diff options
| author | Pasha Tatashin <pasha.tatashin@soleen.com> | 2021-09-30 14:31:10 +0000 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-10-01 13:31:00 +0100 |
| commit | efc2d0f20a9dab2d0e92a271dc4b8e3496377739 (patch) | |
| tree | fa0b24a0c10e8f42a9da2e267bc0ba93856546dc /arch/arm64/kernel/machine_kexec.c | |
| parent | 3744b5280e67f54579abe92576deec0079242323 (diff) | |
arm64: kexec: keep MMU enabled during kexec relocation
Now, that we have linear map page tables configured, keep MMU enabled
to allow faster relocation of segments to final destination.
Cavium ThunderX2:
Kernel Image size: 38M Iniramfs size: 46M Total relocation size: 84M
MMU-disabled:
relocation 7.489539915s
MMU-enabled:
relocation 0.03946095s
Broadcom Stingray:
The performance data: for a moderate size kernel + initramfs: 25M the
relocation was taking 0.382s, with enabled MMU it now takes
0.019s only or x20 improvement.
The time is proportional to the size of relocation, therefore if initramfs
is larger, 100M it could take over a second.
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210930143113.1502553-13-pasha.tatashin@soleen.com
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/machine_kexec.c')
| -rw-r--r-- | arch/arm64/kernel/machine_kexec.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index fbff545565f1..1e9a2a45e016 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -196,6 +196,11 @@ int machine_kexec_post_load(struct kimage *kimage) reloc_size = __relocate_new_kernel_end - __relocate_new_kernel_start; memcpy(reloc_code, __relocate_new_kernel_start, reloc_size); kimage->arch.kern_reloc = __pa(reloc_code); + rc = trans_pgd_idmap_page(&info, &kimage->arch.ttbr0, + &kimage->arch.t0sz, reloc_code); + if (rc) + return rc; + kimage->arch.phys_offset = virt_to_phys(kimage) - (long)kimage; /* Flush the reloc_code in preparation for its execution. */ dcache_clean_inval_poc((unsigned long)reloc_code, @@ -230,9 +235,9 @@ void machine_kexec(struct kimage *kimage) local_daif_mask(); /* - * Both restart and cpu_soft_restart will shutdown the MMU, disable data + * Both restart and kernel_reloc will shutdown the MMU, disable data * caches. However, restart will start new kernel or purgatory directly, - * cpu_soft_restart will transfer control to arm64_relocate_new_kernel + * kernel_reloc contains the body of arm64_relocate_new_kernel * In kexec case, kimage->start points to purgatory assuming that * kernel entry and dtb address are embedded in purgatory by * userspace (kexec-tools). @@ -246,10 +251,13 @@ void machine_kexec(struct kimage *kimage) restart(is_hyp_nvhe(), kimage->start, kimage->arch.dtb_mem, 0, 0); } else { + void (*kernel_reloc)(struct kimage *kimage); + if (is_hyp_nvhe()) __hyp_set_vectors(kimage->arch.el2_vectors); - cpu_soft_restart(kimage->arch.kern_reloc, - virt_to_phys(kimage), 0, 0); + cpu_install_ttbr0(kimage->arch.ttbr0, kimage->arch.t0sz); + kernel_reloc = (void *)kimage->arch.kern_reloc; + kernel_reloc(kimage); } BUG(); /* Should never get here. */ |