acpi.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  RISC-V Specific Low-Level ACPI Boot Support
  4 *
  5 *  Copyright (C) 2013-2014, Linaro Ltd.
  6 *	Author: Al Stone <al.stone@linaro.org>
  7 *	Author: Graeme Gregory <graeme.gregory@linaro.org>
  8 *	Author: Hanjun Guo <hanjun.guo@linaro.org>
  9 *	Author: Tomasz Nowicki <tomasz.nowicki@linaro.org>
 10 *	Author: Naresh Bhat <naresh.bhat@linaro.org>
 11 *
 12 *  Copyright (C) 2021-2023, Ventana Micro Systems Inc.
 13 *	Author: Sunil V L <sunilvl@ventanamicro.com>
 14 */
 15
 16#include <linux/acpi.h>
 17#include <linux/efi-bgrt.h>
 18#include <linux/efi.h>
 19#include <linux/io.h>
 20#include <linux/memblock.h>
 21#include <linux/of_fdt.h>
 22#include <linux/pci.h>
 23#include <linux/serial_core.h>
 24
 25int acpi_noirq = 1;		/* skip ACPI IRQ initialization */
 26int acpi_disabled = 1;
 27EXPORT_SYMBOL(acpi_disabled);
 28
 29int acpi_pci_disabled = 1;	/* skip ACPI PCI scan and IRQ initialization */
 30EXPORT_SYMBOL(acpi_pci_disabled);
 31
 32static bool param_acpi_off __initdata;
 33static bool param_acpi_on __initdata;
 34static bool param_acpi_force __initdata;
 35
 36static struct acpi_madt_rintc cpu_madt_rintc[NR_CPUS];
 37
 38static int __init parse_acpi(char *arg)
 39{
 40	if (!arg)
 41		return -EINVAL;
 42
 43	/* "acpi=off" disables both ACPI table parsing and interpreter */
 44	if (strcmp(arg, "off") == 0)
 45		param_acpi_off = true;
 46	else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */
 47		param_acpi_on = true;
 48	else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */
 49		param_acpi_force = true;
 50	else
 51		return -EINVAL;	/* Core will print when we return error */
 52
 53	return 0;
 54}
 55early_param("acpi", parse_acpi);
 56
 57/*
 58 * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity
 59 *			      checks on it
 60 *
 61 * Return 0 on success,  <0 on failure
 62 */
 63static int __init acpi_fadt_sanity_check(void)
 64{
 65	struct acpi_table_header *table;
 66	struct acpi_table_fadt *fadt;
 67	acpi_status status;
 68	int ret = 0;
 69
 70	/*
 71	 * FADT is required on riscv; retrieve it to check its presence
 72	 * and carry out revision and ACPI HW reduced compliancy tests
 73	 */
 74	status = acpi_get_table(ACPI_SIG_FADT, 0, &table);
 75	if (ACPI_FAILURE(status)) {
 76		const char *msg = acpi_format_exception(status);
 77
 78		pr_err("Failed to get FADT table, %s\n", msg);
 79		return -ENODEV;
 80	}
 81
 82	fadt = (struct acpi_table_fadt *)table;
 83
 84	/*
 85	 * The revision in the table header is the FADT's Major revision. The
 86	 * FADT also has a minor revision, which is stored in the FADT itself.
 87	 *
 88	 * TODO: Currently, we check for 6.5 as the minimum version to check
 89	 * for HW_REDUCED flag. However, once RISC-V updates are released in
 90	 * the ACPI spec, we need to update this check for exact minor revision
 91	 */
 92	if (table->revision < 6 || (table->revision == 6 && fadt->minor_revision < 5))
 93		pr_err(FW_BUG "Unsupported FADT revision %d.%d, should be 6.5+\n",
 94		       table->revision, fadt->minor_revision);
 95
 96	if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) {
 97		pr_err("FADT not ACPI hardware reduced compliant\n");
 98		ret = -EINVAL;
 99	}
100
101	/*
102	 * acpi_get_table() creates FADT table mapping that
103	 * should be released after parsing and before resuming boot
104	 */
105	acpi_put_table(table);
106	return ret;
107}
108
109/*
110 * acpi_boot_table_init() called from setup_arch(), always.
