Re: [PATCH V3 2/8] soc: qcom: geni: Support for ICC voting

Akash Asthana <akashast@xxxxxxxxxxxxxx> · Tue, 7 Apr 2020 12:15:25 +0530

Hi Bjorn,

On 4/1/2020 5:02 AM, Bjorn Andersson wrote:
On Tue 31 Mar 04:09 PDT 2020, Akash Asthana wrote:

Add necessary macros and structure variables to support ICC BW
voting from individual SE drivers.

Signed-off-by: Akash Asthana <akashast@xxxxxxxxxxxxxx>
---
Changes in V2:
  - As per Bjorn's comment dropped enums for ICC paths, given the three
    paths individual members

Changes in V3:
  - Add geni_icc_get, geni_icc_vote_on and geni_icc_vote_off as helper API.
  - Add geni_icc_path structure in common header

  drivers/soc/qcom/qcom-geni-se.c | 98 +++++++++++++++++++++++++++++++++++++++++
  include/linux/qcom-geni-se.h    | 36 +++++++++++++++
  2 files changed, 134 insertions(+)

diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c
index 7d622ea..9344c14 100644
--- a/drivers/soc/qcom/qcom-geni-se.c
+++ b/drivers/soc/qcom/qcom-geni-se.c
@@ -720,6 +720,104 @@ void geni_se_rx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len)
  }
  EXPORT_SYMBOL(geni_se_rx_dma_unprep);
  
+int geni_icc_get(struct geni_se *se, const char *icc_core, const char *icc_cpu,
+		const char *icc_ddr)
+{
+	if (icc_core) {
Afaict it's only this that might be passed as NULL, so please drop these
conditionals (keep the last one).
IIUC you're suggesting to drop if (icc_core/cpu) but keep if (icc_ddr) ?

+		se->to_core.path = devm_of_icc_get(se->dev, "qup-core");
+		if (IS_ERR(se->to_core.path))
It would be useful to print an error message here (if PTR_ERR(path) !=
-EPROBE_DEFER).
okay

+			return PTR_ERR(se->to_core.path);
+	}
+
+	if (icc_cpu) {
+		se->from_cpu.path = devm_of_icc_get(se->dev, "qup-config");
+		if (IS_ERR(se->from_cpu.path))
+			return PTR_ERR(se->from_cpu.path);
+	}
+
+	if (icc_ddr) {
+		se->to_ddr.path = devm_of_icc_get(se->dev, "qup-memory");
+		if (IS_ERR(se->to_ddr.path))
+			return PTR_ERR(se->to_ddr.path);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(geni_icc_get);
+
+int geni_icc_vote_on(struct geni_se *se)
+{
+	int ret;
+
+	if (se->to_core.path) {
icc_set_bw(NULL, ...) is valid and will return 0, so these checks
doesn't add any value.
Yeah, ok

+		ret = icc_set_bw(se->to_core.path, se->to_core.avg_bw,
+			se->to_core.peak_bw);
+		if (ret) {
+			dev_err_ratelimited(se->dev, "%s: ICC BW voting failed for core\n",
+						__func__);
Please drop the __func__, the message is specific enough.

ok

Regards,

Akash


+			return ret;
+		}
+	}
+
+	if (se->from_cpu.path) {
+		ret = icc_set_bw(se->from_cpu.path, se->from_cpu.avg_bw,
+			se->from_cpu.peak_bw);
+		if (ret) {
+			dev_err_ratelimited(se->dev, "%s: ICC BW voting failed for cpu\n",
+						__func__);
+			return ret;
+		}
+	}
+
+	if (se->to_ddr.path) {
+		ret = icc_set_bw(se->to_ddr.path, se->to_ddr.avg_bw,
+			se->to_ddr.peak_bw);
+		if (ret) {
+			dev_err_ratelimited(se->dev, "%s: ICC BW voting failed for ddr\n",
+						__func__);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(geni_icc_vote_on);
+
+int geni_icc_vote_off(struct geni_se *se)
+{
+	int ret;
+
+	if (se->to_core.path) {
+		ret = icc_set_bw(se->to_core.path, 0, 0);
+		if (ret) {
+			dev_err_ratelimited(se->dev, "%s: ICC BW remove failed for core\n",
+						__func__);
+			return ret;
+		}
+	}
+
+	if (se->from_cpu.path) {
+		ret = icc_set_bw(se->from_cpu.path, 0, 0);
+		if (ret) {
+			dev_err_ratelimited(se->dev, "%s: ICC BW remove failed for cpu\n",
+						__func__);
+			return ret;
+		}
+	}
+
+	if (se->to_ddr.path) {
+		ret = icc_set_bw(se->to_ddr.path, 0, 0);
+		if (ret) {
+			dev_err_ratelimited(se->dev, "%s: ICC BW remove failed for ddr\n",
+						__func__);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(geni_icc_vote_off);
Given that these two functions only switch the bandwidth request between
some value and 0, I really think we should carry a "bool enabled" on the
path and replace these two functions with
icc_bulk_enable()/icc_bulk_disable().

