x86: Add support for the Simple Firmware Interface (SFI)
This provides a way of passing information to Linux without requiring the
full ACPI horror. Provide a rudimentary implementation sufficient to be
recognised and parsed by Linux.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/lib/sfi.c b/arch/x86/lib/sfi.c
new file mode 100644
index 0000000..3d36580
--- /dev/null
+++ b/arch/x86/lib/sfi.c
@@ -0,0 +1,154 @@
+/*
+ * Copyright (c) 2015 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+/*
+ * Intel Simple Firmware Interface (SFI)
+ *
+ * Yet another way to pass information to the Linux kernel.
+ *
+ * See https://simplefirmware.org/ for details
+ */
+
+#include <common.h>
+#include <cpu.h>
+#include <dm.h>
+#include <asm/cpu.h>
+#include <asm/ioapic.h>
+#include <asm/sfi.h>
+#include <asm/tables.h>
+#include <dm/uclass-internal.h>
+
+struct table_info {
+ u32 base;
+ int ptr;
+ u32 entry_start;
+ u64 table[SFI_TABLE_MAX_ENTRIES];
+ int count;
+};
+
+static void *get_entry_start(struct table_info *tab)
+{
+ if (tab->count == SFI_TABLE_MAX_ENTRIES)
+ return NULL;
+ tab->entry_start = tab->base + tab->ptr;
+ tab->table[tab->count] = tab->entry_start;
+ tab->entry_start += sizeof(struct sfi_table_header);
+
+ return (void *)tab->entry_start;
+}
+
+static void finish_table(struct table_info *tab, const char *sig, void *entry)
+{
+ struct sfi_table_header *hdr;
+
+ hdr = (struct sfi_table_header *)(tab->base + tab->ptr);
+ strcpy(hdr->sig, sig);
+ hdr->len = sizeof(*hdr) + ((ulong)entry - tab->entry_start);
+ hdr->rev = 1;
+ strncpy(hdr->oem_id, "U-Boot", SFI_OEM_ID_SIZE);
+ strncpy(hdr->oem_table_id, "Table v1", SFI_OEM_TABLE_ID_SIZE);
+ hdr->csum = 0;
+ hdr->csum = table_compute_checksum(hdr, hdr->len);
+ tab->ptr += hdr->len;
+ tab->ptr = ALIGN(tab->ptr, 16);
+ tab->count++;
+}
+
+static int sfi_write_system_header(struct table_info *tab)
+{
+ u64 *entry = get_entry_start(tab);
+ int i;
+
+ if (!entry)
+ return -ENOSPC;
+
+ for (i = 0; i < tab->count; i++)
+ *entry++ = tab->table[i];
+ finish_table(tab, SFI_SIG_SYST, entry);
+
+ return 0;
+}
+
+static int sfi_write_cpus(struct table_info *tab)
+{
+ struct sfi_cpu_table_entry *entry = get_entry_start(tab);
+ struct udevice *dev;
+ int count = 0;
+
+ if (!entry)
+ return -ENOSPC;
+
+ for (uclass_find_first_device(UCLASS_CPU, &dev);
+ dev;
+ uclass_find_next_device(&dev)) {
+ struct cpu_platdata *plat = dev_get_parent_platdata(dev);
+
+ if (!device_active(dev))
+ continue;
+ entry->apic_id = plat->cpu_id;
+ entry++;
+ count++;
+ }
+
+ /* Omit the table if there is only one CPU */
+ if (count > 1)
+ finish_table(tab, SFI_SIG_CPUS, entry);
+
+ return 0;
+}
+
+static int sfi_write_apic(struct table_info *tab)
+{
+ struct sfi_apic_table_entry *entry = get_entry_start(tab);
+
+ if (!entry)
+ return -ENOSPC;
+
+ entry->phys_addr = IO_APIC_ADDR;
+ entry++;
+ finish_table(tab, SFI_SIG_APIC, entry);
+
+ return 0;
+}
+
+static int sfi_write_xsdt(struct table_info *tab)
+{
+ struct sfi_xsdt_header *entry = get_entry_start(tab);
+
+ if (!entry)
+ return -ENOSPC;
+
+ entry->oem_revision = 1;
+ entry->creator_id = 1;
+ entry->creator_revision = 1;
+ entry++;
+ finish_table(tab, SFI_SIG_XSDT, entry);
+
+ return 0;
+}
+
+u32 write_sfi_table(u32 base)
+{
+ struct table_info table;
+
+ table.base = base;
+ table.ptr = 0;
+ table.count = 0;
+ sfi_write_cpus(&table);
+ sfi_write_apic(&table);
+
+ /*
+ * The SFI specification marks the XSDT table as option, but Linux 4.0
+ * crashes on start-up when it is not provided.
+ */
+ sfi_write_xsdt(&table);
+
+ /* Finally, write out the system header which points to the others */
+ sfi_write_system_header(&table);
+
+ return base + table.ptr;
+}