1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * DMA translation between STA2x11 AMBA memory mapping and the x86 memory mapping 4 * 5 * ST Microelectronics ConneXt (STA2X11/STA2X10) 6 * 7 * Copyright (c) 2010-2011 Wind River Systems, Inc. 8 */ 9 10 #include <linux/pci.h> 11 #include <linux/pci_ids.h> 12 #include <linux/export.h> 13 #include <linux/list.h> 14 #include <linux/dma-map-ops.h> 15 #include <linux/swiotlb.h> 16 #include <asm/iommu.h> 17 18 #define STA2X11_SWIOTLB_SIZE (4*1024*1024) 19 20 /* 21 * We build a list of bus numbers that are under the ConneXt. The 22 * main bridge hosts 4 busses, which are the 4 endpoints, in order. 23 */ 24 #define STA2X11_NR_EP 4 /* 0..3 included */ 25 #define STA2X11_NR_FUNCS 8 /* 0..7 included */ 26 #define STA2X11_AMBA_SIZE (512 << 20) 27 28 struct sta2x11_ahb_regs { /* saved during suspend */ 29 u32 base, pexlbase, pexhbase, crw; 30 }; 31 32 struct sta2x11_mapping { 33 int is_suspended; 34 struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS]; 35 }; 36 37 struct sta2x11_instance { 38 struct list_head list; 39 int bus0; 40 struct sta2x11_mapping map[STA2X11_NR_EP]; 41 }; 42 43 static LIST_HEAD(sta2x11_instance_list); 44 45 /* At probe time, record new instances of this bridge (likely one only) */ 46 static void sta2x11_new_instance(struct pci_dev *pdev) 47 { 48 struct sta2x11_instance *instance; 49 50 instance = kzalloc(sizeof(*instance), GFP_ATOMIC); 51 if (!instance) 52 return; 53 /* This has a subordinate bridge, with 4 more-subordinate ones */ 54 instance->bus0 = pdev->subordinate->number + 1; 55 56 if (list_empty(&sta2x11_instance_list)) { 57 int size = STA2X11_SWIOTLB_SIZE; 58 /* First instance: register your own swiotlb area */ 59 dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size); 60 if (swiotlb_late_init_with_default_size(size)) 61 dev_emerg(&pdev->dev, "init swiotlb failed\n"); 62 } 63 list_add(&instance->list, &sta2x11_instance_list); 64 } 65 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance); 66 67 /* 68 * Utility functions used in this file from below 69 */ 70 static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev) 71 { 72 struct sta2x11_instance *instance; 73 int ep; 74 75 list_for_each_entry(instance, &sta2x11_instance_list, list) { 76 ep = pdev->bus->number - instance->bus0; 77 if (ep >= 0 && ep < STA2X11_NR_EP) 78 return instance; 79 } 80 return NULL; 81 } 82 83 static int sta2x11_pdev_to_ep(struct pci_dev *pdev) 84 { 85 struct sta2x11_instance *instance; 86 87 instance = sta2x11_pdev_to_instance(pdev); 88 if (!instance) 89 return -1; 90 91 return pdev->bus->number - instance->bus0; 92 } 93 94 /* This is exported, as some devices need to access the MFD registers */ 95 struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev) 96 { 97 return sta2x11_pdev_to_instance(pdev); 98 } 99 EXPORT_SYMBOL(sta2x11_get_instance); 100 101 /* At setup time, we use our own ops if the device is a ConneXt one */ 102 static void sta2x11_setup_pdev(struct pci_dev *pdev) 103 { 104 struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev); 105 106 if (!instance) /* either a sta2x11 bridge or another ST device */ 107 return; 108 109 /* We must enable all devices as master, for audio DMA to work */ 110 pci_set_master(pdev); 111 } 112 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev); 113 114 /* 115 * At boot we must set up the mappings for the pcie-to-amba bridge. 