[PATCH v3 0/3] pcie-designware: add iATU unroll feature

[PATCH v3 0/3] pcie-designware: add iATU unroll feature

[Joao Pinto]

The new DWC PCIe Core version (4.80) implements iATU in a different way.
This new mechanism is called iATU Unroll Mode. The Core still supports
the "old" mechanism calling it Legacy Mode if configured to do so, but
the standard way will be using Unroll.
This patch adds the necessary support for the mechanism and makes
some minor improvements to the existent one.

Joao Pinto (3):
  pcie-designware: move definitions
  pcie-designware: add iATU Unroll feature
  pcie-designware: fix typo

 drivers/pci/host/pcie-designware.c | 138 ++++++++++++++++++++++++++++++++-----
 drivers/pci/host/pcie-designware.h |   6 +-
 2 files changed, 122 insertions(+), 22 deletions(-)

-- 
1.8.1.5

[PATCH v3 1/3] pcie-designware: move definitions

[Joao Pinto]

This patch moves the sleep definitions to the *.c file like suggested
by Jisheng Zhang in a previous patch.

Signed-off-by: Joao Pinto <jpinto@synopsys.com>
CC: Jisheng Zhang <jszhang@marvell.com>
---
changes v2->v3 (Bjorn Helgaas):
- Separated from the new iATU unroll mechanism patch

 drivers/pci/host/pcie-designware.c | 5 +++++
 drivers/pci/host/pcie-designware.h | 5 -----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index 12afce1..6fb88de 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -26,6 +26,11 @@
 
 #include "pcie-designware.h"
 
+/* Parameters for the waiting for link up routine */
+#define LINK_WAIT_MAX_RETRIES		10
+#define LINK_WAIT_USLEEP_MIN		90000
+#define LINK_WAIT_USLEEP_MAX		100000
+
 /* Synopsis specific PCIE configuration registers */
 #define PCIE_PORT_LINK_CONTROL		0x710
 #define PORT_LINK_MODE_MASK		(0x3f << 16)
diff --git a/drivers/pci/host/pcie-designware.h b/drivers/pci/host/pcie-designware.h
index f437f9b..384e79b 100644
--- a/drivers/pci/host/pcie-designware.h
+++ b/drivers/pci/host/pcie-designware.h
@@ -22,11 +22,6 @@
 #define MAX_MSI_IRQS			32
 #define MAX_MSI_CTRLS			(MAX_MSI_IRQS / 32)
 
-/* Parameters for the waiting for link up routine */
-#define LINK_WAIT_MAX_RETRIES		10
-#define LINK_WAIT_USLEEP_MIN		90000
-#define LINK_WAIT_USLEEP_MAX		100000
-
 struct pcie_port {
 	struct device		*dev;
 	u8			root_bus_nr;
-- 
1.8.1.5

[PATCH v3 2/3] pcie-designware: add iATU Unroll feature

[Joao Pinto]

This patch adds the support to the new iATU mechanism that will be used
from Core version 4.80, which is called iATU Unroll.
The new Cores can support the iATU Unroll or support the "old" iATU 
method now called Legacy Mode. The driver is perfectly capable of
performing well for both.

In order to make sure that the iATU is really enabled a for loop was
introduced in dw_pcie_prog_outbound_atu() to improve reliability.

Signed-off-by: Joao Pinto <jpinto@synopsys.com>
---
changes v2->v3 (Bjorn Helgaas):
- Unused *CTRL3 and *UPPR iATU Unroll registers were removed
- Inbound addr builder macro was removed to simplifiy the code
- *readl_unroll and *writel_unroll functions were simplified. Now the
scope is always outbound.
- dw_pcie_get_atu_mode changed to return the status
- iATU enable check routine was improved in dw_pcie_prog_outbound_atu()
changes v1->v2:
- Patch was breaking kernel build due to bad definition in macro funtion.
- Rebased on top of pci/next.

 drivers/pci/host/pcie-designware.c | 131 ++++++++++++++++++++++++++++++++-----
 drivers/pci/host/pcie-designware.h |   1 +
 2 files changed, 116 insertions(+), 16 deletions(-)

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index 6fb88de..3fb9036 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -31,6 +31,11 @@
 #define LINK_WAIT_USLEEP_MIN		90000
 #define LINK_WAIT_USLEEP_MAX		100000
 
+/* Parameters for the waiting for iATU enabled routine */
+#define LINK_WAIT_MAX_IATU_RETRIES	5
+#define LINK_WAIT_IATU_MIN		9000
+#define LINK_WAIT_IATU_MAX		10000
+
 /* Synopsis specific PCIE configuration registers */
 #define PCIE_PORT_LINK_CONTROL		0x710
 #define PORT_LINK_MODE_MASK		(0x3f << 16)
@@ -75,6 +80,26 @@
 #define PCIE_ATU_FUNC(x)		(((x) & 0x7) << 16)
 #define PCIE_ATU_UPPER_TARGET		0x91C
 
