Re: [PATCH v2] PCI: keystone: fix msi code that retrieves the pp struct ptr

[Murali Karicheri <m-karicheri2@ti.com>]

On 02/29/2016 06:20 PM, Bjorn Helgaas wrote:
> [-cc stable, +cc Zhou]
> 
> On Mon, Feb 29, 2016 at 10:51:53AM -0500, Murali Karicheri wrote:
>> Recent update to pcie-designware core driver, 
>> 'commit cbce7900598c ("PCI: designware: Make driver arch-agnostic")'
>> broke the keystone PCI driver. After this commit, we see a kernel crash on
>> Keystone SoC as shown below in the boot log. This is because, the way pp
>> struct ptr is retrieved from  msi desc has changed and require similar
>> update in pci-keystone-dw.c as well. This patch fixes this issue. 
>>
>> [    1.012999] pci 0000:00:00.0: PCI bridge to [bus 01]
>> [    1.018073] pci 0000:00:00.0:   bridge window [io  0x1000-0x1fff]
>> [    1.024308] pci 0000:00:00.0:   bridge window [mem 0x60000000-0x600fffff]
>> [    1.031216] pci 0000:00:00.0:   bridge window [mem 0x60100000-0x601fffff
>> pref]
>> [    1.038736] Unable to handle kernel NULL pointer dereference at virtual
>> address 00000030
>> [    1.046950] pgd = c0003000
>> [    1.049750] [00000030] *pgd=80000800004003, *pmd=00000000
>> [    1.055265] Internal error: Oops: 206 [#1] PREEMPT SMP ARM
>> [    1.060860] Modules linked in:
>> [    1.064013] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.2-00139-gb74f926 #2
>> [    1.071266] Hardware name: Keystone
>> [    1.074853] task: eb888000 ti: eb890000 task.ti: eb890000
>> [    1.080364] PC is at ks_dw_pcie_msi_irq_unmask+0x24/0x58
>> [    1.085785] LR is at ks_dw_pcie_msi_irq_unmask+0x18/0x58
>> [    1.091206] pc : [<c02f65c8>]    lr : [<c02f65bc>]    psr: 60000093
>> [    1.091206] sp : eb891bc8  ip : 00000000  fp : ebb15010
>> [    1.102915] r10: 00000051  r9 : 60000013  r8 : ebafaa20
>> [    1.108247] r7 : ebaa9f80  r6 : eb9fd0c0  r5 : ebafa9d0  r4 : ebafa9c0
>> [    1.114889] r3 : 00000051  r2 : 00000000  r1 : 00000001  r0 : ebb14c18
>> [    1.121533] Flags: nZCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment
>> kernel
>> [    1.129049] Control: 30c5387d  Table: 00003000  DAC: fffffffd
>> [    1.134905] Process swapper/0 (pid: 1, stack limit = 0xeb890210)
>> [    1.141023] Stack: (0xeb891bc8 to 0xeb892000)
>>
>> Cc: Bjorn Helgaas <bhelgaas@google.com>
>> Cc: <stable@vger.kernel.org> # 4.4.x
>> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
> 
> This fixes a regression, so I applied this to for-linus for v4.5, with
> changelog as follows:
> 
Thanks Bjorn,

Regards,

Murali
> commit 79e3f4a853ed161cd4c06d84b50beebf961a47c6
> Author: Murali Karicheri <m-karicheri2@ti.com>
> Date:   Mon Feb 29 17:18:22 2016 -0600
> 
>     PCI: keystone: Fix MSI code that retrieves struct pcie_port pointer
>     
>     Commit cbce7900598c ("PCI: designware: Make driver arch-agnostic") changed
>     the host bridge sysdata pointer from the ARM pci_sys_data to the DesignWare
>     pcie_port structure, and changed pcie-designware.c to reflect that.  But it
>     did not change the corresponding code in pci-keystone-dw.c, so it caused
>     crashes on Keystone:
>     
>       Unable to handle kernel NULL pointer dereference at virtual address 00000030
>       pgd = c0003000
>       [00000030] *pgd=80000800004003, *pmd=00000000
>       Internal error: Oops: 206 [#1] PREEMPT SMP ARM
>       CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.2-00139-gb74f926 #2
>       Hardware name: Keystone
>       PC is at ks_dw_pcie_msi_irq_unmask+0x24/0x58
>     
>     Change pci-keystone-dw.c to expect sysdata to be the struct pcie_port
>     pointer.
>     
>     [bhelgaas: changelog]
>     Fixes: cbce7900598c ("PCI: designware: Make driver arch-agnostic")
>     Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
>     Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
>     CC: stable@vger.kernel.org	# v4.4+
>     CC: Zhou Wang <wangzhou1@hisilicon.com>
> 
>> ---
>>  v2 - Looks like I missed the fix version format for stable.
>>       Fixed it per best of my knowledge.
>>  v1 - Resending as per stable submission procedure
>>  drivers/pci/host/pci-keystone-dw.c | 11 +++--------
>>  1 file changed, 3 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/pci/host/pci-keystone-dw.c b/drivers/pci/host/pci-keystone-dw.c
>> index ed34c95..6153853 100644
>> --- a/drivers/pci/host/pci-keystone-dw.c
>> +++ b/drivers/pci/host/pci-keystone-dw.c
>> @@ -58,11 +58,6 @@
>>  
>>  #define to_keystone_pcie(x)	container_of(x, struct keystone_pcie, pp)
>>  
>> -static inline struct pcie_port *sys_to_pcie(struct pci_sys_data *sys)
>> -{
>> -	return sys->private_data;
>> -}
>> -
>>  static inline void update_reg_offset_bit_pos(u32 offset, u32 *reg_offset,
>>  					     u32 *bit_pos)
>>  {
>> @@ -108,7 +103,7 @@ static void ks_dw_pcie_msi_irq_ack(struct irq_data *d)
>>  	struct pcie_port *pp;
>>  
>>  	msi = irq_data_get_msi_desc(d);
>> -	pp = sys_to_pcie(msi_desc_to_pci_sysdata(msi));
>> +	pp = (struct pcie_port *) msi_desc_to_pci_sysdata(msi);
>>  	ks_pcie = to_keystone_pcie(pp);
>>  	offset = d->irq - irq_linear_revmap(pp->irq_domain, 0);
>>  	update_reg_offset_bit_pos(offset, &reg_offset, &bit_pos);
>> @@ -146,7 +141,7 @@ static void ks_dw_pcie_msi_irq_mask(struct irq_data *d)
>>  	u32 offset;
>>  
>>  	msi = irq_data_get_msi_desc(d);
>> -	pp = sys_to_pcie(msi_desc_to_pci_sysdata(msi));
>> +	pp = (struct pcie_port *) msi_desc_to_pci_sysdata(msi);
>>  	ks_pcie = to_keystone_pcie(pp);
>>  	offset = d->irq - irq_linear_revmap(pp->irq_domain, 0);
>>  
>> @@ -167,7 +162,7 @@ static void ks_dw_pcie_msi_irq_unmask(struct irq_data *d)
>>  	u32 offset;
>>  
>>  	msi = irq_data_get_msi_desc(d);
>> -	pp = sys_to_pcie(msi_desc_to_pci_sysdata(msi));
>> +	pp = (struct pcie_port *) msi_desc_to_pci_sysdata(msi);
>>  	ks_pcie = to_keystone_pcie(pp);
>>  	offset = d->irq - irq_linear_revmap(pp->irq_domain, 0);
>>  
>> -- 
>> 1.9.1
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html


-- 
Murali Karicheri
Linux Kernel, Keystone