linux-kernel - [PATCH 4/5] x86/mm: Remove unnecessary call layer for __set_memory_enc

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Message-Id: <1696011549-28036-5-git-send-email-mikelley@microsoft.com>
Date:   Fri, 29 Sep 2023 11:19:08 -0700
From:   Michael Kelley <mikelley@...rosoft.com>
To:     kys@...rosoft.com, haiyangz@...rosoft.com, wei.liu@...nel.org,
        decui@...rosoft.com, tglx@...utronix.de, mingo@...hat.com,
        bp@...en8.de, dave.hansen@...ux.intel.com, hpa@...or.com,
        luto@...nel.org, peterz@...radead.org, thomas.lendacky@....com,
        sathyanarayanan.kuppuswamy@...ux.intel.com,
        kirill.shutemov@...ux.intel.com, seanjc@...gle.com,
        rick.p.edgecombe@...el.com, linux-kernel@...r.kernel.org,
        linux-hyperv@...r.kernel.org, x86@...nel.org
Cc:     mikelley@...rosoft.com
Subject: [PATCH 4/5] x86/mm: Remove unnecessary call layer for __set_memory_enc_pgtable()

__set_memory_enc_pgtable() is only called from __set_memory_enc_dec()
after doing a simple validation check. Prior to commit 812b0597fb40,
__set_memory_enc_dec() did more complex checking, but now the code
can be simplified by collapsing the two functions.

No functional change.

Signed-off-by: Michael Kelley <mikelley@...rosoft.com>
---
 arch/x86/mm/pat/set_memory.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index d062e01..1578077 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -2131,15 +2131,18 @@ int set_memory_global(unsigned long addr, int numpages)
 }
 
 /*
- * __set_memory_enc_pgtable() is used for the hypervisors that get
+ * __set_memory_enc_dec() is used for the hypervisors that get
  * informed about "encryption" status via page tables.
  */
-static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
+static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 {
 	pgprot_t empty = __pgprot(0);
 	struct cpa_data cpa;
 	int ret;
 
+	if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
+		return 0;
+
 	/* Should not be working on unaligned addresses */
 	if (WARN_ONCE(addr & ~PAGE_MASK, "misaligned address: %#lx\n", addr))
 		addr &= PAGE_MASK;
@@ -2200,14 +2203,6 @@ static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc)
 	return set_memory_p(&addr, numpages);
 }
 
-static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
-{
-	if (cc_platform_has(CC_ATTR_MEM_ENCRYPT))
-		return __set_memory_enc_pgtable(addr, numpages, enc);
-
-	return 0;
-}
-
 int set_memory_encrypted(unsigned long addr, int numpages)
 {
 	return __set_memory_enc_dec(addr, numpages, true);
-- 
1.8.3.1