Check it just in case. We might just as well panic there because runtime
won't be functioning anyway.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

We map the EFI regions needed for runtime services non-contiguously,
with preserved alignment on virtual addresses starting from -4G down
for a total max space of 64G. This way, we provide for stable runtime
services addresses across kernels so that a kexec'd kernel can still use
them.

Thus, they're mapped in a separate pagetable so that we don't pollute
the kernel namespace.

Add an efi= kernel command line parameter for passing miscellaneous
options and chicken bits from the command line.

While at it, add a chicken bit called "efi=old_map" which can be used as
a fallback to the old runtime services mapping method in case there's
some b0rkage with a particular EFI implementation (haha, it is hard to
hold up the sarcasm here...).

Also, add the UEFI RT VA space to Documentation/x86/x86_64/mm.txt.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Add the ability to map pages in an arbitrary pgd. This wires in the
remaining stuff so that there's a new interface with which you can map a
region into an arbitrary PGD.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

We try to free the pagetable pages once we've unmapped our portion.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

In case we encounter an error during the mapping of a region, we want to
unwind what we've established so far exactly the way we did the mapping.
This is the PUD part kept deliberately small for easier review.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Handle last level by unconditionally writing the PTEs into the PTE page
while paying attention to the NX bit.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Handle PMD-level mappings the same as PUD ones.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Add the next level of the pagetable populating function, we handle
chunks around a 1G boundary by mapping them with the lower level
functions - otherwise we use 1G pages for the mappings, thus using as
less amount of pagetable pages as possible.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

This allocates, if necessary, and populates the corresponding PGD entry
with a PUD page. The next population level is a dummy macro which will
be removed by the next patch and it is added here to keep the patch
small and easily reviewable but not break bisection, at the same time.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

This is preparatory work in order to be able to map pages into a
specified PGD and not implicitly and only into init_mm.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

... and lose one #ifdef .. #endif sandwich.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

It's incredibly difficult to diagnose early EFI boot issues without
special hardware because earlyprintk=vga doesn't work on EFI systems.

Add support for writing to the EFI framebuffer, via earlyprintk=efi,
which will actually give users a chance of providing debug output.

Cc: H. Peter Anvin <hpa@zytor.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Jones <pjones@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Remove a redundant memset() call from efi_relocate_kernel() that
was clearing memory that would be used by BSS in non-compressed
images loaded with this function.  This clear was redundant with
the clearing done in the image itself, and also implemented incorrectly
with a 0 length.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Acked-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Incorrect use of 0 in terminating entry of arch_tables[] causes the
following sparse warning,

  arch/x86/platform/efi/efi.c:74:27: sparse: Using plain integer as NULL pointer

Replace with NULL.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
[ Included sparse warning in commit message. ]
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

The problem in efi_main was that the idt was cleared before the
interrupts were disabled.

The UEFI spec states that interrupts aren't used so this shouldn't be
too much of a problem. Peripherals however don't necessarily know about
this and thus might cause interrupts to happen anyway. Even if
ExitBootServices() has been called.

This means there is a risk of an interrupt being triggered while the IDT
register is nullified and the interrupt bit hasn't been cleared,
allowing for a triple fault.

This patch disables the interrupt flag, while leaving the existing IDT
in place. The CPU won't care about the IDT at all as long as the
interrupt bit is off, so it's safe to leave it in place as nothing will
ever happen to it.

[ Removed the now unused 'idt' variable - Matt ]
Signed-off-by: Bart Kuivenhoven <bemk@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

This patch fixes a problem with EFI memory maps larger than 128 entries
when booting using the EFI stub, which results in overflowing e820_map
in boot_params and an eventual halt when checking the map size in
sanitize_e820_map().

If the number of map entries is greater than what can fit in e820_map,
add the extra entries to the setup_data list using type SETUP_E820_EXT.
These extra entries are then picked up when the setup_data list is
parsed in parse_e820_ext().
Signed-off-by: Linn Crosetto <linn@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

warnings from gcc:
warning: label 'free_pool' defined but not used [-Wunused-label]
warning: value computed is not used [-Wunused-value]
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

