diff mbox series

[kvm-unit-tests,v3,1/2] arm64: Check if the configured translation granule is supported

Message ID 20201104130352.17633-2-nikos.nikoleris@arm.com (mailing list archive)
State New, archived
Headers show
Series arm64: Add support for configuring the translation granule | expand

Commit Message

Nikos Nikoleris Nov. 4, 2020, 1:03 p.m. UTC 
As arm64 implementations may support a subset of the architecturally
defined granules, we need to check and warn the user if the configured
translation granule is not supported.

Signed-off-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
---
 lib/arm64/asm/processor.h | 36 ++++++++++++++++++++++++++++++++++++
 lib/arm/mmu.c             |  3 +++
 2 files changed, 39 insertions(+)
diff mbox series

Patch

diff --git a/lib/arm64/asm/processor.h b/lib/arm64/asm/processor.h
index 02665b8..9248689 100644
--- a/lib/arm64/asm/processor.h
+++ b/lib/arm64/asm/processor.h
@@ -117,5 +117,41 @@  static inline u64 get_ctr(void)
 
 extern u32 dcache_line_size;
 
+static inline unsigned long get_id_aa64mmfr0_el1(void)
+{
+	return read_sysreg(id_aa64mmfr0_el1);
+}
+
+#define ID_AA64MMFR0_TGRAN4_SHIFT	28
+#define ID_AA64MMFR0_TGRAN64_SHIFT	24
+#define ID_AA64MMFR0_TGRAN16_SHIFT	20
+
+#define ID_AA64MMFR0_TGRAN4_SUPPORTED	0x0
+#define ID_AA64MMFR0_TGRAN64_SUPPORTED	0x0
+#define ID_AA64MMFR0_TGRAN16_SUPPORTED	0x1
+
+static inline bool system_supports_granule(size_t granule)
+{
+	u32 shift;
+	u32 val;
+	u64 mmfr0;
+
+	if (granule == SZ_4K) {
+		shift = ID_AA64MMFR0_TGRAN4_SHIFT;
+		val = ID_AA64MMFR0_TGRAN4_SUPPORTED;
+	} else if (granule == SZ_16K) {
+		shift = ID_AA64MMFR0_TGRAN16_SHIFT;
+		val = ID_AA64MMFR0_TGRAN16_SUPPORTED;
+	} else {
+		assert(granule == SZ_64K);
+		shift = ID_AA64MMFR0_TGRAN64_SHIFT;
+		val = ID_AA64MMFR0_TGRAN64_SUPPORTED;
+	}
+
+	mmfr0 = get_id_aa64mmfr0_el1();
+
+	return ((mmfr0 >> shift) & 0xf) == val;
+}
+
 #endif /* !__ASSEMBLY__ */
 #endif /* _ASMARM64_PROCESSOR_H_ */
diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c
index 540a1e8..a3758a0 100644
--- a/lib/arm/mmu.c
+++ b/lib/arm/mmu.c
@@ -160,6 +160,9 @@  void *setup_mmu(phys_addr_t phys_end)
 
 #ifdef __aarch64__
 	init_alloc_vpage((void*)(4ul << 30));
+
+	assert_msg(system_supports_granule(PAGE_SIZE),
+			"Unsupported translation granule %ld\n", PAGE_SIZE);
 #endif
 
 	mmu_idmap = alloc_page();