lkml.org 
[lkml]   [2018]   [Apr]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC 01/10] PCI: dwc: Add MSI-X callbacks handler
From
Date

Hi Kishon,

On 24/04/2018 12:24, Kishon Vijay Abraham I wrote:
> Hi,
>
> On Tuesday 24 April 2018 03:06 PM, Gustavo Pimentel wrote:
>> Hi Kishon,
>>
>> On 24/04/2018 08:07, Kishon Vijay Abraham I wrote:
>>> Hi,
>>>
>>> On Monday 23 April 2018 03:06 PM, Gustavo Pimentel wrote:
>>>> Hi Kishon,
>>>>
>>>> On 16/04/2018 10:29, Kishon Vijay Abraham I wrote:
>>>>> Hi Gustavo,
>>>>>
>>>>> On Tuesday 10 April 2018 10:44 PM, Gustavo Pimentel wrote:
>>>>>> Changes the pcie_raise_irq function signature, namely the interrupt_num
>>>>>> variable type from u8 to u16 to accommodate the MSI-X maximum interrupts
>>>>>> of 2048.
>>>>>>
>>>>>> Implements a PCIe config space capability iterator function to search and
>>>>>> save the MSI and MSI-X pointers. With this method the code becomes more
>>>>>> generic and flexible.
>>>>>>
>>>>>> Implements MSI-X set/get functions for sysfs interface in order to change
>>>>>> the EP entries number.
>>>>>>
>>>>>> Implements EP MSI-X interface for triggering interruptions.
>>>>>>
>>>>>> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
>>>>>> ---
>>>>>> drivers/pci/dwc/pci-dra7xx.c | 2 +-
>>>>>> drivers/pci/dwc/pcie-artpec6.c | 2 +-
>>>>>> drivers/pci/dwc/pcie-designware-ep.c | 145 ++++++++++++++++++++++++++++++++-
>>>>>> drivers/pci/dwc/pcie-designware-plat.c | 6 +-
>>>>>> drivers/pci/dwc/pcie-designware.h | 23 +++++-
>>>>>> 5 files changed, 173 insertions(+), 5 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
>>>>>> index ed8558d..5265725 100644
>>>>>> --- a/drivers/pci/dwc/pci-dra7xx.c
>>>>>> +++ b/drivers/pci/dwc/pci-dra7xx.c
>>>>>> @@ -369,7 +369,7 @@ static void dra7xx_pcie_raise_msi_irq(struct dra7xx_pcie *dra7xx,
>>>>>> }
>>>>>>
>>>>>> static int dra7xx_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
>>>>>> - enum pci_epc_irq_type type, u8 interrupt_num)
>>>>>> + enum pci_epc_irq_type type, u16 interrupt_num)
>>>>>> {
>>>>>> struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
>>>>>> struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
>>>>>> diff --git a/drivers/pci/dwc/pcie-artpec6.c b/drivers/pci/dwc/pcie-artpec6.c
>>>>>> index e66cede..96dc259 100644
>>>>>> --- a/drivers/pci/dwc/pcie-artpec6.c
>>>>>> +++ b/drivers/pci/dwc/pcie-artpec6.c
>>>>>> @@ -428,7 +428,7 @@ static void artpec6_pcie_ep_init(struct dw_pcie_ep *ep)
>>>>>> }
>>>>>>
>>>>>> static int artpec6_pcie_raise_irq(struct dw_pcie_ep *ep, u8 func_no,
>>>>>> - enum pci_epc_irq_type type, u8 interrupt_num)
>>>>>> + enum pci_epc_irq_type type, u16 interrupt_num)
>>>>>> {
>>>>>> struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
>>>>>>
>>>>>> diff --git a/drivers/pci/dwc/pcie-designware-ep.c b/drivers/pci/dwc/pcie-designware-ep.c
>>>>>> index 15b22a6..874d4c2 100644
>>>>>> --- a/drivers/pci/dwc/pcie-designware-ep.c
>>>>>> +++ b/drivers/pci/dwc/pcie-designware-ep.c
>>>>>> @@ -40,6 +40,44 @@ void dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar)
>>>>>> __dw_pcie_ep_reset_bar(pci, bar, 0);
>>>>>> }
>>>>>>
>>>>>> +void dw_pcie_ep_find_cap_addr(struct dw_pcie_ep *ep)
>>>>>> +{
>>>>>
>>>>> This should be implemented in a generic way similar to pci_find_capability().
>>>>> It'll be useful when we try to implement other capabilities as well.
>>>>
>>>> Hum, what you suggest? Something implemented on the pci-epf-core?
>>>
>>> yeah, Initially thought it could be implemented as a helper function in
>>> pci-epc-core so that both designware and cadence can use it.
>>
>> That would be nice, however I couldn't find out how to access the config space,
>> through the pci_epf or pci_epc structs.
>
> It's just a helper function so it can directly take the base address of the
> configuration space as argument (in our case, it should be dbi_base).

I don't think it will bring much benefit to this particular scope at this time
being. In any case this could be improved later.

Regards,
Gustavo

>
> Thanks
> Kishon
>
>>
>> So, I reworked the functions like this:
>>
>> (on pcie-designware-ep.c)
>>
>> u8 __dw_pcie_ep_find_next_cap(struct dw_pcie *pci, u8 cap_ptr,
>> u8 cap)
>> {
>> u8 cap_id, next_cap_ptr;
>> u16 reg;
>>
>> reg = dw_pcie_readw_dbi(pci, cap_ptr);
>> next_cap_ptr = (reg & 0xff00) >> 8;
>> cap_id = (reg & 0x00ff);
>>
>> if (!next_cap_ptr || cap_id > PCI_CAP_ID_MAX)
>> return 0;
>>
>> if (cap_id == cap)
>> return cap_ptr;
>>
>> return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap);
>> }
>>
>> u8 dw_pcie_ep_find_capability(struct dw_pcie *pci, u8 cap)
>> {
>> u8 next_cap_ptr;
>> u16 reg;
>>
>> reg = dw_pcie_readw_dbi(pci, PCI_CAPABILITY_LIST);
>> next_cap_ptr = (reg & 0x00ff);
>>
>> if (!next_cap_ptr)
>> return 0;
>>
>> return __dw_pcie_ep_find_next_cap(pci, next_cap_ptr, cap);
>> }
>>
>> int dw_pcie_ep_init(struct dw_pcie_ep *ep)
>> {
>> [...]
>> ep->msi_cap = dw_pcie_ep_find_capability(pci, PCI_CAP_ID_MSI);
>> ep->msix_cap = dw_pcie_ep_find_capability(pci, PCI_CAP_ID_MSIX);
>> [...]
>> }
>>
>>>
>>> But do we really have to find the address like this? since all designware IP's
>>> will have a particular capability at a fixed address offset, why not follow use
>>> existing mechanism in dw_pcie_ep_get_msi?
>>
>> The capabilities are not fixed to a specific address offset by default they
>> assume those values, but they can be easily change at design stage.
>>
>>>
>>> Or is it possible for a particular capability to have address offsets for
>>> different vendors? How is it for cadence?
>>
>> Yes, it's possible to have different address offset for different vendors.
>>
>>>
>>> Thanks
>>> Kishon
>>>
>>
>> Thanks,
>> Gustavo
>>


\
 
 \ /
  Last update: 2018-04-26 17:31    [W:0.114 / U:0.592 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site