[U-Boot] [PATCH v4 06/10] ARM: HYP/non-sec: allow relocation to secure RAM
Marc Zyngier
marc.zyngier at arm.com
Sat Apr 26 14:17:07 CEST 2014
The current non-sec switching code suffers from one major issue:
it cannot run in secure RAM, as a large part of u-boot still needs
to be run while we're switched to non-secure.
This patch reworks the whole HYP/non-secure strategy by:
- making sure the secure code is the *last* thing u-boot executes
before entering the payload
- performing an exception return from secure mode directly into
the payload
- allowing the code to be dynamically relocated to secure RAM
before switching to non-secure.
This involves quite a bit of horrible code, specially as u-boot
relocation is quite primitive.
Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
---
arch/arm/cpu/armv7/nonsec_virt.S | 161 +++++++++++++++++++--------------------
arch/arm/cpu/armv7/virt-v7.c | 59 +++++---------
arch/arm/include/asm/armv7.h | 10 ++-
arch/arm/include/asm/secure.h | 26 +++++++
arch/arm/lib/bootm.c | 22 +++---
5 files changed, 138 insertions(+), 140 deletions(-)
create mode 100644 arch/arm/include/asm/secure.h
diff --git a/arch/arm/cpu/armv7/nonsec_virt.S b/arch/arm/cpu/armv7/nonsec_virt.S
index b5c946f..2a43e3c 100644
--- a/arch/arm/cpu/armv7/nonsec_virt.S
+++ b/arch/arm/cpu/armv7/nonsec_virt.S
@@ -10,10 +10,13 @@
#include <linux/linkage.h>
#include <asm/gic.h>
#include <asm/armv7.h>
+#include <asm/proc-armv/ptrace.h>
.arch_extension sec
.arch_extension virt
+ .pushsection ._secure.text, "ax"
+
.align 5
/* the vector table for secure state and HYP mode */
_monitor_vectors:
@@ -22,51 +25,86 @@ _monitor_vectors:
adr pc, _secure_monitor
.word 0
.word 0
- adr pc, _hyp_trap
+ .word 0
.word 0
.word 0
+.macro is_cpu_virt_capable tmp
+ mrc p15, 0, \tmp, c0, c1, 1 @ read ID_PFR1
+ and \tmp, \tmp, #CPUID_ARM_VIRT_MASK @ mask virtualization bits
+ cmp \tmp, #(1 << CPUID_ARM_VIRT_SHIFT)
+.endm
+
/*
* secure monitor handler
* U-boot calls this "software interrupt" in start.S
* This is executed on a "smc" instruction, we use a "smc #0" to switch
* to non-secure state.
- * We use only r0 and r1 here, due to constraints in the caller.
+ * r0, r1, r2: passed to the callee
+ * ip: target PC
*/
_secure_monitor:
- mrc p15, 0, r1, c1, c1, 0 @ read SCR
- bic r1, r1, #0x4e @ clear IRQ, FIQ, EA, nET bits
- orr r1, r1, #0x31 @ enable NS, AW, FW bits
+ mrc p15, 0, r5, c1, c1, 0 @ read SCR
+ bic r5, r5, #0x4e @ clear IRQ, FIQ, EA, nET bits
+ orr r5, r5, #0x31 @ enable NS, AW, FW bits
- mrc p15, 0, r0, c0, c1, 1 @ read ID_PFR1
- and r0, r0, #CPUID_ARM_VIRT_MASK @ mask virtualization bits
- cmp r0, #(1 << CPUID_ARM_VIRT_SHIFT)
+ mov r6, #SVC_MODE @ default mode is SVC
+ is_cpu_virt_capable r4
#ifdef CONFIG_ARMV7_VIRT
- orreq r1, r1, #0x100 @ allow HVC instruction
+ orreq r5, r5, #0x100 @ allow HVC instruction
+ moveq r6, #HYP_MODE @ Enter the kernel as HYP
#endif
- mcr p15, 0, r1, c1, c1, 0 @ write SCR (with NS bit set)
