1 files changed, 29 insertions, 1 deletions

diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index d0bb52296fa..e03530aebfd 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 = .;
@@ -256,11 +267,28 @@ 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)
+                __iommu_table_end = .;
+        }
+        . = ALIGN(8);
+        /*
          * .exit.text is discard at runtime, not link time, to deal with
          *  references from .altinstructions and .eh_frame
          */
@@ -273,7 +301,7 @@ SECTIONS
         }
 
 #if !defined(CONFIG_X86_64) || !defined(CONFIG_SMP)
-        PERCPU(PAGE_SIZE)
+        PERCPU(THREAD_SIZE)
 #endif
 
         . = ALIGN(PAGE_SIZE);