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/*
* (C) Copyright 2013
* Andre Przywara, Linaro
*
* Routines to transition ARMv7 processors from secure into non-secure state
* and from non-secure SVC into HYP mode
* 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_cpsr(void)
{
unsigned int reg;
asm volatile ("mrs %0, cpsr\n" : "=r" (reg));
return reg;
}
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
}
static void kick_secondary_cpus_gic(unsigned long gicdaddr)
{
/* kick all CPUs (except this one) by writing to GICD_SGIR */
writel(1U << 24, gicdaddr + GICD_SGIR);
}
void __weak smp_kick_all_cpus(void)
{
kick_secondary_cpus_gic(gic_dist_addr);
}
int armv7_switch_hyp(void)
{
unsigned int reg;
/* check whether we are in HYP mode already */
if ((read_cpsr() & 0x1f) == 0x1a) {
debug("CPU already in HYP mode\n");
return 0;
}
/* check whether the CPU supports the virtualization extensions */
reg = read_id_pfr1();
if ((reg & CPUID_ARM_VIRT_MASK) != 1 << CPUID_ARM_VIRT_SHIFT) {
printf("HYP mode: Virtualization extensions not implemented.\n");
return -1;
}
/* call the HYP switching code on this CPU also */
_switch_to_hyp();
if ((read_cpsr() & 0x1F) != 0x1a) {
printf("HYP mode: switch not successful.\n");
return -1;
}
return 0;
}
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);
smp_set_core_boot_addr((unsigned long)_smp_pen, -1);
smp_kick_all_cpus();
/* call the non-sec switching code on this CPU also */
_nonsec_init();
return 0;
}
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