@@ -22,6 +22,7 @@ endif
ifneq ($(CONFIG_ARMV7_NONSEC),)
SOBJS += nonsec_virt.o
+COBJS += virt-v7.o
endif
SRCS := $(START:.o=.S) $(COBJS:.o=.c)
new file mode 100644
@@ -0,0 +1,122 @@
+/*
+ * (C) Copyright 2013
+ * Andre Przywara, Linaro
+ *
+ * Routines to transition ARMv7 processors from secure into non-secure state
+ * needed to enable ARMv7 virtualization for current hypervisors
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <asm/armv7.h>
+#include <asm/gic.h>
+#include <asm/io.h>
+
+unsigned long gic_dist_addr;
+
+static unsigned int read_id_pfr1(void)
+{
+ unsigned int reg;
+
+ asm("mrc p15, 0, %0, c0, c1, 1\n" : "=r"(reg));
+ return reg;
+}
+
+static unsigned long get_gicd_base_address(void)
+{
+#ifdef CONFIG_ARM_GIC_BASE_ADDRESS
+ return CONFIG_ARM_GIC_BASE_ADDRESS + GIC_DIST_OFFSET;
+#else
+ unsigned midr;
+ unsigned periphbase;
+
+ /* check whether we are an Cortex-A15 or A7.
+ * The actual HYP switch should work with all CPUs supporting
+ * the virtualization extension, but we need the GIC address,
+ * which we know only for sure for those two CPUs.
+ */
+ asm("mrc p15, 0, %0, c0, c0, 0\n" : "=r"(midr));
+ switch (midr & MIDR_PRIMARY_PART_MASK) {
+ case MIDR_CORTEX_A9_R0P1:
+ case MIDR_CORTEX_A15_R0P0:
+ case MIDR_CORTEX_A7_R0P0:
+ break;
+ default:
+ printf("nonsec: could not determine GIC address.\n");
+ return -1;
+ }
+
+ /* get the GIC base address from the CBAR register */
+ asm("mrc p15, 4, %0, c15, c0, 0\n" : "=r" (periphbase));
+
+ /* the PERIPHBASE can be mapped above 4 GB (lower 8 bits used to
+ * encode this). Bail out here since we cannot access this without
+ * enabling paging.
+ */
+ if ((periphbase & 0xff) != 0) {
+ printf("nonsec: PERIPHBASE is above 4 GB, no access.\n");
+ return -1;
+ }
+
+ return (periphbase & CBAR_MASK) + GIC_DIST_OFFSET;
+#endif
+}
+
+int armv7_switch_nonsec(void)
+{
+ unsigned int reg;
+ unsigned itlinesnr, i;
+
+ /* check whether the CPU supports the security extensions */
+ reg = read_id_pfr1();
+ if ((reg & 0xF0) == 0) {
+ printf("nonsec: Security extensions not implemented.\n");
+ return -1;
+ }
+
+ /* the SCR register will be set directly in the monitor mode handler,
+ * according to the spec one should not tinker with it in secure state
+ * in SVC mode. Do not try to read it once in non-secure state,
+ * any access to it will trap.
+ */
+
+ gic_dist_addr = get_gicd_base_address();
+ if (gic_dist_addr == -1)
+ return -1;
+
+ /* enable the GIC distributor */
+ writel(readl(gic_dist_addr + GICD_CTLR) | 0x03,
+ gic_dist_addr + GICD_CTLR);
+
+ /* TYPER[4:0] contains an encoded number of available interrupts */
+ itlinesnr = readl(gic_dist_addr + GICD_TYPER) & 0x1f;
+
+ /* set all bits in the GIC group registers to one to allow access
+ * from non-secure state. The first 32 interrupts are private per
+ * CPU and will be set later when enabling the GIC for each core
+ */
+ for (i = 1; i <= itlinesnr; i++)
+ writel((unsigned)-1, gic_dist_addr + GICD_IGROUPRn + 4 * i);
+
+ /* call the non-sec switching code on this CPU */
+ _nonsec_init();
+
+ return 0;
+}
@@ -77,6 +77,9 @@ void v7_outer_cache_flush_range(u32 start, u32 end);
void v7_outer_cache_inval_range(u32 start, u32 end);
#ifdef CONFIG_ARMV7_NONSEC
+
+int armv7_switch_nonsec(void);
+
/* defined in assembly file */
unsigned int _nonsec_init(void);
#endif /* CONFIG_ARMV7_NONSEC */
The core specific part of the work is done in the assembly routine in nonsec_virt.S, introduced with the previous patch, but for the full glory we need to setup the GIC distributor interface once for the whole system, which is done in C here. The routine is placed in arch/arm/cpu/armv7 to allow easy access from other ARMv7 boards. We check the availability of the security extensions first. Since we need a safe way to access the GIC, we use the PERIPHBASE registers on Cortex-A15 and A7 CPUs and do some sanity checks. Boards not implementing the CBAR can override this value via a configuration file variable. Then we actually do the GIC enablement: a) enable the GIC distributor, both for non-secure and secure state (GICD_CTLR[1:0] = 11b) b) allow all interrupts to be handled from non-secure state (GICD_IGROUPRn = 0xFFFFFFFF) The core specific GIC setup is then done in the assembly routine. Signed-off-by: Andre Przywara <andre.przywara@linaro.org> --- arch/arm/cpu/armv7/Makefile | 1 + arch/arm/cpu/armv7/virt-v7.c | 122 +++++++++++++++++++++++++++++++++++++++++++ arch/arm/include/asm/armv7.h | 3 ++ 3 files changed, 126 insertions(+) create mode 100644 arch/arm/cpu/armv7/virt-v7.c Changes: v3..v4: w/s fixes, change GIC address variable, embed error reporting, remove bootm part (next patch) v4..v5: only clear unbanked registers during GIC distributor init