linux/drivers/firmware, branch v3.18

Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2014-10-23T21:45:09Z

Pull x86 EFI updates from Peter Anvin: "This patchset falls under the "maintainers that grovel" clause in the v3.18-rc1 announcement. We had intended to push it late in the merge window since we got it into the -tip tree relatively late. Many of these are relatively simple things, but there are a couple of key bits, especially Ard's and Matt's patches" * 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) rtc: Disable EFI rtc for x86 efi: rtc-efi: Export platform:rtc-efi as module alias efi: Delete the in_nmi() conditional runtime locking efi: Provide a non-blocking SetVariable() operation x86/efi: Adding efi_printks on memory allocationa and pci.reads x86/efi: Mark initialization code as such x86/efi: Update comment regarding required phys mapped EFI services x86/efi: Unexport add_efi_memmap variable x86/efi: Remove unused efi_call* macros efi: Resolve some shadow warnings arm64: efi: Format EFI memory type & attrs with efi_md_typeattr_format() ia64: efi: Format EFI memory type & attrs with efi_md_typeattr_format() x86: efi: Format EFI memory type & attrs with efi_md_typeattr_format() efi: Introduce efi_md_typeattr_format() efi: Add macro for EFI_MEMORY_UCE memory attribute x86/efi: Clear EFI_RUNTIME_SERVICES if failing to enter virtual mode arm64/efi: Do not enter virtual mode if booting with efi=noruntime or noefi arm64/efi: uefi_init error handling fix efi: Add kernel param efi=noruntime lib: Add a generic cmdline parse function parse_option_str ...

drivers/firmware/memmap.c: don't create memmap sysfs of same firmware_map_entry

2014-10-10T02:26:00Z

By the following commits, we prevented from allocating firmware_map_entry of same memory range: f0093ede: drivers/firmware/memmap.c: don't allocate firmware_map_entry of same memory range 49c8b24d: drivers/firmware/memmap.c: pass the correct argument to firmware_map_find_entry_bootmem() But it's not enough. When PNP0C80 device is added by acpi_scan_init(), memmap sysfses of same firmware_map_entry are created twice as follows: # cat /sys/firmware/memmap/*/start 0x40000000000 0x60000000000 0x4a837000 0x4a83a000 0x4a8b5000 ... 0x40000000000 0x60000000000 ... The flows of the issues are as follows: 1. e820_reserve_resources() allocates firmware_map_entrys of all memory ranges defined in e820. And, these firmware_map_entrys are linked with map_entries list. map_entries -> entry 1 -> ... -> entry N 2. When PNP0C80 device is limited by mem= boot option, acpi_scan_init() added the memory device. In this case, firmware_map_add_hotplug() allocates firmware_map_entry and creates memmap sysfs. map_entries -> entry 1 -> ... -> entry N -> entry N+1 | memmap 1 3. firmware_memmap_init() creates memmap sysfses of firmware_map_entrys linked with map_entries. map_entries -> entry 1 -> ... -> entry N -> entry N+1 | | | memmap 2 memmap N+1 memmap 1 memmap N+2 So while hot removing the PNP0C80 device, kernel panic occurs as follows: BUG: unable to handle kernel paging request at 00000001003e000b IP: sysfs_open_file+0x46/0x2b0 PGD 203a89fe067 PUD 0 Oops: 0000 [#1] SMP ... Call Trace: do_dentry_open+0x1ef/0x2a0 finish_open+0x31/0x40 do_last+0x57c/0x1220 path_openat+0xc2/0x4c0 do_filp_open+0x4b/0xb0 do_sys_open+0xf3/0x1f0 SyS_open+0x1e/0x20 system_call_fastpath+0x16/0x1b The patch adds a check of confirming whether memmap sysfs of firmware_map_entry has been created, and does not create memmap sysfs of same firmware_map_entry. Signed-off-by: Yasuaki Ishimatsu Cc: Santosh Shilimkar Cc: Toshi Kani Cc: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'next' into efi-next-merge

