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b2441318 1// SPDX-License-Identifier: GPL-2.0
a712ffbc 2/*
05454c26 3 * Intel MID PCI support
a712ffbc
JB
4 * Copyright (c) 2008 Intel Corporation
5 * Jesse Barnes <[email protected]>
6 *
7 * Moorestown has an interesting PCI implementation:
8 * - configuration space is memory mapped (as defined by MCFG)
9 * - Lincroft devices also have a real, type 1 configuration space
10 * - Early Lincroft silicon has a type 1 access bug that will cause
11 * a hang if non-existent devices are accessed
12 * - some devices have the "fixed BAR" capability, which means
13 * they can't be relocated or modified; check for that during
14 * BAR sizing
15 *
16 * So, we use the MCFG space for all reads and writes, but also send
17 * Lincroft writes to type 1 space. But only read/write if the device
18 * actually exists, otherwise return all 1s for reads and bit bucket
19 * the writes.
20 */
21
22#include <linux/sched.h>
23#include <linux/pci.h>
24#include <linux/ioport.h>
25#include <linux/init.h>
26#include <linux/dmi.h>
7cc24e12
VM
27#include <linux/acpi.h>
28#include <linux/io.h>
29#include <linux/smp.h>
a712ffbc 30
3cc00862 31#include <asm/cpu_device_id.h>
a712ffbc 32#include <asm/segment.h>
a712ffbc
JB
33#include <asm/pci_x86.h>
34#include <asm/hw_irq.h>
35#include <asm/io_apic.h>
3cc00862 36#include <asm/intel-family.h>
bc20aa48 37#include <asm/intel-mid.h>
035fff1f 38#include <asm/acpi.h>
a712ffbc
JB
39
40#define PCIE_CAP_OFFSET 0x100
41
39d9b77b 42/* Quirks for the listed devices */
707a605b
AS
43#define PCI_DEVICE_ID_INTEL_MRFLD_MMC 0x1190
44#define PCI_DEVICE_ID_INTEL_MRFLD_HSU 0x1191
39d9b77b 45
a712ffbc
JB
46/* Fixed BAR fields */
47#define PCIE_VNDR_CAP_ID_FIXED_BAR 0x00 /* Fixed BAR (TBD) */
48#define PCI_FIXED_BAR_0_SIZE 0x04
49#define PCI_FIXED_BAR_1_SIZE 0x08
50#define PCI_FIXED_BAR_2_SIZE 0x0c
51#define PCI_FIXED_BAR_3_SIZE 0x10
52#define PCI_FIXED_BAR_4_SIZE 0x14
53#define PCI_FIXED_BAR_5_SIZE 0x1c
54
7cc24e12 55static int pci_soc_mode;
823806ff 56
a712ffbc
JB
57/**
58 * fixed_bar_cap - return the offset of the fixed BAR cap if found
59 * @bus: PCI bus
60 * @devfn: device in question
61 *
62 * Look for the fixed BAR cap on @bus and @devfn, returning its offset
63 * if found or 0 otherwise.
64 */
65static int fixed_bar_cap(struct pci_bus *bus, unsigned int devfn)
66{
67 int pos;
68 u32 pcie_cap = 0, cap_data;
69
70 pos = PCIE_CAP_OFFSET;
c5411382
JP
71
72 if (!raw_pci_ext_ops)
73 return 0;
74
a712ffbc
JB
75 while (pos) {
76 if (raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number,
77 devfn, pos, 4, &pcie_cap))
78 return 0;
79
f82c3d71
JP
80 if (PCI_EXT_CAP_ID(pcie_cap) == 0x0000 ||
81 PCI_EXT_CAP_ID(pcie_cap) == 0xffff)
82 break;
a712ffbc
JB
83
84 if (PCI_EXT_CAP_ID(pcie_cap) == PCI_EXT_CAP_ID_VNDR) {
85 raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number,
86 devfn, pos + 4, 4, &cap_data);
87 if ((cap_data & 0xffff) == PCIE_VNDR_CAP_ID_FIXED_BAR)
88 return pos;
89 }
90
f82c3d71 91 pos = PCI_EXT_CAP_NEXT(pcie_cap);
a712ffbc
JB
92 }
93
94 return 0;
95}
96
97static int pci_device_update_fixed(struct pci_bus *bus, unsigned int devfn,
98 int reg, int len, u32 val, int offset)
99{
100 u32 size;
101 unsigned int domain, busnum;
102 int bar = (reg - PCI_BASE_ADDRESS_0) >> 2;
103
104 domain = pci_domain_nr(bus);
105 busnum = bus->number;
106
107 if (val == ~0 && len == 4) {
108 unsigned long decode;
109
110 raw_pci_ext_ops->read(domain, busnum, devfn,
111 offset + 8 + (bar * 4), 4, &size);
112
113 /* Turn the size into a decode pattern for the sizing code */
114 if (size) {
115 decode = size - 1;
116 decode |= decode >> 1;
117 decode |= decode >> 2;
118 decode |= decode >> 4;
119 decode |= decode >> 8;
120 decode |= decode >> 16;
121 decode++;
122 decode = ~(decode - 1);
123 } else {
e4af4268 124 decode = 0;
a712ffbc
JB
125 }
126
127 /*
128 * If val is all ones, the core code is trying to size the reg,
129 * so update the mmconfig space with the real size.
