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 #include <asm/sta2x11.h> 18 19 #define STA2X11_SWIOTLB_SIZE (4*1024*1024) 20 21 /* 22 * We build a list of bus numbers that are under the ConneXt. The 23 * main bridge hosts 4 busses, which are the 4 endpoints, in order. 24 */ 25 #define STA2X11_NR_EP 4 /* 0..3 included */ 26 #define STA2X11_NR_FUNCS 8 /* 0..7 included */ 27 #define STA2X11_AMBA_SIZE (512 << 20) 28 29 struct sta2x11_ahb_regs { /* saved during suspend */ 30 u32 base, pexlbase, pexhbase, crw; 31 }; 32 33 struct sta2x11_mapping { 34 int is_suspended; 35 struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS]; 36 }; 37 38 struct sta2x11_instance { 39 struct list_head list; 40 int bus0; 41 struct sta2x11_mapping map[STA2X11_NR_EP]; 42 }; 43 44 static LIST_HEAD(sta2x11_instance_list); 45 46 /* At probe time, record new instances of this bridge (likely one only) */ 47 static void sta2x11_new_instance(struct pci_dev *pdev) 48 { 49 struct sta2x11_instance *instance; 50 51 instance = kzalloc(sizeof(*instance), GFP_ATOMIC); 52 if (!instance) 53 return; 54 /* This has a subordinate bridge, with 4 more-subordinate ones */ 55 instance->bus0 = pdev->subordinate->number + 1; 56 57 if (list_empty(&sta2x11_instance_list)) { 58 int size = STA2X11_SWIOTLB_SIZE; 59 /* First instance: register your own swiotlb area */ 60 dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size); 61 if (swiotlb_init_late(size, GFP_DMA, NULL)) 62 dev_emerg(&pdev->dev, "init swiotlb failed\n"); 63 } 64 list_add(&instance->list, &sta2x11_instance_list); 65 } 66 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance); 67 68 /* 69 * Utility functions used in this file from below 70 */ 71 static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev) 72 { 73 struct sta2x11_instance *instance; 74 int ep; 75 76 list_for_each_entry(instance, &sta2x11_instance_list, list) { 77 ep = pdev->bus->number - instance->bus0; 78 if (ep >= 0 && ep < STA2X11_NR_EP) 79 return instance; 80 } 81 return NULL; 82 } 83 84 static int sta2x11_pdev_to_ep(struct pci_dev *pdev) 85 { 86 struct sta2x11_instance *instance; 87 88 instance = sta2x11_pdev_to_instance(pdev); 89 if (!instance) 90 return -1; 91 92 return pdev->bus->number - instance->bus0; 93 } 94 95 /* This is exported, as some devices need to access the MFD registers */ 96 struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev) 97 { 98 return sta2x11_pdev_to_instance(pdev); 99 } 100 EXPORT_SYMBOL(sta2x11_get_instance); 101 102 /* At setup time, we use our own ops if the device is a ConneXt one */ 103 static void sta2x11_setup_pdev(struct pci_dev *pdev) 104 { 105 struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev); 106 107 if (!instance) /* either a sta2x11 bridge or another ST device */ 108 return; 109 110 /* We must enable all devices as master, for audio DMA to work */ 111 pci_set_master(pdev); 112 } 113 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev); 114 115 /* 116 * At boot we must set up the mappings for the pcie-to-amba bridge. 117 * It involves device access, and the same happens at suspend/resume time 118 */ 119 120 #define AHB_MAPB 0xCA4 121 #define AHB_CRW(i) (AHB_MAPB + 0 + (i) * 0x10) 122 #define AHB_CRW_SZMASK 0xfffffc00UL 123 #define AHB_CRW_ENABLE (1 << 0) 124 #define AHB_CRW_WTYPE_MEM (2 << 1) 125 #define AHB_CRW_ROE (1UL << 3) /* Relax Order Ena */ 126 #define AHB_CRW_NSE (1UL << 4) /* No Snoop Enable */ 127 #define AHB_BASE(i) (AHB_MAPB + 4 + (i) * 0x10) 128 #define AHB_PEXLBASE(i) (AHB_MAPB + 8 + (i) * 0x10) 129 #define AHB_PEXHBASE(i) (AHB_MAPB + 12 + (i) * 0x10) 130 131 /* At probe time, enable mapping for each endpoint, using the pdev */ 132 static void sta2x11_map_ep(struct pci_dev *pdev) 133 { 134 struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev); 135 struct device *dev = &pdev->dev; 136 u32 amba_base, max_amba_addr; 137 int i, ret; 138 139 if (!instance) 140 return; 141 142 pci_read_config_dword(pdev, AHB_BASE(0), &amba_base); 143 max_amba_addr = amba_base + STA2X11_AMBA_SIZE - 1; 144 145 ret = dma_direct_set_offset(dev, 0, amba_base, STA2X11_AMBA_SIZE); 146 if (ret) 147 dev_err(dev, "sta2x11: could not set DMA offset\n"); 148 149 dev->bus_dma_limit = max_amba_addr; 150 dma_set_mask_and_coherent(&pdev->dev, max_amba_addr); 151 152 /* Configure AHB mapping */ 153 pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0); 154 pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0); 155 pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE | 156 AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE); 157 158 /* Disable all the other windows */ 159 for (i = 1; i < STA2X11_NR_FUNCS; i++) 160 pci_write_config_dword(pdev, AHB_CRW(i), 0); 161 162 dev_info(&pdev->dev, 163 "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n", 164 sta2x11_pdev_to_ep(pdev), amba_base, max_amba_addr); 165 } 166 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep); 167 168 #ifdef CONFIG_PM /* Some register values must be saved and restored */ 169 170 static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev) 171 { 172 struct sta2x11_instance *instance; 173 int ep; 174 175 instance = sta2x11_pdev_to_instance(pdev); 176 if (!instance) 177 return NULL; 178 ep = sta2x11_pdev_to_ep(pdev); 179 return instance->map + ep; 180 } 181 182 static void suspend_mapping(struct pci_dev *pdev) 183 { 184 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev); 185 int i; 186 187 if (!map) 188 return; 189 190 if (map->is_suspended) 191 return; 192 map->is_suspended = 1; 193 194 /* Save all window configs */ 195 for (i = 0; i < STA2X11_NR_FUNCS; i++) { 196 struct sta2x11_ahb_regs *regs = map->regs + i; 197 198 pci_read_config_dword(pdev, AHB_BASE(i), ®s->base); 199 pci_read_config_dword(pdev, AHB_PEXLBASE(i), ®s->pexlbase); 200 pci_read_config_dword(pdev, AHB_PEXHBASE(i), ®s->pexhbase); 201 pci_read_config_dword(pdev, AHB_CRW(i), ®s->crw); 202 } 203 } 204 DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping); 205 206 static void resume_mapping(struct pci_dev *pdev) 207 { 208 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev); 209 int i; 210 211 if (!map) 212 return; 213 214 215 if (!map->is_suspended) 216 goto out; 217 map->is_suspended = 0; 218 219 /* Restore all window configs */ 220 for (i = 0; i < STA2X11_NR_FUNCS; i++) { 221 struct sta2x11_ahb_regs *regs = map->regs + i; 222 223 pci_write_config_dword(pdev, AHB_BASE(i), regs->base); 224 pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase); 225 pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase); 226 pci_write_config_dword(pdev, AHB_CRW(i), regs->crw); 227 } 228 out: 229 pci_set_master(pdev); /* Like at boot, enable master on all devices */ 230 } 231 DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping); 232 233 #endif /* CONFIG_PM */ 234