Imitate the ACPI code to parse ACPI tables. Functions are simplified
cause some operations are not needed here.
And also, this method won't influence the initialization of ACPI.
Signed-off-by: Chao Fan <fanc.f...@cn.fujitsu.com>
---
arch/x86/boot/compressed/Makefile | 4 +
arch/x86/boot/compressed/acpitb.c | 272 ++++++++++++++++++++++++++++++
2 files changed, 276 insertions(+)
create mode 100644 arch/x86/boot/compressed/acpitb.c
diff --git a/arch/x86/boot/compressed/Makefile
b/arch/x86/boot/compressed/Makefile
index 169c2feda14a..a382bb50f599 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -83,6 +83,10 @@ ifdef CONFIG_X86_64
vmlinux-objs-y += $(obj)/pgtable_64.o
endif
+ifdef CONFIG_MEMORY_HOTREMOVE
+vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/acpitb.o
+endif
+
$(obj)/eboot.o: KBUILD_CFLAGS += -fshort-wchar -mno-red-zone
vmlinux-objs-$(CONFIG_EFI_STUB) += $(obj)/eboot.o $(obj)/efi_stub_$(BITS).o \
diff --git a/arch/x86/boot/compressed/acpitb.c
b/arch/x86/boot/compressed/acpitb.c
new file mode 100644
index 000000000000..a1ec0d9313fe
--- /dev/null
+++ b/arch/x86/boot/compressed/acpitb.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0
+#define BOOT_CTYPE_H
+#include "misc.h"
+#include "acpitb.h"
+
+#include <linux/efi.h>
+#include <asm/efi.h>
+#include <linux/numa.h>
+
+extern unsigned long get_cmd_line_ptr(void);
+
+#ifdef CONFIG_EFI
+/* Search EFI table for rsdp table. */
+static bool efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
+{
+ efi_system_table_t *systab;
+ bool find_rsdp = false;
+ bool efi_64 = false;
+ void *config_tables;
+ struct efi_info *e;
+ char *sig;
+ int size;
+ int i;
+
+ e = &boot_params->efi_info;
+ sig = (char *)&e->efi_loader_signature;
+
+ if (!strncmp(sig, EFI64_LOADER_SIGNATURE, 4))
+ efi_64 = true;
+ else if (!strncmp(sig, EFI32_LOADER_SIGNATURE, 4))
+ efi_64 = false;
+ else {
+ debug_putstr("Wrong EFI loader signature.\n");
+ return false;
+ }
+
+ /* Get systab from boot params. Based on efi_init(). */
+#ifdef CONFIG_X86_32
+ if (e->efi_systab_hi || e->efi_memmap_hi) {
+ debug_putstr("Table located above 4GB, disabling EFI.\n");
+ return false;
+ }
+ systab = (efi_system_table_t *)e->efi_systab;
+#else
+ systab = (efi_system_table_t *)(
+ e->efi_systab | ((__u64)e->efi_systab_hi<<32));
+#endif
+
+ if (systab == NULL)
+ return false;
+
+ /*
+ * Get EFI tables from systab. Based on efi_config_init() and
+ * efi_config_parse_tables(). Only dig the useful tables but not
+ * do the initialization jobs.
+ */
+ size = efi_64 ? sizeof(efi_config_table_64_t) :
+ sizeof(efi_config_table_32_t);
+
+ for (i = 0; i < systab->nr_tables; i++) {
+ efi_guid_t guid;
+ unsigned long table;
+
+ config_tables = (void *)(systab->tables + size * i);
+ if (efi_64) {
+ efi_config_table_64_t *tmp_table;
+
+ tmp_table = (efi_config_table_64_t *)config_tables;
+ guid = tmp_table->guid;
+ table = tmp_table->table;
+#ifndef CONFIG_64BIT
+ if (table >> 32) {
+ debug_putstr("Table located above 4G, disabling
EFI.\n");
+ return false;
+ }
+#endif
+ } else {
+ efi_config_table_32_t *tmp_table;
+
+ tmp_table = (efi_config_table_32_t *)config_tables;
+ guid = tmp_table->guid;
+ table = tmp_table->table;
+ }
+
+ /*
+ * Get rsdp from EFI tables.
+ * If ACPI20 table found, use it and return true.
+ * If ACPI20 table not found, but ACPI table found,
+ * use the ACPI table and return true.
+ * If neither ACPI table nor ACPI20 table found,
+ * return false.
+ */
+ if (!(efi_guidcmp(guid, ACPI_TABLE_GUID))) {
+ *rsdp_addr = (acpi_physical_address)table;
+ find_rsdp = true;
+ } else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) {
+ *rsdp_addr = (acpi_physical_address)table;
+ return true;
+ }
+ }
+ return find_rsdp;
+}
+#else
+static bool efi_get_rsdp_addr(acpi_physical_address *rsdp_addr)
+{
+ return false;
+}
+#endif
+
+static u8 checksum(u8 *buffer, u32 length)
+{
+ u8 sum = 0;
+ u8 *end = buffer + length;
+
+ while (buffer < end)
+ sum = (u8)(sum + *(buffer++));
+
+ return sum;
+}
+
+/*
+ * Used to search a block of memory for the RSDP signature.
+ * Return Pointer to the RSDP if found, otherwise NULL.
+ * Based on acpi_tb_scan_memory_for_rsdp().