+/*
+ * iATU unroll specific registers and definitions
+ * from 4.80 core version the address translation will be made by unroll
+ */
+
+/* Registers */
+#define PCIE_ATU_UNR_REGION_CTRL1	0x00
+#define PCIE_ATU_UNR_REGION_CTRL2	0x01
+#define PCIE_ATU_UNR_LOWER_BASE		0x02
+#define PCIE_ATU_UNR_UPPER_BASE		0x03
+#define PCIE_ATU_UNR_LIMIT		0x04
+#define PCIE_ATU_UNR_LOWER_TARGET	0x05
+#define PCIE_ATU_UNR_UPPER_TARGET	0x06
+
+/* Register address builder */
+#define PCIE_GET_ATU_OUTB_UNR_REG_ADDR(region, register)		\
+					((0x3 << 20) | (region << 9) |	\
+					(register << 2))
+/* End of Unroll specific */
+
 /* PCIe Port Logic registers */
 #define PLR_OFFSET			0x700
 #define PCIE_PHY_DEBUG_R1		(PLR_OFFSET + 0x2c)
@@ -136,6 +161,28 @@ static inline void dw_pcie_writel_rc(struct pcie_port *pp, u32 val, u32 reg)
 		writel(val, pp->dbi_base + reg);
 }
 
+static inline void dw_pcie_readl_unroll(struct pcie_port *pp,
+						u32 index, u32 reg, u32 *val)
+{
+	u32 reg_addr = PCIE_GET_ATU_OUTB_UNR_REG_ADDR(index, reg);
+
+	if (pp->ops->readl_rc)
+		pp->ops->readl_rc(pp, pp->dbi_base + reg_addr, val);
+	else
+		*val = readl(pp->dbi_base + reg_addr);
+}
+
+static inline void dw_pcie_writel_unroll(struct pcie_port *pp,
+						u32 index, u32 val, u32 reg)
+{
+	u32 reg_addr = PCIE_GET_ATU_OUTB_UNR_REG_ADDR(index, reg);
+
+	if (pp->ops->writel_rc)
+		pp->ops->writel_rc(pp, val, pp->dbi_base + reg_addr);
+	else
+		writel(val, pp->dbi_base + reg_addr);
+}
+
 static int dw_pcie_rd_own_conf(struct pcie_port *pp, int where, int size,
 			       u32 *val)
 {
@@ -157,24 +204,61 @@ static int dw_pcie_wr_own_conf(struct pcie_port *pp, int where, int size,
 static void dw_pcie_prog_outbound_atu(struct pcie_port *pp, int index,
 		int type, u64 cpu_addr, u64 pci_addr, u32 size)
 {
-	u32 val;
-
-	dw_pcie_writel_rc(pp, PCIE_ATU_REGION_OUTBOUND | index,
-			  PCIE_ATU_VIEWPORT);
-	dw_pcie_writel_rc(pp, lower_32_bits(cpu_addr), PCIE_ATU_LOWER_BASE);
-	dw_pcie_writel_rc(pp, upper_32_bits(cpu_addr), PCIE_ATU_UPPER_BASE);
-	dw_pcie_writel_rc(pp, lower_32_bits(cpu_addr + size - 1),
-			  PCIE_ATU_LIMIT);
-	dw_pcie_writel_rc(pp, lower_32_bits(pci_addr), PCIE_ATU_LOWER_TARGET);
-	dw_pcie_writel_rc(pp, upper_32_bits(pci_addr), PCIE_ATU_UPPER_TARGET);
-	dw_pcie_writel_rc(pp, type, PCIE_ATU_CR1);
-	dw_pcie_writel_rc(pp, PCIE_ATU_ENABLE, PCIE_ATU_CR2);
+	u32 val = 0;
+	u32 retries = 0;
+
+	if (pp->iatu_unroll_status) {
+		dw_pcie_writel_unroll(pp, index,
+			lower_32_bits(cpu_addr), PCIE_ATU_UNR_LOWER_BASE);
+		dw_pcie_writel_unroll(pp, index,
+			upper_32_bits(cpu_addr), PCIE_ATU_UNR_UPPER_BASE);
+		dw_pcie_writel_unroll(pp, index,
+			lower_32_bits(cpu_addr + size - 1), PCIE_ATU_UNR_LIMIT);
+		dw_pcie_writel_unroll(pp, index,
+			lower_32_bits(pci_addr), PCIE_ATU_UNR_LOWER_TARGET);
+		dw_pcie_writel_unroll(pp, index,
+			upper_32_bits(pci_addr), PCIE_ATU_UNR_UPPER_TARGET);
+		dw_pcie_writel_unroll(pp, index,
+			type, PCIE_ATU_UNR_REGION_CTRL1);
+		dw_pcie_writel_unroll(pp, index,
+			PCIE_ATU_ENABLE, PCIE_ATU_UNR_REGION_CTRL2);
+	} else {
+		dw_pcie_writel_rc(pp, PCIE_ATU_REGION_OUTBOUND | index,
+						PCIE_ATU_VIEWPORT);
+		dw_pcie_writel_rc(pp, lower_32_bits(cpu_addr),
+						PCIE_ATU_LOWER_BASE);
+		dw_pcie_writel_rc(pp, upper_32_bits(cpu_addr),
+						PCIE_ATU_UPPER_BASE);
+		dw_pcie_writel_rc(pp, lower_32_bits(cpu_addr + size - 1),
+						PCIE_ATU_LIMIT);
+		dw_pcie_writel_rc(pp, lower_32_bits(pci_addr),
+						PCIE_ATU_LOWER_TARGET);
+		dw_pcie_writel_rc(pp, upper_32_bits(pci_addr),
+						PCIE_ATU_UPPER_TARGET);
+		dw_pcie_writel_rc(pp, type, PCIE_ATU_CR1);
+		dw_pcie_writel_rc(pp, PCIE_ATU_ENABLE, PCIE_ATU_CR2);
+	}
 
