Hi, > Am 07.04.2021 um 11:23 schrieb Huacai Chen <chenhuacai@xxxxxxxxxx>: > > There are four errors in div64.h caused by commit c21004cd5b4cb7d479514 > ("MIPS: Rewrite <asm/div64.h> to work with gcc 4.4.0."): > > 1, Only 32bit kernel need __div64_32(), but the above commit makes it > depend on 64bit kernel by mistake. > > 2, asm-generic/div64.h should be included after __div64_32() definition. > > 3, __n should be initialized as *n before use (and "*__n >> 32" should > be "__n >> 32") in __div64_32() definition. > > 4, linux/types.h should be included at the first place, otherwise BITS_ > PER_LONG is not defined. Ok, this explains the bug. > > Fixes: c21004cd5b4cb7d479514 ("MIPS: Rewrite <asm/div64.h> to work with gcc 4.4.0.") > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx> > --- > arch/mips/include/asm/div64.h | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/arch/mips/include/asm/div64.h b/arch/mips/include/asm/div64.h > index dc5ea5736440..d827c13c3bc5 100644 > --- a/arch/mips/include/asm/div64.h > +++ b/arch/mips/include/asm/div64.h > @@ -9,12 +9,10 @@ > #ifndef __ASM_DIV64_H > #define __ASM_DIV64_H > > -#include <asm-generic/div64.h> > - > -#if BITS_PER_LONG == 64 > - > #include <linux/types.h> > > +#if BITS_PER_LONG == 32 > + > /* > * No traps on overflows for any of these... > */ > @@ -24,9 +22,9 @@ > unsigned long __cf, __tmp, __tmp2, __i; \ > unsigned long __quot32, __mod32; \ > unsigned long __high, __low; \ > - unsigned long long __n; \ > + unsigned long long __n = *n; \ > \ > - __high = *__n >> 32; \ > + __high = __n >> 32; \ > __low = __n; \ > __asm__( \ > " .set push \n" \ > @@ -63,6 +61,8 @@ > __mod32; \ > }) > > -#endif /* BITS_PER_LONG == 64 */ > +#endif /* BITS_PER_LONG == 32 */ > + > +#include <asm-generic/div64.h> > > #endif /* __ASM_DIV64_H */ > -- > 2.27.0 > Now it compiles and links fine. Here is the test result on real hardware. CI20 (jz4780) hangs during boot: Starting kernel ... [ 0.000000] printk: debug: ignoring loglevel setting. [ 0.000000] User-defined physical RAM map overwrite [ 0.000000] Initrd not found or empty - disabling initrd [ 0.000000] cma: Reserved 32 MiB at 0x01000000 [ 0.000000] Primary instruction cache 32kB, VIPT, 8-way, linesize 32 bytes. [ 0.000000] Primary data cache 32kB, 8-way, VIPT, no aliases, linesize 32 bytes [ 0.000000] MIPS secondary cache 256kB, 8-way, linesize 128 bytes. [ 0.000000] Zone ranges: [ 0.000000] Normal [mem 0x0000000000000000-0x000000000fffffff] [ 0.000000] HighMem [mem 0x0000000010000000-0x000000005fffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000000000000-0x000000000fffffff] [ 0.000000] node 0: [mem 0x0000000030000000-0x000000005fffffff] [ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x000000005fffffff] [ 0.000000] On node 0 totalpages: 262144 [ 0.000000] Normal zone: 576 pages used for memmap [ 0.000000] Normal zone: 0 pages reserved [ 0.000000] Normal zone: 65536 pages, LIFO batch:15 [ 0.000000] HighMem zone: 196608 pages, LIFO batch:63 [ 0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768 [ 0.000000] pcpu-alloc: [0] 0 [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 261568 [ 0.000000] Kernel