+ mcr p15, 0, r5, c1, c1, 0 @ write SCR (with NS bit set)
isb
-#ifdef CONFIG_ARMV7_VIRT
- mrceq p15, 0, r0, c12, c0, 1 @ get MVBAR value
- mcreq p15, 4, r0, c12, c0, 0 @ write HVBAR
-#endif
bne 1f
@ Reset CNTVOFF to 0 before leaving monitor mode
- mrc p15, 0, r0, c0, c1, 1 @ read ID_PFR1
- ands r0, r0, #CPUID_ARM_GENTIMER_MASK @ test arch timer bits
- movne r0, #0
- mcrrne p15, 4, r0, r0, c14 @ Reset CNTVOFF to zero
+ mrc p15, 0, r4, c0, c1, 1 @ read ID_PFR1
+ ands r4, r4, #CPUID_ARM_GENTIMER_MASK @ test arch timer bits
+ movne r4, #0
+ mcrrne p15, 4, r4, r4, c14 @ Reset CNTVOFF to zero
1:
- movs pc, lr @ return to non-secure SVC
-
-_hyp_trap:
- mrs lr, elr_hyp @ for older asm: .byte 0x00, 0xe3, 0x0e, 0xe1
- mov pc, lr @ do no switch modes, but
- @ return to caller
-
+ mov lr, ip
+ mov ip, #(F_BIT | I_BIT | A_BIT) @ Set A, I and F
+ tst lr, #1 @ Check for Thumb PC
+ orrne ip, ip, #T_BIT @ Set T if Thumb
+ orr ip, ip, r6 @ Slot target mode in
+ msr spsr_cxfs, ip @ Set full SPSR
+ movs pc, lr @ ERET to non-secure
+
+ENTRY(_do_nonsec_entry)
+ mov ip, r0
+ mov r0, r1
+ mov r1, r2
+ mov r2, r3
+ smc #0
+ENDPROC(_do_nonsec_entry)
+
+.macro get_cbar_addr addr
+#ifdef CONFIG_ARM_GIC_BASE_ADDRESS
+ ldr \addr, =CONFIG_ARM_GIC_BASE_ADDRESS
+#else
+ mrc p15, 4, \addr, c15, c0, 0 @ read CBAR
+ bfc \addr, #0, #15 @ clear reserved bits
+#endif
+.endm
+
+.macro get_gicd_addr addr
+ get_cbar_addr \addr
+ add \addr, \addr, #GIC_DIST_OFFSET @ GIC dist i/f offset
+.endm
+
+.macro get_gicc_addr addr, tmp
+ get_cbar_addr \addr
+ is_cpu_virt_capable \tmp
+ movne \tmp, #GIC_CPU_OFFSET_A9 @ GIC CPU offset for A9
+ moveq \tmp, #GIC_CPU_OFFSET_A15 @ GIC CPU offset for A15/A7
+ add \addr, \addr, \tmp
+.endm
+
+#ifndef CONFIG_ARMV7_PSCI
/*
* Secondary CPUs start here and call the code for the core specific parts
* of the non-secure and HYP mode transition. The GIC distributor specific
@@ -74,31 +112,21 @@ _hyp_trap:
* Then they go back to wfi and wait to be woken up by the kernel again.
*/
ENTRY(_smp_pen)
- mrs r0, cpsr
- orr r0, r0, #0xc0
- msr cpsr, r0 @ disable interrupts
- ldr r1, =_start
- mcr p15, 0, r1, c12, c0, 0 @ set VBAR
+ cpsid i
+ cpsid f
bl _nonsec_init
- mov r12, r0 @ save GICC address
-#ifdef CONFIG_ARMV7_VIRT
- bl _switch_to_hyp
-#endif
-
- ldr r1, [r12, #GICC_IAR] @ acknowledge IPI
- str r1, [r12, #GICC_EOIR] @ signal end of interrupt
adr r0, _smp_pen @ do not use this address again
b smp_waitloop @ wait for IPIs, board specific
ENDPROC(_smp_pen)
+#endif
/*
* Switch a core to non-secure state.
*
* 1. initialize the GIC per-core interface
* 2. allow coprocessor access in non-secure modes
- * 3. switch the cpu mode (by calling "smc #0")
*
* Called from smp_pen by secondary cores and directly by the BSP.
* Do not assume that the stack is available and only use registers
@@ -108,38 +136,23 @@ ENDPROC(_smp_pen)
* though, but we check this in C before calling this function.
