On Tue, Oct 20, 2020 at 2:59 PM Vidya Sagar <vidyas@xxxxxxxxxx> wrote:
>
> DWC sub-system currently doesn't differentiate between prefetchable and
> non-prefetchable memory aperture entries in the 'ranges' property and
> provides ATU mapping only for the first memory aperture entry out of all
> the entries present. This was introduced by the
> commit 0f71c60ffd26 ("PCI: dwc: Remove storing of PCI resources").
> Mapping for a memory apreture is required if its CPU address and the bus
> address are different and the current mechanism works only if the memory
> aperture which needs mapping happens to be the first entry. It doesn't
> work either if the memory aperture that needs mapping is not the first
> entry or if both prefetchable and non-prefetchable apertures need mapping.
Well that's subtle...
> This patch fixes this issue by differentiating between prefetchable and
> non-prefetchable apertures in the 'ranges' property there by removing the
> dependency on the order in which they are specified and adds support for
> mapping prefetchable aperture using ATU region-3 if required.
Now you don't do any iATU entry for a 1:1 memory range which is a
change for pretty much every other platform. That means we leave the
PCI transaction config to the whims of how h/w designers hooked up the
sideband signals. I guess this is how Uniphier works as it only has 1
viewport...
I think the assignment should be in this order:
- config space
- non-prefetchable (IIRC, it's required)
- prefetchable
- i/o
Stopping assignment and warning if you run out of viewports. Looking
at the platforms, I think that would always work. There's only
uniphier and ls1012a where we run out. Those would still behave the
same.
>
> Fixes: 0f71c60ffd26 ("PCI: dwc: Remove storing of PCI resources")
> Link: http://patchwork.ozlabs.org/project/linux-pci/patch/20200513190855.23318-1-vidyas@xxxxxxxxxx/
>
> Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
> ---
> V2:
> * Rewrote commit subject and description
> * Addressed review comments from Lorenzo
>
> .../pci/controller/dwc/pcie-designware-host.c | 42 ++++++++++++++++---
> drivers/pci/controller/dwc/pcie-designware.c | 12 +++---
> drivers/pci/controller/dwc/pcie-designware.h | 4 +-
> 3 files changed, 46 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index db547ee6ff3a..dae6da39bb90 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -521,9 +521,42 @@ static struct pci_ops dw_pcie_ops = {
> .write = pci_generic_config_write,
> };
>
> +static void dw_pcie_setup_mem_atu(struct pcie_port *pp,
> + struct resource_entry *win)
> +{
> + struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> +
> + /* Check for prefetchable memory aperture */
> + if (win->res->flags & IORESOURCE_PREFETCH && win->offset) {
> + /* Number of view ports must at least be 4 to enable mapping */
> + if (pci->num_viewport < 4) {
> + dev_warn(pci->dev,
> + "Insufficient ATU regions to map Prefetchable memory\n");
> + } else {
> + dw_pcie_prog_outbound_atu(pci,
> + PCIE_ATU_REGION_INDEX3,
> + PCIE_ATU_TYPE_MEM,
> + win->res->start,
> + win->res->start - win->offset,
> + resource_size(win->res));
> + }
> + } else if (win->offset) { /* Non-prefetchable memory aperture */
> + if (upper_32_bits(resource_size(win->res)))
> + dev_warn(pci->dev,
> + "Memory resource size exceeds max for 32 bits\n");
This is not designware specific. Either core code should check this or
write a DT schema to check it.
> + dw_pcie_prog_outbound_atu(pci,
> + PCIE_ATU_REGION_INDEX0,
> + PCIE_ATU_TYPE_MEM,
> + win->res->start,
> + win->res->start - win->offset,
> + resource_size(win->res));
> + }
> +}
> +
> void dw_pcie_setup_rc(struct pcie_port *pp)
> {
> u32 val, ctrl, num_ctrls;
> + struct resource_entry *win;
> struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
>
> /*
> @@ -578,13 +611,10 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
> * ATU, so we should not program the ATU here.
