The EFI memory map at 'boot_memmap' is crucial for kdump to understand
the primary kernel's memory layout. This memory region, typically part
of EFI Boot Services (BS) data, can be overwritten after ExitBootServices
if not explicitly preserved by the kernel.
This commit addresses this by:
1. Calling memblock_reserve() to reserve the entire physical region
occupied by the EFI memory map (header + descriptors). This prevents
the primary kernel from reallocating and corrupting this area.
2. Setting the EFI_PRESERVE_BS_REGIONS flag in efi.flags. This indicates
that efforts have been made to preserve critical BS code/data regions
which can be useful for other kernel subsystems or debugging.
These changes ensure the original EFI memory map data remains intact,
improving kdump reliability and potentially aiding other EFI-related
functionalities that might rely on preserved BS code/data.
Signed-off-by: Ming Wang <wangming01@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Since screen_info.lfb_base is a __u32 type, an above-4G address need an
ext_lfb_base to present its higher 32bits. In init_screen_info() we can
use __screen_info_lfb_base() to handle this case for reserving screen
info memory.
Signed-off-by: Xuefeng Zhao <zhaoxuefeng@loongson.cn>
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
efi_shutdown_init() can register a general sys_off handler named
efi_power_off(). Enable this by providing efi_poweroff_required(),
like arm and x86. Since EFI poweroff is also supported on LoongArch,
and the enablement makes the poweroff function usable for hardwares
which lack ACPI S5.
We prefer ACPI poweroff rather than EFI poweroff (like x86), so we only
require EFI poweroff if acpi_gbl_reduced_hardware or acpi_no_s5 is true.
Cc: stable@vger.kernel.org
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Miao Wang <shankerwangmiao@gmail.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
ESRT (EFI System Resource Table) is needed for UEFI's "Capsule Update"
feature. But ESRT initialization is missing on LoongArch now, so add a
call to efi_esrt_init() at the end of efi_init().
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
After the vga console no longer relies on global screen_info, there are
only two remaining use cases:
- on the x86 architecture, it is used for multiple boot methods
(bzImage, EFI, Xen, kexec) to commucate the initial VGA or framebuffer
settings to a number of device drivers.
- on other architectures, it is only used as part of the EFI stub,
and only for the three sysfb framebuffers (simpledrm, simplefb, efifb).
Remove the duplicate data structure definitions by moving it into the
efi-init.c file that sets it up initially for the EFI case, leaving x86
as an exception that retains its own definition for non-EFI boots.
The added #ifdefs here are optional, I added them to further limit the
reach of screen_info to configurations that have at least one of the
users enabled.
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20231017093947.3627976-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The header file <linux/efi.h> does not need anything from
<linux/screen_info.h>. Declare struct screen_info and remove
the include statements. Update a number of source files that
require struct screen_info's definition.
v2:
* update loongarch (Jingfeng)
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20230706104852.27451-2-tzimmermann@suse.de
Since commit 40cd01a9c324("efi/loongarch: libstub: remove dependency on
flattened DT"), we can parse the FDT from efi system table.
And now, LoongArch is coming to support booting with FDT, so we add the
relevant booting support as well as parameter parsing.
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Currently, arm64, RISC-V and LoongArch rely on the fact that struct
screen_info can be accessed directly, due to the fact that the EFI stub
and the core kernel are part of the same image. This will change after a
future patch, so let's ensure that the screen_info handling is able to
deal with this, by adopting the arm32 approach of passing it as a
configuration table. While at it, switch to ACPI reclaim memory to hold
the screen_info data, which is more appropriate for this kind of
allocation.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
LoongArch does not use FDT or DT natively [yet], and the only reason it
currently uses it is so that it can reuse the existing EFI stub code.
Overloading the DT with data passed between the EFI stub and the core
kernel has been a source of problems: there is the overlap between
information provided by EFI which DT can also provide (initrd base/size,
command line, memory descriptions), requiring us to reason about which
is which and what to prioritize. It has also resulted in ABI leaks,
i.e., internal ABI being promoted to external ABI inadvertently because
the bootloader can set the EFI stub's DT properties as well (e.g.,
"kaslr-seed"). This has become especially problematic with boot
environments that want to pretend that EFI boot is being done (to access
ACPI and SMBIOS tables, for instance) but have no ability to execute the
EFI stub, and so the environment that the EFI stub creates is emulated
[poorly, in some cases].
Another downside of treating DT like this is that the DT binary that the
kernel receives is different from the one created by the firmware, which
is undesirable in the context of secure and measured boot.
Given that LoongArch support in Linux is brand new, we can avoid these
pitfalls, and treat the DT strictly as a hardware description, and use a
separate handover method between the EFI stub and the kernel. Now that
initrd loading and passing the EFI memory map have been refactored into
pure EFI routines that use EFI configuration tables, the only thing we
need to pass directly is the kernel command line (even if we could pass
this via a config table as well, it is used extremely early, so passing
it directly is preferred in this case.)
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
This patch adds efistub booting support, which is the standard UEFI boot
protocol for LoongArch to use.
We use generic efistub, which means we can pass boot information (i.e.,
system table, memory map, kernel command line, initrd) via a light FDT
and drop a lot of non-standard code.
We use a flat mapping to map the efi runtime in the kernel's address
space. In efi, VA = PA; in kernel, VA = PA + PAGE_OFFSET. As a result,
flat mapping is not identity mapping, SetVirtualAddressMap() is still
needed for the efi runtime.
Tested-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
[ardb: change fpic to fpie as suggested by Xi Ruoyao]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Add basic boot, setup and reset routines for LoongArch. Now, LoongArch
machines use UEFI-based firmware. The firmware passes configuration
information to the kernel via ACPI and DMI/SMBIOS.
Currently an existing interface between the kernel and the bootloader
is implemented. Kernel gets 2 values from the bootloader, passed in
registers a0 and a1; a0 is an "EFI boot flag" distinguishing UEFI and
non-UEFI firmware, while a1 is a pointer to an FDT with systable,
memmap, cmdline and initrd information.
The standard UEFI boot protocol (EFISTUB) will be added later.
Cc: linux-efi@vger.kernel.org
Cc: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Co-developed-by: Yun Liu <liuyun@loongson.cn>
Signed-off-by: Yun Liu <liuyun@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
