[RFC v5 15/38] powerpc: helper function to read,write AMR,IAMR,UAMOR registers

From: Ram Pai
Date: Wed Jul 05 2017 - 17:31:10 EST


Implements helper functions to read and write the key related
registers; AMR, IAMR, UAMOR.

AMR register tracks the read,write permission of a key
IAMR register tracks the execute permission of a key
UAMOR register enables and disables a key

Signed-off-by: Ram Pai <linuxram@xxxxxxxxxx>
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 60 ++++++++++++++++++++++++++
1 files changed, 60 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 85bc987..435d6a7 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -428,6 +428,66 @@ static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
pte_update(mm, addr, ptep, 0, _PAGE_PRIVILEGED, 1);
}

+#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
+
+#include <asm/reg.h>
+static inline u64 read_amr(void)
+{
+ return mfspr(SPRN_AMR);
+}
+static inline void write_amr(u64 value)
+{
+ mtspr(SPRN_AMR, value);
+}
+static inline u64 read_iamr(void)
+{
+ return mfspr(SPRN_IAMR);
+}
+static inline void write_iamr(u64 value)
+{
+ mtspr(SPRN_IAMR, value);
+}
+static inline u64 read_uamor(void)
+{
+ return mfspr(SPRN_UAMOR);
+}
+static inline void write_uamor(u64 value)
+{
+ mtspr(SPRN_UAMOR, value);
+}
+
+#else /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
+static inline u64 read_amr(void)
+{
+ WARN(1, "%s called with MEMORY PROTECTION KEYS disabled\n", __func__);
+ return -1;
+}
+static inline void write_amr(u64 value)
+{
+ WARN(1, "%s called with MEMORY PROTECTION KEYS disabled\n", __func__);
+}
+static inline u64 read_uamor(void)
+{
+ WARN(1, "%s called with MEMORY PROTECTION KEYS disabled\n", __func__);
+ return -1;
+}
+static inline void write_uamor(u64 value)
+{
+ WARN(1, "%s called with MEMORY PROTECTION KEYS disabled\n", __func__);
+}
+static inline u64 read_iamr(void)
+{
+ WARN(1, "%s called with MEMORY PROTECTION KEYS disabled\n", __func__);
+ return -1;
+}
+static inline void write_iamr(u64 value)
+{
+ WARN(1, "%s called with MEMORY PROTECTION KEYS disabled\n", __func__);
+}
+
+#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
+
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
--
1.7.1