1 files changed, 215 insertions, 52 deletions

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index b84bbcdc3fec..5416f2b2ac21 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -33,6 +33,7 @@
 #include <linux/of_platform.h>
 #include <linux/percpu.h>
 #include <linux/slab.h>
+#include <linux/syscore_ops.h>
 
 #include <linux/irqchip.h>
 #include <linux/irqchip/arm-gic-v3.h>
@@ -46,6 +47,7 @@
 #define ITS_FLAGS_CMDQ_NEEDS_FLUSHING		(1ULL << 0)
 #define ITS_FLAGS_WORKAROUND_CAVIUM_22375	(1ULL << 1)
 #define ITS_FLAGS_WORKAROUND_CAVIUM_23144	(1ULL << 2)
+#define ITS_FLAGS_SAVE_SUSPEND_STATE		(1ULL << 3)
 
 #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING	(1 << 0)
 
@@ -101,6 +103,8 @@ struct its_node {
 	struct its_collection	*collections;
 	struct fwnode_handle	*fwnode_handle;
 	u64			(*get_msi_base)(struct its_device *its_dev);
+	u64			cbaser_save;
+	u32			ctlr_save;
 	struct list_head	its_device_list;
 	u64			flags;
 	unsigned long		list_nr;
@@ -1875,16 +1879,6 @@ static void its_cpu_init_lpis(void)
 		gic_data_rdist()->pend_page = pend_page;
 	}
 
-	/* Disable LPIs */
-	val = readl_relaxed(rbase + GICR_CTLR);
-	val &= ~GICR_CTLR_ENABLE_LPIS;
-	writel_relaxed(val, rbase + GICR_CTLR);
-
-	/*
-	 * Make sure any change to the table is observable by the GIC.
-	 */
-	dsb(sy);
-
 	/* set PROPBASE */
 	val = (page_to_phys(gic_rdists->prop_page) |
 	       GICR_PROPBASER_InnerShareable |
@@ -1938,52 +1932,53 @@ static void its_cpu_init_lpis(void)
 	dsb(sy);
 }
 
-static void its_cpu_init_collection(void)
+static void its_cpu_init_collection(struct its_node *its)
 {
-	struct its_node *its;
-	int cpu;
-
-	spin_lock(&its_lock);
-	cpu = smp_processor_id();
-
-	list_for_each_entry(its, &its_nodes, entry) {
-		u64 target;
+	int cpu = smp_processor_id();
+	u64 target;
 
-		/* avoid cross node collections and its mapping */
-		if (its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144) {
-			struct device_node *cpu_node;
+	/* avoid cross node collections and its mapping */
+	if (its->flags & ITS_FLAGS_WORKAROUND_CAVIUM_23144) {
+		struct device_node *cpu_node;
 
-			cpu_node = of_get_cpu_node(cpu, NULL);
-			if (its->numa_node != NUMA_NO_NODE &&
-				its->numa_node != of_node_to_nid(cpu_node))
-				continue;
-		}
+		cpu_node = of_get_cpu_node(cpu, NULL);
+		if (its->numa_node != NUMA_NO_NODE &&
+			its->numa_node != of_node_to_nid(cpu_node))
+			return;
+	}
 
+	/*
+	 * We now have to bind each collection to its target
+	 * redistributor.
+	 */
+	if (gic_read_typer(its->base + GITS_TYPER) & GITS_TYPER_PTA) {
 		/*
-		 * We now have to bind each collection to its target
+		 * This ITS wants the physical address of the
 		 * redistributor.
 		 */
-		if (gic_read_typer(its->base + GITS_TYPER) & GITS_TYPER_PTA) {
-			/*
-			 * This ITS wants the physical address of the
-			 * redistributor.
-			 */
-			target = gic_data_rdist()->phys_base;
-		} else {
-			/*
-			 * This ITS wants a linear CPU number.
-			 */
-			target = gic_read_typer(gic_data_rdist_rd_base() + GICR_TYPER);
-			target = GICR_TYPER_CPU_NUMBER(target) << 16;
-		}
+		target = gic_data_rdist()->phys_base;
+	} else {
+		/* This ITS wants a linear CPU number. */
+		target = gic_read_typer(gic_data_rdist_rd_base() + GICR_TYPER);
+		target = GICR_TYPER_CPU_NUMBER(target) << 16;
+	}
 
