perf/arm-cci: Untangle global cci_ctrl_base

Depending directly on the bus driver's global cci_ctrl_base variable
is a little unpleasant, and exporting it to allow the PMU driver to
be modular would be even more so. Let's make things a little better
abstracted by adding the control register block to the cci_pmu instance
data alongside the PMU register block, and communicating the mapped
address from the bus driver via platform data.

It's not practical to try the same thing for the bus driver itself,
given that the globals are entangled with the hairy assembly code for
port control, so we leave them be there. It would however be prudent
to move them to the __ro_after_init section in passing, since the
addresses really should never be changing once set.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

drivers/bus/arm-cci.c

@@ -25,9 +25,8 @@
 #include <asm/cacheflush.h>
 #include <asm/smp_plat.h>
 
-/* Referenced read-only by the PMU driver; see drivers/perf/arm-cci.c */
-void __iomem *cci_ctrl_base;
-static unsigned long cci_ctrl_phys;
+static void __iomem *cci_ctrl_base __ro_after_init;
+static unsigned long cci_ctrl_phys __ro_after_init;
 
 #ifdef CONFIG_ARM_CCI400_PORT_CTRL
 struct cci_nb_ports {
@@ -56,6 +55,15 @@ static const struct of_device_id arm_cci_matches[] = {
 	{},
 };
 
+static const struct of_dev_auxdata arm_cci_auxdata[] = {
+	OF_DEV_AUXDATA("arm,cci-400-pmu", 0, NULL, &cci_ctrl_base),
+	OF_DEV_AUXDATA("arm,cci-400-pmu,r0", 0, NULL, &cci_ctrl_base),
+	OF_DEV_AUXDATA("arm,cci-400-pmu,r1", 0, NULL, &cci_ctrl_base),
+	OF_DEV_AUXDATA("arm,cci-500-pmu,r0", 0, NULL, &cci_ctrl_base),
+	OF_DEV_AUXDATA("arm,cci-550-pmu,r0", 0, NULL, &cci_ctrl_base),
+	{}
+};
+
 #define DRIVER_NAME		"ARM-CCI"
 
 static int cci_platform_probe(struct platform_device *pdev)
@@ -63,7 +71,8 @@ static int cci_platform_probe(struct platform_device *pdev)
 	if (!cci_probed())
 		return -ENODEV;
 
-	return of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
+	return of_platform_populate(pdev->dev.of_node, NULL,
+				    arm_cci_auxdata, &pdev->dev);
 }
 
 static struct platform_driver cci_platform_driver = {

drivers/perf/arm-cci.c

@@ -16,8 +16,6 @@
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 
-extern void __iomem *const cci_ctrl_base;
-
 #define DRIVER_NAME		"ARM-CCI PMU"
 
 #define CCI_PMCR		0x0100
@@ -90,6 +88,7 @@ static struct cci_pmu_model cci_pmu_models[];
 
 struct cci_pmu {
 	void __iomem *base;
+	void __iomem *ctrl_base;
 	struct pmu pmu;
 	int cpu;
 	int nr_irqs;
@@ -360,10 +359,10 @@ static int cci400_validate_hw_event(struct cci_pmu *cci_pmu, unsigned long hw_ev
 	return -ENOENT;
 }
 
-static int probe_cci400_revision(void)
+static int probe_cci400_revision(struct cci_pmu *cci_pmu)
 {
 	int rev;
-	rev = readl_relaxed(cci_ctrl_base + CCI_PID2) & CCI_PID2_REV_MASK;
+	rev = readl_relaxed(cci_pmu->ctrl_base + CCI_PID2) & CCI_PID2_REV_MASK;
 	rev >>= CCI_PID2_REV_SHIFT;
 
 	if (rev < CCI400_R1_PX)
@@ -372,14 +371,14 @@ static int probe_cci400_revision(void)
 		return CCI400_R1;
 }
 
-static const struct cci_pmu_model *probe_cci_model(void)
+static const struct cci_pmu_model *probe_cci_model(struct cci_pmu *cci_pmu)
 {
 	if (platform_has_secure_cci_access())
-		return &cci_pmu_models[probe_cci400_revision()];
+		return &cci_pmu_models[probe_cci400_revision(cci_pmu)];
 	return NULL;
 }
 #else	/* !CONFIG_ARM_CCI400_PMU */
-static inline struct cci_pmu_model *probe_cci_model(void)
+static inline struct cci_pmu_model *probe_cci_model(struct cci_pmu *cci_pmu)
 {
 	return NULL;
 }
@@ -662,8 +661,8 @@ static void __cci_pmu_enable_nosync(struct cci_pmu *cci_pmu)
 	u32 val;
 
