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Subject[PATCH v4 2/4] x86/boot: Add acpitb.c to parse acpi tables
Date
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.fnst@cn.fujitsu.com>
---
arch/x86/boot/compressed/Makefile | 4 +
arch/x86/boot/compressed/acpitb.c | 251 ++++++++++++++++++++++++++++++
2 files changed, 255 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 fa42f895fdde..41017dc98b61 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..5f73c8711f89
--- /dev/null
+++ b/arch/x86/boot/compressed/acpitb.c
@@ -0,0 +1,251 @@
+/* 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 acpi_20 = 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. */
+#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. */
+ 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 we find acpi table, go on searching for acpi20 table.
+ * If we didn't get acpi20 table then use acpi table.
+ * If neither acpi table nor acpi20 table found,
+ * return false.
+ */
+ if (!(efi_guidcmp(guid, ACPI_TABLE_GUID)) && !acpi_20) {
+ *rsdp_addr = (acpi_physical_address)table;
+ acpi_20 = false;
+ find_rsdp = true;
+ } else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) {
+ *rsdp_addr = (acpi_physical_address)table;
+ acpi_20 = true;
+ 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;
+}
+
+static u8 *scan_memory_for_rsdp(u8 *start_address, u32 length)
+{
+ struct acpi_table_rsdp *rsdp;
+ u8 *end_address;
+ u8 *mem_rover;
+
+ end_address = start_address + length;
+
+ for (mem_rover = start_address; mem_rover < end_address;
+ mem_rover += ACPI_RSDP_SCAN_STEP) {
+ 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;
+ return mem_rover;
+ }
+ return NULL;
+}
+
+static void bios_get_rsdp_addr(acpi_physical_address *rsdp_addr)
+{
+ struct acpi_table_rsdp *rsdp;
+ u32 physical_address;
+ u8 *table_ptr;
+ u8 *mem_rover;
+
+ table_ptr = (u8 *)ACPI_EBDA_PTR_LOCATION;
+ *(u32 *)(void *)&physical_address = *(u16 *)(void *)table_ptr;
+ physical_address <<= 4;
+ table_ptr = (u8 *)(acpi_physical_address)physical_address;
+
+ if (physical_address > 0x400) {
+ mem_rover = scan_memory_for_rsdp(table_ptr,
+ ACPI_EBDA_WINDOW_SIZE);
+
+ if (mem_rover) {
+ physical_address += (u32)ACPI_PTR_DIFF(mem_rover,
+ table_ptr);
+ *rsdp_addr = (acpi_physical_address)physical_address;
+ return;
+ }
+ }
+
+ table_ptr = (u8 *)ACPI_HI_RSDP_WINDOW_BASE;
+ mem_rover = scan_memory_for_rsdp(table_ptr, ACPI_HI_RSDP_WINDOW_SIZE);
+
+ if (mem_rover) {
+ physical_address = (u32)(ACPI_HI_RSDP_WINDOW_BASE +
+ ACPI_PTR_DIFF(mem_rover, table_ptr));
+ *rsdp_addr = (acpi_physical_address)physical_address;
+ return;
+ }
+}
+
+/*
+ * Used to dig rsdp table from efi table or bios.
+ * If rsdp table found in efi table, use it. Or search bios.
+ */
+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;
+ u32 size;
+ u8 *entry;
+ u32 count;
+ 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


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