--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/efi.h>
+#include <asm/efi.h>
+#include "efistub.h"
+
+struct efi_unaccepted_memory *unaccepted_table;
+
+efi_status_t allocate_unaccepted_bitmap(__u32 nr_desc,
+ struct efi_boot_memmap *map)
+{
+ efi_guid_t unaccepted_table_guid = LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID;
+ u64 unaccepted_start = ULLONG_MAX, unaccepted_end = 0, bitmap_size;
+ efi_status_t status;
+ int i;
+
+ /* Check if the table is already installed */
+ unaccepted_table = get_efi_config_table(unaccepted_table_guid);
+ if (unaccepted_table) {
+ if (unaccepted_table->version != 1) {
+ efi_err("Unknown version of unaccepted memory table\n");
+ return EFI_UNSUPPORTED;
+ }
+ return EFI_SUCCESS;
+ }
+
+ /* Check if there's any unaccepted memory and find the max address */
+ for (i = 0; i < nr_desc; i++) {
+ efi_memory_desc_t *d;
+ unsigned long m = (unsigned long)map->map;
+
+ d = efi_early_memdesc_ptr(m, map->desc_size, i);
+ if (d->type != EFI_UNACCEPTED_MEMORY)
+ continue;
+
+ unaccepted_start = min(unaccepted_start, d->phys_addr);
+ unaccepted_end = max(unaccepted_end,
+ d->phys_addr + d->num_pages * PAGE_SIZE);
+ }
+
+ if (unaccepted_start == ULLONG_MAX)
+ return EFI_SUCCESS;
+
+ unaccepted_start = round_down(unaccepted_start,
+ EFI_UNACCEPTED_UNIT_SIZE);
+ unaccepted_end = round_up(unaccepted_end, EFI_UNACCEPTED_UNIT_SIZE);
+
+ /*
+ * If unaccepted memory is present, allocate a bitmap to track what
+ * memory has to be accepted before access.
+ *
+ * One bit in the bitmap represents 2MiB in the address space:
+ * A 4k bitmap can track 64GiB of physical address space.
+ *
+ * In the worst case scenario -- a huge hole in the middle of the
+ * address space -- It needs 256MiB to handle 4PiB of the address
+ * space.
+ *
+ * The bitmap will be populated in setup_e820() according to the memory
+ * map after efi_exit_boot_services().
+ */
+ bitmap_size = DIV_ROUND_UP(unaccepted_end - unaccepted_start,
+ EFI_UNACCEPTED_UNIT_SIZE * BITS_PER_BYTE);
+
+ status = efi_bs_call(allocate_pool, EFI_LOADER_DATA,
+ sizeof(*unaccepted_table) + bitmap_size,
+ (void **)&unaccepted_table);
+ if (status != EFI_SUCCESS) {
+ efi_err("Failed to allocate unaccepted memory config table\n");
+ return status;
+ }
+
+ unaccepted_table->version = 1;
+ unaccepted_table->unit_size = EFI_UNACCEPTED_UNIT_SIZE;
+ unaccepted_table->phys_base = unaccepted_start;
+ unaccepted_table->size = bitmap_size;
+ memset(unaccepted_table->bitmap, 0, bitmap_size);
+
+ status = efi_bs_call(install_configuration_table,
+ &unaccepted_table_guid, unaccepted_table);
+ if (status != EFI_SUCCESS) {
+ efi_bs_call(free_pool, unaccepted_table);
+ efi_err("Failed to install unaccepted memory config table!\n");
+ }
+
+ return status;
+}
+
+/*
+ * The accepted memory bitmap only works at unit_size granularity. Take
+ * unaligned start/end addresses and either:
+ * 1. Accepts the memory immediately and in its entirety
+ * 2. Accepts unaligned parts, and marks *some* aligned part unaccepted
+ *
+ * The function will never reach the bitmap_set() with zero bits to set.
+ */
+void process_unaccepted_memory(u64 start, u64 end)
+{
+ u64 unit_size = unaccepted_table->unit_size;
+ u64 unit_mask = unaccepted_table->unit_size - 1;
+ u64 bitmap_size = unaccepted_table->size;
+
+ /*
+ * Ensure that at least one bit will be set in the bitmap by
+ * immediately accepting all regions under 2*unit_size. This is
+ * imprecise and may immediately accept some areas that could
+ * have been represented in the bitmap. But, results in simpler
+ * code below
+ *
+ * Consider case like this (assuming unit_size == 2MB):
+ *
+ * | 4k | 2044k | 2048k |
+ * ^ 0x0 ^ 2MB ^ 4MB
+ *
+ * Only the first 4k has been accepted. The 0MB->2MB region can not be
+ * represented in the bitmap. The 2MB->4MB region can be represented in
+ * the bitmap. But, the 0MB->4MB region is <2*unit_size and will be
+ * immediately accepted in its entirety.
+ */
+ if (end - start < 2 * unit_size) {
+ arch_accept_memory(start, end);
+ return;
+ }
+
+ /*
+ * No matter how the start and end are aligned, at least one unaccepted
+ * unit_size area will remain to be marked in the bitmap.
