[PATCH v2] PCI: designware: Add support 4 ATUs assignment

Srikanth Thokala sriku.linux at gmail.com
Wed Nov 12 01:01:09 PST 2014


Hi Minghuan,

On Wed, Nov 12, 2014 at 12:44 PM, Lian Minghuan-B31939
<B31939 at freescale.com> wrote:
> Hi  Srikanth,
>
> Thanks for your comments, please see my reply inline.
>
>
> On 2014年11月12日 14:22, Srikanth Thokala wrote:
>>
>> Hi,
>>
>> On Tue, Nov 11, 2014 at 10:37 AM, Minghuan Lian
>> <Minghuan.Lian at freescale.com> wrote:
>>>
>>> Currently, pcie-designware.c only supports two ATUs, ATU0 is used
>>> for CFG0 and MEM, ATU1 is used for CFG1 and IO. There is a conflict
>>> when MEM and CFG0 are accessed simultaneously. The patch adds
>>> 'num-atus' property to PCIe dts node to describe the number of
>>> PCIe controller's ATUs. If num_atus is bigger than or equal to 4,
>>> we will change ATUs assignment: ATU0 for CFG0, ATU1 for CFG1,
>>> ATU2 for MEM, ATU3 for IO.
>>>
>>> Signed-off-by: Minghuan Lian <Minghuan.Lian at freescale.com>
>>> ---
>>> change log:
>>> v1-v2:
>>> 1. add the default value to property num-atus description
>>> 2. Use atu_idx[] instead of single values
>>> 3. initialize num_atus to 2
>>>
>>>   .../devicetree/bindings/pci/designware-pcie.txt    |  1 +
>>>   drivers/pci/host/pcie-designware.c                 | 53
>>> ++++++++++++++++------
>>>   drivers/pci/host/pcie-designware.h                 |  9 ++++
>>>   3 files changed, 50 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/pci/designware-pcie.txt
>>> b/Documentation/devicetree/bindings/pci/designware-pcie.txt
>>> index 9f4faa8..64d0533 100644
>>> --- a/Documentation/devicetree/bindings/pci/designware-pcie.txt
>>> +++ b/Documentation/devicetree/bindings/pci/designware-pcie.txt
>>> @@ -26,3 +26,4 @@ Optional properties:
>>>   - bus-range: PCI bus numbers covered (it is recommended for new
>>> devicetrees to
>>>     specify this property, to keep backwards compatibility a range of
>>> 0x00-0xff
>>>     is assumed if not present)
>>> +- num-atus: number of ATUs. The default value is 2 if not present.
>>> diff --git a/drivers/pci/host/pcie-designware.c
>>> b/drivers/pci/host/pcie-designware.c
>>> index dfed00a..46a609d 100644
>>> --- a/drivers/pci/host/pcie-designware.c
>>> +++ b/drivers/pci/host/pcie-designware.c
>>> @@ -48,6 +48,8 @@
>>>   #define PCIE_ATU_VIEWPORT              0x900
>>>   #define PCIE_ATU_REGION_INBOUND                (0x1 << 31)
>>>   #define PCIE_ATU_REGION_OUTBOUND       (0x0 << 31)
>>> +#define PCIE_ATU_REGION_INDEX3         (0x3 << 0)
>>> +#define PCIE_ATU_REGION_INDEX2         (0x2 << 0)
>>>   #define PCIE_ATU_REGION_INDEX1         (0x1 << 0)
>>>   #define PCIE_ATU_REGION_INDEX0         (0x0 << 0)
>>>   #define PCIE_ATU_CR1                   0x904
>>> @@ -346,7 +348,7 @@ int __init dw_pcie_host_init(struct pcie_port *pp)
>>>          struct of_pci_range range;
>>>          struct of_pci_range_parser parser;
>>>          struct resource *cfg_res;
>>> -       u32 val, na, ns;
>>> +       u32 num_atus = 2, val, na, ns;
>>
>> I think this can be u8?
>
> [Minghuan] I define num-atus like this: num-atus = <6> (our controller
> supports 6 outbound ATUs)
> So, num_atus should be u32 type.
> If we use u8 type to define num_atus, the dts node should be changed to
> num_atus = /bits/ 8 <8>.
> I prefer the previous definition num-atus = <6> which is more simple and
> clear.