116 * It involves device access, and the same happens at suspend/resume time 117 */ 118 119 #define AHB_MAPB 0xCA4 120 #define AHB_CRW(i) (AHB_MAPB + 0 + (i) * 0x10) 121 #define AHB_CRW_SZMASK 0xfffffc00UL 122 #define AHB_CRW_ENABLE (1 << 0) 123 #define AHB_CRW_WTYPE_MEM (2 << 1) 124 #define AHB_CRW_ROE (1UL << 3) /* Relax Order Ena */ 125 #define AHB_CRW_NSE (1UL << 4) /* No Snoop Enable */ 126 #define AHB_BASE(i) (AHB_MAPB + 4 + (i) * 0x10) 127 #define AHB_PEXLBASE(i) (AHB_MAPB + 8 + (i) * 0x10) 128 #define AHB_PEXHBASE(i) (AHB_MAPB + 12 + (i) * 0x10) 129 130 /* At probe time, enable mapping for each endpoint, using the pdev */ 131 static void sta2x11_map_ep(struct pci_dev *pdev) 132 { 133 struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev); 134 struct device *dev = &pdev->dev; 135 u32 amba_base, max_amba_addr; 136 int i, ret; 137 138 if (!instance) 139 return; 140 141 pci_read_config_dword(pdev, AHB_BASE(0), &amba_base); 142 max_amba_addr = amba_base + STA2X11_AMBA_SIZE - 1; 143 144 ret = dma_direct_set_offset(dev, 0, amba_base, STA2X11_AMBA_SIZE); 145 if (ret) 146 dev_err(dev, "sta2x11: could not set DMA offset\n"); 147 148 dev->bus_dma_limit = max_amba_addr; 149 dma_set_mask_and_coherent(&pdev->dev, max_amba_addr); 150 151 /* Configure AHB mapping */ 152 pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0); 153 pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0); 154 pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE | 155 AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE); 156 157 /* Disable all the other windows */ 158 for (i = 1; i < STA2X11_NR_FUNCS; i++) 159 pci_write_config_dword(pdev, AHB_CRW(i), 0); 160 161 dev_info(&pdev->dev, 162 "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n", 163 sta2x11_pdev_to_ep(pdev), amba_base, max_amba_addr); 164 } 165 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep); 166 167 #ifdef CONFIG_PM /* Some register values must be saved and restored */ 168 169 static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev) 170 { 171 struct sta2x11_instance *instance; 172 int ep; 173 174 instance = sta2x11_pdev_to_instance(pdev); 175 if (!instance) 176 return NULL; 177 ep = sta2x11_pdev_to_ep(pdev); 178 return instance->map + ep; 179 } 180 181 static void suspend_mapping(struct pci_dev *pdev) 182 { 183 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev); 184 int i; 185 186 if (!map) 187 return; 188 189 if (map->is_suspended) 190 return; 191 map->is_suspended = 1; 192 193 /* Save all window configs */ 194 for (i = 0; i < STA2X11_NR_FUNCS; i++) { 195 struct sta2x11_ahb_regs *regs = map->regs + i; 196 197 pci_read_config_dword(pdev, AHB_BASE(i), ®s->base); 198 pci_read_config_dword(pdev, AHB_PEXLBASE(i), ®s->pexlbase); 199 pci_read_config_dword(pdev, AHB_PEXHBASE(i), ®s->pexhbase); 200 pci_read_config_dword(pdev, AHB_CRW(i), ®s->crw); 201 } 202 } 203 DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping); 204 205 static void resume_mapping(struct pci_dev *pdev) 206 { 207 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev); 208 int i; 209 210 if (!map) 211 return; 212 213 214 if (!map->is_suspended) 215 goto out; 216 map->is_suspended = 0; 217 218 /* Restore all window configs */ 219 for (i = 0; i < STA2X11_NR_FUNCS; i++) { 220 struct sta2x11_ahb_regs *regs = map->regs + i; 221 222 pci_write_config_dword(pdev, AHB_BASE(i), regs->base); 223 pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase); 224 pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase); 225 pci_write_config_dword(pdev, AHB_CRW(i), regs->crw); 226 } 227 out: 228 pci_set_master(pdev); /* Like at boot, enable master on all devices */ 229 } 230 DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping); 231 232 #endif /* CONFIG_PM */ 233