memory protection not selected by kernel config.
Run /init as init process
  with arguments:
    /init
  with environment:
    HOME=/
    TERM=linux
    HOST=powerpc-440fp
8139cp 0000:00:01.0 eth0: link up, 100Mbps, full-duplex, lpa 0x05E1
(powerpc-440fp:1) / $ ping 10.0.2.2
10.0.2.2 is alive!