Yes, I agree.  But as it holds only 6 possible distinct values, I
prefer to use u8.

>>>
>>>          const __be32 *addrp;
>>>          int i, index, ret;
>>>
>>> @@ -486,6 +488,19 @@ int __init dw_pcie_host_init(struct pcie_port *pp)
>>>                  }
>>>          }
>>>
>>> +       of_property_read_u32(np, "num-atus", &num_atus);
>>
>> and here too?
>
> [Minghuan] please refer to the above interpretation.
>
>>> +       if (num_atus >= 4) {
>>> +               pp->atu_idx[ATU_TYPE_CFG0] = PCIE_ATU_REGION_INDEX0;
>>> +               pp->atu_idx[ATU_TYPE_CFG1] = PCIE_ATU_REGION_INDEX1;
>>> +               pp->atu_idx[ATU_TYPE_MEM] = PCIE_ATU_REGION_INDEX2;
>>> +               pp->atu_idx[ATU_TYPE_IO] = PCIE_ATU_REGION_INDEX3;
>>> +       } else {
>>> +               pp->atu_idx[ATU_TYPE_CFG0] = PCIE_ATU_REGION_INDEX0;
>>> +               pp->atu_idx[ATU_TYPE_MEM] = PCIE_ATU_REGION_INDEX0;
>>> +               pp->atu_idx[ATU_TYPE_CFG1] = PCIE_ATU_REGION_INDEX1;
>>> +               pp->atu_idx[ATU_TYPE_IO] = PCIE_ATU_REGION_INDEX1;
>>> +       }
>>> +
>>>          if (pp->ops->host_init)
>>>                  pp->ops->host_init(pp);
>>>
>>> @@ -511,8 +526,9 @@ int __init dw_pcie_host_init(struct pcie_port *pp)
>>>
>>>   static void dw_pcie_prog_viewport_cfg0(struct pcie_port *pp, u32
>>> busdev)
>>>   {
>>> -       /* Program viewport 0 : OUTBOUND : CFG0 */
>>> -       dw_pcie_writel_rc(pp, PCIE_ATU_REGION_OUTBOUND |
>>> PCIE_ATU_REGION_INDEX0,
>>> +       /* Program viewport : OUTBOUND : CFG0 */
>>> +       dw_pcie_writel_rc(pp,
>>> +                         PCIE_ATU_REGION_OUTBOUND |
>>> pp->atu_idx[ATU_TYPE_CFG0],
>>>                            PCIE_ATU_VIEWPORT);
>>>          dw_pcie_writel_rc(pp, pp->cfg0_mod_base, PCIE_ATU_LOWER_BASE);
>>>          dw_pcie_writel_rc(pp, (pp->cfg0_mod_base >> 32),
>>> PCIE_ATU_UPPER_BASE);
>>> @@ -526,8 +542,9 @@ static void dw_pcie_prog_viewport_cfg0(struct
>>> pcie_port *pp, u32 busdev)
>>>
>>>   static void dw_pcie_prog_viewport_cfg1(struct pcie_port *pp, u32
>>> busdev)
>>>   {
>>> -       /* Program viewport 1 : OUTBOUND : CFG1 */
>>> -       dw_pcie_writel_rc(pp, PCIE_ATU_REGION_OUTBOUND |
>>> PCIE_ATU_REGION_INDEX1,
>>> +       /* Program viewport : OUTBOUND : CFG1 */
>>> +       dw_pcie_writel_rc(pp,
>>> +                         PCIE_ATU_REGION_OUTBOUND |
>>> pp->atu_idx[ATU_TYPE_CFG1],
>>>                            PCIE_ATU_VIEWPORT);
>>>          dw_pcie_writel_rc(pp, PCIE_ATU_TYPE_CFG1, PCIE_ATU_CR1);
>>>          dw_pcie_writel_rc(pp, pp->cfg1_mod_base, PCIE_ATU_LOWER_BASE);
>>> @@ -541,8 +558,9 @@ static void dw_pcie_prog_viewport_cfg1(struct
>>> pcie_port *pp, u32 busdev)
>>>
>>>   static void dw_pcie_prog_viewport_mem_outbound(struct pcie_port *pp)
>>>   {
>>> -       /* Program viewport 0 : OUTBOUND : MEM */
>>> -       dw_pcie_writel_rc(pp, PCIE_ATU_REGION_OUTBOUND |
>>> PCIE_ATU_REGION_INDEX0,
>>> +       /* Program viewport : OUTBOUND : MEM */
>>> +       dw_pcie_writel_rc(pp,
>>> +                         PCIE_ATU_REGION_OUTBOUND |
>>> pp->atu_idx[ATU_TYPE_MEM],
>>>                            PCIE_ATU_VIEWPORT);
>>>          dw_pcie_writel_rc(pp, PCIE_ATU_TYPE_MEM, PCIE_ATU_CR1);
>>>          dw_pcie_writel_rc(pp, pp->mem_mod_base, PCIE_ATU_LOWER_BASE);
>>> @@ -557,8 +575,9 @@ static void dw_pcie_prog_viewport_mem_outbound(struct
