diff mbox series

[v4,10/10] PCI: tegra194: add interconnect support in Tegra234

Message ID 20230327161426.32639-11-sumitg@nvidia.com
State Superseded
Headers show
Series [v4,01/10] dt-bindings: memory: tegra: add bpmp ref in tegra234-mc node | expand

Commit Message

Sumit Gupta March 27, 2023, 4:14 p.m. UTC
Add support to request DRAM bandwidth with Memory Interconnect
in Tegra234 SoC. The DRAM BW required for different modes depends
on speed (Gen-1/2/3/4) and width/lanes (x1/x2/x4/x8).

Suggested-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
---
 drivers/pci/controller/dwc/pcie-tegra194.c | 40 +++++++++++++++++-----
 1 file changed, 32 insertions(+), 8 deletions(-)

Comments

Bjorn Helgaas March 28, 2023, 5:53 p.m. UTC | #1
Capitalize subject line please, to match pcie-tegra194.c history.

On Mon, Mar 27, 2023 at 09:44:26PM +0530, Sumit Gupta wrote:
> Add support to request DRAM bandwidth with Memory Interconnect
> in Tegra234 SoC. The DRAM BW required for different modes depends
> on speed (Gen-1/2/3/4) and width/lanes (x1/x2/x4/x8).
> 
> Suggested-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
> Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
> ---
>  drivers/pci/controller/dwc/pcie-tegra194.c | 40 +++++++++++++++++-----
>  1 file changed, 32 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
> index 09825b4a075e..d2513c9d3feb 100644
> --- a/drivers/pci/controller/dwc/pcie-tegra194.c
> +++ b/drivers/pci/controller/dwc/pcie-tegra194.c
> @@ -15,6 +15,7 @@
>  #include <linux/gpio.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/interrupt.h>
> +#include <linux/interconnect.h>

Almost alphabetized, swap interrupt.h and interconnect.h.

>  #include <linux/iopoll.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
> @@ -287,6 +288,7 @@ struct tegra_pcie_dw {
>  	unsigned int pex_rst_irq;
>  	int ep_state;
>  	long link_status;
> +	struct icc_path *icc_path;
>  };
>  
>  static inline struct tegra_pcie_dw *to_tegra_pcie(struct dw_pcie *pci)
> @@ -309,6 +311,24 @@ struct tegra_pcie_soc {
>  	enum dw_pcie_device_mode mode;
>  };
>  
> +static void tegra_pcie_icc_set(struct tegra_pcie_dw *pcie)
> +{
> +	struct dw_pcie *pci = &pcie->pci;
> +	u32 val, speed, width;
> +
> +	val = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA);
> +
> +	speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, val);
> +	width = FIELD_GET(PCI_EXP_LNKSTA_NLW, val);
> +
> +	val = width * (PCIE_SPEED2MBS_ENC(pcie_link_speed[speed]) / BITS_PER_BYTE);
> +
> +	if (icc_set_bw(pcie->icc_path, MBps_to_icc(val), 0))
> +		dev_err(pcie->dev, "can't set bw[%u]\n", val);
> +
> +	clk_set_rate(pcie->core_clk, pcie_gen_freq[speed - 1]);

Array bounds violation; PCI_EXP_LNKSTA_CLS is 0x000f, so possible
speed (CLS) values are 0..0xf and "speed - 1" values are -1..0xe.

pcie_gen_freq[] is of size 4 (valid indices 0..3).

I see that you're just *moving* this code, but might as well fix it.

> +}
> +
>  static void apply_bad_link_workaround(struct dw_pcie_rp *pp)
>  {
>  	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
> @@ -452,14 +472,12 @@ static irqreturn_t tegra_pcie_ep_irq_thread(int irq, void *arg)
>  	struct tegra_pcie_dw *pcie = arg;
>  	struct dw_pcie_ep *ep = &pcie->pci.ep;
>  	struct dw_pcie *pci = &pcie->pci;
> -	u32 val, speed;
> +	u32 val;
>  
>  	if (test_and_clear_bit(0, &pcie->link_status))
>  		dw_pcie_ep_linkup(ep);
>  
> -	speed = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA) &
> -		PCI_EXP_LNKSTA_CLS;
> -	clk_set_rate(pcie->core_clk, pcie_gen_freq[speed - 1]);
> +	tegra_pcie_icc_set(pcie);
diff mbox series

