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Re: [Xen-devel] Dom0 kernel panic when porting xen to new arm soc

To: Julien Grall <julien.grall.oss@xxxxxxxxx>, Ian Campbell <ian.campbell@xxxxxxxxxx>

From: Peng Fan <van.freenix@xxxxxxxxx>

Date: Sat, 20 Jun 2015 22:08:16 +0800

Cc: julien.grall@xxxxxxxxxx, xen-devel@xxxxxxxxxxxxx

Delivery-date: Sat, 20 Jun 2015 14:08:27 +0000

List-id: Xen developer discussion <xen-devel.lists.xen.org>

Hi Julien, On 6/20/2015 6:19 PM, Julien Grall wrote: > Hi, > > On 19/06/2015 14:22, Peng Fan wrote: >> diff --git a/kernel/timer.c b/kernel/timer.c >> index 38f0d40..4a025cc 100644 >> --- a/kernel/timer.c >> +++ b/kernel/timer.c >> @@ -1175,6 +1175,10 @@ static inline void __run_timers(struct tvec_base >> *base) >> >> base->running_timer = timer; >> detach_expired_timer(timer, base); >> + if (!fn) { >> + printk("fn is null why????\n"); ----> >> This log only shows once. Not sure why fn is null and only once. >> + continue; >> + } >> >> if (irqsafe) { >> spin_unlock(&base->lock); > > By any chance, does your board has a another timer (i.e other than the > generic timer)? Yeah. There is a another timer whose rating is lower that generic timer. > > I would also track down to see who is adding this timer. > >> But after apply the above kernel patch, Dom0 Linux can handle shell >> input. >> Just have another question, How can Dom0 handle DMA for arm. > > When Xen is allocating the RAM bank for DOM0 we use a direct mapping > (i.e the Physical Address = Intermediate Address for the RAM). So DOM0 > can perform DMA as on baremetal. Thanks. Current, without using rootfs in sd card, my Dom0 kernel can boot using ramfs. But if with sdhc which use ADMA, Dom0 kernel will panic. Below is the log: sdhci: Secure Digital Host Controller Interface driver sdhci: Copyright(c) Pierre Ossman sdhci-pltfm: SDHCI platform and OF driver helper Unable to handle kernel NULL pointer dereference at virtual address 00000000 pgd = 80004000 [00000000] *pgd=00000000 Internal error: Oops: 5 [#1] PREEMPT SMP ARM Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.38-02383-g5ccf32b-dirty #22 task: 84074000 ti: 84078000 task.ti: 84078000 PC is at bitmap_clear+0xc0/0xdc LR is at bitmap_clear+0x54/0xdc pc : [<8029deb8>] lr : [<8029de4c>] psr: 20000193 sp : 84079d80 ip : 00000001 fp : 00000000 r10: 00077fff r9 : 00000404 r8 : 00000001 r7 : 00000001 r6 : 00000001 r5 : 00000000 r4 : ffffffff r3 : 00000001 r2 : 00000001 r1 : 20000193 r0 : 00000015 Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel Control: 10c53c7d Table: 8800406a DAC: 00000015 Process swapper/0 (pid: 1, stack limit = 0x84078238) Stack: (0x84079d80 to 0x8407a000) 9d80: 80000113 00000000 87efa000 81109918 00001000 800197f8 84128558 00080008 9da0: 84079dec 000000d0 84bfeac0 84126c10 84126c10 ffffffff 00000404 ffffffff 9dc0: 00000000 00000402 00000000 00000000 84126c10 80310ba8 ffffffff 00000000 9de0: 00000000 00000524 84078000 00000000 00000000 ffffffff ffffffff 84bfeac0 9e00: 84bfe800 8000b407 07eb0000 8116e0f8 00000000 804ee81c ffffffff ffffffff 9e20: 00000000 84126c10 84c92010 84bfeac0 00000000 84126c10 84126c00 84bfeac0 9e40: 84078030 804f08e4 804f03d8 84126c10 fffffdfb 8115401c 