> */
> if (pp->bridge->child_ops == &dw_child_pcie_ops) {
> - struct resource_entry *entry =
> - resource_list_first_type(&pp->bridge->windows, IORESOURCE_MEM);
> + resource_list_for_each_entry(win, &pp->bridge->windows)
> + if (resource_type(win->res) == IORESOURCE_MEM)
> + dw_pcie_setup_mem_atu(pp, win);
>
> - dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX0,
> - PCIE_ATU_TYPE_MEM, entry->res->start,
> - entry->res->start - entry->offset,
> - resource_size(entry->res));
> if (pci->num_viewport > 2)
> dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX2,
> PCIE_ATU_TYPE_IO, pp->io_base,
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index c2dea8fc97c8..b5e438b70cd5 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -228,7 +228,7 @@ static void dw_pcie_writel_ob_unroll(struct dw_pcie *pci, u32 index, u32 reg,
> static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, u8 func_no,
> int index, int type,
> u64 cpu_addr, u64 pci_addr,
> - u32 size)
> + u64 size)
How was this working for you before? Looks like a different change
from what I broke.
> {
> u32 retries, val;
> u64 limit_addr = cpu_addr + size - 1;
> @@ -245,8 +245,10 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, u8 func_no,
> lower_32_bits(pci_addr));
> dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_UPPER_TARGET,
> upper_32_bits(pci_addr));
> - dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL1,
> - type | PCIE_ATU_FUNC_NUM(func_no));
> + val = type | PCIE_ATU_FUNC_NUM(func_no);
> + val = upper_32_bits(size - 1) ?
> + val | PCIE_ATU_INCREASE_REGION_SIZE : val;
> + dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL1, val);
> dw_pcie_writel_ob_unroll(pci, index, PCIE_ATU_UNR_REGION_CTRL2,
> PCIE_ATU_ENABLE);
>
> @@ -267,7 +269,7 @@ static void dw_pcie_prog_outbound_atu_unroll(struct dw_pcie *pci, u8 func_no,
>
> static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
> int index, int type, u64 cpu_addr,
> - u64 pci_addr, u32 size)
> + u64 pci_addr, u64 size)
> {
> u32 retries, val;
>
> @@ -311,7 +313,7 @@ static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
> }
>
> void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
> - u64 cpu_addr, u64 pci_addr, u32 size)
> + u64 cpu_addr, u64 pci_addr, u64 size)
> {
> __dw_pcie_prog_outbound_atu(pci, 0, index, type,
> cpu_addr, pci_addr, size);
> diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> index 9d2f511f13fa..21dd06831b50 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.h
> +++ b/drivers/pci/controller/dwc/pcie-designware.h
> @@ -80,10 +80,12 @@
> #define PCIE_ATU_VIEWPORT 0x900
> #define PCIE_ATU_REGION_INBOUND BIT(31)
> #define PCIE_ATU_REGION_OUTBOUND 0
> +#define PCIE_ATU_REGION_INDEX3 0x3
> #define PCIE_ATU_REGION_INDEX2 0x2
> #define PCIE_ATU_REGION_INDEX1 0x1
> #define PCIE_ATU_REGION_INDEX0 0x0
> #define PCIE_ATU_CR1 0x904
> +#define PCIE_ATU_INCREASE_REGION_SIZE BIT(13)
> #define PCIE_ATU_TYPE_MEM 0x0
> #define PCIE_ATU_TYPE_IO 0x2
> #define PCIE_ATU_TYPE_CFG0 0x4
> @@ -295,7 +297,7 @@ void dw_pcie_upconfig_setup(struct dw_pcie *pci);
> int dw_pcie_wait_for_link(struct dw_pcie *pci);
> void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index,
> int type, u64 cpu_addr, u64 pci_addr,
> - u32 size);
> + u64 size);
> void dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci, u8 func_no, int index,
> int type, u64 cpu_addr, u64 pci_addr,
> u32 size);
> --
> 2.17.1
>