111 *	1. find RSDP and get its address, and then find XSDT
112 *	2. extract all tables and checksums them all
113 *	3. check ACPI FADT HW reduced flag
114 *
115 * We can parse ACPI boot-time tables such as MADT after
116 * this function is called.
117 *
118 * On return ACPI is enabled if either:
119 *
120 * - ACPI tables are initialized and sanity checks passed
121 * - acpi=force was passed in the command line and ACPI was not disabled
122 *   explicitly through acpi=off command line parameter
123 *
124 * ACPI is disabled on function return otherwise
125 */
126void __init acpi_boot_table_init(void)
127{
128	/*
129	 * Enable ACPI instead of device tree unless
130	 * - ACPI has been disabled explicitly (acpi=off), or
131	 * - firmware has not populated ACPI ptr in EFI system table
132	 *   and ACPI has not been [force] enabled (acpi=on|force)
133	 */
134	if (param_acpi_off ||
135	    (!param_acpi_on && !param_acpi_force &&
136	     efi.acpi20 == EFI_INVALID_TABLE_ADDR))
137		goto done;
138
139	/*
140	 * ACPI is disabled at this point. Enable it in order to parse
141	 * the ACPI tables and carry out sanity checks
142	 */
143	enable_acpi();
144
145	/*
146	 * If ACPI tables are initialized and FADT sanity checks passed,
147	 * leave ACPI enabled and carry on booting; otherwise disable ACPI
148	 * on initialization error.
149	 * If acpi=force was passed on the command line it forces ACPI
150	 * to be enabled even if its initialization failed.
151	 */
152	if (acpi_table_init() || acpi_fadt_sanity_check()) {
153		pr_err("Failed to init ACPI tables\n");
154		if (!param_acpi_force)
155			disable_acpi();
156	}
157
158done:
159	if (acpi_disabled) {
160		if (earlycon_acpi_spcr_enable)
161			early_init_dt_scan_chosen_stdout();
162	} else {
163		acpi_parse_spcr(earlycon_acpi_spcr_enable, true);
164		if (IS_ENABLED(CONFIG_ACPI_BGRT))
165			acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt);
166	}
167}
168
169static int acpi_parse_madt_rintc(union acpi_subtable_headers *header, const unsigned long end)
170{
171	struct acpi_madt_rintc *rintc = (struct acpi_madt_rintc *)header;
172	int cpuid;
173
174	if (!(rintc->flags & ACPI_MADT_ENABLED))
175		return 0;
176
177	cpuid = riscv_hartid_to_cpuid(rintc->hart_id);
178	/*
179	 * When CONFIG_SMP is disabled, mapping won't be created for
180	 * all cpus.
181	 * CPUs more than num_possible_cpus, will be ignored.
182	 */
183	if (cpuid >= 0 && cpuid < num_possible_cpus())
184		cpu_madt_rintc[cpuid] = *rintc;
185
186	return 0;
187}
188
189/*
190 * Instead of parsing (and freeing) the ACPI table, cache
191 * the RINTC structures since they are frequently used
192 * like in  cpuinfo.
193 */
194void __init acpi_init_rintc_map(void)
195{
196	if (acpi_table_parse_madt(ACPI_MADT_TYPE_RINTC, acpi_parse_madt_rintc, 0) <= 0) {
197		pr_err("No valid RINTC entries exist\n");
198		BUG();
199	}
200}
201
202struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu)
203{
204	return &cpu_madt_rintc[cpu];
205}
206
207/*
208 * __acpi_map_table() will be called before paging_init(), so early_ioremap()
209 * or early_memremap() should be called here to for ACPI table mapping.
