Linux-libre 4.6.2-gnu

1 files changed, 80 insertions, 0 deletions

diff --git a/arch/arm64/kvm/hyp/s2-setup.c b/arch/arm64/kvm/hyp/s2-setup.c
new file mode 100644
index 000000000..bcbe761a5
--- /dev/null
+++ b/arch/arm64/kvm/hyp/s2-setup.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2016 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/types.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_hyp.h>
+
+u32 __hyp_text __init_stage2_translation(void)
+{
+	u64 val = VTCR_EL2_FLAGS;
+	u64 parange;
+	u64 tmp;
+
+	/*
+	 * Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS
+	 * bits in VTCR_EL2. Amusingly, the PARange is 4 bits, while
+	 * PS is only 3. Fortunately, bit 19 is RES0 in VTCR_EL2...
+	 */
+	parange = read_sysreg(id_aa64mmfr0_el1) & 7;
+	val |= parange << 16;
+
+	/* Compute the actual PARange... */
+	switch (parange) {
+	case 0:
+		parange = 32;
+		break;
+	case 1:
+		parange = 36;
+		break;
+	case 2:
+		parange = 40;
+		break;
+	case 3:
+		parange = 42;
+		break;
+	case 4:
+		parange = 44;
+		break;
+	case 5:
+	default:
+		parange = 48;
+		break;
+	}
+
+	/*
+	 * ... and clamp it to 40 bits, unless we have some braindead
+	 * HW that implements less than that. In all cases, we'll
+	 * return that value for the rest of the kernel to decide what
+	 * to do.
+	 */
+	val |= 64 - (parange > 40 ? 40 : parange);
+
+	/*
+	 * Read the VMIDBits bits from ID_AA64MMFR1_EL1 and set the VS
+	 * bit in VTCR_EL2.
+	 */
+	tmp = (read_sysreg(id_aa64mmfr1_el1) >> ID_AA64MMFR1_VMIDBITS_SHIFT) & 0xf;
+	val |= (tmp == ID_AA64MMFR1_VMIDBITS_16) ?
+			VTCR_EL2_VS_16BIT :
+			VTCR_EL2_VS_8BIT;
+
+	write_sysreg(val, vtcr_el2);
+
+	return parange;
+}