Now there 5 places which calculate max_pfn & max_low_pfn:
1. in fdt_setup() for FDT systems;
2. in memblock_init() for ACPI systems;
3. in init_numa_memory() for NUMA systems;
4. in arch_mem_init() to recalculate for "mem=" cmdline;
5. in paging_init() to recalculate for NUMA systems.
Since memblock_init() is called both for ACPI and FDT systems, move the
calculation out of the for_each_efi_memory_desc() loop can eliminate the
first case. The last case is very questionable (may be derived from the
MIPS/Loongson code) and breaks the "mem=" cmdline, so should be removed.
And then the NUMA version of paging_init() can be also eliminated.
After consolidation there are 3 places of calculation:
1. in memblock_init() for both ACPI and FDT systems;
2. in init_numa_memory() to recalculate for NUMA systems;
3. in arch_mem_init() to recalculate for the "mem=" cmdline.
For all cases the calculation is:
max_pfn = PFN_DOWN(memblock_end_of_DRAM());
max_low_pfn = min(PFN_DOWN(HIGHMEM_START), max_pfn);
Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This patch adds support for kdump. In kdump case the normal kernel will
reserve a region for the crash kernel and jump there on panic.
Arch-specific functions are added to allow for implementing a crash dump
file interface, /proc/vmcore, which can be viewed as a ELF file.
A user-space tool, such as kexec-tools, is responsible for allocating a
separate region for the core's ELF header within the crash kdump kernel
memory and filling it in when executing kexec_load().
Then, its location will be advertised to the crash dump kernel via a
command line argument "elfcorehdr=", and the crash dump kernel will
preserve this region for later use with arch_reserve_vmcore() at boot
time.
At the same time, the crash kdump kernel is also limited within the
"crashkernel" area via a command line argument "mem=", so as not to
destroy the original kernel dump data.
In the crash dump kernel environment, /proc/vmcore is used to access the
primary kernel's memory with copy_oldmem_page().
I tested kdump on LoongArch machines (Loongson-3A5000) and it works as
expected (suggested crashkernel parameter is "crashkernel=512M@2560M"),
you may test it by triggering a crash through /proc/sysrq-trigger:
$ sudo kexec -p /boot/vmlinux-kdump --reuse-cmdline --append="nr_cpus=1"
# echo c > /proc/sysrq-trigger
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
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>
