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| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2010-08-27 14:19:33 -0400 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2010-08-27 18:14:31 -0700 |
| commit | 6f44d0337cc54a46e83b4c8a6195607e78fff71d (patch) | |
| tree | a72545f439eac02ea0a1f519d5ee9bc883f3c094 | |
| parent | ee1f284f38c8dfcbc7b656915a039dde016de7d3 (diff) | |
| download | blackbird-obmc-linux-6f44d0337cc54a46e83b4c8a6195607e78fff71d.tar.gz blackbird-obmc-linux-6f44d0337cc54a46e83b4c8a6195607e78fff71d.zip | |
x86, doc: Adding comments about .iommu_table and its neighbors.
Updating the linker section with comments about .iommu_table and
some other ones that I know of.
CC: Sam Ravnborg <sam@ravnborg.org>
CC: H. Peter Anvin <hpa@zytor.com>
CC: Fujita Tomonori <fujita.tomonori@lab.ntt.co.jp>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
LKML-Reference: <1282933173-19960-1-git-send-email-konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| -rw-r--r-- | arch/x86/kernel/vmlinux.lds.S | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index b92e040466c1..3f07c370f761 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -242,6 +242,12 @@ SECTIONS __x86_cpu_dev_end = .; } + /* + * start address and size of operations which during runtime + * can be patched with virtualization friendly instructions or + * baremetal native ones. Think page table operations. + * Details in paravirt_types.h + */ . = ALIGN(8); .parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) { __parainstructions = .; @@ -249,6 +255,11 @@ SECTIONS __parainstructions_end = .; } + /* + * struct alt_inst entries. From the header (alternative.h): + * "Alternative instructions for different CPU types or capabilities" + * Think locking instructions on spinlocks. + */ . = ALIGN(8); .altinstructions : AT(ADDR(.altinstructions) - LOAD_OFFSET) { __alt_instructions = .; @@ -256,10 +267,21 @@ SECTIONS __alt_instructions_end = .; } + /* + * And here are the replacement instructions. The linker sticks + * them as binary blobs. The .altinstructions has enough data to + * get the address and the length of them to patch the kernel safely. + */ .altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) { *(.altinstr_replacement) } + /* + * struct iommu_table_entry entries are injected in this section. + * It is an array of IOMMUs which during run time gets sorted depending + * on its dependency order. After rootfs_initcall is complete + * this section can be safely removed. + */ .iommu_table : AT(ADDR(.iommu_table) - LOAD_OFFSET) { __iommu_table = .; *(.iommu_table) |
