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PCI: dwc: Support multiple ATU memory regions
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The current ATU setup only supports a single memory resource which
isn't sufficient if there are also prefetchable memory regions. In order
to support multiple memory regions, we need to move away from fixed ATU
slots and rework the assignment. As there's always an ATU entry for
config space, let's assign index 0 to config space. Then we assign
memory resources to index 1 and up. Finally, if we have an I/O region
and slots remaining, we assign the I/O region last. If there aren't
remaining slots, we keep the same config and I/O space sharing.

Link: https://lore.kernel.org/r/20201026181652.418729-1-robh@kernel.org
Tested-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Vidya Sagar <vidyas@nvidia.com>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
Cc: Vidya Sagar <vidyas@nvidia.com>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
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Rob Herring authored and Lorenzo Pieralisi committed Nov 18, 2020
1 parent f8394f2 commit 9f9e59a
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Showing 2 changed files with 34 additions and 26 deletions.
54 changes: 32 additions & 22 deletions drivers/pci/controller/dwc/pcie-designware-host.c
Original file line number Diff line number Diff line change
Expand Up @@ -464,9 +464,7 @@ static void __iomem *dw_pcie_other_conf_map_bus(struct pci_bus *bus,
type = PCIE_ATU_TYPE_CFG1;


dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX1,
type, pp->cfg0_base,
busdev, pp->cfg0_size);
dw_pcie_prog_outbound_atu(pci, 0, type, pp->cfg0_base, busdev, pp->cfg0_size);

return pp->va_cfg0_base + where;
}
Expand All @@ -480,9 +478,8 @@ static int dw_pcie_rd_other_conf(struct pci_bus *bus, unsigned int devfn,

ret = pci_generic_config_read(bus, devfn, where, size, val);

if (!ret && pci->num_viewport <= 2)
dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX1,
PCIE_ATU_TYPE_IO, pp->io_base,
if (!ret && pci->io_cfg_atu_shared)
dw_pcie_prog_outbound_atu(pci, 0, PCIE_ATU_TYPE_IO, pp->io_base,
pp->io_bus_addr, pp->io_size);

return ret;
Expand All @@ -497,9 +494,8 @@ static int dw_pcie_wr_other_conf(struct pci_bus *bus, unsigned int devfn,

ret = pci_generic_config_write(bus, devfn, where, size, val);

if (!ret && pci->num_viewport <= 2)
dw_pcie_prog_outbound_atu(pci, PCIE_ATU_REGION_INDEX1,
PCIE_ATU_TYPE_IO, pp->io_base,
if (!ret && pci->io_cfg_atu_shared)
dw_pcie_prog_outbound_atu(pci, 0, PCIE_ATU_TYPE_IO, pp->io_base,
pp->io_bus_addr, pp->io_size);

return ret;
Expand Down Expand Up @@ -586,21 +582,35 @@ 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 *tmp, *entry = NULL;
int atu_idx = 0;
struct resource_entry *entry;

/* Get last memory resource entry */
resource_list_for_each_entry(tmp, &pp->bridge->windows)
if (resource_type(tmp->res) == IORESOURCE_MEM)
entry = tmp;

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,
pp->io_bus_addr, pp->io_size);
resource_list_for_each_entry(entry, &pp->bridge->windows) {
if (resource_type(entry->res) != IORESOURCE_MEM)
continue;

if (pci->num_viewport <= ++atu_idx)
break;

dw_pcie_prog_outbound_atu(pci, atu_idx,
PCIE_ATU_TYPE_MEM, entry->res->start,
entry->res->start - entry->offset,
resource_size(entry->res));
}

if (pp->io_size) {
if (pci->num_viewport > ++atu_idx)
dw_pcie_prog_outbound_atu(pci, atu_idx,
PCIE_ATU_TYPE_IO, pp->io_base,
pp->io_bus_addr, pp->io_size);
else
pci->io_cfg_atu_shared = true;
}

if (pci->num_viewport <= atu_idx)
dev_warn(pci->dev, "Resources exceed number of ATU entries (%d)",
pci->num_viewport);
}

dw_pcie_writel_dbi(pci, PCI_BASE_ADDRESS_0, 0);
Expand Down
6 changes: 2 additions & 4 deletions drivers/pci/controller/dwc/pcie-designware.h
Original file line number Diff line number Diff line change
Expand Up @@ -80,9 +80,6 @@
#define PCIE_ATU_VIEWPORT 0x900
#define PCIE_ATU_REGION_INBOUND BIT(31)
#define PCIE_ATU_REGION_OUTBOUND 0
#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_TYPE_MEM 0x0
#define PCIE_ATU_TYPE_IO 0x2
Expand Down Expand Up @@ -266,14 +263,15 @@ struct dw_pcie {
/* Used when iatu_unroll_enabled is true */
void __iomem *atu_base;
u32 num_viewport;
u8 iatu_unroll_enabled;
struct pcie_port pp;
struct dw_pcie_ep ep;
const struct dw_pcie_ops *ops;
unsigned int version;
int num_lanes;
int link_gen;
u8 n_fts[2];
bool iatu_unroll_enabled: 1;
bool io_cfg_atu_shared: 1;
};

#define to_dw_pcie_from_pp(port) container_of((port), struct dw_pcie, pp)
Expand Down

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