This patch adds support for EFI memory maps larger than 128 entries when
booted using the EFI boot stub.

The e820 map in struct boot_params can only hold 128 entries, but the
memory map provided by EFI may be larger. If the map contained more than
128 entries, exit_boot() would write beyond the e820_map array in
boot_params and the system would eventually halt in the BUG_ON check in
sanitize_e820_map().

In the case we come in through efi_main(), the EFI memory map is used.
Instead of populating e820_map in boot_params, create the e820 from the
EFI memory map in setup_arch() via a memory_setup hook.

The EFI memory map may also be added in efi_init() if the command line
parameter "add_efi_memmap" is specified. This is left intact to allow
the command line parameter to remain effective.

Signed-off-by: Linn Crosetto <l...@hp.com>
---
 arch/x86/boot/compressed/eboot.c | 64 ++--------------------------------------
 arch/x86/kernel/setup.c          |  3 ++
 2 files changed, 6 insertions(+), 61 deletions(-)

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index b7388a4..66b8d3d 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -973,6 +973,9 @@ struct boot_params *make_boot_params(void *handle, 
efi_system_table_t *_table)
        if (status != EFI_SUCCESS)
                goto fail2;
 
+       /* Use EFI memory map */
+       boot_params->e820_entries = 0;
+
        return boot_params;
 fail2:
        if (options_size)
@@ -986,8 +989,6 @@ static efi_status_t exit_boot(struct boot_params 
*boot_params,
                              void *handle)
 {
        struct efi_info *efi = &boot_params->efi_info;
-       struct e820entry *e820_map = &boot_params->e820_map[0];
-       struct e820entry *prev = NULL;
        unsigned long size, key, desc_size, _size;
        efi_memory_desc_t *mem_map;
        efi_status_t status;
@@ -1049,65 +1050,6 @@ get_map:
        /* Historic? */
        boot_params->alt_mem_k = 32 * 1024;
 
-       /*
-        * Convert the EFI memory map to E820.
-        */
-       nr_entries = 0;
-       for (i = 0; i < size / desc_size; i++) {
-               efi_memory_desc_t *d;
-               unsigned int e820_type = 0;
-               unsigned long m = (unsigned long)mem_map;
-
-               d = (efi_memory_desc_t *)(m + (i * desc_size));
-               switch (d->type) {
-               case EFI_RESERVED_TYPE:
-               case EFI_RUNTIME_SERVICES_CODE:
-               case EFI_RUNTIME_SERVICES_DATA:
-               case EFI_MEMORY_MAPPED_IO:
-               case EFI_MEMORY_MAPPED_IO_PORT_SPACE:
-               case EFI_PAL_CODE:
-                       e820_type = E820_RESERVED;
-                       break;
-
-               case EFI_UNUSABLE_MEMORY:
-                       e820_type = E820_UNUSABLE;
-                       break;
-
-               case EFI_ACPI_RECLAIM_MEMORY:
-                       e820_type = E820_ACPI;
-                       break;
-
-               case EFI_LOADER_CODE:
-               case EFI_LOADER_DATA:
-               case EFI_BOOT_SERVICES_CODE:
-               case EFI_BOOT_SERVICES_DATA:
-               case EFI_CONVENTIONAL_MEMORY:
-                       e820_type = E820_RAM;
-                       break;
-
-               case EFI_ACPI_MEMORY_NVS:
-                       e820_type = E820_NVS;
-                       break;
-
-               default:
-                       continue;
-               }
-
-               /* Merge adjacent mappings */
-               if (prev && prev->type == e820_type &&
-                   (prev->addr + prev->size) == d->phys_addr)
-                       prev->size += d->num_pages << 12;
-               else {
-                       e820_map->addr = d->phys_addr;
-                       e820_map->size = d->num_pages << 12;
-                       e820_map->type = e820_type;
-                       prev = e820_map++;
-                       nr_entries++;
-               }
-       }
-
-       boot_params->e820_entries = nr_entries;
-
        return EFI_SUCCESS;
 
 free_mem_map:
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index f8ec578..9682c8c 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -920,6 +920,9 @@ void __init setup_arch(char **cmdline_p)
 
        if (efi_enabled(EFI_BOOT))
                efi_memblock_x86_reserve_range();
+
+       if (efi_memmap_needed())
+               x86_init.resources.memory_setup = efi_memory_setup;
 #endif
 
        x86_init.oem.arch_setup();
-- 
1.7.11.3

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