[RFC][PATCH 2/2] powerpc/fsl-pci Make PCIe hotplug work with Freescale
Kumar Gala
galak at kernel.crashing.org
Sat Apr 6 04:37:52 EST 2013
On Apr 3, 2013, at 2:09 AM, Rojhalat Ibrahim wrote:
> Hi Kumar,
>
> what about this patch? Any reasons not to apply?
>
> Rojhalat
Was on vacation, getting back to it now. Do send a proper patch w/commit message & signed-off-by.
- k
>
>
> On Monday 18 March 2013 10:22:40 Rojhalat Ibrahim wrote:
>> On Thursday 14 March 2013 15:35:40 Kumar Gala wrote:
>>> On Mar 14, 2013, at 4:43 AM, Rojhalat Ibrahim wrote:
>>>> On Wednesday 13 March 2013 14:07:16 Kumar Gala wrote:
>>>>> diff --git a/arch/powerpc/sysdev/fsl_pci.c
>>>>> b/arch/powerpc/sysdev/fsl_pci.c
>>>>> index 41bbcc4..b18c377 100644
>>>>> --- a/arch/powerpc/sysdev/fsl_pci.c
>>>>> +++ b/arch/powerpc/sysdev/fsl_pci.c
>>>>> @@ -74,6 +74,35 @@ static int __init fsl_pcie_check_link(struct
>>>>> pci_controller *hose) return 0;
>>>>> }
>>>>>
>>>>> +static int fsl_indirect_read_config(struct pci_bus *bus, unsigned int
>>>>> devfn, + int offset, int len, u32 *val)
>>>>> +{
>>>>> + struct pci_controller *hose = pci_bus_to_host(bus);
>>>>> +
>>>>> + /* check the link status */
>>>>> + if ((bus->number == hose->first_busno) && (devfn == 0)) {
>>>>> + if (fsl_pcie_check_link(hose))
>>>>> + hose->indirect_type |= PPC_INDIRECT_TYPE_NO_PCIE_LINK;
>>>>> + else
>>>>> + hose->indirect_type &= ~PPC_INDIRECT_TYPE_NO_PCIE_LINK;
>>>>> + }
>>>>> + return indirect_read_config(bus, devfn, offset, len, val);
>>>>> +}
>>>>> +
>>>>
>>>> This does not work because fsl_indirect_read_config calls
>>>> fsl_pcie_check_link which calls early_read_config_dword which eventually
>>>> calls fsl_indirect_read_config, so the kernel hangs in a recursion loop.
>>>> Below is a modified patch that does work.
>>>
>>> ok, that makes sense, but I guess now its making me question the following
> statement:
>>>> if ((bus->number == hose->first_busno) && (devfn == 0)) {
>>>
>>> Why do we have this conditional?
>>>
>>> - k
>>
>> Right. This is not necessary anymore. I modified the patch accordingly.
>>
>>
>> Signed-off-by: Rojhalat Ibrahim <imr at rtschenk.de>
>> ---
>> arch/powerpc/include/asm/pci-bridge.h | 6 ++++
>> arch/powerpc/sysdev/fsl_pci.c | 51
>> +++++++++++++++++++++++++++++----- arch/powerpc/sysdev/indirect_pci.c |
>> 10 ++----
>> 3 files changed, 54 insertions(+), 13 deletions(-)
>>
>> diff --git a/arch/powerpc/include/asm/pci-bridge.h
>> b/arch/powerpc/include/asm/pci-bridge.h index c0278f0..ffbc5fd 100644
>> --- a/arch/powerpc/include/asm/pci-bridge.h
>> +++ b/arch/powerpc/include/asm/pci-bridge.h
>> @@ -120,6 +120,12 @@ extern void setup_indirect_pci(struct pci_controller*
>> hose, resource_size_t cfg_addr,
>> resource_size_t cfg_data, u32 flags);
>>
>> +extern int indirect_read_config(struct pci_bus *bus, unsigned int devfn,
>> + int offset, int len, u32 *val);
>> +
>> +extern int indirect_write_config(struct pci_bus *bus, unsigned int devfn,
>> + int offset, int len, u32 val);
>> +
>> static inline struct pci_controller *pci_bus_to_host(const struct pci_bus
>> *bus) {
>> return bus->sysdata;
>> diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
>> index 41bbcc4..9c0fcc9 100644
>> --- a/arch/powerpc/sysdev/fsl_pci.c
>> +++ b/arch/powerpc/sysdev/fsl_pci.c
>> @@ -54,12 +54,22 @@ static void quirk_fsl_pcie_header(struct pci_dev *dev)
>> return;
>> }
>>
>> -static int __init fsl_pcie_check_link(struct pci_controller *hose)
>> +static int fsl_indirect_read_config(struct pci_bus *, unsigned int,
>> + int, int, u32 *);
>> +
