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Subject[PATCH v6 15/18] PCI: dwc: Make cpu_addr_fixup take struct dw_pcie as argument
Date
The current cpu addr fixup mask for ARTPEC-6, GENMASK(27, 0), is wrong.
The correct cpu addr fixup mask for ARTPEC-6 is GENMASK(28, 0).

However, having a hardcoded cpu addr fixup mask in each driver is
arguably wrong.
A device tree property called something like "cpu-addr-fixup-mask"
would have been a better solution.
Introducing such a property is not needed though, since we already have
pp->cfg0_base and ep->phys_base, which is derived from already existing
device tree properties.

It is also worth noting that for ARTPEC-7, hardcoding the cpu addr fixup
mask is not possible, since it uses a High Address Bits Look Up Table,
which means that it can, at runtime, map the PCIe window to an arbitrary
address in the 32-bit address space.

By using pp->cfg0_base and ep->phys_base, we avoid hardcoding a mask
in each driver. This should work for ARTPEC-6, DRA7xx, and ARTPEC-7.
I have not changed the code in DRA7xx though, since their existing
code works, but if they want, they could use the same logic as
artpec6_pcie_cpu_addr_fixup, and thus remove their hardcoded mask.

The reason why the fixup mask is needed is explained in commit f4c55c5a3f7f
("PCI: designware: Program ATU with untranslated address").

Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
---
drivers/pci/dwc/pci-dra7xx.c | 2 +-
drivers/pci/dwc/pcie-artpec6.c | 18 ++++++++++++++----
drivers/pci/dwc/pcie-designware.c | 2 +-
drivers/pci/dwc/pcie-designware.h | 2 +-
4 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
index 224ff8affdce..89d87844abb3 100644
--- a/drivers/pci/dwc/pci-dra7xx.c
+++ b/drivers/pci/dwc/pci-dra7xx.c
@@ -110,7 +110,7 @@ static inline void dra7xx_pcie_writel(struct dra7xx_pcie *pcie, u32 offset,
writel(value, pcie->base + offset);
}

-static u64 dra7xx_pcie_cpu_addr_fixup(u64 pci_addr)
+static u64 dra7xx_pcie_cpu_addr_fixup(struct dw_pcie *pci, u64 pci_addr)
{
return pci_addr & DRA7XX_CPU_TO_BUS_ADDR;
}
diff --git a/drivers/pci/dwc/pcie-artpec6.c b/drivers/pci/dwc/pcie-artpec6.c
index e7de4e4649eb..318a2bd0d97e 100644
--- a/drivers/pci/dwc/pcie-artpec6.c
+++ b/drivers/pci/dwc/pcie-artpec6.c
@@ -67,8 +67,6 @@ static const struct of_device_id artpec6_pcie_of_match[];
#define PHY_STATUS 0x118
#define PHY_COSPLLLOCK BIT(0)

-#define ARTPEC6_CPU_TO_BUS_ADDR GENMASK(27, 0)
-
static u32 artpec6_pcie_readl(struct artpec6_pcie *artpec6_pcie, u32 offset)
{
u32 val;
@@ -82,9 +80,21 @@ static void artpec6_pcie_writel(struct artpec6_pcie *artpec6_pcie, u32 offset, u
regmap_write(artpec6_pcie->regmap, offset, val);
}

-static u64 artpec6_pcie_cpu_addr_fixup(u64 pci_addr)
+static u64 artpec6_pcie_cpu_addr_fixup(struct dw_pcie *pci, u64 pci_addr)
{
- return pci_addr & ARTPEC6_CPU_TO_BUS_ADDR;
+ struct artpec6_pcie *artpec6_pcie = to_artpec6_pcie(pci);
+ struct pcie_port *pp = &pci->pp;
+ struct dw_pcie_ep *ep = &pci->ep;
+
+ switch (artpec6_pcie->mode) {
+ case DW_PCIE_RC_TYPE:
+ return pci_addr - pp->cfg0_base;
+ case DW_PCIE_EP_TYPE:
+ return pci_addr - ep->phys_base;
+ default:
+ dev_err(pci->dev, "UNKNOWN device type\n");
+ }
+ return pci_addr;
}

static int artpec6_pcie_establish_link(struct dw_pcie *pci)
diff --git a/drivers/pci/dwc/pcie-designware.c b/drivers/pci/dwc/pcie-designware.c
index 88abdddee2ad..800be7a4f087 100644
--- a/drivers/pci/dwc/pcie-designware.c
+++ b/drivers/pci/dwc/pcie-designware.c
@@ -149,7 +149,7 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
u32 retries, val;

if (pci->ops->cpu_addr_fixup)
- cpu_addr = pci->ops->cpu_addr_fixup(cpu_addr);
+ cpu_addr = pci->ops->cpu_addr_fixup(pci, cpu_addr);

if (pci->iatu_unroll_enabled) {
dw_pcie_prog_outbound_atu_unroll(pci, index, type, cpu_addr,
diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index 24edac035160..cca5a81c1c74 100644
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -205,7 +205,7 @@ struct dw_pcie_ep {
};

struct dw_pcie_ops {
- u64 (*cpu_addr_fixup)(u64 cpu_addr);
+ u64 (*cpu_addr_fixup)(struct dw_pcie *pcie, u64 cpu_addr);
u32 (*read_dbi)(struct dw_pcie *pcie, void __iomem *base, u32 reg,
size_t size);
void (*write_dbi)(struct dw_pcie *pcie, void __iomem *base, u32 reg,
--
2.14.2
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