1 // SPDX-License-Identifier: GPL-2.0-only 2 // Copyright (C) 2019-2020 NVIDIA CORPORATION. All rights reserved. 3 4 #include <linux/bitfield.h> 5 #include <linux/delay.h> 6 #include <linux/of.h> 7 #include <linux/platform_device.h> 8 #include <linux/slab.h> 9 10 #include <soc/tegra/mc.h> 11 12 #include "arm-smmu.h" 13 14 /* 15 * Tegra194 has three ARM MMU-500 Instances. 16 * Two of them are used together and must be programmed identically for 17 * interleaved IOVA accesses across them and translates accesses from 18 * non-isochronous HW devices. 19 * Third one is used for translating accesses from isochronous HW devices. 20 * 21 * In addition, the SMMU driver needs to coordinate with the memory controller 22 * driver to ensure that the right SID override is programmed for any given 23 * memory client. This is necessary to allow for use-case such as seamlessly 24 * handing over the display controller configuration from the firmware to the 25 * kernel. 26 * 27 * This implementation supports programming of the two instances that must 28 * be programmed identically and takes care of invoking the memory controller 29 * driver for SID override programming after devices have been attached to an 30 * SMMU instance. 31 */ 32 #define MAX_SMMU_INSTANCES 2 33 34 struct nvidia_smmu { 35 struct arm_smmu_device smmu; 36 void __iomem *bases[MAX_SMMU_INSTANCES]; 37 unsigned int num_instances; 38 struct tegra_mc *mc; 39 }; 40 41 static inline struct nvidia_smmu *to_nvidia_smmu(struct arm_smmu_device *smmu) 42 { 43 return container_of(smmu, struct nvidia_smmu, smmu); 44 } 45 46 static inline void __iomem *nvidia_smmu_page(struct arm_smmu_device *smmu, 47 unsigned int inst, int page) 48 { 49 struct nvidia_smmu *nvidia_smmu; 50 51 nvidia_smmu = container_of(smmu, struct nvidia_smmu, smmu); 52 return nvidia_smmu->bases[inst] + (page << smmu->pgshift); 53 } 54 55 static u32 nvidia_smmu_read_reg(struct arm_smmu_device *smmu, 56 int page, int offset) 57 { 58 void __iomem *reg = nvidia_smmu_page(smmu, 0, page) + offset; 59 60 return readl_relaxed(reg); 61 } 62 63 static void nvidia_smmu_write_reg(struct arm_smmu_device *smmu, 64 int page, int offset, u32 val) 65 { 66 struct nvidia_smmu *nvidia = to_nvidia_smmu(smmu); 67 unsigned int i; 68 69 for (i = 0; i < nvidia->num_instances; i++) { 70 void __iomem *reg = nvidia_smmu_page(smmu, i, page) + offset; 71 72 writel_relaxed(val, reg); 73 } 74 } 75 76 static u64 nvidia_smmu_read_reg64(struct arm_smmu_device *smmu, 77 int page, int offset) 78 { 79 void __iomem *reg = nvidia_smmu_page(smmu, 0, page) + offset; 80 81 return readq_relaxed(reg); 82 } 83 84 static void nvidia_smmu_write_reg64(struct arm_smmu_device *smmu, 85 int page, int offset, u64 val) 86 { 87 struct nvidia_smmu *nvidia = to_nvidia_smmu(smmu); 88 unsigned int i; 89 90 for (i = 0; i < nvidia->num_instances; i++) { 91 void __iomem *reg = nvidia_smmu_page(smmu, i, page) + offset; 92 93 writeq_relaxed(val, reg); 94 } 95 } 96 97 static void nvidia_smmu_tlb_sync(struct arm_smmu_device *smmu, int page, 98 int sync, int status) 99 { 100 struct nvidia_smmu *nvidia = to_nvidia_smmu(smmu); 101 unsigned int delay; 102 103 arm_smmu_writel(smmu, page, sync, 0); 104 105 for (delay = 1; delay < TLB_LOOP_TIMEOUT; delay *= 2) { 106 unsigned int spin_cnt; 107 108 for (spin_cnt = TLB_SPIN_COUNT; spin_cnt > 0; spin_cnt--) { 109 u32 val = 0; 110 unsigned int i; 111 112 for (i = 0; i < nvidia->num_instances; i++) { 113 void __iomem *reg; 114 115 reg = nvidia_smmu_page(smmu, i, page) + status; 116 val |= readl_relaxed(reg); 117 } 118 119 if (!