This patch adds the ability to load and link ACPI tables provided by QEMU.
QEMU tells guests how to load and patch ACPI tables through its fw_cfg
interface, by adding a firmware file 'etc/table-loader'. Guests are
supposed to parse this file and execute corresponding QEMU commands.
Signed-off-by: Miao Yan
---
Changes in v2:
- add function comment
- improve error handling
arch/x86/cpu/qemu/fw_cfg.c| 253 ++
arch/x86/include/asm/fw_cfg.h | 61 ++
arch/x86/lib/acpi_table.c | 4 +
3 files changed, 318 insertions(+)
diff --git a/arch/x86/cpu/qemu/fw_cfg.c b/arch/x86/cpu/qemu/fw_cfg.c
index bcd34af..5ea7a6e 100644
--- a/arch/x86/cpu/qemu/fw_cfg.c
+++ b/arch/x86/cpu/qemu/fw_cfg.c
@@ -10,7 +10,10 @@
#include
#include
#include
+#include
+#include
#include
+#include
static bool fwcfg_present;
static bool fwcfg_dma_present;
@@ -204,6 +207,256 @@ err:
return -ENOMEM;
}
+#ifdef CONFIG_QEMU_ACPI_TABLE
+static struct fw_file *qemu_fwcfg_find_file(const char *name)
+{
+ struct list_head *entry;
+ struct fw_file *file;
+
+ list_for_each(entry, &fw_list) {
+ file = list_entry(entry, struct fw_file, list);
+ if (!strcmp(file->cfg.name, name))
+ return file;
+ }
+
+ return NULL;
+}
+
+/*
+ * This function allocates memory for ACPI tables
+ *
+ * @entry : BIOS linker command entry which tells where to allocate memory
+ * (either high memory or low memory)
+ * @addr : The address that should be used for low memory allcation. If the
+ * memory allocation request is 'ZONE_HIGH' then this parameter will
+ * be ignored.
+ * @return: 0 on success, or negative value on failure
+ */
+static int bios_linker_allocate(struct bios_linker_entry *entry,
+ unsigned long *addr)
+{
+ uint32_t size, align;
+ struct fw_file *file;
+ unsigned long aligned_addr;
+
+ align = le32_to_cpu(entry->alloc.align);
+ /* align must be power of 2 */
+ if (align & (align - 1)) {
+ printf("error: wrong alignment %u\n", align);
+ return -EINVAL;
+ }
+
+ file = qemu_fwcfg_find_file(entry->alloc.file);
+ if (!file) {
+ printf("error: can't find file %s\n", entry->alloc.file);
+ return -ENOENT;
+ }
+
+ size = be32_to_cpu(file->cfg.size);
+
+ /*
+* ZONE_HIGH means we need to allocate from high memory, since
+* malloc space is already at the end of RAM, so we directly use it.
+* If allocation zone is ZONE_FSEG, then we use the 'addr' passed
+* in which is low memory
+*/
+ if (entry->alloc.zone == BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH) {
+ aligned_addr = (unsigned long)memalign(align, size);
+ if (!aligned_addr) {
+ printf("error: allocating resource\n");
+ return -ENOMEM;
+ }
+ } else if (entry->alloc.zone == BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG) {
+ aligned_addr = ALIGN(*addr, align);
+ } else {
+ printf("error: invalid allocation zone\n");
+ return -EINVAL;
+ }
+
+ debug("bios_linker_allocate: allocate file %s, size %u, zone %d, align
%u, addr 0x%lx\n",
+ file->cfg.name, size, entry->alloc.zone, align, aligned_addr);
+
+ qemu_fwcfg_read_entry(be16_to_cpu(file->cfg.select),
+ size, (void *)aligned_addr);
+ file->addr = aligned_addr;
+
+ /* adjust address for low memory allocation */
+ if (entry->alloc.zone == BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG)
+ *addr = (aligned_addr + size);
+
+ return 0;
+}
+
+/*
+ * This function patches ACPI tables previously loaded
+ * by bios_linker_allocate()
+ *
+ * @entry : BIOS linker command entry which tells how to patch
+ * ACPI tables
+ * @return: 0 on success, or negative value on failure
+ */
+static int bios_linker_add_pointer(struct bios_linker_entry *entry)
+{
+ struct fw_file *dest, *src;
+ uint32_t offset = le32_to_cpu(entry->pointer.offset);
+ uint64_t pointer = 0;
+
+ dest = qemu_fwcfg_find_file(entry->pointer.dest_file);
+ if (!dest || !dest->addr)
+ return -ENOENT;
+ src = qemu_fwcfg_find_file(entry->pointer.src_file);
+ if (!src || !src->addr)
+ return -ENOENT;
+
+ debug("bios_linker_add_pointer: dest->addr 0x%lx, src->addr 0x%lx,
offset 0x%x size %u, 0x%llx\n",
+ dest->addr, src->addr, offset, entry->pointer.size, pointer);
+
+ memcpy(&pointer, (char *)dest->addr + offset, entry->pointer.size);
+ pointer = le64_to_cpu(pointer);
+ pointer += (unsigned long)src->addr;
+ pointer = cpu_to_le64(pointer);
+ memcpy((char *)dest->addr + offset, &pointer, entry->pointer.size);
+
+
