[PATCH V7 03/18] x86/pks: Add additional PKEY helper macros

From: ira . weiny
Date: Wed Aug 04 2021 - 00:32:55 EST


From: Ira Weiny <ira.weiny@xxxxxxxxx>

Avoid open coding shift and mask operations by defining and using helper
macros for PKey operations.

Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
---
arch/x86/include/asm/pkeys_common.h | 6 +++++-
arch/x86/include/asm/pkru.h | 6 ++----
arch/x86/mm/pkeys.c | 8 +++-----
3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/arch/x86/include/asm/pkeys_common.h b/arch/x86/include/asm/pkeys_common.h
index f3277717faeb..8a3c6d2e6a8a 100644
--- a/arch/x86/include/asm/pkeys_common.h
+++ b/arch/x86/include/asm/pkeys_common.h
@@ -6,6 +6,10 @@
#define PKR_WD_BIT 0x2
#define PKR_BITS_PER_PKEY 2

-#define PKR_AD_KEY(pkey) (PKR_AD_BIT << ((pkey) * PKR_BITS_PER_PKEY))
+#define PKR_PKEY_SHIFT(pkey) (pkey * PKR_BITS_PER_PKEY)
+#define PKR_PKEY_MASK(pkey) (((1 << PKR_BITS_PER_PKEY) - 1) << PKR_PKEY_SHIFT(pkey))
+
+#define PKR_AD_KEY(pkey) (PKR_AD_BIT << PKR_PKEY_SHIFT(pkey))
+#define PKR_WD_KEY(pkey) (PKR_WD_BIT << PKR_PKEY_SHIFT(pkey))

#endif /*_ASM_X86_PKEYS_COMMON_H */
diff --git a/arch/x86/include/asm/pkru.h b/arch/x86/include/asm/pkru.h
index a74325b0d1df..fb44ff542028 100644
--- a/arch/x86/include/asm/pkru.h
+++ b/arch/x86/include/asm/pkru.h
@@ -15,15 +15,13 @@ extern u32 init_pkru_value;

static inline bool __pkru_allows_read(u32 pkru, u16 pkey)
{
- int pkru_pkey_bits = pkey * PKR_BITS_PER_PKEY;
- return !(pkru & (PKR_AD_BIT << pkru_pkey_bits));
+ return !(pkru & PKR_AD_KEY(pkey));
}

static inline bool __pkru_allows_write(u32 pkru, u16 pkey)
{
- int pkru_pkey_bits = pkey * PKR_BITS_PER_PKEY;
/* Access-disable disables writes too so check both bits here. */
- return !(pkru & ((PKR_AD_BIT|PKR_WD_BIT) << pkru_pkey_bits));
+ return !(pkru & (PKR_AD_KEY(pkey) | PKR_WD_KEY(pkey)));
}

static inline u32 read_pkru(void)
diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c
index ca2e20b18645..75437aa8fc56 100644
--- a/arch/x86/mm/pkeys.c
+++ b/arch/x86/mm/pkeys.c
@@ -200,16 +200,14 @@ __setup("init_pkru=", setup_init_pkru);
*/
u32 update_pkey_val(u32 pk_reg, int pkey, unsigned int flags)
{
- int pkey_shift = pkey * PKR_BITS_PER_PKEY;
-
/* Mask out old bit values */
- pk_reg &= ~(((1 << PKR_BITS_PER_PKEY) - 1) << pkey_shift);
+ pk_reg &= ~PKR_PKEY_MASK(pkey);

/* Or in new values */
if (flags & PKEY_DISABLE_ACCESS)
- pk_reg |= PKR_AD_BIT << pkey_shift;
+ pk_reg |= PKR_AD_KEY(pkey);
if (flags & PKEY_DISABLE_WRITE)
- pk_reg |= PKR_WD_BIT << pkey_shift;
+ pk_reg |= PKR_WD_KEY(pkey);

return pk_reg;
}
--
2.28.0.rc0.12.gb6a658bd00c9