--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2019-2020 NVIDIA CORPORATION. All rights reserved.
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "arm-smmu.h"
+
+/*
+ * Tegra194 has three ARM MMU-500 Instances.
+ * Two of them are used together and must be programmed identically for
+ * interleaved IOVA accesses across them and translates accesses from
+ * non-isochronous HW devices.
+ * Third one is used for translating accesses from isochronous HW devices.
+ * This implementation supports programming of the two instances that must
+ * be programmed identically.
+ * The third instance usage is through standard arm-smmu driver itself and
+ * is out of scope of this implementation.
+ */
+#define NUM_SMMU_INSTANCES 2
+
+struct nvidia_smmu {
+ struct arm_smmu_device smmu;
+ void __iomem *bases[NUM_SMMU_INSTANCES];
+};
+
+static inline void __iomem *nvidia_smmu_page(struct arm_smmu_device *smmu,
+ unsigned int inst, int page)
+{
+ struct nvidia_smmu *nvidia_smmu;
+
+ nvidia_smmu = container_of(smmu, struct nvidia_smmu, smmu);
+ return nvidia_smmu->bases[inst] + (page << smmu->pgshift);
+}
+
+static u32 nvidia_smmu_read_reg(struct arm_smmu_device *smmu,
+ int page, int offset)
+{
+ void __iomem *reg = nvidia_smmu_page(smmu, 0, page) + offset;
+
+ return readl_relaxed(reg);
+}
+
+static void nvidia_smmu_write_reg(struct arm_smmu_device *smmu,
+ int page, int offset, u32 val)
+{
+ unsigned int i;
+
+ for (i = 0; i < NUM_SMMU_INSTANCES; i++) {
+ void __iomem *reg = nvidia_smmu_page(smmu, i, page) + offset;
+
+ writel_relaxed(val, reg);
+ }
+}
+
+static u64 nvidia_smmu_read_reg64(struct arm_smmu_device *smmu,
+ int page, int offset)
+{
+ void __iomem *reg = nvidia_smmu_page(smmu, 0, page) + offset;
+
+ return readq_relaxed(reg);
+}
+
+static void nvidia_smmu_write_reg64(struct arm_smmu_device *smmu,
+ int page, int offset, u64 val)
+{
+ unsigned int i;
+
+ for (i = 0; i < NUM_SMMU_INSTANCES; i++) {
+ void __iomem *reg = nvidia_smmu_page(smmu, i, page) + offset;
+
+ writeq_relaxed(val, reg);
+ }
+}
+
+static void nvidia_smmu_tlb_sync(struct arm_smmu_device *smmu, int page,
+ int sync, int status)
+{
+ unsigned int delay;
+
+ arm_smmu_writel(smmu, page, sync, 0);
+
+ for (delay = 1; delay < TLB_LOOP_TIMEOUT; delay *= 2) {
+ unsigned int spin_cnt;
+
+ for (spin_cnt = TLB_SPIN_COUNT; spin_cnt > 0; spin_cnt--) {
+ u32 val = 0;
+ unsigned int i;
+
+ for (i = 0; i < NUM_SMMU_INSTANCES; i++) {
+ void __iomem *reg;
+
+ reg = nvidia_smmu_page(smmu, i, page) + status;
+ val |= readl_relaxed(reg);
+ }
+
+ if (!(val & ARM_SMMU_sTLBGSTATUS_GSACTIVE))
+ return;
+
+ cpu_relax();
+ }
+
+ udelay(delay);
+ }
+
+ dev_err_ratelimited(smmu->dev,
+ "TLB sync timed out -- SMMU may be deadlocked\n");
+}
+
+static int nvidia_smmu_reset(struct arm_smmu_device *smmu)
+{
+ unsigned int i;
+
+ for (i = 0; i < NUM_SMMU_INSTANCES; i++) {
+ u32 val;
+ void __iomem *reg = nvidia_smmu_page(smmu, i, ARM_SMMU_GR0) +
+ ARM_SMMU_GR0_sGFSR;
+
+ /* clear global FSR */
+ val = readl_relaxed(reg);
+ writel_relaxed(val, reg);
+ }
+
+ return 0;
+}
+
+static const struct arm_smmu_impl nvidia_smmu_impl = {
+ .read_reg = nvidia_smmu_read_reg,
+ .write_reg = nvidia_smmu_write_reg,
+ .read_reg64 = nvidia_smmu_read_reg64,
+ .write_reg64 = nvidia_smmu_write_reg64,
+ .reset = nvidia_smmu_reset,
+ .tlb_sync = nvidia_smmu_tlb_sync,
+};
+
+struct arm_smmu_device *nvidia_smmu_impl_init(struct arm_smmu_device *smmu)
+{
+ struct resource *res;
+ struct device *dev = smmu->dev;
+ struct nvidia_smmu *nvidia_smmu;
+ struct platform_device *pdev = to_platform_device(dev);
+
+ nvidia_smmu = devm_kzalloc(dev, sizeof(*nvidia_smmu), GFP_KERNEL);
+ if (!nvidia_smmu)
+ return ERR_PTR(-ENOMEM);
+
+ /*
+ * Copy the data from struct arm_smmu_device *smmu allocated in
+ * arm-smmu.c. The smmu from struct nvidia_smmu replaces the smmu
+ * pointer used in arm-smmu.c once this function returns.
+ * This is necessary to derive nvidia_smmu from smmu pointer passed
+ * through arm_smmu_impl function calls subsequently.
+ */
+ nvidia_smmu->smmu = *smmu;
+ /* Instance 0 is ioremapped by arm-smmu.c. */
+ nvidia_smmu->bases[0] = smmu->base;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+ if (!res)
+ return ERR_PTR(-ENODEV);
+
+ nvidia_smmu->bases[1] = devm_ioremap_resource(dev, res);
+ if (IS_ERR(nvidia_smmu->bases[1]))
+ return ERR_CAST(nvidia_smmu->bases[1]);
+
+ nvidia_smmu->smmu.impl = &nvidia_smmu_impl;
+
+ /*
+ * Free the struct arm_smmu_device *smmu allocated in arm-smmu.c.
+ * Once this function returns, arm-smmu.c would use arm_smmu_device
+ * allocated as part of struct nvidia_smmu.
+ */
+ devm_kfree(dev, smmu);
+
+ return &nvidia_smmu->smmu;
+}
projects / platform / kernel / linux-starfive.git / commitdiff