From: Oscar Salvador <osalvador@suse.de>
Date: Fri, 30 Apr 2021 05:57:16 +0000 (-0700)
Subject: x86/vmemmap: drop handling of 1GB vmemmap ranges
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=69ccfe74e16bcb61e4817f78ead31b973c36339c;p=linux.git

x86/vmemmap: drop handling of 1GB vmemmap ranges

There is no code to allocate 1GB pages when mapping the vmemmap range as
this might waste some memory and requires more complexity which is not
really worth.

Drop the dead code both for the aligned and unaligned cases and leave only
the direct map handling.

Link: https://lkml.kernel.org/r/20210309214050.4674-3-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index ff312a87e58d8..af217ff6da577 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -1062,7 +1062,6 @@ remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
 	unsigned long next, pages = 0;
 	pmd_t *pmd_base;
 	pud_t *pud;
-	void *page_addr;
 
 	pud = pud_start + pud_index(addr);
 	for (; addr < end; addr = next, pud++) {
@@ -1071,33 +1070,13 @@ remove_pud_table(pud_t *pud_start, unsigned long addr, unsigned long end,
 		if (!pud_present(*pud))
 			continue;
 
-		if (pud_large(*pud)) {
-			if (IS_ALIGNED(addr, PUD_SIZE) &&
-			    IS_ALIGNED(next, PUD_SIZE)) {
-				if (!direct)
-					free_pagetable(pud_page(*pud),
-						       get_order(PUD_SIZE));
-
-				spin_lock(&init_mm.page_table_lock);
-				pud_clear(pud);
-				spin_unlock(&init_mm.page_table_lock);
-				pages++;
-			} else {
-				/* If here, we are freeing vmemmap pages. */
-				memset((void *)addr, PAGE_INUSE, next - addr);
-
-				page_addr = page_address(pud_page(*pud));
-				if (!memchr_inv(page_addr, PAGE_INUSE,
-						PUD_SIZE)) {
-					free_pagetable(pud_page(*pud),
-						       get_order(PUD_SIZE));
-
-					spin_lock(&init_mm.page_table_lock);
-					pud_clear(pud);
-					spin_unlock(&init_mm.page_table_lock);
-				}
-			}
-
+		if (pud_large(*pud) &&
+		    IS_ALIGNED(addr, PUD_SIZE) &&
+		    IS_ALIGNED(next, PUD_SIZE)) {
+			spin_lock(&init_mm.page_table_lock);
+			pud_clear(pud);
+			spin_unlock(&init_mm.page_table_lock);
+			pages++;
 			continue;
 		}