[RFC][PATCH 10/24] x86/cea: Refactor stack mapping macros

[Dave Hansen <dave.hansen@linux.intel.com>]

Continuing the trend, the stack mapping macros can currently
only work with the "_stack" structure member. Make them more
flexible by taking a partial structure member name.

Also make the mapping permission explicit. This will allow
shadow stack permission mappings in the near future.

This does make following the macro maze a bit harder. But,
in the end, it's quite readable to have code that looks like
this:

	cea_map_stack(MCE, stack, PAGE_KERNEL);
vs.
	cea_map_stack(MCE, shadow_stack, PAGE_KERNEL_SHSTK);


---

 b/arch/x86/mm/cpu_entry_area.c |   20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff -puN arch/x86/mm/cpu_entry_area.c~cea-estacks-shadows-refactor-0 arch/x86/mm/cpu_entry_area.c
--- a/arch/x86/mm/cpu_entry_area.c~cea-estacks-shadows-refactor-0	2026-10-21 12:36:37.273879808 -0700
+++ b/arch/x86/mm/cpu_entry_area.c	2026-10-21 12:36:37.275879812 -0700
@@ -130,10 +130,10 @@ static void __init percpu_setup_debug_st
 
 #ifdef CONFIG_X86_64
 
-#define cea_map_stack(name) do {					\
-	npages = sizeof(estacks->name## _stack) / PAGE_SIZE;		\
-	cea_map_percpu_pages(cea->estacks.name## _stack,		\
-			estacks->name## _stack, npages, PAGE_KERNEL);	\
+#define cea_map_stack(name, member, perm) do {				\
+	npages = sizeof(estacks->name## _ ##member) / PAGE_SIZE;	\
+	cea_map_percpu_pages(cea->estacks.name## _ ##member,		\
+			estacks->name## _ ##member, npages, perm);	\
 	} while (0)
 
 static void __init percpu_setup_exception_stacks(unsigned int cpu)
@@ -151,15 +151,15 @@ static void __init percpu_setup_exceptio
 	 * by guard pages so each stack must be mapped separately. DB2 is
 	 * not mapped; it just exists to catch triple nesting of #DB.
 	 */
-	cea_map_stack(DF);
-	cea_map_stack(NMI);
-	cea_map_stack(DB);
-	cea_map_stack(MCE);
+	cea_map_stack(DF,  stack, PAGE_KERNEL);
+	cea_map_stack(NMI, stack, PAGE_KERNEL);
+	cea_map_stack(DB,  stack, PAGE_KERNEL);
+	cea_map_stack(MCE, stack, PAGE_KERNEL);
 
 	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
 		if (cc_platform_has(CC_ATTR_GUEST_STATE_ENCRYPT)) {
-			cea_map_stack(VC);
-			cea_map_stack(VC2);
+			cea_map_stack(VC,  stack, PAGE_KERNEL);
+			cea_map_stack(VC2, stack, PAGE_KERNEL);
 		}
 	}
 }
_