 	/*
-	 * Make sure ATU enable takes effect before any subsequent config
-	 * and I/O accesses.
-	 */
-	dw_pcie_readl_rc(pp, PCIE_ATU_CR2, &val);
+	 * Make sure ATU enable takes effect before any subsequent config
+	 * and I/O accesses.
+	 */
+	for (retries = 0; retries < LINK_WAIT_MAX_IATU_RETRIES; retries++) {
+
+		if (pp->iatu_unroll_status) {
+			dw_pcie_readl_unroll(pp, index,
+					PCIE_ATU_UNR_REGION_CTRL2, &val);
+		} else {
+			dw_pcie_readl_rc(pp, PCIE_ATU_CR2, &val);
+		}
+
+		if (val == PCIE_ATU_ENABLE)
+			break;
+
+		usleep_range(LINK_WAIT_IATU_MIN, LINK_WAIT_IATU_MAX);
+	}
+
+	dev_dbg(pp->dev, "iATU is not being enabled\n");
 }
 
 static struct irq_chip dw_msi_irq_chip = {
@@ -433,6 +517,19 @@ static const struct irq_domain_ops msi_domain_ops = {
 	.map = dw_pcie_msi_map,
 };
 
+static u8 dw_pcie_get_atu_mode(struct pcie_port *pp)
+{
+	u32 val = 0;
+
+	/* Check if the iATU unroll is enabled or not */
+	dw_pcie_readl_rc(pp, PCIE_ATU_VIEWPORT, &val);
+
+	if (val == 0xFFFFFFFF)
+		return 1; /* enabled */
+
+	return 0; /* disabled */
+}
+
 int dw_pcie_host_init(struct pcie_port *pp)
 {
 	struct device_node *np = pp->dev->of_node;
@@ -552,6 +649,8 @@ int dw_pcie_host_init(struct pcie_port *pp)
 	if (pp->ops->host_init)
 		pp->ops->host_init(pp);
 
+	pp->iatu_unroll_status = dw_pcie_get_atu_mode(pp);
+
 	pp->root_bus_nr = pp->busn->start;
 	if (IS_ENABLED(CONFIG_PCI_MSI)) {
 		bus = pci_scan_root_bus_msi(pp->dev, pp->root_bus_nr,
diff --git a/drivers/pci/host/pcie-designware.h b/drivers/pci/host/pcie-designware.h
index 384e79b..354a981 100644
--- a/drivers/pci/host/pcie-designware.h
+++ b/drivers/pci/host/pcie-designware.h
@@ -48,6 +48,7 @@ struct pcie_port {
 	int			msi_irq;
 	struct irq_domain	*irq_domain;
 	unsigned long		msi_data;
+	u8			iatu_unroll_status;
 	DECLARE_BITMAP(msi_irq_in_use, MAX_MSI_IRQS);
 };
 
-- 
1.8.1.5

[PATCH v3 3/3] pcie-designware: fix typo

[Joao Pinto]

Simple fix typo.

Signed-off-by: Joao Pinto <jpinto@synopsys.com>
---
changes v1->v3:
- Nothing changed. Just to keep up patch set version.

 drivers/pci/host/pcie-designware.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c
index 3fb9036..a09455cd 100644
--- a/drivers/pci/host/pcie-designware.c
+++ b/drivers/pci/host/pcie-designware.c
@@ -36,7 +36,7 @@
 #define LINK_WAIT_IATU_MIN		9000
 #define LINK_WAIT_IATU_MAX		10000
 
-/* Synopsis specific PCIE configuration registers */
+/* Synopsys specific PCIE configuration registers */
 #define PCIE_PORT_LINK_CONTROL		0x710
 #define PORT_LINK_MODE_MASK		(0x3f << 16)
 #define PORT_LINK_MODE_1_LANES		(0x1 << 16)
-- 
1.8.1.5