[tip: x86/cc] powerpc/pseries/svm: Add a powerpc version of cc_platform_has()

[tip-bot2 for Tom Lendacky]

The following commit has been merged into the x86/cc branch of tip:

Commit-ID:     bfebd37e99dece9c83a373cf9f35def440fdd5df
Gitweb:        https://git.kernel.org/tip/bfebd37e99dece9c83a373cf9f35def440fdd5df
Author:        Tom Lendacky <thomas.lendacky@xxxxxxx>
AuthorDate:    Wed, 08 Sep 2021 17:58:35 -05:00
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Mon, 04 Oct 2021 11:46:33 +02:00

powerpc/pseries/svm: Add a powerpc version of cc_platform_has()

Introduce a powerpc version of the cc_platform_has() function. This will
be used to replace the powerpc mem_encrypt_active() implementation, so
the implementation will initially only support the CC_ATTR_MEM_ENCRYPT
attribute.

Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20210928191009.32551-5-bp@xxxxxxxxx
---
 arch/powerpc/platforms/pseries/Kconfig       |  1 +-
 arch/powerpc/platforms/pseries/Makefile      |  2 +-
 arch/powerpc/platforms/pseries/cc_platform.c | 26 +++++++++++++++++++-
 3 files changed, 29 insertions(+)
 create mode 100644 arch/powerpc/platforms/pseries/cc_platform.c

diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig
index 5e037df..2e57391 100644
--- a/arch/powerpc/platforms/pseries/Kconfig
+++ b/arch/powerpc/platforms/pseries/Kconfig
@@ -159,6 +159,7 @@ config PPC_SVM
 	select SWIOTLB
 	select ARCH_HAS_MEM_ENCRYPT
 	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
+	select ARCH_HAS_CC_PLATFORM
 	help
 	 There are certain POWER platforms which support secure guests using
 	 the Protected Execution Facility, with the help of an Ultravisor
diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile
index 4cda0ef..41d8aee 100644
--- a/arch/powerpc/platforms/pseries/Makefile
+++ b/arch/powerpc/platforms/pseries/Makefile
@@ -31,3 +31,5 @@ obj-$(CONFIG_FA_DUMP)		+= rtas-fadump.o
 
 obj-$(CONFIG_SUSPEND)		+= suspend.o
 obj-$(CONFIG_PPC_VAS)		+= vas.o
+
+obj-$(CONFIG_ARCH_HAS_CC_PLATFORM)	+= cc_platform.o
diff --git a/arch/powerpc/platforms/pseries/cc_platform.c b/arch/powerpc/platforms/pseries/cc_platform.c
new file mode 100644
index 0000000..e8021af
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/cc_platform.c
@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Confidential Computing Platform Capability checks
+ *
+ * Copyright (C) 2021 Advanced Micro Devices, Inc.
+ *
+ * Author: Tom Lendacky <thomas.lendacky@xxxxxxx>
+ */
+
+#include <linux/export.h>
+#include <linux/cc_platform.h>
+
+#include <asm/machdep.h>
+#include <asm/svm.h>
+
+bool cc_platform_has(enum cc_attr attr)
+{
+	switch (attr) {
+	case CC_ATTR_MEM_ENCRYPT:
+		return is_secure_guest();
+
+	default:
+		return false;
+	}
+}
+EXPORT_SYMBOL_GPL(cc_platform_has);