linux-kernel - [tip:x86/mm] x86/mm/cpa: Simplify the code after making cpa->vaddr invariant

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Message-ID: <tip-5fe26b7a8f4693d532c7a3c3632e47e7d7016238@git.kernel.org>
Date:   Mon, 17 Dec 2018 10:23:00 -0800
From:   tip-bot for Peter Zijlstra <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     riel@...riel.com, linux-kernel@...r.kernel.org, tglx@...utronix.de,
        luto@...nel.org, dave.hansen@...ux.intel.com, hpa@...or.com,
        torvalds@...ux-foundation.org, bp@...en8.de, mingo@...nel.org,
        peterz@...radead.org
Subject: [tip:x86/mm] x86/mm/cpa: Simplify the code after making cpa->vaddr
 invariant

Commit-ID:  5fe26b7a8f4693d532c7a3c3632e47e7d7016238
Gitweb:     https://git.kernel.org/tip/5fe26b7a8f4693d532c7a3c3632e47e7d7016238
Author:     Peter Zijlstra <peterz@...radead.org>
AuthorDate: Mon, 3 Dec 2018 18:03:48 +0100
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Mon, 17 Dec 2018 18:54:25 +0100

x86/mm/cpa: Simplify the code after making cpa->vaddr invariant

Since cpa->vaddr is invariant, this means we can remove all
workarounds that deal with it changing.

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Rik van Riel <riel@...riel.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Tom.StDenis@....com
Cc: dave.hansen@...el.com
Link: http://lkml.kernel.org/r/20181203171043.366619025@infradead.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/mm/pageattr-test.c |  7 ++-----
 arch/x86/mm/pageattr.c      | 13 ++++---------
 2 files changed, 6 insertions(+), 14 deletions(-)

diff --git a/arch/x86/mm/pageattr-test.c b/arch/x86/mm/pageattr-test.c
index b6b6468530f1..facce271e8b9 100644
--- a/arch/x86/mm/pageattr-test.c
+++ b/arch/x86/mm/pageattr-test.c
@@ -124,7 +124,6 @@ static int pageattr_test(void)
 	unsigned int level;
 	int i, k;
 	int err;
-	unsigned long test_addr;
 
 	if (print)
 		printk(KERN_INFO "CPA self-test:\n");
@@ -181,8 +180,7 @@ static int pageattr_test(void)
 
 		switch (i % 3) {
 		case 0:
-			test_addr = addr[i];
-			err = change_page_attr_set(&test_addr, len[i], PAGE_CPA_TEST, 0);
+			err = change_page_attr_set(&addr[i], len[i], PAGE_CPA_TEST, 0);
 			break;
 
 		case 1:
@@ -226,8 +224,7 @@ static int pageattr_test(void)
 			failed++;
 			continue;
 		}
-		test_addr = addr[i];
-		err = change_page_attr_clear(&test_addr, len[i], PAGE_CPA_TEST, 0);
+		err = change_page_attr_clear(&addr[i], len[i], PAGE_CPA_TEST, 0);
 		if (err < 0) {
 			printk(KERN_ERR "CPA reverting failed: %d\n", err);
 			failed++;
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index ce8af3f08628..afa98b7b6050 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -1908,15 +1908,13 @@ EXPORT_SYMBOL_GPL(set_memory_array_wt);
 int _set_memory_wc(unsigned long addr, int numpages)
 {
 	int ret;
-	unsigned long addr_copy = addr;
 
 	ret = change_page_attr_set(&addr, numpages,
 				   cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS),
 				   0);
 	if (!ret) {
-		ret = change_page_attr_set_clr(&addr_copy, numpages,
-					       cachemode2pgprot(
-						_PAGE_CACHE_MODE_WC),
+		ret = change_page_attr_set_clr(&addr, numpages,
+					       cachemode2pgprot(_PAGE_CACHE_MODE_WC),
 					       __pgprot(_PAGE_CACHE_MASK),
 					       0, 0, NULL);
 	}
@@ -2064,7 +2062,6 @@ int set_memory_global(unsigned long addr, int numpages)
 static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 {
 	struct cpa_data cpa;
-	unsigned long start;
 	int ret;
 
 	/* Nothing to do if memory encryption is not active */
@@ -2075,8 +2072,6 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 	if (WARN_ONCE(addr & ~PAGE_MASK, "misaligned address: %#lx\n", addr))
 		addr &= PAGE_MASK;
 
-	start = addr;
-
 	memset(&cpa, 0, sizeof(cpa));
 	cpa.vaddr = &addr;
 	cpa.numpages = numpages;
@@ -2091,7 +2086,7 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 	/*
 	 * Before changing the encryption attribute, we need to flush caches.
 	 */
-	cpa_flush_range(start, numpages, 1);
+	cpa_flush_range(addr, numpages, 1);
 
 	ret = __change_page_attr_set_clr(&cpa, 1);
 
@@ -2102,7 +2097,7 @@ static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc)
 	 * in case TLB flushing gets optimized in the cpa_flush_range()
 	 * path use the same logic as above.
 	 */
-	cpa_flush_range(start, numpages, 0);
+	cpa_flush_range(addr, numpages, 0);
 
 	return ret;
 }