If enter virtual mode failed due to some reason other than the efi call
the EFI_RUNTIME_SERVICES bit in efi.flags should be cleared thus users
of efi runtime services can check the bit and handle the case instead of
assume efi runtime is ok.

Per Matt, if efi call SetVirtualAddressMap fails we will be not sure
it's safe to make any assumptions about the state of the system. So
kernel panics instead of clears EFI_RUNTIME_SERVICES bit.
Signed-off-by: NDave Young <dyoung@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

noefi kernel param means actually disabling efi runtime, Per suggestion
from Leif Lindholm efi=noruntime should be better. But since noefi is
already used in X86 thus just adding another param efi=noruntime for
same purpose.
Signed-off-by: NDave Young <dyoung@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

There should be a generic function to parse params like a=b,c
Adding parse_option_str in lib/cmdline.c which will return true
if there's specified option set in the params.

Also updated efi=old_map parsing code to use the new function
Signed-off-by: NDave Young <dyoung@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

noefi param can be used for arches other than X86 later, thus move it
out of x86 platform code.
Signed-off-by: NDave Young <dyoung@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

We need a way to customize the behaviour of the EFI boot stub, in
particular, we need a way to disable the "chunking" workaround, used
when reading files from the EFI System Partition.

One of my machines doesn't cope well when reading files in 1MB chunks to
a buffer above the 4GB mark - it appears that the "chunking" bug
workaround triggers another firmware bug. This was only discovered with
commit 4bf7111f ("x86/efi: Support initrd loaded above 4G"), and
that commit is perfectly valid. The symptom I observed was a corrupt
initrd rather than any kind of crash.

efi= is now used to specify EFI parameters in two very different
execution environments, the EFI boot stub and during kernel boot.

There is also a slight performance optimization by enabling efi=nochunk,
but that's offset by the fact that you're more likely to run into
firmware issues, at least on x86. This is the rationale behind leaving
the workaround enabled by default.

Also provide some documentation for EFI_READ_CHUNK_SIZE and why we're
using the current value of 1MB.
Tested-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Roy Franz <roy.franz@linaro.org>
Cc: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

efi_set_rtc_mmss() is never used to set RTC due to bugs found
on many EFI platforms. It is set directly by mach_set_rtc_mmss().
Hence, remove unused efi_set_rtc_mmss() function.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Remove redundant set_bit(EFI_MEMMAP, &efi.flags) call.
It is executed earlier in efi_memmap_init().
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Remove redundant set_bit(EFI_SYSTEM_TABLES, &efi.flags) call.
It is executed earlier in efi_systab_init().
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Introduce EFI_PARAVIRT flag. If it is set then kernel runs
on EFI platform but it has not direct control on EFI stuff
like EFI runtime, tables, structures, etc. If not this means
that Linux Kernel has direct access to EFI infrastructure
and everything runs as usual.

This functionality is used in Xen dom0 because hypervisor
has full control on EFI stuff and all calls from dom0 to
EFI must be requested via special hypercall which in turn
executes relevant EFI code in behalf of dom0.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Do not access EFI memory map if it is not available. At least
Xen dom0 EFI implementation does not have an access to it.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Use early_mem*() instead of early_io*() because all mapped EFI regions
are memory (usually RAM but they could also be ROM, EPROM, EEPROM, flash,
etc.) not I/O regions. Additionally, I/O family calls do not work correctly
under Xen in our case. early_ioremap() skips the PFN to MFN conversion
when building the PTE. Using it for memory will attempt to map the wrong
machine frame. However, all artificial EFI structures created under Xen
live in dom0 memory and should be mapped/unmapped using early_mem*() family
calls which map domain memory.
Signed-off-by: NDaniel Kiper <daniel.kiper@oracle.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Mark Salter <msalter@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

In order for other archs (such as arm64) to be able to reuse the virtual
mode function call wrappers, move them to drivers/firmware/efi/runtime-wrappers.c.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Currently, it's difficult to find all the workarounds that are
applied when running on EFI, because they're littered throughout
various code paths. This change moves all of them into a separate
file with the hope that it will be come the single location for all
our well documented quirks.
Signed-off-by: NSaurabh Tangri <saurabh.tangri@intel.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

For ioremapped efi memory aka old_map the virt addresses are not persistant
across kexec reboot. kexec-tools will read the runtime maps from sysfs then
pass them to 2nd kernel and assuming kexec efi boot is ok. This will cause
kexec boot failure.

To address this issue do not export runtime maps in case efi old_map so
userspace can use no efi boot instead.
Signed-off-by: NDave Young <dyoung@redhat.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

For i386, all the EFI system runtime services functions return efi_status_t
except efi_reset_system_system. Therefore, not all functions can be covered
by the same macro in case the macro needs to do more than calling the function
(i.e., return a value). The purpose of the __efi_call_virt macro is to be used
when no return value is expected.