210 */
211void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
212{
213	if (!size)
214		return NULL;
215
216	return early_memremap(phys, size);
217}
218
219void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
220{
221	if (!map || !size)
222		return;
223
224	early_memunmap(map, size);
225}
226
227void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
228{
229	efi_memory_desc_t *md, *region = NULL;
230	pgprot_t prot;
231
232	if (WARN_ON_ONCE(!efi_enabled(EFI_MEMMAP)))
233		return NULL;
234
235	for_each_efi_memory_desc(md) {
236		u64 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
237
238		if (phys < md->phys_addr || phys >= end)
239			continue;
240
241		if (phys + size > end) {
242			pr_warn(FW_BUG "requested region covers multiple EFI memory regions\n");
243			return NULL;
244		}
245		region = md;
246		break;
247	}
248
249	/*
250	 * It is fine for AML to remap regions that are not represented in the
251	 * EFI memory map at all, as it only describes normal memory, and MMIO
252	 * regions that require a virtual mapping to make them accessible to
253	 * the EFI runtime services.
254	 */
255	prot = PAGE_KERNEL_IO;
256	if (region) {
257		switch (region->type) {
258		case EFI_LOADER_CODE:
259		case EFI_LOADER_DATA:
260		case EFI_BOOT_SERVICES_CODE:
261		case EFI_BOOT_SERVICES_DATA:
262		case EFI_CONVENTIONAL_MEMORY:
263		case EFI_PERSISTENT_MEMORY:
264			if (memblock_is_map_memory(phys) ||
265			    !memblock_is_region_memory(phys, size)) {
266				pr_warn(FW_BUG "requested region covers kernel memory\n");
267				return NULL;
268			}
269
270			/*
271			 * Mapping kernel memory is permitted if the region in
272			 * question is covered by a single memblock with the
273			 * NOMAP attribute set: this enables the use of ACPI
274			 * table overrides passed via initramfs.
275			 * This particular use case only requires read access.
276			 */
277			fallthrough;
278
279		case EFI_RUNTIME_SERVICES_CODE:
280			/*
281			 * This would be unusual, but not problematic per se,
282			 * as long as we take care not to create a writable
283			 * mapping for executable code.
284			 */
285			prot = PAGE_KERNEL_RO;
286			break;
287
288		case EFI_ACPI_RECLAIM_MEMORY:
289			/*
290			 * ACPI reclaim memory is used to pass firmware tables
291			 * and other data that is intended for consumption by
292			 * the OS only, which may decide it wants to reclaim
293			 * that memory and use it for something else. We never
294			 * do that, but we usually add it to the linear map
295			 * anyway, in which case we should use the existing
296			 * mapping.
297			 */
298			if (memblock_is_map_memory(phys))
299				return (void __iomem *)__va(phys);
300			fallthrough;
301
302		default:
303			if (region->attribute & EFI_MEMORY_WB)
304				prot = PAGE_KERNEL;
305			else if ((region->attribute & EFI_MEMORY_WC) ||
306				 (region->attribute & EFI_MEMORY_WT))
307				prot = pgprot_writecombine(PAGE_KERNEL);
308		}
309	}
310
311	return ioremap_prot(phys, size, prot);
312}
313
314#ifdef CONFIG_PCI
315
316/*
317 * raw_pci_read/write - Platform-specific PCI config space access.
318 */
319int raw_pci_read(unsigned int domain, unsigned int bus,
320		 unsigned int devfn, int reg, int len, u32 *val)
321{
322	struct pci_bus *b = pci_find_bus(domain, bus);
323
324	if (!b)
325		return PCIBIOS_DEVICE_NOT_FOUND;
326	return b->ops->read(b, devfn, reg, len, val);
327}
328
329int raw_pci_write(unsigned int domain, unsigned int bus,
330		  unsigned int devfn, int reg, int len, u32 val)
331{
332	struct pci_bus *b = pci_find_bus(domain, bus);
333
334	if (!b)
335		return PCIBIOS_DEVICE_NOT_FOUND;
336	return b->ops->write(b, devfn, reg, len, val);
337}
338
339#endif	/* CONFIG_PCI */