(val & ARM_SMMU_sTLBGSTATUS_GSACTIVE)) 120 return; 121 122 cpu_relax(); 123 } 124 125 udelay(delay); 126 } 127 128 dev_err_ratelimited(smmu->dev, 129 "TLB sync timed out -- SMMU may be deadlocked\n"); 130 } 131 132 static int nvidia_smmu_reset(struct arm_smmu_device *smmu) 133 { 134 struct nvidia_smmu *nvidia = to_nvidia_smmu(smmu); 135 unsigned int i; 136 137 for (i = 0; i < nvidia->num_instances; i++) { 138 u32 val; 139 void __iomem *reg = nvidia_smmu_page(smmu, i, ARM_SMMU_GR0) + 140 ARM_SMMU_GR0_sGFSR; 141 142 /* clear global FSR */ 143 val = readl_relaxed(reg); 144 writel_relaxed(val, reg); 145 } 146 147 return 0; 148 } 149 150 static irqreturn_t nvidia_smmu_global_fault_inst(int irq, 151 struct arm_smmu_device *smmu, 152 int inst) 153 { 154 u32 gfsr, gfsynr0, gfsynr1, gfsynr2; 155 void __iomem *gr0_base = nvidia_smmu_page(smmu, inst, 0); 156 157 gfsr = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSR); 158 if (!gfsr) 159 return IRQ_NONE; 160 161 gfsynr0 = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSYNR0); 162 gfsynr1 = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSYNR1); 163 gfsynr2 = readl_relaxed(gr0_base + ARM_SMMU_GR0_sGFSYNR2); 164 165 dev_err_ratelimited(smmu->dev, 166 "Unexpected global fault, this could be serious\n"); 167 dev_err_ratelimited(smmu->dev, 168 "\tGFSR 0x%08x, GFSYNR0 0x%08x, GFSYNR1 0x%08x, GFSYNR2 0x%08x\n", 169 gfsr, gfsynr0, gfsynr1, gfsynr2); 170 171 writel_relaxed(gfsr, gr0_base + ARM_SMMU_GR0_sGFSR); 172 return IRQ_HANDLED; 173 } 174 175 static irqreturn_t nvidia_smmu_global_fault(int irq, void *dev) 176 { 177 unsigned int inst; 178 irqreturn_t ret = IRQ_NONE; 179 struct arm_smmu_device *smmu = dev; 180 struct nvidia_smmu *nvidia = to_nvidia_smmu(smmu); 181 182 for (inst = 0; inst < nvidia->num_instances; inst++) { 183 irqreturn_t irq_ret; 184 185 irq_ret = nvidia_smmu_global_fault_inst(irq, smmu, inst); 186 if (irq_ret == IRQ_HANDLED) 187 ret = IRQ_HANDLED; 188 } 189 190 return ret; 191 } 192 193 static irqreturn_t nvidia_smmu_context_fault_bank(int irq, 194 struct arm_smmu_device *smmu, 195 int idx, int inst) 196 { 197 u32 fsr, fsynr, cbfrsynra; 198 unsigned long iova; 199 void __iomem *gr1_base = nvidia_smmu_page(smmu, inst, 1); 200 void __iomem *cb_base = nvidia_smmu_page(smmu, inst, smmu->numpage + idx); 201 202 fsr = readl_relaxed(cb_base + ARM_SMMU_CB_FSR); 203 if (!(fsr & ARM_SMMU_CB_FSR_FAULT)) 204 return IRQ_NONE; 205 206 fsynr = readl_relaxed(cb_base + ARM_SMMU_CB_FSYNR0); 207 iova = readq_relaxed(cb_base + ARM_SMMU_CB_FAR); 208 cbfrsynra = readl_relaxed(gr1_base + ARM_SMMU_GR1_CBFRSYNRA(idx)); 209 210 dev_err_ratelimited(smmu->dev, 211 "Unhandled context fault: fsr=0x%x, iova=0x%08lx, fsynr=0x%x, cbfrsynra=0x%x, cb=%d\n", 212 fsr, iova, fsynr, cbfrsynra, idx); 213 214 writel_relaxed(fsr, cb_base + ARM_SMMU_CB_FSR); 215 return IRQ_HANDLED; 216 } 217 218 static irqreturn_t nvidia_smmu_context_fault(int irq, void *dev) 219 { 220 int idx; 221 unsigned int inst; 222 irqreturn_t ret = IRQ_NONE; 223 struct arm_smmu_device *smmu; 224 struct arm_smmu_domain *smmu_domain = dev; 225 struct nvidia_smmu *nvidia; 226 227 smmu = smmu_domain->smmu; 228 nvidia = to_nvidia_smmu(smmu); 229 230 for (inst = 0; inst < nvidia->num_instances; inst++) { 231 irqreturn_t irq_ret; 232 233 /* 234 * Interrupt line is shared between all contexts. 235 * Check for faults across all contexts. 