AGESA f15: Drop CAR teardown without POSTCAR_STAGE

Change-Id: Ie5ff62ee1c7ca193ba841c5b2fb20940ec657625
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/21467
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

1 files changed, 4 insertions, 45 deletions

diff --git a/src/vendorcode/amd/agesa/f15/gcccar.inc b/src/vendorcode/amd/agesa/f15/gcccar.inc
index 5076272e11..b5f8fddcbf 100644
--- a/src/vendorcode/amd/agesa/f15/gcccar.inc
+++ b/src/vendorcode/amd/agesa/f15/gcccar.inc
@@ -361,13 +361,6 @@ fam10_enable_stack_hook_exit:
 *   Return any family specific controls to their 'standard'
 *   settings for using cache with main memory.
 *
-* Note: Customized for coreboot:
-*   A wbinvd is used to send cache to memory.  The existing stack is preserved
-*   at its original location and additional information is preserved (e.g.
-*   coreboot CAR globals, heap structures, etc.). This implementation should
-*   NOT be used with S3 resume IF the stack/cache area is not reserved and
-*   over system memory.
-*
 * Inputs:
 *       ESI - [31:24] flags; [15,8]= Node#; [7,0]= core#
 * Outputs:
@@ -427,18 +420,7 @@ fam10_enable_stack_hook_exit:
     mov     %ax, %bx                      # Save INVD -> WBINVD bit
     btr    $INVD_WBINVD, %eax            # Disable INVD -> WBINVD conversion for the invd instruction.
     _WRMSR
-
-    #--------------------------------------------------------------------------
-    # Send cache to memory. Preserve stack and coreboot CAR globals.
-    # This shouldn't be used with S3 resume IF the stack/cache area is
-    # not reserved and over system memory.
-    #--------------------------------------------------------------------------
-#if !IS_ENABLED(CONFIG_POSTCAR_STAGE)
-    wbinvd
-#else
-    invd
-#endif
-
+    invd                                # Clear the cache tag RAMs
     mov    %bx, %ax                      # Restore INVD -> WBINVD bit
     _WRMSR
 
@@ -957,13 +939,6 @@ fam15_enable_stack_hook_exit:
 *   Return any family specific controls to their 'standard'
 *   settings for using cache with main memory.
 *
-* Note: Customized for coreboot:
-*   A wbinvd is used to send cache to memory.  The existing stack is preserved
-*   at its original location and additional information is preserved (e.g.
-*   coreboot CAR globals, heap structures, etc.). This implementation should
-*   NOT be used with S3 resume IF the stack/cache area is not reserved and
-*   over system memory.
-*
 * Inputs:
 *       ESI - [31:24] flags; [15,8]= Node#; [7,0]= core#
 * Outputs:
@@ -1022,14 +997,7 @@ fam15_enable_stack_hook_exit:
     _RDMSR
     btr     $INVD_WBINVD, %eax            # Disable INVD -> WBINVD conversion
     _WRMSR
-
-    #--------------------------------------------------------------------------
-    # Send cache to memory. Preserve stack and coreboot CAR globals.
-    # This shouldn't be used with S3 resume IF the stack/cache area is
-    # not reserved and over system memory.
-    #--------------------------------------------------------------------------
-    wbinvd
-
+    invd                                # Clear the cache tag RAMs
     bts     $INVD_WBINVD, %eax            # Turn on Conversion of INVD to WBINVD
     _WRMSR
     #.endif                              # end
@@ -1606,17 +1574,8 @@ ClearTheStack:                          # Stack base is in SS, stack pointer is
 .endm
 
 /*****************************************************************************
-* AMD_DISABLE_STACK:  Implementation is modified for coreboot from
-*                     the original AMD intent.  A WBINVD is used in the HOOK
-*                     to send dirty cache contents to DRAM backing before
-*                     disabling cache-as-ram.  This is not safe for S3 resume.
-*
-*                     todo:
-*                       * rework PI/AGESA source to set DRAM to UC to send
-*                         writes directly to memory
-*                       * move DCACHE_BASE or use postcar stage for teardown
-*                         to eliminate car_migrated problem that will occur
-*                         after wbinvd is changed back to invd
+* AMD_DISABLE_STACK:  Destroy the stack inside the cache. This routine
+*                     should only be executed on the BSP
 *
 *   In:
 *       none