2014-10-03T21:15:56Z

Conflicts: arch/x86/boot/compressed/eboot.c

efi: Delete the in_nmi() conditional runtime locking

2014-10-03T17:41:03Z

commit 5dc3826d9f08 ("efi: Implement mandatory locking for UEFI Runtime Services") implemented some conditional locking when accessing variable runtime services that Ingo described as "pretty disgusting". The intention with the !efi_in_nmi() checks was to avoid live-locks when trying to write pstore crash data into an EFI variable. Such lockless accesses are allowed according to the UEFI specification when we're in a "non-recoverable" state, but whether or not things are implemented correctly in actual firmware implementations remains an unanswered question, and so it would seem sensible to avoid doing any kind of unsynchronized variable accesses. Furthermore, the efi_in_nmi() tests are inadequate because they don't account for the case where we call EFI variable services from panic or oops callbacks and aren't executing in NMI context. In other words, live-locking is still possible. Let's just remove the conditional locking altogether. Now we've got the ->set_variable_nonblocking() EFI variable operation we can abort if the runtime lock is already held. Aborting is by far the safest option. Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Ard Biesheuvel Cc: Matthew Garrett Signed-off-by: Matt Fleming

efi: Provide a non-blocking SetVariable() operation

2014-10-03T17:41:03Z

There are some circumstances that call for trying to write an EFI variable in a non-blocking way. One such scenario is when writing pstore data in efi_pstore_write() via the pstore_dump() kdump callback. Now that we have an EFI runtime spinlock we need a way of aborting if there is contention instead of spinning, since when writing pstore data from the kdump callback, the runtime lock may already be held by the CPU that's running the callback if we crashed in the middle of an EFI variable operation. The situation is sufficiently special that a new EFI variable operation is warranted. Introduce ->set_variable_nonblocking() for this use case. It is an optional EFI backend operation, and need only be implemented by those backends that usually acquire locks to serialize access to EFI variables, as is the case for virt_efi_set_variable() where we now grab the EFI runtime spinlock. Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Ard Biesheuvel Cc: Matthew Garrett Signed-off-by: Matt Fleming

efi: Resolve some shadow warnings

2014-10-03T17:41:01Z

It is a really bad idea to declare variables or parameters that have the same name as common types. It is valid C, but it gets surprising if a macro expansion attempts to declare an inner local with that type. Change the local names to eliminate the hazard. Change s16 => str16, s8 => str8. This resolves warnings seen when using W=2 during make, for instance: drivers/firmware/efi/vars.c: In function ‘dup_variable_bug’: drivers/firmware/efi/vars.c:324:44: warning: declaration of ‘s16’ shadows a global declaration [-Wshadow] static void dup_variable_bug(efi_char16_t *s16, efi_guid_t *vendor_guid, drivers/firmware/efi/vars.c:328:8: warning: declaration of ‘s8’ shadows a global declaration [-Wshadow] char *s8; Signed-off-by: Mark Rustad Signed-off-by: Jeff Kirsher Signed-off-by: Matt Fleming

efi: Introduce efi_md_typeattr_format()

2014-10-03T17:41:00Z

At the moment, there are three architectures debug-printing the EFI memory map at initialization: x86, ia64, and arm64. They all use different format strings, plus the EFI memory type and the EFI memory attributes are similarly hard to decode for a human reader. Introduce a helper __init function that formats the memory type and the memory attributes in a unified way, to a user-provided character buffer. The array "memory_type_name" is copied from the arm64 code, temporarily duplicating it. The (otherwise optional) braces around each string literal in the initializer list are dropped in order to match the kernel coding style more closely. The element size is tightened from 32 to 20 bytes (maximum actual string length + 1) so that we can derive the field width from the element size. Signed-off-by: Laszlo Ersek Tested-by: Ard Biesheuvel Acked-by: Ard Biesheuvel [ Dropped useless 'register' keyword, which compiler will ignore ] Signed-off-by: Matt Fleming

efi: Add kernel param efi=noruntime

2014-10-03T17:40:59Z

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: Dave Young Signed-off-by: Matt Fleming

efi: Move noefi early param code out of x86 arch code

2014-10-03T17:40:58Z

noefi param can be used for arches other than X86 later, thus move it out of x86 platform code. Signed-off-by: Dave Young Signed-off-by: Matt Fleming

efi: Add efi= parameter parsing to the EFI boot stub

2014-10-03T17:40:57Z

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 4bf7111f5016 ("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: Ard Biesheuvel Cc: Roy Franz Cc: Maarten Lankhorst Cc: Leif Lindholm Cc: Borislav Petkov Signed-off-by: Matt Fleming