On 2023/3/21 4:42, Chen Jiahao wrote: > Now "crashkernel=" parameter on riscv has been updated to support > crashkernel=X,[high,low]. Through which we can reserve memory region > above/within 32bit addressible DMA zone. > > Here update the parameter description accordingly. Reviewed-by: Zhen Lei <thunder.leizhen@xxxxxxxxxx> > > Signed-off-by: Chen Jiahao <chenjiahao16@xxxxxxxxxx> > --- > Documentation/admin-guide/kernel-parameters.txt | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 6221a1d057dd..89e26a4864f8 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -843,7 +843,7 @@ > memory region [offset, offset + size] for that kernel > image. If '@offset' is omitted, then a suitable offset > is selected automatically. > - [KNL, X86-64, ARM64] Select a region under 4G first, and > + [KNL, X86-64, ARM64, RISCV] Select a region under 4G first, and > fall back to reserve region above 4G when '@offset' > hasn't been specified. > See Documentation/admin-guide/kdump/kdump.rst for further details. > @@ -856,14 +856,14 @@ > Documentation/admin-guide/kdump/kdump.rst for an example. > > crashkernel=size[KMG],high > - [KNL, X86-64, ARM64] range could be above 4G. Allow kernel > - to allocate physical memory region from top, so could > - be above 4G if system have more than 4G ram installed. > - Otherwise memory region will be allocated below 4G, if > - available. > + [KNL, X86-64, ARM64, RISCV] range could be above 4G. > + Allow kernel to allocate physical memory region from top, > + so could be above 4G if system have more than 4G ram > + installed. Otherwise memory region will be allocated > + below 4G, if available. > It will be ignored if crashkernel=X is specified. > crashkernel=size[KMG],low > - [KNL, X86-64, ARM64] range under 4G. When crashkernel=X,high > + [KNL, X86-64, ARM64, RISCV] range under 4G. When crashkernel=X,high > is passed, kernel could allocate physical memory region > above 4G, that cause second kernel crash on system > that require some amount of low memory, e.g. swiotlb > @@ -874,6 +874,7 @@ > size is platform dependent. > --> x86: max(swiotlb_size_or_default() + 8MiB, 256MiB) > --> arm64: 128MiB > + --> riscv: 128MiB > This one lets the user specify own low range under 4G > for second kernel instead. > 0: to disable low allocation. > -- Regards, Zhen Lei
