x86: Add comments to the SIPI vector

The Intel SIPI (start-up inter-processor interrupt) vector is the entry
point for each secondary CPU (also called an AP - applications processor).
The assembler and C code are linked, so add comments to indicate this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/arch/x86/cpu/sipi_vector.S b/arch/x86/cpu/sipi_vector.S
index 0c4a157f38153682bba98193068b13f0c3fd8abc..94c0f5a702ba76d606182a2b5147e35f29a9bfbc 100644 (file)
--- a/arch/x86/cpu/sipi_vector.S
+++ b/arch/x86/cpu/sipi_vector.S
@@ -193,6 +193,7 @@ load_msr:
        mov     c_handler, %esi
        call    *%esi
 
+       /* This matches struct sipi_param */
        .align  4
 .globl sipi_params
 sipi_params:

diff --git a/arch/x86/include/asm/sipi.h b/arch/x86/include/asm/sipi.h
index 25d7d311d2cd926f8cf2a6cece807c735332ec1c..da91a485d81f21d77ecf8fa653be28aed73bb473 100644 (file)
--- a/arch/x86/include/asm/sipi.h
+++ b/arch/x86/include/asm/sipi.h
@@ -42,6 +42,7 @@ struct __packed sipi_params_16bit {
  * struct sipi_params - 32-bit SIP entry-point parameters
  *
  * These are used by the AP init code and must be set up before the APs start.
+ * The members must match with the sipi_params layout in sipi_vector.S.
  *
  * The stack area extends down from @stack_top, with @stack_size allocated
  * for each AP.