For x86_64, this macro would not be needed as all the runtime services return
u64. However, the same code is used for both x86_64 and i386. Thus, the macro
__efi_call_virt is also defined to not break compilation.
Signed-off-by: NRicardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

We really only need one phys and one virt function call, and then only
one assembly function to make firmware calls.

Since we are not using the C type system anyway, we're not really losing
much by deleting the macros apart from no longer having a check that
we are passing the correct number of parameters. The lack of duplicated
code seems like a worthwhile trade-off.

Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Dan reported that phys_efi_get_time() is doing kmalloc(..., GFP_KERNEL)
under a spinlock which is very clearly a bug. Since phys_efi_get_time()
has no users let's just delete it instead of trying to fix it.

Note that since there are no users of phys_efi_get_time(), it is not
possible to actually trigger a GFP_KERNEL alloc under the spinlock.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Nathan Zimmer <nzimmer@sgi.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Jan Beulich <JBeulich@suse.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Alex reported hitting the following BUG after the EFI 1:1 virtual
mapping work was merged,

 kernel BUG at arch/x86/mm/init_64.c:351!
 invalid opcode: 0000 [#1] SMP
 Call Trace:
  [<ffffffff818aa71d>] init_extra_mapping_uc+0x13/0x15
  [<ffffffff818a5e20>] uv_system_init+0x22b/0x124b
  [<ffffffff8108b886>] ? clockevents_register_device+0x138/0x13d
  [<ffffffff81028dbb>] ? setup_APIC_timer+0xc5/0xc7
  [<ffffffff8108b620>] ? clockevent_delta2ns+0xb/0xd
  [<ffffffff818a3a92>] ? setup_boot_APIC_clock+0x4a8/0x4b7
  [<ffffffff8153d955>] ? printk+0x72/0x74
  [<ffffffff818a1757>] native_smp_prepare_cpus+0x389/0x3d6
  [<ffffffff818957bc>] kernel_init_freeable+0xb7/0x1fb
  [<ffffffff81535530>] ? rest_init+0x74/0x74
  [<ffffffff81535539>] kernel_init+0x9/0xff
  [<ffffffff81541dfc>] ret_from_fork+0x7c/0xb0
  [<ffffffff81535530>] ? rest_init+0x74/0x74

Getting this thing to work with the new mapping scheme would need more
work, so automatically switch to the old memmap layout for SGI UV.
Acked-by: NRuss Anderson <rja@sgi.com>
Cc: Alex Thorlton <athorlton@sgi.com
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Add the Kconfig option and bump the kernel header version so that boot
loaders can check whether the handover code is available if they want.

The xloadflags field in the bzImage header is also updated to reflect
that the kernel supports both entry points by setting both of
XLF_EFI_HANDOVER_32 and XLF_EFI_HANDOVER_64 when CONFIG_EFI_MIXED=y.
XLF_CAN_BE_LOADED_ABOVE_4G is disabled so that the kernel text is
guaranteed to be addressable with 32-bits.

Note that no boot loaders should be using the bits set in xloadflags to
decide which entry point to jump to. The entire scheme is based on the
concept that 32-bit bootloaders always jump to ->handover_offset and
64-bit loaders always jump to ->handover_offset + 512. We set both bits
merely to inform the boot loader that it's safe to use the native
handover offset even if the machine type in the PE/COFF header claims
otherwise.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Setup the runtime services based on whether we're booting in EFI native
mode or not. For non-native mode we need to thunk from 64-bit into
32-bit mode before invoking the EFI runtime services.

Using the runtime services after SetVirtualAddressMap() is slightly more
complicated because we need to ensure that all the addresses we pass to
the firmware are below the 4GB boundary so that they can be addressed
with 32-bit pointers, see efi_setup_page_tables().
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Both efi_free_boot_services() and efi_enter_virtual_mode() are invoked
from init/main.c, but only if the EFI runtime services are available.
This is not the case for non-native boots, e.g. where a 64-bit kernel is
booted with 32-bit EFI firmware.

Delete the dead code.
Acked-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

... into a kexec flavor for better code readability and simplicity. The
original one was getting ugly with ifdeffery.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Tested-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Currently, running SetVirtualAddressMap() and passing the physical
address of the virtual map array was working only by a lucky coincidence
because the memory was present in the EFI page table too. Until Toshi
went and booted this on a big HP box - the krealloc() manner of resizing
the memmap we're doing did allocate from such physical addresses which
were not mapped anymore and boom:

http://lkml.kernel.org/r/1386806463.1791.295.camel@misato.fc.hp.com

One way to take care of that issue is to reimplement the krealloc thing
but with pages. We start with contiguous pages of order 1, i.e. 2 pages,
and when we deplete that memory (shouldn't happen all that often but you
know firmware) we realloc the next power-of-two pages.

Having the pages, it is much more handy and easy to map them into the
EFI page table with the already existing mapping code which we're using
for building the virtual mappings.

