From 2130a790ca49763f724ec45cf93b9dd765e2023e Mon Sep 17 00:00:00 2001
From: Juergen Gross
Date: Thu, 2 Jun 2022 15:05:26 +0200
Subject: kernel: add platform_has() infrastructure

Add a simple infrastructure for setting, resetting and querying
platform feature flags.

Flags can be either global or architecture specific.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 only
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Juergen Gross <jgross@suse.com>
---
 kernel/platform-feature.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 kernel/platform-feature.c

(limited to 'kernel/platform-feature.c')

diff --git a/kernel/platform-feature.c b/kernel/platform-feature.c
new file mode 100644
index 000000000000..cb6a6c3e4fed
--- /dev/null
+++ b/kernel/platform-feature.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/bitops.h>
+#include <linux/cache.h>
+#include <linux/export.h>
+#include <linux/platform-feature.h>
+
+#define PLATFORM_FEAT_ARRAY_SZ  BITS_TO_LONGS(PLATFORM_FEAT_N)
+static unsigned long __read_mostly platform_features[PLATFORM_FEAT_ARRAY_SZ];
+
+void platform_set(unsigned int feature)
+{
+	set_bit(feature, platform_features);
+}
+EXPORT_SYMBOL_GPL(platform_set);
+
+void platform_clear(unsigned int feature)
+{
+	clear_bit(feature, platform_features);
+}
+EXPORT_SYMBOL_GPL(platform_clear);
+
+bool platform_has(unsigned int feature)
+{
+	return test_bit(feature, platform_features);
+}
+EXPORT_SYMBOL_GPL(platform_has);
-- 
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