>> +static int fsl_pcie_check_link(struct pci_controller *hose)
>> {
>> - u32 val;
>> + u32 val = 0;
>>
>> if (hose->indirect_type & PPC_INDIRECT_TYPE_FSL_CFG_REG_LINK) {
>> - early_read_config_dword(hose, 0, 0, PCIE_LTSSM, &val);
>> + if (hose->ops->read == fsl_indirect_read_config) {
>> + struct pci_bus bus;
>> + bus.number = 0;
>> + bus.sysdata = hose;
>> + bus.ops = hose->ops;
>> + indirect_read_config(&bus, 0, PCIE_LTSSM, 4, &val);
>> + } else
>> + early_read_config_dword(hose, 0, 0, PCIE_LTSSM, &val);
>> if (val < PCIE_LTSSM_L0)
>> return 1;
>> } else {
>> @@ -74,6 +84,33 @@ static int __init fsl_pcie_check_link(struct
>> pci_controller *hose) return 0;
>> }
>>
>> +static int fsl_indirect_read_config(struct pci_bus *bus, unsigned int
>> devfn, + int offset, int len, u32 *val)
>> +{
>> + struct pci_controller *hose = pci_bus_to_host(bus);
>> +
>> + if (fsl_pcie_check_link(hose))
>> + hose->indirect_type |= PPC_INDIRECT_TYPE_NO_PCIE_LINK;
>> + else
>> + hose->indirect_type &= ~PPC_INDIRECT_TYPE_NO_PCIE_LINK;
>> +
>> + return indirect_read_config(bus, devfn, offset, len, val);
>> +}
>> +
>> +static struct pci_ops fsl_indirect_pci_ops =
>> +{
>> + .read = fsl_indirect_read_config,
>> + .write = indirect_write_config,
>> +};
>> +
>> +static void __init fsl_setup_indirect_pci(struct pci_controller* hose,
>> + resource_size_t cfg_addr,
>> + resource_size_t cfg_data, u32 flags)
>> +{
>> + setup_indirect_pci(hose, cfg_addr, cfg_data, flags);
>> + hose->ops = &fsl_indirect_pci_ops;
>> +}
>> +
>> #if defined(CONFIG_FSL_SOC_BOOKE) || defined(CONFIG_PPC_86xx)
>>
>> #define MAX_PHYS_ADDR_BITS 40
>> @@ -469,8 +506,8 @@ int __init fsl_add_bridge(struct platform_device *pdev,
>> int is_primary) if (!hose->private_data)
>> goto no_bridge;
>>
>> - setup_indirect_pci(hose, rsrc.start, rsrc.start + 0x4,
>> - PPC_INDIRECT_TYPE_BIG_ENDIAN);
>> + fsl_setup_indirect_pci(hose, rsrc.start, rsrc.start + 0x4,
>> + PPC_INDIRECT_TYPE_BIG_ENDIAN);
>>
>> if (in_be32(&pci->block_rev1) < PCIE_IP_REV_3_0)
>> hose->indirect_type |= PPC_INDIRECT_TYPE_FSL_CFG_REG_LINK;
>> @@ -779,8 +816,8 @@ int __init mpc83xx_add_bridge(struct device_node *dev)
>> if (ret)
>> goto err0;
>> } else {
>> - setup_indirect_pci(hose, rsrc_cfg.start,
>> - rsrc_cfg.start + 4, 0);
>> + fsl_setup_indirect_pci(hose, rsrc_cfg.start,
>> + rsrc_cfg.start + 4, 0);
>> }
>>
>> printk(KERN_INFO "Found FSL PCI host bridge at 0x%016llx. "
>> diff --git a/arch/powerpc/sysdev/indirect_pci.c
>> b/arch/powerpc/sysdev/indirect_pci.c index 82fdad8..c6c8b52 100644
>> --- a/arch/powerpc/sysdev/indirect_pci.c
>> +++ b/arch/powerpc/sysdev/indirect_pci.c
>> @@ -20,9 +20,8 @@
>> #include <asm/pci-bridge.h>
>> #include <asm/machdep.h>
>>
>> -static int
>> -indirect_read_config(struct pci_bus *bus, unsigned int devfn, int offset,
>> - int len, u32 *val)
>> +int indirect_read_config(struct pci_bus *bus, unsigned int devfn,
>> + int offset, int len, u32 *val)
>> {
>> struct pci_controller *hose = pci_bus_to_host(bus);
>> volatile void __iomem *cfg_data;
>> @@ -78,9 +77,8 @@ indirect_read_config(struct pci_bus *bus, unsigned int
>> devfn, int offset, return PCIBIOS_SUCCESSFUL;
>> }
>>
>> -static int
>> -indirect_write_config(struct pci_bus *bus, unsigned int devfn, int offset,
>> - int len, u32 val)
>> +int indirect_write_config(struct pci_bus *bus, unsigned int devfn,
>> + int offset, int len, u32 val)
>> {
>> struct pci_controller *hose = pci_bus_to_host(bus);
>> volatile void __iomem *cfg_data;
>>
>>
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