The added benefit of this would be that you call icc_set_bw() instead of
changing the geni_icc_path->{avg_bw,peak_bw} and don't need to keep
track of them here.

Regards,
Bjorn
+
  static int geni_se_probe(struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;
diff --git a/include/linux/qcom-geni-se.h b/include/linux/qcom-geni-se.h
index dd46494..a83c86b 100644
--- a/include/linux/qcom-geni-se.h
+++ b/include/linux/qcom-geni-se.h
@@ -6,6 +6,8 @@
  #ifndef _LINUX_QCOM_GENI_SE
  #define _LINUX_QCOM_GENI_SE
  
+#include <linux/interconnect.h>
+
  /* Transfer mode supported by GENI Serial Engines */
  enum geni_se_xfer_mode {
  	GENI_SE_INVALID,
@@ -25,6 +27,12 @@ enum geni_se_protocol_type {
  struct geni_wrapper;
  struct clk;
  
+struct geni_icc_path {
+	struct icc_path *path;
+	unsigned int avg_bw;
+	unsigned int peak_bw;
+};
+
  /**
   * struct geni_se - GENI Serial Engine
   * @base:		Base Address of the Serial Engine's register block
@@ -33,6 +41,9 @@ struct clk;
   * @clk:		Handle to the core serial engine clock
   * @num_clk_levels:	Number of valid clock levels in clk_perf_tbl
   * @clk_perf_tbl:	Table of clock frequency input to serial engine clock
+ * @to_core:	ICC path structure for geni to core
+ * @from_cpu:	ICC path structure for cpu to geni
+ * @to_ddr:	ICC path structure for geni to ddr
   */
  struct geni_se {
  	void __iomem *base;
@@ -41,6 +52,9 @@ struct geni_se {
  	struct clk *clk;
  	unsigned int num_clk_levels;
  	unsigned long *clk_perf_tbl;
+	struct geni_icc_path to_core;
+	struct geni_icc_path from_cpu;
+	struct geni_icc_path to_ddr;
  };
  
  /* Common SE registers */
@@ -229,6 +243,21 @@ struct geni_se {
  #define GENI_SE_VERSION_MINOR(ver) ((ver & HW_VER_MINOR_MASK) >> HW_VER_MINOR_SHFT)
  #define GENI_SE_VERSION_STEP(ver) (ver & HW_VER_STEP_MASK)
  
+/*
+ * Define bandwidth thresholds that cause the underlying Core 2X interconnect
+ * clock to run at the named frequency. These baseline values are recommended
+ * by the hardware team, and are not dynamically scaled with GENI bandwidth
+ * beyond basic on/off.
+ */
+#define CORE_2X_19_2_MHZ		960
+#define CORE_2X_50_MHZ			2500
+#define CORE_2X_100_MHZ			5000
+#define CORE_2X_150_MHZ			7500
+#define CORE_2X_200_MHZ			10000
+#define CORE_2X_236_MHZ			16383
+
+#define GENI_DEFAULT_BW			Bps_to_icc(1000)
+
  #if IS_ENABLED(CONFIG_QCOM_GENI_SE)
  
  u32 geni_se_get_qup_hw_version(struct geni_se *se);
@@ -416,5 +445,12 @@ int geni_se_rx_dma_prep(struct geni_se *se, void *buf, size_t len,
  void geni_se_tx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len);
  
  void geni_se_rx_dma_unprep(struct geni_se *se, dma_addr_t iova, size_t len);
+
+int geni_icc_get(struct geni_se *se, const char *icc_core, const char *icc_cpu,
+		const char *icc_ddr);
+
+int geni_icc_vote_on(struct geni_se *se);
+
+int geni_icc_vote_off(struct geni_se *se);
  #endif
  #endif
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project

--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project






