[PATCH v2] PCI: dwc: Add upper limit address for outbound iATU

From: Shradha Todi
Date: Wed Jan 06 2021 - 05:53:07 EST


The size parameter is unsigned long type which can accept size > 4GB. In
that case, the upper limit address must be programmed. Add support to
program the upper limit address and set INCREASE_REGION_SIZE in case size >
4GB.

Signed-off-by: Shradha Todi <shradha.t@xxxxxxxxxxx>
---
v1: https://lkml.org/lkml/2020/12/20/187
v2:
Addressed Rob's review comment and added PCI version check condition to
avoid writing to reserved registers.

drivers/pci/controller/dwc/pcie-designware.c | 9 +++++++--
drivers/pci/controller/dwc/pcie-designware.h | 1 +
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 74590c7..1d62ca9 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -290,12 +290,17 @@ static void __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
upper_32_bits(cpu_addr));
dw_pcie_writel_dbi(pci, PCIE_ATU_LIMIT,
lower_32_bits(cpu_addr + size - 1));
+ if (pci->version >= 0x460A)
+ dw_pcie_writel_dbi(pci, PCIE_ATU_UPPER_LIMIT,
+ upper_32_bits(cpu_addr + size - 1));
dw_pcie_writel_dbi(pci, PCIE_ATU_LOWER_TARGET,
lower_32_bits(pci_addr));
dw_pcie_writel_dbi(pci, PCIE_ATU_UPPER_TARGET,
upper_32_bits(pci_addr));
- dw_pcie_writel_dbi(pci, PCIE_ATU_CR1, type |
- PCIE_ATU_FUNC_NUM(func_no));
+ val = type | PCIE_ATU_FUNC_NUM(func_no);
+ val = ((upper_32_bits(size - 1)) && (pci->version >= 0x460A)) ?
+ val | PCIE_ATU_INCREASE_REGION_SIZE : val;
+ dw_pcie_writel_dbi(pci, PCIE_ATU_CR1, val);
dw_pcie_writel_dbi(pci, PCIE_ATU_CR2, PCIE_ATU_ENABLE);

/*
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 8b905a2..7da79eb 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -102,6 +102,7 @@
#define PCIE_ATU_DEV(x) FIELD_PREP(GENMASK(23, 19), x)
#define PCIE_ATU_FUNC(x) FIELD_PREP(GENMASK(18, 16), x)
#define PCIE_ATU_UPPER_TARGET 0x91C
+#define PCIE_ATU_UPPER_LIMIT 0x924

#define PCIE_MISC_CONTROL_1_OFF 0x8BC
#define PCIE_DBI_RO_WR_EN BIT(0)
--
2.7.4