command line: console=ttyS4,115200 console=tty0 mem=256M@0x0 mem=768M@0x30000000 rootwait quiet rw root=/dev/mmcblk0p1 dm9000.mac_addr=d0:31:10:ff:6e:86 earlycon console=ttyS4,115200 clk_ignore_unused ignore_loglevel [ 0.000000] Dentry cache hash table entries: 32768 (order: 5, 131072 bytes, linear) [ 0.000000] Inode-cache hash table entries: 16384 (order: 4, 65536 bytes, linear) [ 0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off [ 0.000000] Memory: 989600K/1048576K available (7980K kernel code, 803K rwdata, 2752K rodata, 356K init, 159K bss, 26208K reserved, 32768K cma-reserved, 786432K highmem) [ 0.000000] rcu: Preemptible hierarchical RCU implementation. [ 0.000000] Trampoline variant of Tasks RCU enabled. [ 0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 10 jiffies. [ 0.000000] NR_IRQS: 256 [ 0.000000] random: get_random_bytes called from start_kernel+0x730/0x96c with crng_init=0 [ 0.000000] ingenic_tcu_clocksource_init: 65535 vs. 65535 [ 0.000000] ingenic_tcu_clocksource_init: 65535 vs. 65535 [ 0.000000] clocksource: ingenic-timer: mask: 0xffff max_cycles: 0xffff, max_idle_ns: 38886830 ns [ 0.000000] ingenic_tcu_setup_cevt: 65535 vs. 65535 [ 0.000000] ingenic_tcu_init: 16 vs. 16 [ 0.000002] sched_clock: 16 bits at 750kHz, resolution 1333ns, wraps every 43687269ns [ 0.008587] Console: colour dummy device 80x25 [ 0.014519] printk: console [tty0] enabled [ 0.018674] Calibrating delay loop... 1168.17 BogoMIPS (lpj=5840896) [ 0.064170] pid_max: default: 32768 minimum: 301 [ 0.068981] LSM: Security Framework initializing [ 0.073695] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) [ 0.081130] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) [ 0.090621] Performance counters: No available PMU. [ 0.095691] rcu: Hierarchical SRCU implementation. [ 0.101059] devtmpfs: initialized [ 0.110407] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns [ 0.121000] futex hash table entries: 256 (order: -1, 3072 bytes, linear) [ 0.129361] pinctrl core: initialized pinctrl subsystem [ 0.135554] regulator-dummy: no parameters, enabled [ 0.141947] NET: Registered protocol family 16 [ 0.149141] thermal_sys: Registered thermal governor 'fair_share' [ 0.149158] thermal_sys: Registered thermal governor 'step_wise' -- hangs --- -- next log steps would have been --- [ 0.156225] thermal_sys: Registered thermal governor 'user_space' [ 0.280761] jz4780_dma_probe [ 0.301402] jz4780-dma 13420000.dma: JZ4780 DMA controller initialised [ 0.309861] fixedregulator@0 GPIO handle specifies active low - ignored [ 0.316601] eth0_power: 3300 mV, disabled [ 0.321627] reg-fixed-voltage fixedregulator@0: eth0_power supplying 3300000uV [ 0.329498] fixedregulator@2 GPIO handle specifies active low - ignored [ 0.336422] otg_power: 5000 mV, enabled [ 0.340541] reg-fixed-voltage fixedregulator@2: otg_power supplying 5000000uV [ 0.348401] usb_power: 5000 mV, enabled [ 0.352813] reg-fixed-voltage fixedregulator@3: usb_power supplying 5000000uV [ 0.360343] fixedregulator@1 GPIO handle specifies active low - ignored [ 0.367062] wlan0_power: no parameters, disabled ... Alpha400/jz4730 (work-in-progress for future upstreaming) as