linux/arch/x86
Ingo Molnar 5da217ca96 x86/boot/e820: Rename early_reserve_e820() to e820__memblock_alloc() and document it
early_reserve_e820() is an early hack for kexec that does a limited fixup of the
mptable and passes it to the kexec kernel as if it was the real thing.

For this it needs to allocate memory - but no memory allocator is available yet
beyond the memblock allocator, so early_reserve_e820() is really a wrapper
around memblock_alloc() plus a hack to update the e820_table_firmware entries.

The name 'reserve' is really a bit of a misnomer, as 'reserved' memory typically
means memory completely inaccessible to the kernel - while here what we want to do
is a special RAM allocation for our own purposes and insert that as RAM_RESERVED.

Rename the function to e820__memblock_alloc_reserved() to better signal this dual
purpose, plus document it better, which was omitted when it was merged. The barely
comprehensible and cryptic comment:

  /*
   * pre allocated 4k and reserved it in memblock and e820_table_firmware
   */
  u64 __init e820__memblock_alloc_reserved(u64 size, u64 align)

... does not count as documentation, replace it with:

  /*
   * Allocate the requested number of bytes with the requsted alignment
   * and return (the physical address) to the caller. Also register this
   * range in the 'firmware' E820 table.
   *
   * This allows kexec to fake a new mptable, as if it came from the real
   * system.
   */
  u64 __init e820__memblock_alloc_reserved(u64 size, u64 align)

No change in functionality.

Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28 14:42:30 +01:00
..
boot x86/boot/e820: Rename everything to e820_table 2017-01-28 09:33:16 +01:00
configs IOMMU Updates for Linux v4.9 2016-10-11 12:52:41 -07:00
crypto crypto: aesni - Fix failure when built-in with modular pcbc 2016-12-30 18:20:45 +08:00
entry x86/entry: Fix the end of the stack for newly forked tasks 2017-01-12 09:28:29 +01:00
events Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-01-18 11:13:41 -08:00
ia32 Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
include x86/boot/e820: Rename early_reserve_e820() to e820__memblock_alloc() and document it 2017-01-28 14:42:30 +01:00
kernel x86/boot/e820: Rename early_reserve_e820() to e820__memblock_alloc() and document it 2017-01-28 14:42:30 +01:00
kvm KVM: x86: fix fixing of hypercalls 2017-01-17 15:06:05 +01:00
lguest x86/boot/e820: Rename everything to e820_table 2017-01-28 09:33:16 +01:00
lib x86/boot/e820: Move asm/e820.h to asm/e820/api.h 2017-01-28 09:31:13 +01:00
math-emu Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
mm x86/boot/e820: Move the memblock_find_dma_reserve() function and rename it to memblock_set_dma_reserve() 2017-01-28 14:42:28 +01:00
net bpf: change back to orig prog on too many passes 2017-01-08 17:00:18 -05:00
oprofile x86/oprofile/nmi: Convert to hotplug state machine 2016-11-22 23:34:43 +01:00
pci x86/boot/e820: Remove spurious asm/e820/api.h inclusions 2017-01-28 09:31:14 +01:00
platform x86/boot/e820: Harmonize the 'struct e820_table' fields 2017-01-28 09:33:16 +01:00
power x86/boot/e820: Rename e820_table_saved to e820_table_firmware and improve the description 2017-01-28 14:42:27 +01:00
purgatory x86/kexec: add -fno-PIE 2016-11-09 22:28:09 +01:00
ras x86/RAS: Add TSC timestamp to the injected MCE 2016-11-08 17:10:13 +01:00
realmode x86/build: Don't use $(LINUXINCLUDE) twice 2016-11-28 07:49:17 +01:00
tools x86/tools: Fix gcc-7 warning in relocs.c 2016-12-19 11:50:24 +01:00
um Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
video
xen x86/boot/e820: Harmonize the 'struct e820_table' fields 2017-01-28 09:33:16 +01:00
.gitignore
Kbuild
Kconfig Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-22 09:25:45 -08:00
Kconfig.cpu
Kconfig.debug
Makefile lib/raid6: Add AVX512 optimized gen_syndrome functions 2016-09-21 09:09:44 -07:00
Makefile_32.cpu
Makefile.um