+ */
+
+ /* Immediately accept a <unit_size piece at the start: */
+ if (start & unit_mask) {
+ arch_accept_memory(start, round_up(start, unit_size));
+ start = round_up(start, unit_size);
+ }
+
+ /* Immediately accept a <unit_size piece at the end: */
+ if (end & unit_mask) {
+ arch_accept_memory(round_down(end, unit_size), end);
+ end = round_down(end, unit_size);
+ }
+
+ /*
+ * Accept part of the range that before phys_base and cannot be recorded
+ * into the bitmap.
+ */
+ if (start < unaccepted_table->phys_base) {
+ arch_accept_memory(start,
+ min(unaccepted_table->phys_base, end));
+ start = unaccepted_table->phys_base;
+ }
+
+ /* Nothing to record */
+ if (end < unaccepted_table->phys_base)
+ return;
+
+ /* Translate to offsets from the beginning of the bitmap */
+ start -= unaccepted_table->phys_base;
+ end -= unaccepted_table->phys_base;
+
+ /* Accept memory that doesn't fit into bitmap */
+ if (end > bitmap_size * unit_size * BITS_PER_BYTE) {
+ unsigned long phys_start, phys_end;
+
+ phys_start = bitmap_size * unit_size * BITS_PER_BYTE +
+ unaccepted_table->phys_base;
+ phys_end = end + unaccepted_table->phys_base;
+
+ arch_accept_memory(phys_start, phys_end);
+ end = bitmap_size * unit_size * BITS_PER_BYTE;
+ }
+
+ /*
+ * 'start' and 'end' are now both unit_size-aligned.
+ * Record the range as being unaccepted:
+ */
+ bitmap_set(unaccepted_table->bitmap,
+ start / unit_size, (end - start) / unit_size);
+}
+
+void accept_memory(phys_addr_t start, phys_addr_t end)
+{
+ unsigned long range_start, range_end;
+ unsigned long bitmap_size;
+ u64 unit_size;
+
+ if (!unaccepted_table)
+ return;
+
+ unit_size = unaccepted_table->unit_size;
+
+ /*
+ * Only care for the part of the range that is represented
+ * in the bitmap.
+ */
+ if (start < unaccepted_table->phys_base)
+ start = unaccepted_table->phys_base;
+ if (end < unaccepted_table->phys_base)
+ return;
+
+ /* Translate to offsets from the beginning of the bitmap */
+ start -= unaccepted_table->phys_base;
+ end -= unaccepted_table->phys_base;
+
+ /* Make sure not to overrun the bitmap */
+ if (end > unaccepted_table->size * unit_size * BITS_PER_BYTE)
+ end = unaccepted_table->size * unit_size * BITS_PER_BYTE;
+
+ range_start = start / unit_size;
+ bitmap_size = DIV_ROUND_UP(end, unit_size);
+
+ for_each_set_bitrange_from(range_start, range_end,
+ unaccepted_table->bitmap, bitmap_size) {
+ unsigned long phys_start, phys_end;
+
+ phys_start = range_start * unit_size + unaccepted_table->phys_base;
+ phys_end = range_end * unit_size + unaccepted_table->phys_base;
+
+ arch_accept_memory(phys_start, phys_end);
+ bitmap_clear(unaccepted_table->bitmap,
+ range_start, range_end - range_start);
+ }
+}
#define EFI_MEMORY_MAPPED_IO_PORT_SPACE 12
#define EFI_PAL_CODE 13
#define EFI_PERSISTENT_MEMORY 14
-#define EFI_MAX_MEMORY_TYPE 15
+#define EFI_UNACCEPTED_MEMORY 15
+#define EFI_MAX_MEMORY_TYPE 16
/* Attribute values: */
#define EFI_MEMORY_UC ((u64)0x0000000000000001ULL) /* uncached */
#define LINUX_EFI_MOK_VARIABLE_TABLE_GUID EFI_GUID(0xc451ed2b, 0x9694, 0x45d3, 0xba, 0xba, 0xed, 0x9f, 0x89, 0x88, 0xa3, 0x89)
#define LINUX_EFI_COCO_SECRET_AREA_GUID EFI_GUID(0xadf956ad, 0xe98c, 0x484c, 0xae, 0x11, 0xb5, 0x1c, 0x7d, 0x33, 0x64, 0x47)
#define LINUX_EFI_BOOT_MEMMAP_GUID EFI_GUID(0x800f683f, 0xd08b, 0x423a, 0xa2, 0x93, 0x96, 0x5c, 0x3c, 0x6f, 0xe2, 0xb4)
+#define LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID EFI_GUID(0xd5d1de3c, 0x105c, 0x44f9, 0x9e, 0xa9, 0xbc, 0xef, 0x98, 0x12, 0x00, 0x31)
#define RISCV_EFI_BOOT_PROTOCOL_GUID EFI_GUID(0xccd15fec, 0x6f73, 0x4eec, 0x83, 0x95, 0x3e, 0x69, 0xe4, 0xb9, 0x40, 0xbf)
efi_memory_desc_t map[];
};
+struct efi_unaccepted_memory {
+ u32 version;
+ u32 unit_size;
+ u64 phys_base;
+ u64 size;
+ unsigned long bitmap[];
+};
+
/*
* Architecture independent structure for describing a memory map for the
* benefit of efi_memmap_init_early(), and for passing context between
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