Thanks to Toshi Kani and Matt for the great debugging help.
Reported-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Tested-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

This is very useful for debugging issues with the recently added
pagetable switching code for EFI virtual mode.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Tested-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Coalesce formats and remove spaces before tabs.
Move __initdata after the variable declaration.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

For now we only ensure about 5kb free space for avoiding our board
refusing boot. But the comment lies that we retain 50% space.
Signed-off-by: NMadper Xie <cxie@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

It makes more sense to set the feature flag in the success path of the
detection function than it does to rely on the caller doing it. Apart
from it being more logical to group the code and data together, it sets
a much better example for new EFI architectures.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

As we grow support for more EFI architectures they're going to want the
ability to query which EFI features are available on the running system.
Instead of storing this information in an architecture-specific place,
stick it in the global 'struct efi', which is already the central
location for EFI state.

While we're at it, let's change the return value of efi_enabled() to be
bool and replace all references to 'facility' with 'feature', which is
the usual word used to describe the attributes of the running system.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

We do not enable the new efi memmap on 32-bit and thus we need to run
runtime_code_page_mkexec() unconditionally there. Fix that.
Reported-and-tested-by: NLejun Zhu <lejun.zhu@intel.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

There's no need to save the runtime map details in global variables, the
values are only required to pass to efi_runtime_map_setup().

And because 'nr_efi_runtime_map' isn't needed, get_nr_runtime_map() can
be deleted along with 'efi_data_len'.

Cc: Dave Young <dyoung@redhat.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Add a new setup_data type SETUP_EFI for kexec use.  Passing the saved
fw_vendor, runtime, config tables and EFI runtime mappings.

When entering virtual mode, directly mapping the EFI runtime regions
which we passed in previously. And skip the step to call
SetVirtualAddressMap().

Specially for HP z420 workstation we need save the smbios physical
address.  The kernel boot sequence proceeds in the following order.
Step 2 requires efi.smbios to be the physical address.  However, I found
that on HP z420 EFI system table has a virtual address of SMBIOS in step
1.  Hence, we need set it back to the physical address with the smbios
in efi_setup_data.  (When it is still the physical address, it simply
sets the same value.)

1. efi_init() - Set efi.smbios from EFI system table
2. dmi_scan_machine() - Temporary map efi.smbios to access SMBIOS table
3. efi_enter_virtual_mode() - Map EFI ranges

Tested on ovmf+qemu, lenovo thinkpad, a dell laptop and an
HP z420 workstation.
Signed-off-by: NDave Young <dyoung@redhat.com>
Tested-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

kexec kernel will need exactly same mapping for EFI runtime memory
ranges. Thus here export the runtime ranges mapping to sysfs,
kexec-tools will assemble them and pass to 2nd kernel via setup_data.

Introducing a new directory /sys/firmware/efi/runtime-map just like
/sys/firmware/memmap. Containing below attribute in each file of that
directory:

attribute  num_pages  phys_addr  type  virt_addr
Signed-off-by: NDave Young <dyoung@redhat.com>
Tested-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Export fw_vendor, runtime and config table physical addresses to
/sys/firmware/efi/{fw_vendor,runtime,config_table} because kexec kernels
need them.

From EFI spec these 3 variables will be updated to virtual address after
entering virtual mode. But kernel startup code will need the physical
address.
Signed-off-by: NDave Young <dyoung@redhat.com>
Tested-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Add two small functions:
efi_merge_regions() and efi_map_regions(), efi_enter_virtual_mode()
calls them instead of embedding two long for loop.
Signed-off-by: NDave Young <dyoung@redhat.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Tested-by: NToshi Kani <toshi.kani@hp.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

Current code check boot service region with kernel text region by:
start+size >= __pa_symbol(_text)
The end of the above region should be start + size - 1 instead.

I see this problem in ovmf + Fedora 19 grub boot:
text start: 1000000 md start: 800000 md size: 800000
Signed-off-by: NDave Young <dyoung@redhat.com>
Acked-by: NBorislav Petkov <bp@suse.de>
Acked-by: NToshi Kani <toshi.kani@hp.com>
Tested-by: NToshi Kani <toshi.kani@hp.com>
Cc: stable@vger.kernel.org
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

UEFI time services are often broken once we're in virtual mode. We were
already refusing to use them on 64-bit systems, but it turns out that
they're also broken on some 32-bit firmware, including the Dell Venue.
Disable them for now, we can revisit once we have the 1:1 mappings code
incorporated.
Signed-off-by: NMatthew Garrett <matthew.garrett@nebula.com>
Link: http://lkml.kernel.org/r/1385754283-2464-1-git-send-email-matthew.garrett@nebula.com
Cc: <stable@vger.kernel.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

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

... and lose one #ifdef .. #endif sandwich.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Signed-off-by: NMatt 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: NLeif Lindholm <leif.lindholm@linaro.org>
[ Included sparse warning in commit message. ]
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>