236 */ 237 for (idx = 0; idx < smmu->num_context_banks; idx++) { 238 irq_ret = nvidia_smmu_context_fault_bank(irq, smmu, 239 idx, inst); 240 if (irq_ret == IRQ_HANDLED) 241 ret = IRQ_HANDLED; 242 } 243 } 244 245 return ret; 246 } 247 248 static void nvidia_smmu_probe_finalize(struct arm_smmu_device *smmu, struct device *dev) 249 { 250 struct nvidia_smmu *nvidia = to_nvidia_smmu(smmu); 251 int err; 252 253 err = tegra_mc_probe_device(nvidia->mc, dev); 254 if (err < 0) 255 dev_err(smmu->dev, "memory controller probe failed for %s: %d\n", 256 dev_name(dev), err); 257 } 258 259 static int nvidia_smmu_init_context(struct arm_smmu_domain *smmu_domain, 260 struct io_pgtable_cfg *pgtbl_cfg, 261 struct device *dev) 262 { 263 struct arm_smmu_device *smmu = smmu_domain->smmu; 264 const struct device_node *np = smmu->dev->of_node; 265 266 /* 267 * Tegra194 and Tegra234 SoCs have the erratum that causes walk cache 268 * entries to not be invalidated correctly. The problem is that the walk 269 * cache index generated for IOVA is not same across translation and 270 * invalidation requests. This is leading to page faults when PMD entry 271 * is released during unmap and populated with new PTE table during 272 * subsequent map request. Disabling large page mappings avoids the 273 * release of PMD entry and avoid translations seeing stale PMD entry in 274 * walk cache. 275 * Fix this by limiting the page mappings to PAGE_SIZE on Tegra194 and 276 * Tegra234. 277 */ 278 if (of_device_is_compatible(np, "nvidia,tegra234-smmu") || 279 of_device_is_compatible(np, "nvidia,tegra194-smmu")) { 280 smmu->pgsize_bitmap &= GENMASK(PAGE_SHIFT, 0); 281 pgtbl_cfg->pgsize_bitmap = smmu->pgsize_bitmap; 282 } 283 284 return 0; 285 } 286 287 static const struct arm_smmu_impl nvidia_smmu_impl = { 288 .read_reg = nvidia_smmu_read_reg, 289 .write_reg = nvidia_smmu_write_reg, 290 .read_reg64 = nvidia_smmu_read_reg64, 291 .write_reg64 = nvidia_smmu_write_reg64, 292 .reset = nvidia_smmu_reset, 293 .tlb_sync = nvidia_smmu_tlb_sync, 294 .global_fault = nvidia_smmu_global_fault, 295 .context_fault = nvidia_smmu_context_fault, 296 .probe_finalize = nvidia_smmu_probe_finalize, 297 .init_context = nvidia_smmu_init_context, 298 }; 299 300 static const struct arm_smmu_impl nvidia_smmu_single_impl = { 301 .probe_finalize = nvidia_smmu_probe_finalize, 302 .init_context = nvidia_smmu_init_context, 303 }; 304 305 struct arm_smmu_device *nvidia_smmu_impl_init(struct arm_smmu_device *smmu) 306 { 307 struct resource *res; 308 struct device *dev = smmu->dev; 309 struct nvidia_smmu *nvidia_smmu; 310 struct platform_device *pdev = to_platform_device(dev); 311 unsigned int i; 312 313 nvidia_smmu = devm_krealloc(dev, smmu, sizeof(*nvidia_smmu), GFP_KERNEL); 314 if (!nvidia_smmu) 315 return ERR_PTR(-ENOMEM); 316 317 nvidia_smmu->mc = devm_tegra_memory_controller_get(dev); 318 if (IS_ERR(nvidia_smmu->mc)) 319 return ERR_CAST(nvidia_smmu->mc); 320 321 /* Instance 0 is ioremapped by arm-smmu.c. */ 322 nvidia_smmu->bases[0] = smmu->base; 323 nvidia_smmu->num_instances++; 324 325 for (i = 1; i < MAX_SMMU_INSTANCES; i++) { 326 res = platform_get_resource(pdev, IORESOURCE_MEM, i); 327 if (!res) 328 break; 329 330 nvidia_smmu->bases[i] = devm_ioremap_resource(dev, res); 331 if (IS_ERR(nvidia_smmu->bases[i])) 332 return ERR_CAST(nvidia_smmu->bases[i]); 333 334 nvidia_smmu->num_instances++; 335 } 336 337 if (nvidia_smmu->num_instances == 1) 338 nvidia_smmu->smmu.impl = &nvidia_smmu_single_impl; 339 else 340 nvidia_smmu->smmu.impl = &nvidia_smmu_impl; 341 342 return &nvidia_smmu->smmu; 343 } 344