[PATCH v12 11/14] accel/rocket: select the per-core clock and reset counts from match data

[Jiaxing Hu]

The RK3576 carries the same RKNN block with a different set of clocks and
resets, so the counts cannot stay compile-time constants. Add a soc_data
struct to the of_device_id match data and take the bulk counts from it.
RK3588 keeps four clocks and two resets, so nothing changes for it, and the
arrays keep their present sizes: the SoC that needs a longer one grows it
in the patch that adds the names.

rocket_core_reset() is switched over as well. It is the same array, and
leaving it on ARRAY_SIZE() would walk entries that were never acquired once
a SoC asks for fewer.

soc is checked at the top of rocket_probe(), before anything is allocated
and before the per-core fields are stored. of_device_get_match_data()
returns NULL for a device that bound by name rather than by compatible, and
such a device has no of_node, so it was never counted by the walk of
matching nodes that sizes rdev->cores[]. Storing into that array first and
checking afterwards would be writing past the end under the check's own
premise, and returning from there is the one error path in this function
that would skip the unwind the path below it does.

Signed-off-by: Jiaxing Hu <gahing@xxxxxxxxxxxxx>
---
 drivers/accel/rocket/rocket_core.c |  8 ++++----
 drivers/accel/rocket/rocket_core.h |  7 +++++++
 drivers/accel/rocket/rocket_drv.c  | 26 +++++++++++++++++++++++---
 3 files changed, 34 insertions(+), 7 deletions(-)

diff --git a/drivers/accel/rocket/rocket_core.c b/drivers/accel/rocket/rocket_core.c
index 5dd260bac..b202d1581 100644
--- a/drivers/accel/rocket/rocket_core.c
+++ b/drivers/accel/rocket/rocket_core.c
@@ -23,7 +23,7 @@ int rocket_core_init(struct rocket_core *core)
 
 	core->resets[0].id = "srst_a";
 	core->resets[1].id = "srst_h";
-	err = devm_reset_control_bulk_get_exclusive(&pdev->dev, ARRAY_SIZE(core->resets),
+	err = devm_reset_control_bulk_get_exclusive(&pdev->dev, core->soc->num_resets,
 						    core->resets);
 	if (err)
 		return dev_err_probe(dev, err, "failed to get resets for core %d\n", core->index);
@@ -32,7 +32,7 @@ int rocket_core_init(struct rocket_core *core)
 	core->clks[1].id = "hclk";
 	core->clks[2].id = "npu";
 	core->clks[3].id = "pclk";
-	err = devm_clk_bulk_get(dev, ARRAY_SIZE(core->clks), core->clks);
+	err = devm_clk_bulk_get(dev, core->soc->num_clks, core->clks);
 	if (err)
 		return dev_err_probe(dev, err, "failed to get clocks for core %d\n", core->index);
 
@@ -109,9 +109,9 @@ void rocket_core_fini(struct rocket_core *core)
 
 void rocket_core_reset(struct rocket_core *core)
 {
-	reset_control_bulk_assert(ARRAY_SIZE(core->resets), core->resets);
+	reset_control_bulk_assert(core->soc->num_resets, core->resets);
 
 	udelay(10);
 
-	reset_control_bulk_deassert(ARRAY_SIZE(core->resets), core->resets);
+	reset_control_bulk_deassert(core->soc->num_resets, core->resets);
 }
diff --git a/drivers/accel/rocket/rocket_core.h b/drivers/accel/rocket/rocket_core.h
index f6d738285..ba74c5339 100644
--- a/drivers/accel/rocket/rocket_core.h
+++ b/drivers/accel/rocket/rocket_core.h
@@ -27,9 +27,16 @@
 #define rocket_core_writel(core, reg, value) \
 	writel(value, (core)->core_iomem + (REG_CORE_##reg) - REG_CORE_S_STATUS)
 
+/* Per-SoC differences, selected by the of_device_id match data. */
+struct rocket_soc_data {
+	unsigned int num_clks;		/* clk_bulk count */
+	unsigned int num_resets;	/* reset_bulk count */
+};
+
 struct rocket_core {
 	struct device *dev;
 	struct rocket_device *rdev;
+	const struct rocket_soc_data *soc;
 	unsigned int index;
 
 	int irq;
diff --git a/drivers/accel/rocket/rocket_drv.c b/drivers/accel/rocket/rocket_drv.c
index 8bbbce594..7ed64c131 100644
--- a/drivers/accel/rocket/rocket_drv.c
+++ b/drivers/accel/rocket/rocket_drv.c
@@ -159,8 +159,22 @@ static const struct drm_driver rocket_drm_driver = {
 
 static int rocket_probe(struct platform_device *pdev)
 {
+	const struct rocket_soc_data *soc = of_device_get_match_data(&pdev->dev);
 	int ret;
 
+	/*
+	 * soc is dereferenced without a check by every one of its users, and
+	 * rocket_core_init() below is the first of them. A device that bound
+	 * by name rather than by compatible has no match data, so fail before
+	 * anything is allocated rather than at the first dereference: the
+	 * number of cores comes from a walk of matching DT nodes, and a device
+	 * with no of_node was never counted by it.
+	 */
+	if (!soc) {
+		dev_err(&pdev->dev, "no match data for this device\n");
+		return -ENODEV;
+	}
+
 	if (rdev == NULL) {
 		/* First core probing, initialize DRM device. */
 		rdev = rocket_device_init(drm_dev, &rocket_drm_driver);
@@ -176,6 +190,7 @@ static int rocket_probe(struct platform_device *pdev)
 
 	rdev->cores[core].rdev = rdev;
 	rdev->cores[core].dev = &pdev->dev;
+	rdev->cores[core].soc = soc;
 	rdev->cores[core].index = core;
 
 	rdev->num_cores++;
@@ -213,8 +228,13 @@ static void rocket_remove(struct platform_device *pdev)
 	}
 }
 
+static const struct rocket_soc_data rk3588_soc_data = {
+	.num_clks = 4,
+	.num_resets = 2,
+};
+
 static const struct of_device_id dt_match[] = {
-	{ .compatible = "rockchip,rk3588-rknn-core" },
+	{ .compatible = "rockchip,rk3588-rknn-core", .data = &rk3588_soc_data },
 	{}
 };
 MODULE_DEVICE_TABLE(of, dt_match);
@@ -240,7 +260,7 @@ static int rocket_device_runtime_resume(struct device *dev)
 	if (core < 0)
 		return -ENODEV;
 
-	err = clk_bulk_prepare_enable(ARRAY_SIZE(rdev->cores[core].clks), rdev->cores[core].clks);
+	err = clk_bulk_prepare_enable(rdev->cores[core].soc->num_clks, rdev->cores[core].clks);
 	if (err) {
 		dev_err(dev, "failed to enable (%d) clocks for core %d\n", err, core);
 		return err;
@@ -260,7 +280,7 @@ static int rocket_device_runtime_suspend(struct device *dev)
 	if (!rocket_job_is_idle(&rdev->cores[core]))
 		return -EBUSY;
 
-	clk_bulk_disable_unprepare(ARRAY_SIZE(rdev->cores[core].clks), rdev->cores[core].clks);
+	clk_bulk_disable_unprepare(rdev->cores[core].soc->num_clks, rdev->cores[core].clks);
 
 	return 0;
 }
-- 
2.43.0