-		/* Perform collection mapping */
-		its->collections[cpu].target_address = target;
-		its->collections[cpu].col_id = cpu;
+	/* Perform collection mapping */
+	its->collections[cpu].target_address = target;
+	its->collections[cpu].col_id = cpu;
 
-		its_send_mapc(its, &its->collections[cpu], 1);
-		its_send_invall(its, &its->collections[cpu]);
-	}
+	its_send_mapc(its, &its->collections[cpu], 1);
+	its_send_invall(its, &its->collections[cpu]);
+}
+
+static void its_cpu_init_collections(void)
+{
+	struct its_node *its;
+
+	spin_lock(&its_lock);
+
+	list_for_each_entry(its, &its_nodes, entry)
+		its_cpu_init_collection(its);
 
 	spin_unlock(&its_lock);
 }
@@ -3041,6 +3036,113 @@ static void its_enable_quirks(struct its_node *its)
 	gic_enable_quirks(iidr, its_quirks, its);
 }
 
+static int its_save_disable(void)
+{
+	struct its_node *its;
+	int err = 0;
+
+	spin_lock(&its_lock);
+	list_for_each_entry(its, &its_nodes, entry) {
+		void __iomem *base;
+
+		if (!(its->flags & ITS_FLAGS_SAVE_SUSPEND_STATE))
+			continue;
+
+		base = its->base;
+		its->ctlr_save = readl_relaxed(base + GITS_CTLR);
+		err = its_force_quiescent(base);
+		if (err) {
+			pr_err("ITS@%pa: failed to quiesce: %d\n",
+			       &its->phys_base, err);
+			writel_relaxed(its->ctlr_save, base + GITS_CTLR);
+			goto err;
+		}
+
+		its->cbaser_save = gits_read_cbaser(base + GITS_CBASER);
+	}
+
+err:
+	if (err) {
+		list_for_each_entry_continue_reverse(its, &its_nodes, entry) {
+			void __iomem *base;
+
+			if (!(its->flags & ITS_FLAGS_SAVE_SUSPEND_STATE))
+				continue;
+
+			base = its->base;
+			writel_relaxed(its->ctlr_save, base + GITS_CTLR);
+		}
+	}
+	spin_unlock(&its_lock);
+
+	return err;
+}
+
+static void its_restore_enable(void)
+{
+	struct its_node *its;
+	int ret;
+
+	spin_lock(&its_lock);
+	list_for_each_entry(its, &its_nodes, entry) {
+		void __iomem *base;
+		int i;
+
+		if (!(its->flags & ITS_FLAGS_SAVE_SUSPEND_STATE))
+			continue;
+
+		base = its->base;
+
+		/*
+		 * Make sure that the ITS is disabled. If it fails to quiesce,
+		 * don't restore it since writing to CBASER or BASER<n>
+		 * registers is undefined according to the GIC v3 ITS
+		 * Specification.
+		 */
+		ret = its_force_quiescent(base);
+		if (ret) {
+			pr_err("ITS@%pa: failed to quiesce on resume: %d\n",
+			       &its->phys_base, ret);
+			continue;
+		}
+
+		gits_write_cbaser(its->cbaser_save, base + GITS_CBASER);
+
+		/*
+		 * Writing CBASER resets CREADR to 0, so make CWRITER and
+		 * cmd_write line up with it.
+		 */
+		its->cmd_write = its->cmd_base;
+		gits_write_cwriter(0, base + GITS_CWRITER);
+
+		/* Restore GITS_BASER from the value cache. */
+		for (i = 0; i < GITS_BASER_NR_REGS; i++) {
+			struct its_baser *baser = &its->tables[i];
+
+			if (!(baser->val & GITS_BASER_VALID))
+				continue;
+
+			its_write_baser(its, baser, baser->val);
+		}
+		writel_relaxed(its->ctlr_save, base + GITS_CTLR);
+
+		/*
+		 * Reinit the collection if it's stored in the ITS. This is
+		 * indicated by the col_id being less than the HCC field.
+		 * CID < HCC as specified in the GIC v3 Documentation.
+		 */
+		if (its->collections[smp_processor_id()].col_id <
+		    GITS_TYPER_HCC(gic_read_typer(base + GITS_TYPER)))
+			its_cpu_init_collection(its);
+	}
+	spin_unlock(&its_lock);
+}
+
+static struct syscore_ops its_syscore_ops = {
+	.suspend = its_save_disable,
+	.resume = its_restore_enable,
+};
+
 static int its_init_domain(struct fwnode_handle *handle, struct its_node *its)
 {
 	struct irq_domain *inner_domain;
@@ -3260,6 +3362,9 @@ static int __init its_probe_one(struct resource *res,
 		ctlr |= GITS_CTLR_ImDe;
 	writel_relaxed(ctlr, its->base + GITS_CTLR);
 