8115401c 00000000 9e60: 0000010f 80362330 803622ec 84126c10 811c8098 00000000 8115401c 80360b1c 9e80: 84126c10 8115401c 84126c44 00000000 80de1888 80360d28 00000000 8115401c 9ea0: 80360c9c 8035f10c 8406965c 84123634 8115401c 84c8bf80 8112f3c8 803602bc 9ec0: 80d08314 8115401c 00000006 8115401c 00000006 8116e080 8116e080 8036130c 9ee0: 00000000 80e00f78 00000006 800088dc 8400f900 80c94fe0 840bd480 80735184 9f00: 00000000 8116e080 0000150c 8012d430 00000000 811105b0 60000113 00000001 9f20: 87ffc576 8075ca38 0000010f 8004b0f0 80d66884 00000006 87ffc583 00000006 9f40: 811105a0 80e00f78 00000006 8116e080 8116e080 80da150c 0000010f 80df4154 9f60: 80df4148 80da1c4c 00000006 00000006 80da150c 9355553c 84079f9c 80731338 9f80: 00000000 00000000 80727254 00000000 00000000 00000000 00000000 00000000 9fa0: 00000000 8072725c 00000000 8000ecf8 00000000 00000000 00000000 00000000 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 9355553c 9355553c [<8029deb8>] (bitmap_clear) from [<800197f8>] (__arm_dma_free.isra.18+0xe4/0x228) [<800197f8>] (__arm_dma_free.isra.18) from [<80310ba8>] (xen_swiotlb_free_coherent+0xfc/0x140) [<80310ba8>] (xen_swiotlb_free_coherent) from [<804ee81c>] (sdhci_add_host+0xb34/0xe64) [<804ee81c>] (sdhci_add_host) from [<804f08e4>] (sdhci_esdhc_imx_probe+0x50c/0x808) [<804f08e4>] (sdhci_esdhc_imx_probe) from [<80362330>] (platform_drv_probe+0x44/0xa4) [<80362330>] (platform_drv_probe) from [<80360b1c>] (driver_probe_device+0x120/0x25c) [<80360b1c>] (driver_probe_device) from [<80360d28>] (__driver_attach+0x8c/0x90) [<80360d28>] (__driver_attach) from [<8035f10c>] (bus_for_each_dev+0x60/0x94) [<8035f10c>] (bus_for_each_dev) from [<803602bc>] (bus_add_driver+0x148/0x1f0) [<803602bc>] (bus_add_driver) from [<8036130c>] (driver_register+0x78/0xf8) [<8036130c>] (driver_register) from [<800088dc>] (do_one_initcall+0xf8/0x144) [<800088dc>] (do_one_initcall) from [<80da1c4c>] (kernel_init_freeable+0x138/0x1d8) [<80da1c4c>] (kernel_init_freeable) from [<8072725c>] (kernel_init+0x8/0xf0) [<8072725c>] (kernel_init) from [<8000ecf8>] (ret_from_fork+0x14/0x3c) Code: 10866003 1206601f 10633006 11e02312 (e5953000) ---[ end trace f6f103bb73cc0503 ]--- note: swapper/0[1] exited with preempt_count 1 Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b The piece code is at here: if (host->flags & SDHCI_USE_ADMA) { /* * We need to allocate descriptors for all sg entries * (128) and potentially one alignment transfer for * each of those entries. */ host->adma_desc = dma_alloc_coherent(mmc_dev(host->mmc), ADMA_SIZE, &host->adma_addr, GFP_KERNEL); host->align_buffer = kmalloc(128 * 4, GFP_KERNEL); printk("%p %p\n", host->adma_desc, host->align_buffer); ---> Here host->adma_desc is NULL if (!host->adma_desc || !host->align_buffer) { dma_free_coherent(mmc_dev(host->mmc), ADMA_SIZE, -->Trigger panic host->adma_desc, host->adma_addr); kfree(host->align_buffer); So dma_alloc_coherent failed, dma_free_coherent-->bitmap_clear trigger Dom0 panic. 128M memory is for Dom0, dma_alloc_coherent should not fail. Do you have any suggestions? > > Regards, > Thanks, Peng. _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel

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