+ */
+static u8 *scan_mem_for_rsdp(u8 *start_address, u32 length)
+{
+ struct acpi_table_rsdp *rsdp;
+ u8 *end_address;
+ u8 *mem_rover;
+
+ end_address = start_address + length;
+
+ /* Search from given start address for the requested length */
+ for (mem_rover = start_address; mem_rover < end_address;
+ mem_rover += ACPI_RSDP_SCAN_STEP) {
+ /* The RSDP signature and checksum must both be correct */
+ rsdp = (struct acpi_table_rsdp *)mem_rover;
+ if (!ACPI_VALIDATE_RSDP_SIG(rsdp->signature))
+ continue;
+ if (checksum((u8 *) rsdp, ACPI_RSDP_CHECKSUM_LENGTH) != 0)
+ continue;
+ if ((rsdp->revision >= 2) &&
+ (checksum((u8 *) rsdp, ACPI_RSDP_XCHECKSUM_LENGTH) != 0))
+ continue;
+
+ /* Sig and checksum valid, we have found a real RSDP */
+ return mem_rover;
+ }
+ return NULL;
+}
+
+/*
+ * Used to search RSDP physical address.
+ * Based on acpi_find_root_pointer(). Since only use physical address
+ * in this period, so there is no need to do the memory map jobs.
+ */
+static void bios_get_rsdp_addr(acpi_physical_address *rsdp_addr)
+{
+ struct acpi_table_rsdp *rsdp;
+ u8 *table_ptr;
+ u8 *mem_rover;
+ u32 address;
+
+ /* Get the location of the Extended BIOS Data Area (EBDA) */
+ table_ptr = (u8 *)ACPI_EBDA_PTR_LOCATION;
+ *(u32 *)(void *)&address = *(u16 *)(void *)table_ptr;
+ address <<= 4;
+ table_ptr = (u8 *)(acpi_physical_address)address;
+
+ /*
+ * Search EBDA paragraphs (EBDA is required to be a minimum of
+ * 1K length)
+ */
+ if (address > 0x400) {
+ mem_rover = scan_mem_for_rsdp(table_ptr, ACPI_EBDA_WINDOW_SIZE);
+
+ if (mem_rover) {
+ address += (u32)ACPI_PTR_DIFF(mem_rover, table_ptr);
+ *rsdp_addr = (acpi_physical_address)address;
+ return;
+ }
+ }
+
+ table_ptr = (u8 *)ACPI_HI_RSDP_WINDOW_BASE;
+ mem_rover = scan_mem_for_rsdp(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
+
+ /*
+ * Search upper memory: 16-byte boundaries in E0000h-FFFFFh
+ */
+ if (mem_rover) {
+ address = (u32)(ACPI_HI_RSDP_WINDOW_BASE +
+ ACPI_PTR_DIFF(mem_rover, table_ptr));
+ *rsdp_addr = (acpi_physical_address)address;
+ return;
+ }
+}
+
+/*
+ * Used to dig rsdp table from EFI table or BIOS.
+ * If rsdp table found in EFI table, use it. Or search BIOS.
+ * Based on acpi_os_get_root_pointer().
+ */
+static acpi_physical_address get_rsdp_addr(void)
+{
+ acpi_physical_address pa = 0;
+ bool status = false;
+
+ status = efi_get_rsdp_addr(&pa);
+
+ if (!status || pa == 0)
+ bios_get_rsdp_addr(&pa);
+
+ return pa;
+}
+
+struct acpi_table_header *get_acpi_srat_table(void)
+{
+ char *args = (char *)get_cmd_line_ptr();
+ acpi_physical_address acpi_table;
+ acpi_physical_address root_table;
+ struct acpi_table_header *header;
+ struct acpi_table_rsdp *rsdp;
+ char *signature;
+ u8 *entry;
+ u32 count;
+ u32 size;
+ int i, j;
+ u32 len;
+
+ rsdp = (struct acpi_table_rsdp *)get_rsdp_addr();
+ if (!rsdp)
+ return NULL;
+
+ /* Get rsdt or xsdt from rsdp. */
+ if (!strstr(args, "acpi=rsdt") &&
+ rsdp->xsdt_physical_address && rsdp->revision > 1) {
+ root_table = rsdp->xsdt_physical_address;
+ size = ACPI_XSDT_ENTRY_SIZE;
+ } else {
+ root_table = rsdp->rsdt_physical_address;
+ size = ACPI_RSDT_ENTRY_SIZE;
+ }
+
+ /* Get ACPI root table from rsdt or xsdt.*/
+ header = (struct acpi_table_header *)root_table;
+ len = header->length;
+ count = (u32)((len - sizeof(struct acpi_table_header)) / size);
+ entry = ACPI_ADD_PTR(u8, header, sizeof(struct acpi_table_header));
+
+ for (i = 0; i < count; i++) {
+ u64 address64;
+
+ if (size == ACPI_RSDT_ENTRY_SIZE)
+ acpi_table = ((acpi_physical_address)
+ (*ACPI_CAST_PTR(u32, entry)));
+ else {
+ *(u64 *)(void *)&address64 = *(u64 *)(void *)entry;
+ acpi_table = (acpi_physical_address) address64;
+ }
+
+ if (acpi_table) {
+ header = (struct acpi_table_header *)acpi_table;
+ signature = header->signature;
+
+ if (!strncmp(signature, "SRAT", 4))
+ return header;
+ }
+ entry += size;
+ }
+ return NULL;
+}
--
2.17.1