130 *
131 * Note: this assumes the fixed size we got is a power of two.
132 */
133 return raw_pci_ext_ops->write(domain, busnum, devfn, reg, 4,
134 decode);
135 }
136
137 /* This is some other kind of BAR write, so just do it. */
138 return raw_pci_ext_ops->write(domain, busnum, devfn, reg, len, val);
139}
140
141/**
142 * type1_access_ok - check whether to use type 1
143 * @bus: bus number
144 * @devfn: device & function in question
24c92537 145 * @reg: configuration register offset
a712ffbc
JB
146 *
147 * If the bus is on a Lincroft chip and it exists, or is not on a Lincroft at
148 * all, the we can go ahead with any reads & writes. If it's on a Lincroft,
149 * but doesn't exist, avoid the access altogether to keep the chip from
150 * hanging.
151 */
152static bool type1_access_ok(unsigned int bus, unsigned int devfn, int reg)
153{
7cc24e12
VM
154 /*
155 * This is a workaround for A0 LNC bug where PCI status register does
a712ffbc
JB
156 * not have new CAP bit set. can not be written by SW either.
157 *
158 * PCI header type in real LNC indicates a single function device, this
159 * will prevent probing other devices under the same function in PCI
160 * shim. Therefore, use the header type in shim instead.
161 */
162 if (reg >= 0x100 || reg == PCI_STATUS || reg == PCI_HEADER_TYPE)
6c21b176 163 return false;
f3f01175
BH
164 if (bus == 0 && (devfn == PCI_DEVFN(2, 0)
165 || devfn == PCI_DEVFN(0, 0)
166 || devfn == PCI_DEVFN(3, 0)))
6c21b176
FW
167 return true;
168 return false; /* Langwell on others */
a712ffbc
JB
169}
170
171static int pci_read(struct pci_bus *bus, unsigned int devfn, int where,
172 int size, u32 *value)
173{
174 if (type1_access_ok(bus->number, devfn, where))
175 return pci_direct_conf1.read(pci_domain_nr(bus), bus->number,
176 devfn, where, size, value);
177 return raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number,
178 devfn, where, size, value);
179}
180
181static int pci_write(struct pci_bus *bus, unsigned int devfn, int where,
182 int size, u32 value)
183{
184 int offset;
185
7cc24e12
VM
186 /*
187 * On MRST, there is no PCI ROM BAR, this will cause a subsequent read
a712ffbc
JB
188 * to ROM BAR return 0 then being ignored.
189 */
190 if (where == PCI_ROM_ADDRESS)
191 return 0;
192
193 /*
194 * Devices with fixed BARs need special handling:
195 * - BAR sizing code will save, write ~0, read size, restore
196 * - so writes to fixed BARs need special handling
197 * - other writes to fixed BAR devices should go through mmconfig
198 */
199 offset = fixed_bar_cap(bus, devfn);
200 if (offset &&
201 (where >= PCI_BASE_ADDRESS_0 && where <= PCI_BASE_ADDRESS_5)) {
202 return pci_device_update_fixed(bus, devfn, where, size, value,
203 offset);
204 }
205
206 /*
207 * On Moorestown update both real & mmconfig space
208 * Note: early Lincroft silicon can't handle type 1 accesses to
209 * non-existent devices, so just eat the write in that case.