>>> pcie_port *pp)
>>>
>>>   static void dw_pcie_prog_viewport_io_outbound(struct pcie_port *pp)
>>>   {
>>> -       /* Program viewport 1 : OUTBOUND : IO */
>>> -       dw_pcie_writel_rc(pp, PCIE_ATU_REGION_OUTBOUND |
>>> PCIE_ATU_REGION_INDEX1,
>>> +       /* Program viewport : OUTBOUND : IO */
>>> +       dw_pcie_writel_rc(pp,
>>> +                         PCIE_ATU_REGION_OUTBOUND |
>>> pp->atu_idx[ATU_TYPE_IO],
>>>                            PCIE_ATU_VIEWPORT);
>>>          dw_pcie_writel_rc(pp, PCIE_ATU_TYPE_IO, PCIE_ATU_CR1);
>>>          dw_pcie_writel_rc(pp, pp->io_mod_base, PCIE_ATU_LOWER_BASE);
>>> @@ -585,12 +604,14 @@ static int dw_pcie_rd_other_conf(struct pcie_port
>>> *pp, struct pci_bus *bus,
>>>                  dw_pcie_prog_viewport_cfg0(pp, busdev);
>>>                  ret = dw_pcie_cfg_read(pp->va_cfg0_base + address,
>>> where, size,
>>>                                  val);
>>> -               dw_pcie_prog_viewport_mem_outbound(pp);
>>> +               if (pp->atu_idx[ATU_TYPE_MEM] ==
>>> pp->atu_idx[ATU_TYPE_CFG0])
>>> +                       dw_pcie_prog_viewport_mem_outbound(pp);
>>>          } else {
>>>                  dw_pcie_prog_viewport_cfg1(pp, busdev);
>>>                  ret = dw_pcie_cfg_read(pp->va_cfg1_base + address,
>>> where, size,
>>>                                  val);
>>> -               dw_pcie_prog_viewport_io_outbound(pp);
>>> +               if (pp->atu_idx[ATU_TYPE_IO] ==
>>> pp->atu_idx[ATU_TYPE_CFG1])
>>> +                       dw_pcie_prog_viewport_io_outbound(pp);
>>>          }
>>>
>>>          return ret;
>>> @@ -610,12 +631,14 @@ static int dw_pcie_wr_other_conf(struct pcie_port
>>> *pp, struct pci_bus *bus,
>>>                  dw_pcie_prog_viewport_cfg0(pp, busdev);
>>>                  ret = dw_pcie_cfg_write(pp->va_cfg0_base + address,
>>> where, size,
>>>                                  val);
>>> -               dw_pcie_prog_viewport_mem_outbound(pp);
>>> +               if (pp->atu_idx[ATU_TYPE_MEM] ==
>>> pp->atu_idx[ATU_TYPE_CFG0])
>>> +                       dw_pcie_prog_viewport_mem_outbound(pp);
>>>          } else {
>>>                  dw_pcie_prog_viewport_cfg1(pp, busdev);
>>>                  ret = dw_pcie_cfg_write(pp->va_cfg1_base + address,
>>> where, size,
>>>                                  val);
>>> -               dw_pcie_prog_viewport_io_outbound(pp);
>>> +               if (pp->atu_idx[ATU_TYPE_IO] ==
>>> pp->atu_idx[ATU_TYPE_CFG1])
>>> +                       dw_pcie_prog_viewport_io_outbound(pp);
>>>          }
>>>
>>>          return ret;
>>> @@ -770,6 +793,10 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
>>>          u32 membase;
>>>          u32 memlimit;
>>>
>>> +       /* set ATUs setting for MEM and IO */
>>> +       dw_pcie_prog_viewport_mem_outbound(pp);
>>> +       dw_pcie_prog_viewport_io_outbound(pp);
>>> +
>>
>> I see from the code, these settings are required for the calls other than
>> dw_pcie_(rd/wr)_other_conf, is it correct? If it is so, I feel this change
>> is
>> independent of this patch and should go as a separte patch?
>
> [Minghuan] dw_pcie(rd/wr)_other_confg only calls the
> dw_pcie_prog_viewport_mem/io_outbound when
> we only use 2 ATUs.
> The patch is to support 4ATUs. If no the calls, ATU2(MEM) and ATU3 will
> not be initialized, and PCIe device driver will be broken.