Patch

diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index 09825b4a075e..d2513c9d3feb 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -15,6 +15,7 @@ 
 #include <linux/gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/interrupt.h>
+#include <linux/interconnect.h>
 #include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -287,6 +288,7 @@  struct tegra_pcie_dw {
 	unsigned int pex_rst_irq;
 	int ep_state;
 	long link_status;
+	struct icc_path *icc_path;
 };
 
 static inline struct tegra_pcie_dw *to_tegra_pcie(struct dw_pcie *pci)
@@ -309,6 +311,24 @@  struct tegra_pcie_soc {
 	enum dw_pcie_device_mode mode;
 };
 
+static void tegra_pcie_icc_set(struct tegra_pcie_dw *pcie)
+{
+	struct dw_pcie *pci = &pcie->pci;
+	u32 val, speed, width;
+
+	val = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA);
+
+	speed = FIELD_GET(PCI_EXP_LNKSTA_CLS, val);
+	width = FIELD_GET(PCI_EXP_LNKSTA_NLW, val);
+
+	val = width * (PCIE_SPEED2MBS_ENC(pcie_link_speed[speed]) / BITS_PER_BYTE);
+
+	if (icc_set_bw(pcie->icc_path, MBps_to_icc(val), 0))
+		dev_err(pcie->dev, "can't set bw[%u]\n", val);
+
+	clk_set_rate(pcie->core_clk, pcie_gen_freq[speed - 1]);
+}
+
 static void apply_bad_link_workaround(struct dw_pcie_rp *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
@@ -452,14 +472,12 @@  static irqreturn_t tegra_pcie_ep_irq_thread(int irq, void *arg)
 	struct tegra_pcie_dw *pcie = arg;
 	struct dw_pcie_ep *ep = &pcie->pci.ep;
 	struct dw_pcie *pci = &pcie->pci;
-	u32 val, speed;
+	u32 val;
 
 	if (test_and_clear_bit(0, &pcie->link_status))
 		dw_pcie_ep_linkup(ep);
 
-	speed = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA) &
-		PCI_EXP_LNKSTA_CLS;
-	clk_set_rate(pcie->core_clk, pcie_gen_freq[speed - 1]);
+	tegra_pcie_icc_set(pcie);
 
 	if (pcie->of_data->has_ltr_req_fix)
 		return IRQ_HANDLED;
@@ -945,9 +963,9 @@  static int tegra_pcie_dw_host_init(struct dw_pcie_rp *pp)
 
 static int tegra_pcie_dw_start_link(struct dw_pcie *pci)
 {
-	u32 val, offset, speed, tmp;
 	struct tegra_pcie_dw *pcie = to_tegra_pcie(pci);
 	struct dw_pcie_rp *pp = &pci->pp;
+	u32 val, offset, tmp;
 	bool retry = true;
 
 	if (pcie->of_data->mode == DW_PCIE_EP_TYPE) {
@@ -1018,9 +1036,7 @@  static int tegra_pcie_dw_start_link(struct dw_pcie *pci)
 		goto retry_link;
 	}
 
-	speed = dw_pcie_readw_dbi(pci, pcie->pcie_cap_base + PCI_EXP_LNKSTA) &
-		PCI_EXP_LNKSTA_CLS;
-	clk_set_rate(pcie->core_clk, pcie_gen_freq[speed - 1]);
+	tegra_pcie_icc_set(pcie);
 
 	tegra_pcie_enable_interrupts(pp);
 
@@ -2224,6 +2240,14 @@  static int tegra_pcie_dw_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, pcie);
 
+	pcie->icc_path = devm_of_icc_get(&pdev->dev, "write");
+	ret = PTR_ERR_OR_ZERO(pcie->icc_path);
+	if (ret) {
+		tegra_bpmp_put(pcie->bpmp);
+		dev_err_probe(&pdev->dev, ret, "failed to get write interconnect\n");
+		return ret;
+	}
+
 	switch (pcie->of_data->mode) {
 	case DW_PCIE_RC_TYPE:
 		ret = devm_request_irq(dev, pp->irq, tegra_pcie_rp_irq_handler,