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

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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@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
---
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.
         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.
- 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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