 	/* Enable all the PMU counters. */
-	val = readl_relaxed(cci_ctrl_base + CCI_PMCR) | CCI_PMCR_CEN;
-	writel(val, cci_ctrl_base + CCI_PMCR);
+	val = readl_relaxed(cci_pmu->ctrl_base + CCI_PMCR) | CCI_PMCR_CEN;
+	writel(val, cci_pmu->ctrl_base + CCI_PMCR);
 }
 
 /* Should be called with cci_pmu->hw_events->pmu_lock held */
@@ -674,13 +673,13 @@ static void __cci_pmu_enable_sync(struct cci_pmu *cci_pmu)
 }
 
 /* Should be called with cci_pmu->hw_events->pmu_lock held */
-static void __cci_pmu_disable(void)
+static void __cci_pmu_disable(struct cci_pmu *cci_pmu)
 {
 	u32 val;
 
 	/* Disable all the PMU counters. */
-	val = readl_relaxed(cci_ctrl_base + CCI_PMCR) & ~CCI_PMCR_CEN;
-	writel(val, cci_ctrl_base + CCI_PMCR);
+	val = readl_relaxed(cci_pmu->ctrl_base + CCI_PMCR) & ~CCI_PMCR_CEN;
+	writel(val, cci_pmu->ctrl_base + CCI_PMCR);
 }
 
 static ssize_t cci_pmu_format_show(struct device *dev,
@@ -782,9 +781,9 @@ pmu_restore_counters(struct cci_pmu *cci_pmu, unsigned long *mask)
  * Returns the number of programmable counters actually implemented
  * by the cci
  */
-static u32 pmu_get_max_counters(void)
+static u32 pmu_get_max_counters(struct cci_pmu *cci_pmu)
 {
-	return (readl_relaxed(cci_ctrl_base + CCI_PMCR) &
+	return (readl_relaxed(cci_pmu->ctrl_base + CCI_PMCR) &
 		CCI_PMCR_NCNT_MASK) >> CCI_PMCR_NCNT_SHIFT;
 }
 
@@ -965,7 +964,7 @@ static void cci5xx_pmu_write_counters(struct cci_pmu *cci_pmu, unsigned long *ma
 		pmu_set_event(cci_pmu, i, event->hw.config_base);
 	}
 
-	__cci_pmu_disable();
+	__cci_pmu_disable(cci_pmu);
 
 	pmu_restore_counters(cci_pmu, saved_mask);
 }
@@ -1026,7 +1025,7 @@ static irqreturn_t pmu_handle_irq(int irq_num, void *dev)
 	raw_spin_lock_irqsave(&events->pmu_lock, flags);
 
 	/* Disable the PMU while we walk through the counters */
-	__cci_pmu_disable();
+	__cci_pmu_disable(cci_pmu);
 	/*
 	 * Iterate over counters and update the corresponding perf events.
 	 * This should work regardless of whether we have per-counter overflow
@@ -1108,7 +1107,7 @@ static void cci_pmu_disable(struct pmu *pmu)
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&hw_events->pmu_lock, flags);
-	__cci_pmu_disable();
+	__cci_pmu_disable(cci_pmu);
 	raw_spin_unlock_irqrestore(&hw_events->pmu_lock, flags);
 }
 
@@ -1438,7 +1437,7 @@ static int cci_pmu_init(struct cci_pmu *cci_pmu, struct platform_device *pdev)
 	};
 
 	cci_pmu->plat_device = pdev;
-	num_cntrs = pmu_get_max_counters();
+	num_cntrs = pmu_get_max_counters(cci_pmu);
 	if (num_cntrs > cci_pmu->model->num_hw_cntrs) {
 		dev_warn(&pdev->dev,
 			"PMU implements more counters(%d) than supported by"
@@ -1611,21 +1610,23 @@ static struct cci_pmu *cci_pmu_alloc(struct device *dev)
 	 * them explicitly on an error, as it would end up in driver
 	 * detach.
 	 */
+	cci_pmu = devm_kzalloc(dev, sizeof(*cci_pmu), GFP_KERNEL);
+	if (!cci_pmu)
+		return ERR_PTR(-ENOMEM);
+
+	cci_pmu->ctrl_base = *(void __iomem **)dev->platform_data;
+
 	model = of_device_get_match_data(dev);
 	if (!model) {
 		dev_warn(dev,
 			 "DEPRECATED compatible property, requires secure access to CCI registers");
-		model = probe_cci_model();
+		model = probe_cci_model(cci_pmu);
 	}
 	if (!model) {
 		dev_warn(dev, "CCI PMU version not supported\n");
 		return ERR_PTR(-ENODEV);
 	}
 
-	cci_pmu = devm_kzalloc(dev, sizeof(*cci_pmu), GFP_KERNEL);
-	if (!cci_pmu)
-		return ERR_PTR(-ENOMEM);
-
 	cci_pmu->model = model;
 	cci_pmu->irqs = devm_kcalloc(dev, CCI_PMU_MAX_HW_CNTRS(model),
 					sizeof(*cci_pmu->irqs), GFP_KERNEL);