well: [ 0.000000] Linux version 5.12.0-rc6-letux-l400+ (hns@xxxxxxxxxxxxxx) (mipsel-linux-gnu-gcc (GCC) 4.9.2, GNU ld (GNU Binutils) 2.25) #5548 PREEMPT Wed Apr 7 12:21:49 CEST 2021 [ 0.000000] CPU0 revision is: 02d0024f (Ingenic XBurst) [ 0.000000] MIPS: machine is Skytone Alpha 400 [ 0.000000] earlycon: jz4740_uart0 at MMIO32 0x10030000 (options '115200n8') [ 0.000000] printk: bootconsole [jz4740_uart0] enabled [ 0.000000] printk: debug: ignoring loglevel setting. [ 0.000000] User-defined physical RAM map overwrite [ 0.000000] Initrd not found or empty - disabling initrd [ 0.000000] cma: Reserved 32 MiB at 0x01800000 [ 0.000000] Primary instruction cache 16kB, VIPT, 4-way, linesize 32 bytes. [ 0.000000] Primary data cache 16kB, 4-way, VIPT, no aliases, linesize 32 bytes [ 0.000000] Zone ranges: [ 0.000000] Normal [mem 0x0000000000000000-0x0000000007ffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000000000000-0x0000000007ffffff] [ 0.000000] Initmem setup node 0 [mem 0x0000000000000000-0x0000000007ffffff] [ 0.000000] On node 0 totalpages: 32768 [ 0.000000] Normal zone: 288 pages used for memmap [ 0.000000] Normal zone: 0 pages reserved [ 0.000000] Normal zone: 32768 pages, LIFO batch:7 [ 0.000000] pcpu-alloc: s0 r0 d32768 u32768 alloc=1*32768 [ 0.000000] pcpu-alloc: [0] 0 [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 32480 [ 0.000000] Kernel command line: mem=128M earlycon=jz4740_uart,mmio32,0x10030000,115200n8 ignore_loglevel console=tty0 console=ttyS0,115200n8 root=/dev/mmcblk0p2 rw rootfstype=ext4,ext3 rootwait ethaddr=00:21:4D:01:00:EF [ 0.000000] Dentry cache hash table entries: 16384 (order: 4, 65536 bytes, linear) [ 0.000000] Inode-cache hash table entries: 8192 (order: 3, 32768 bytes, linear) [ 0.000000] mem auto-init: stack:off, heap alloc:off, heap free:off [ 0.000000] Memory: 84904K/131072K available (8031K kernel code, 799K rwdata, 2736K rodata, 328K init, 137K bss, 13400K reserved, 32768K cma-reserved) [ 0.000000] rcu: Preemptible hierarchical RCU implementation. [ 0.000000] Trampoline variant of Tasks RCU enabled. [ 0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 10 jiffies. [ 0.000000] NR_IRQS: 256 [ 0.000000] random: get_random_bytes called from start_kernel+0x720/0x960 with crng_init=0 [ 0.000000] ingenic_tcu_clocksource_init: 67108863 vs. 65535 [ 0.000000] clocksource: ingenic-timer: mask: 0x3ffffff max_cycles: 0x3ffffff, max_idle_ns: 8103395207 ns [ 0.000000] ingenic_tcu_setup_cevt: 67108863 vs. 65535 [ 0.000000] ingenic_tcu_init: 26 vs. 16 [ 0.000008] sched_clock: 26 bits at 3686kHz, resolution 271ns, wraps every 9101639544ns [ 0.010312] Console: colour dummy device 80x25 [ 0.019604] printk: console [tty0] enabled [ 0.024130] Calibrating delay loop... 353.89 BogoMIPS (lpj=1769472) [ 0.094511] pid_max: default: 32768 minimum: 301 [ 0.100152] LSM: Security Framework initializing [ 0.105392] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) [ 0.113288] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes, linear) [ 0.131113] Performance counters: No available PMU. [ 0.137166] rcu: Hierarchical SRCU implementation. [ 0.144948] devtmpfs: initialized [ 