210 */
211 if (type1_access_ok(bus->number, devfn, where))
212 return pci_direct_conf1.write(pci_domain_nr(bus), bus->number,
213 devfn, where, size, value);
214 return raw_pci_ext_ops->write(pci_domain_nr(bus), bus->number, devfn,
215 where, size, value);
216}
217
3cc00862 218static const struct x86_cpu_id intel_mid_cpu_ids[] = {
ac6bee4b 219 X86_MATCH_VFM(INTEL_ATOM_SILVERMONT_MID, NULL),
3cc00862
AS
220 {}
221};
222
712b6aa8 223static int intel_mid_pci_irq_enable(struct pci_dev *dev)
a712ffbc 224{
3cc00862 225 const struct x86_cpu_id *id;
c4d05a2c 226 struct irq_alloc_info info;
a27dca64 227 bool polarity_low;
3cc00862 228 u16 model = 0;
2a61c8ea 229 int ret;
5b395e2b 230 u8 gsi;
a712ffbc 231
67b4eab9 232 if (dev->irq_managed && dev->irq > 0)
cffe0a2b
JL
233 return 0;
234
5b395e2b 235 ret = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
72485205 236 if (ret) {
5b395e2b 237 dev_warn(&dev->dev, "Failed to read interrupt line: %d\n", ret);
72485205 238 return pcibios_err_to_errno(ret);
5b395e2b
AS
239 }
240
3cc00862
AS
241 id = x86_match_cpu(intel_mid_cpu_ids);
242 if (id)
243 model = id->model;
244
245 switch (model) {
ac6bee4b 246 case VFM_MODEL(INTEL_ATOM_SILVERMONT_MID):
a27dca64 247 polarity_low = false;
39d9b77b
AS
248
249 /* Special treatment for IRQ0 */
5b395e2b 250 if (gsi == 0) {
bb275705
AS
251 /*
252 * Skip HS UART common registers device since it has
253 * IRQ0 assigned and not used by the kernel.
254 */
707a605b 255 if (dev->device == PCI_DEVICE_ID_INTEL_MRFLD_HSU)
bb275705 256 return -EBUSY;
39d9b77b
AS
257 /*
258 * TNG has IRQ0 assigned to eMMC controller. But there
259 * are also other devices with bogus PCI configuration
260 * that have IRQ0 assigned. This check ensures that
bb275705
AS
261 * eMMC gets it. The rest of devices still could be
262 * enabled without interrupt line being allocated.
39d9b77b 263 */
707a605b 264 if (dev->device != PCI_DEVICE_ID_INTEL_MRFLD_MMC)
bb275705 265 return 0;
39d9b77b
AS
266 }
267 break;
268 default:
a27dca64 269 polarity_low = true;
39d9b77b
AS
270 break;
271 }
272
a27dca64 273 ioapic_set_alloc_attr(&info, dev_to_node(&dev->dev), 1, polarity_low);
a712ffbc 274
7cc24e12
VM
275 /*
276 * MRST only have IOAPIC, the PCI irq lines are 1:1 mapped to
a712ffbc
JB
277 * IOAPIC RTE entries, so we just enable RTE for the device.
278 */
5b395e2b 279 ret = mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC, &info);
2a61c8ea
AS
280 if (ret < 0)
281 return ret;
1b5d3e00 282
5b395e2b 283 dev->irq = ret;
cffe0a2b
JL
284 dev->irq_managed = 1;
285
a712ffbc
JB
286 return 0;
287}
288
8a3e533d
JL
289static void intel_mid_pci_irq_disable(struct pci_dev *dev)
290{
6c777e87
BH
291 if (!mp_should_keep_irq(&dev->dev) && dev->irq_managed &&
292 dev->irq > 0) {
8a3e533d 293 mp_unmap_irq(dev->irq);
cffe0a2b
JL
294 dev->irq_managed = 0;
295 }
8a3e533d
JL
296}
297
4113b0e6 298static const struct pci_ops intel_mid_pci_ops __initconst = {
a712ffbc
JB
299 .read = pci_read,
300 .write = pci_write,
301};
302
303/**
712b6aa8 304 * intel_mid_pci_init - installs intel_mid_pci_ops
a712ffbc
JB
305 *
306 * Moorestown has an interesting PCI implementation (see above).
