linux-kernel - [RFC][PATCH 05/10] x86/mm/cpa: Cleanup...

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Date:   Mon, 03 Dec 2018 18:03:48 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     dave.hansen@...el.com, luto@...nel.org, peterz@...radead.org
Cc:     x86@...nel.org, Tom.StDenis@....com, linux-kernel@...r.kernel.org
Subject: [RFC][PATCH 05/10] x86/mm/cpa: Cleanup...

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>
---
 arch/x86/mm/pageattr-test.c |    7 ++-----
 arch/x86/mm/pageattr.c      |   13 ++++---------
 2 files changed, 6 insertions(+), 14 deletions(-)

--- 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++;
--- 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
 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
 	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
 	/*
 	 * 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
 	 * 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;
 }