+	if (GITS_TYPER_HCC(typer))
+		its->flags |= ITS_FLAGS_SAVE_SUSPEND_STATE;
+
 	err = its_init_domain(handle, its);
 	if (err)
 		goto out_free_tables;
@@ -3287,15 +3392,71 @@ static bool gic_rdists_supports_plpis(void)
 	return !!(gic_read_typer(gic_data_rdist_rd_base() + GICR_TYPER) & GICR_TYPER_PLPIS);
 }
 
+static int redist_disable_lpis(void)
+{
+	void __iomem *rbase = gic_data_rdist_rd_base();
+	u64 timeout = USEC_PER_SEC;
+	u64 val;
+
+	if (!gic_rdists_supports_plpis()) {
+		pr_info("CPU%d: LPIs not supported\n", smp_processor_id());
+		return -ENXIO;
+	}
+
+	val = readl_relaxed(rbase + GICR_CTLR);
+	if (!(val & GICR_CTLR_ENABLE_LPIS))
+		return 0;
+
+	pr_warn("CPU%d: Booted with LPIs enabled, memory probably corrupted\n",
+		smp_processor_id());
+	add_taint(TAINT_CRAP, LOCKDEP_STILL_OK);
+
+	/* Disable LPIs */
+	val &= ~GICR_CTLR_ENABLE_LPIS;
+	writel_relaxed(val, rbase + GICR_CTLR);
+
+	/* Make sure any change to GICR_CTLR is observable by the GIC */
+	dsb(sy);
+
+	/*
+	 * Software must observe RWP==0 after clearing GICR_CTLR.EnableLPIs
+	 * from 1 to 0 before programming GICR_PEND{PROP}BASER registers.
+	 * Error out if we time out waiting for RWP to clear.
+	 */
+	while (readl_relaxed(rbase + GICR_CTLR) & GICR_CTLR_RWP) {
+		if (!timeout) {
+			pr_err("CPU%d: Timeout while disabling LPIs\n",
+			       smp_processor_id());
+			return -ETIMEDOUT;
+		}
+		udelay(1);
+		timeout--;
+	}
+
+	/*
+	 * After it has been written to 1, it is IMPLEMENTATION
+	 * DEFINED whether GICR_CTLR.EnableLPI becomes RES1 or can be
+	 * cleared to 0. Error out if clearing the bit failed.
+	 */
+	if (readl_relaxed(rbase + GICR_CTLR) & GICR_CTLR_ENABLE_LPIS) {
+		pr_err("CPU%d: Failed to disable LPIs\n", smp_processor_id());
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
 int its_cpu_init(void)
 {
 	if (!list_empty(&its_nodes)) {
-		if (!gic_rdists_supports_plpis()) {
-			pr_info("CPU%d: LPIs not supported\n", smp_processor_id());
-			return -ENXIO;
-		}
+		int ret;
+
+		ret = redist_disable_lpis();
+		if (ret)
+			return ret;
+
 		its_cpu_init_lpis();
-		its_cpu_init_collection();
+		its_cpu_init_collections();
 	}
 
 	return 0;
@@ -3517,5 +3678,7 @@ int __init its_init(struct fwnode_handle *handle, struct rdists *rdists,
 		}
 	}
 
+	register_syscore_ops(&its_syscore_ops);
+
 	return 0;
 }