307 * Called when the early platform detection installs it.
308 */
712b6aa8 309int __init intel_mid_pci_init(void)
a712ffbc 310{
7cc24e12 311 pr_info("Intel MID platform detected, using MID PCI ops\n");
a712ffbc 312 pci_mmcfg_late_init();
712b6aa8 313 pcibios_enable_irq = intel_mid_pci_irq_enable;
8a3e533d 314 pcibios_disable_irq = intel_mid_pci_irq_disable;
712b6aa8 315 pci_root_ops = intel_mid_pci_ops;
823806ff 316 pci_soc_mode = 1;
a712ffbc 317 /* Continue with standard init */
a912a758 318 acpi_noirq_set();
a712ffbc
JB
319 return 1;
320}
321
7cc24e12
VM
322/*
323 * Langwell devices are not true PCI devices; they are not subject to 10 ms
324 * d3 to d0 delay required by PCI spec.
990a30c5 325 */
a18e3690 326static void pci_d3delay_fixup(struct pci_dev *dev)
990a30c5 327{
7cc24e12
VM
328 /*
329 * PCI fixups are effectively decided compile time. If we have a dual
330 * SoC/non-SoC kernel we don't want to mangle d3 on non-SoC devices.
331 */
332 if (!pci_soc_mode)
333 return;
334 /*
335 * True PCI devices in Lincroft should allow type 1 access, the rest
336 * are Langwell fake PCI devices.
990a30c5
JP
337 */
338 if (type1_access_ok(dev->bus->number, dev->devfn, PCI_DEVICE_ID))
339 return;
3789af9a 340 dev->d3hot_delay = 0;
990a30c5
JP
341}
342DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_d3delay_fixup);
343
e99a0745 344static void mid_power_off_one_device(struct pci_dev *dev)
990a30c5 345{
5823d089
AS
346 u16 pmcsr;
347
348 /*
349 * Update current state first, otherwise PCI core enforces PCI_D0 in
350 * pci_set_power_state() for devices which status was PCI_UNKNOWN.
351 */
352 pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr);
353 dev->current_state = (pci_power_t __force)(pmcsr & PCI_PM_CTRL_STATE_MASK);
354
8497f696 355 pci_set_power_state(dev, PCI_D3hot);
990a30c5 356}
5823d089 357
e99a0745 358static void mid_power_off_devices(struct pci_dev *dev)
5823d089
AS
359{
360 int id;
361
362 if (!pci_soc_mode)
363 return;
364
365 id = intel_mid_pwr_get_lss_id(dev);
366 if (id < 0)
367 return;
368
369 /*
370 * This sets only PMCSR bits. The actual power off will happen in
371 * arch/x86/platform/intel-mid/pwr.c.
372 */
e99a0745 373 mid_power_off_one_device(dev);
5823d089
AS
374}
375
e99a0745 376DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, mid_power_off_devices);
990a30c5 377
a712ffbc
JB
378/*
379 * Langwell devices reside at fixed offsets, don't try to move them.
380 */
a18e3690 381static void pci_fixed_bar_fixup(struct pci_dev *dev)
a712ffbc
JB
382{
383 unsigned long offset;
384 u32 size;
385 int i;
386
823806ff
AC
387 if (!pci_soc_mode)
388 return;
389
e9b1d5d0
PA
390 /* Must have extended configuration space */
391 if (dev->cfg_size < PCIE_CAP_OFFSET + 4)
392 return;
393
a712ffbc
JB
394 /* Fixup the BAR sizes for fixed BAR devices and make them unmoveable */
395 offset = fixed_bar_cap(dev->bus, dev->devfn);
396 if (!offset || PCI_DEVFN(2, 0) == dev->devfn ||
397 PCI_DEVFN(2, 2) == dev->devfn)
398 return;
399
c9c13ba4 400 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
a712ffbc
JB
401 pci_read_config_dword(dev, offset + 8 + (i * 4), &size);
402 dev->resource[i].end = dev->resource[i].start + size - 1;
403 dev->resource[i].flags |= IORESOURCE_PCI_FIXED;
404 }
405}
406DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_fixed_bar_fixup);
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