When you have only 2 ATUs (CFG0=MEM & CFG1=IO), you are calling
mem/io_outbound() twice with the same writes which is not the case in the
original driver. So, I mentioned it should go as a separate patch.

- Srikanth

>
>> - Srikanth
>>
>>>          /* set the number of lanes */
>>>          dw_pcie_readl_rc(pp, PCIE_PORT_LINK_CONTROL, &val);
>>>          val &= ~PORT_LINK_MODE_MASK;
>>> diff --git a/drivers/pci/host/pcie-designware.h
>>> b/drivers/pci/host/pcie-designware.h
>>> index c625675..37604f9 100644
>>> --- a/drivers/pci/host/pcie-designware.h
>>> +++ b/drivers/pci/host/pcie-designware.h
>>> @@ -22,6 +22,14 @@
>>>   #define MAX_MSI_IRQS                   32
>>>   #define MAX_MSI_CTRLS                  (MAX_MSI_IRQS / 32)
>>>
>>> +enum ATU_TYPE {
>>> +       ATU_TYPE_CFG0,
>>> +       ATU_TYPE_CFG1,
>>> +       ATU_TYPE_MEM,
>>> +       ATU_TYPE_IO,
>>> +       ATU_TYPE_MAX
>>> +};
>>> +
>>>   struct pcie_port {
>>>          struct device           *dev;
>>>          u8                      root_bus_nr;
>>> @@ -53,6 +61,7 @@ struct pcie_port {
>>>          struct irq_domain       *irq_domain;
>>>          unsigned long           msi_data;
>>>          DECLARE_BITMAP(msi_irq_in_use, MAX_MSI_IRQS);
>>> +       u8                      atu_idx[ATU_TYPE_MAX];
>>>   };
>>>
>>>   struct pcie_host_ops {
>>> --
>>> 1.9.1
>>>
>>> --
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