[PATCH v5 16/20] PCI: dwc: Introduce generic controller capabilities interface

From: Serge Semin
Date: Mon Aug 22 2022 - 14:49:23 EST


Since in addition to the already available iATU unrolled mapping we are
about to add a few more DW PCIe platform-specific capabilities (CDM-check
and generic clocks/resets resources) let's add a generic interface to set
and get the flags indicating their availability. The new interface shall
improve maintainability of the platform-specific code.

Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Rob Herring <robh@xxxxxxxxxx>

---

Note the DW_PCIE_CAP_IATU_UNROLL macro is intentionally set to 1 since
being added afterwards capability will be more suitable to be identified
with position 0.

Changelog v3:
- This is a new patch created on v3 lap of the series.
---
drivers/pci/controller/dwc/pcie-designware.c | 11 ++++++-----
drivers/pci/controller/dwc/pcie-designware.h | 12 +++++++++++-
2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index ca830ee794a7..9d78e7ca61e1 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -211,7 +211,7 @@ void dw_pcie_write_dbi2(struct dw_pcie *pci, u32 reg, size_t size, u32 val)
static inline void __iomem *dw_pcie_select_atu(struct dw_pcie *pci, u32 dir,
u32 index)
{
- if (pci->iatu_unroll_enabled)
+ if (dw_pcie_cap_is(pci, IATU_UNROLL))
return pci->atu_base + PCIE_ATU_UNROLL_BASE(dir, index);

dw_pcie_writel_dbi(pci, PCIE_ATU_VIEWPORT, dir | index);
@@ -591,7 +591,7 @@ static void dw_pcie_iatu_detect_regions(struct dw_pcie *pci)
u32 val, min, dir;
u64 max;

- if (pci->iatu_unroll_enabled) {
+ if (dw_pcie_cap_is(pci, IATU_UNROLL)) {
max_region = min((int)pci->atu_size / 512, 256);
} else {
dw_pcie_writel_dbi(pci, PCIE_ATU_VIEWPORT, 0xFF);
@@ -641,8 +641,9 @@ void dw_pcie_iatu_detect(struct dw_pcie *pci)
{
struct platform_device *pdev = to_platform_device(pci->dev);

- pci->iatu_unroll_enabled = dw_pcie_iatu_unroll_enabled(pci);
- if (pci->iatu_unroll_enabled) {
+ if (dw_pcie_iatu_unroll_enabled(pci)) {
+ dw_pcie_cap_set(pci, IATU_UNROLL);
+
if (!pci->atu_base) {
struct resource *res =
platform_get_resource_byname(pdev, IORESOURCE_MEM, "atu");
@@ -664,7 +665,7 @@ void dw_pcie_iatu_detect(struct dw_pcie *pci)

dw_pcie_iatu_detect_regions(pci);

- dev_info(pci->dev, "iATU unroll: %s\n", pci->iatu_unroll_enabled ?
+ dev_info(pci->dev, "iATU unroll: %s\n", dw_pcie_cap_is(pci, IATU_UNROLL) ?
"enabled" : "disabled");

dev_info(pci->dev, "iATU regions: %u ob, %u ib, align %uK, limit %lluG\n",
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index f1a7f7ef4126..33250d5788e8 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -12,6 +12,7 @@
#define _PCIE_DESIGNWARE_H

#include <linux/bitfield.h>
+#include <linux/bitops.h>
#include <linux/dma-mapping.h>
#include <linux/irq.h>
#include <linux/msi.h>
@@ -43,6 +44,15 @@
(__dw_pcie_ver_cmp(_pci, _ver, ==) && \
__dw_pcie_ver_cmp(_pci, TYPE_ ## _type, >=))

+/* DWC PCIe controller capabilities */
+#define DW_PCIE_CAP_IATU_UNROLL 1
+
+#define dw_pcie_cap_is(_pci, _cap) \
+ test_bit(DW_PCIE_CAP_ ## _cap, &(_pci)->caps)
+
+#define dw_pcie_cap_set(_pci, _cap) \
+ set_bit(DW_PCIE_CAP_ ## _cap, &(_pci)->caps)
+
/* Parameters for the waiting for link up routine */
#define LINK_WAIT_MAX_RETRIES 10
#define LINK_WAIT_USLEEP_MIN 90000
@@ -318,10 +328,10 @@ struct dw_pcie {
const struct dw_pcie_ops *ops;
u32 version;
u32 type;
+ unsigned long caps;
int num_lanes;
int link_gen;
u8 n_fts[2];
- bool iatu_unroll_enabled: 1;
};

#define to_dw_pcie_from_pp(port) container_of((port), struct dw_pcie, pp)
--
2.35.1