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