Messages in this thread | | | Date | Sat, 29 Jun 2013 22:14:11 -0500 | From | Rob Landley <> | Subject | Re: [PATCH 1/2] Documentation: arm: early_ioremap |
| |
On 06/25/2013 12:46:40 PM, Leif Lindholm wrote: > This patch provides documentation of the early_ioremap() > functionality, > including its implementation and usage instructions. > > Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> > --- > Documentation/arm/00-INDEX | 2 ++ > Documentation/arm/early_ioremap.txt | 12 ++++++++++++ > 2 files changed, 14 insertions(+) > create mode 100644 Documentation/arm/early_ioremap.txt > > diff --git a/Documentation/arm/00-INDEX b/Documentation/arm/00-INDEX > index 36420e1..4978456 100644 > --- a/Documentation/arm/00-INDEX > +++ b/Documentation/arm/00-INDEX > @@ -24,6 +24,8 @@ SPEAr > - ST SPEAr platform Linux Overview > VFP/ > - Release notes for Linux Kernel Vector Floating Point support > code > +early_ioremap.txt > + - documentation of the early_ioremap() functionality > empeg/ > - Ltd's Empeg MP3 Car Audio Player > mem_alignment > diff --git a/Documentation/arm/early_ioremap.txt > b/Documentation/arm/early_ioremap.txt > new file mode 100644 > index 0000000..178f791 > --- /dev/null > +++ b/Documentation/arm/early_ioremap.txt > @@ -0,0 +1,12 @@ > +early_ioremap() and early_iounmap() rovide a mechanism for > temporarily mapping
Typo: provide
> +in small blocks of memory, identified by their physical address, > into the > +fixmap virtual address block before paging_init() has been called > and more > +flexible mapping functions are available. > + > +Due to its direct method, it also gets around potential need for > special > +handling of regions that end up in highmem. > + > +It supports up to 7 simultaneously mapped regions of up to 128KB > each. > +All regions are mapped as non-shareable device memory. > + > +Specify 'early_ioremap_debug' on the kernel commandline for verbose > output. > -- > 1.7.10.4
Minor quibble: this explains what it does, but nothing about how to use it. Do these mappings persist if you don't unmap them, or does paging_init() clear them?
Oh well:
Acked-by: Rob Landley <rob@landley.net>
Rob
| |