0.172953] clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 19112604462750000 ns [ 0.185274] futex hash table entries: 256 (order: -1, 3072 bytes, linear) [ 0.200624] pinctrl core: initialized pinctrl subsystem [ 0.211784] regulator-dummy: no parameters, enabled [ 0.225250] NET: Registered protocol family 16 [ 0.254800] thermal_sys: Registered thermal governor 'fair_share' [ 0.254872] thermal_sys: Registered thermal governor 'step_wise' [ 0.261216] thermal_sys: Registered thermal governor 'user_space' [ 0.609902] Kernel bug detected[#1]: [ 0.619939] CPU: 0 PID: 167 Comm: kworker/u2:2 Not tainted 5.12.0-rc6-letux-l400+ #5548 [ 0.628314] $ 0 : 00000000 10000400 81ac4dbb 81ac4dbb [ 0.633876] $ 4 : 00000001 80acb8b0 10000400 ffff00fe [ 0.639433] $ 8 : 83967fe0 00000400 00000000 8091fcc0 [ 0.644990] $12 : 00000068 0000004c 00000033 00000019 [ 0.650544] $16 : 10000401 00000000 8388d980 00000001 [ 0.656099] $20 : 83967ed4 83936894 8388d980 fffffffe [ 0.661659] $24 : 80b8b23c 81ac4dbb [ 0.667212] $28 : 83966000 83967ea8 80bb0000 80151d6c [ 0.672773] Hi : 00000000 [ 0.675780] Lo : 00000000 [ 0.678787] epc : 80151d6c do_task_dead+0x78/0x7c [ 0.683900] ra : 80151d6c do_task_dead+0x78/0x7c [ 0.688996] Status: 10000403 KERNEL EXL IE [ 0.693440] Cause : 00800024 (ExcCode 09) [ 0.697608] PrId : 02d0024f (Ingenic XBurst) [ 0.702137] Modules linked in: [ 0.705349] Process kworker/u2:2 (pid: 167, threadinfo=(ptrval), task=(ptrval), tls=00000000) [ 0.714254] Stack : 83967ed4 81ac4dbb 8388d980 83936660 83936660 8012833c 839bde80 fffffffe [ 0.723225] 10000401 8055ca0c 8398700c 83967ed4 83967ed4 81ac4dbb 839bec80 839bde80 [ 0.732194] fffffffe 80b8b260 80b90000 00000001 8394dc4c fffffffe 80bb0000 8013b4c8 [ 0.741161] 8013b320 80131cac 00000000 00000000 8013b320 839bde80 80b94520 80102cec [ 0.750126] 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 0.759079] ... [ 0.761695] Call Trace: [ 0.764260] [<80151d6c>] do_task_dead+0x78/0x7c [ 0.769018] [<8012833c>] do_exit+0x98c/0x9ac [ 0.773524] [<8013b4c8>] call_usermodehelper_exec_async+0x1a8/0x1c0 [ 0.780079] [<80102cec>] ret_from_kernel_thread+0x14/0x1c [ 0.785739] [ 0.787330] Code: 34428000 0c2348dc ac62000c <000c000d> 27bdffb8 afb7003c 3c1780b9 8ee2b23c afb3002c [ 0.797776] -- hangs --- -- next log steps would have been --- [ 0.872949] jz4780_dma_probe [ 0.896933] jz4780-dma 13020000.dma: JZ4780 DMA controller initialised [ 0.908432] vcc: 3300 mV, enabled [ 0.916920] reg-fixed-voltage regulator@0: vcc supplying 3300000uV [ 0.925474] vmmc: 3300 mV, disabled [ 0.932535] reg-fixed-voltage regulator@1: vmmc supplying 3300000uV [ 0.950092] SCSI subsystem initialized [ 0.958813] libata version 3.00 loaded. ... Any ideas where to look deeper? Is it possible to enable some unit-test early during boot? printk is working, so it could be possible to run some div64_32 test cases if they exist. Or someone can provide a hack for e.g. pinctrl or clocksource driver to run such tests during probe. Well, hacking that into such drivers is something I can do, but what I would need is some series of if (div64_32(...) != ...) printk("div64_32(...) != ...\n"); statements. BR and thanks, Nikolaus Schaller