EFI calls can made directly on ARM, so the function pointers
are directly invoked.  This allows types to be checked at
compile time, so here we ensure that the parameters match
the function signature. The wrappers used by x86 prevent
any type checking.
Correct the type of chunksize to be based on native
width as specified by the EFI_FILE_PROTOCOL read()
function.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Rename variables to be not initrd specific, as now the function
loads arbitrary files.  This change is exclusively renames
and comment changes to reflect the generalization.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Acked-by: Mark Salter <msalter@redhat.com>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

The handle_cmdline_files now takes the option to handle as a string,
and returns the loaded data through parameters, rather than taking
an x86 specific setup_header structure.  For ARM, this will be used
to load a device tree blob in addition to initrd images.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Acked-by: Mark Salter <msalter@redhat.com>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Make efi_free() safely callable with size of 0, similar to free() being
callable with NULL pointers, and do nothing in that case.
Remove size checks that this makes redundant.  This also avoids some
size checks in the ARM EFI stub code that will be added as well.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Replace the open-coded memory map getting with the
efi_get_memory_map() that is now general enough to use.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Add arguments for returning the descriptor version and also
the memory map key.  The key is required for calling
exit_boot_services().
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Rename function in preparation for making it more flexible
and sharing it.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Move the open-coded conversion to a shared function for
use by all architectures.  Change the allocation to prefer
a high address for ARM, as this is required to avoid conflicts
with reserved regions in low memory.  We don't know the specifics
of these regions until after we process the command line and
device tree.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Rename relocate_kernel() to efi_relocate_kernel(), and take
parameters rather than x86 specific structure.  Add max_addr
argument as for ARM we have some address constraints that we
need to enforce when relocating the kernel.  Add alloc_size
parameter for use by ARM64 which uses an uncompressed kernel,
and needs to allocate space for BSS.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

The relocate_kernel() function will be generalized and used
by all architectures, as they all have similar requirements.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

The efi_high_alloc() and efi_low_alloc() functions
use the EFI_ALLOCATE_ADDRESS option to the EFI
function allocate_pages(), which requires a minimum
of page alignment, and rejects all other requests.
The existing code could fail to allocate depending
on allocation size, as although repeated allocation
attempts were made, none were guaranteed to be page
aligned.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Acked-by: Mark Salter <msalter@redhat.com>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Rename them to be more similar, as low_free() could be used to free
memory allocated by both high_alloc() and low_alloc().
high_alloc() -> efi_high_alloc()
low_alloc()  -> efi_low_alloc()
low_free()   -> efi_free()
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Acked-by: Mark Salter <msalter@redhat.com>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Add system table pointer argument to shared EFI stub related functions
so they no longer use a global system table pointer as they did when part
of eboot.c.  For the ARM EFI stub this allows us to avoid global
variables completely and thereby not have to deal with GOT fixups.
Not having the EFI stub fixup its GOT, which is shared with the
decompressor, simplifies the relocating of the zImage to a
bootable address.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

No code changes made, just moving functions and #define from x86 arch
directory to common location.  Code is shared using #include, similar
to how decompression code is shared among architectures.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Acked-by: Mark Salter <msalter@redhat.com>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

The x86/AMD64 EFI stubs must use a call wrapper to convert between
the Linux and EFI ABIs, so void pointers are sufficient.  For ARM,
the ABIs are compatible, so we can directly invoke the function
pointers.  The functions that are used by the ARM stub are updated
to match the EFI definitions.
Also add some EFI types used by EFI functions.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Acked-by: Mark Salter <msalter@redhat.com>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Move efi-stub.txt out of x86 directory and into common directory
in preparation for adding ARM EFI stub support.
Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

efi_lookup_mapped_addr() is a handy utility for other platforms than
x86. Move it from arch/x86 to drivers/firmware. Add memmap pointer
to global efi structure, and initialise it on x86.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

Common to (U)EFI support on all platforms is the global "efi" data
structure, and the code that parses the System Table to locate
addresses to populate that structure with.

This patch adds both of these to the global EFI driver code and
removes the local definition of the global "efi" data structure from
the x86 and ia64 code.

Squashed into one big patch to avoid breaking bisection.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

early_ioremap() on IA64 chooses its mapping type based on the EFI
memory map. This patch adds an alias "early_memremap()" to be used
where the targeted location is memory rather than an i/o device.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Acked-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

This fixes the following sparse warning
drivers/firmware/efi/efivars.c:567:6: warning: symbol 'efivars_sysfs_exit' was not declared. Should it be static?
Signed-off-by: Bojan Prtvar <prtvar.b@gmail.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>