*/
ENTRY(_nonsec_init)
-#ifdef CONFIG_ARM_GIC_BASE_ADDRESS
- ldr r2, =CONFIG_ARM_GIC_BASE_ADDRESS
-#else
- mrc p15, 4, r2, c15, c0, 0 @ read CBAR
- bfc r2, #0, #15 @ clear reserved bits
-#endif
- add r3, r2, #GIC_DIST_OFFSET @ GIC dist i/f offset
+ get_gicd_addr r3
+
mvn r1, #0 @ all bits to 1
str r1, [r3, #GICD_IGROUPRn] @ allow private interrupts
- mrc p15, 0, r0, c0, c0, 0 @ read MIDR
- ldr r1, =MIDR_PRIMARY_PART_MASK
- and r0, r0, r1 @ mask out variant and revision
+ get_gicc_addr r3, r1
- ldr r1, =MIDR_CORTEX_A7_R0P0 & MIDR_PRIMARY_PART_MASK
- cmp r0, r1 @ check for Cortex-A7
-
- ldr r1, =MIDR_CORTEX_A15_R0P0 & MIDR_PRIMARY_PART_MASK
- cmpne r0, r1 @ check for Cortex-A15
-
- movne r1, #GIC_CPU_OFFSET_A9 @ GIC CPU offset for A9
- moveq r1, #GIC_CPU_OFFSET_A15 @ GIC CPU offset for A15/A7
- add r3, r2, r1 @ r3 = GIC CPU i/f addr
-
- mov r1, #1 @ set GICC_CTLR[enable]
+ mov r1, #3 @ Enable both groups
str r1, [r3, #GICC_CTLR] @ and clear all other bits
mov r1, #0xff
str r1, [r3, #GICC_PMR] @ set priority mask register
+ mrc p15, 0, r0, c1, c1, 2
movw r1, #0x3fff
- movt r1, #0x0006
- mcr p15, 0, r1, c1, c1, 2 @ NSACR = all copros to non-sec
+ movt r1, #0x0004
+ orr r0, r0, r1
+ mcr p15, 0, r0, c1, c1, 2 @ NSACR = all copros to non-sec
/* The CNTFRQ register of the generic timer needs to be
* programmed in secure state. Some primary bootloaders / firmware
@@ -157,21 +170,9 @@ ENTRY(_nonsec_init)
adr r1, _monitor_vectors
mcr p15, 0, r1, c12, c0, 1 @ set MVBAR to secure vectors
-
- mrc p15, 0, ip, c12, c0, 0 @ save secure copy of VBAR
-
isb
- smc #0 @ call into MONITOR mode
-
- mcr p15, 0, ip, c12, c0, 0 @ write non-secure copy of VBAR
-
- mov r1, #1
- str r1, [r3, #GICC_CTLR] @ enable non-secure CPU i/f
- add r2, r2, #GIC_DIST_OFFSET
- str r1, [r2, #GICD_CTLR] @ allow private interrupts
mov r0, r3 @ return GICC address
-
bx lr
ENDPROC(_nonsec_init)
@@ -183,18 +184,10 @@ ENTRY(smp_waitloop)
ldr r1, [r1]
cmp r0, r1 @ make sure we dont execute this code
beq smp_waitloop @ again (due to a spurious wakeup)
- mov pc, r1
+ mov r0, r1
+ b _do_nonsec_entry
ENDPROC(smp_waitloop)
.weak smp_waitloop
#endif
-ENTRY(_switch_to_hyp)
- mov r0, lr
- mov r1, sp @ save SVC copy of LR and SP
- isb
- hvc #0 @ for older asm: .byte 0x70, 0x00, 0x40, 0xe1
- mov sp, r1
- mov lr, r0 @ restore SVC copy of LR and SP
-
- bx lr
-ENDPROC(_switch_to_hyp)
+ .popsection
diff --git a/arch/arm/cpu/armv7/virt-v7.c b/arch/arm/cpu/armv7/virt-v7.c
index 2cd604f..6500030 100644
--- a/arch/arm/cpu/armv7/virt-v7.c
+++ b/arch/arm/cpu/armv7/virt-v7.c
@@ -13,17 +13,10 @@
#include <asm/armv7.h>
#include <asm/gic.h>
#include <asm/io.h>
+#include <asm/secure.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;
@@ -72,6 +65,18 @@ static unsigned long get_gicd_base_address(void)
#endif
}
+static void relocate_secure_section(void)
+{
+#ifdef CONFIG_ARMV7_SECURE_BASE
+ size_t sz = __secure_end - __secure_start;
+
+ memcpy((void *)CONFIG_ARMV7_SECURE_BASE, __secure_start, sz);
+ flush_dcache_range(CONFIG_ARMV7_SECURE_BASE,
+ CONFIG_ARMV7_SECURE_BASE + sz + 1);
+ invalidate_icache_all();
+#endif
+}
+
static void kick_secondary_cpus_gic(unsigned long gicdaddr)
{
/* kick all CPUs (except this one) by writing to GICD_SGIR */
@@ -83,35 +88,7 @@ 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)
+int armv7_init_nonsec(void)
{
unsigned int reg;
unsigned itlinesnr, i;
@@ -147,11 +124,13 @@ int armv7_switch_nonsec(void)
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);
+#ifndef CONFIG_ARMV7_PSCI
+ smp_set_core_boot_addr((unsigned long)secure_ram_addr(_smp_pen), -1);
smp_kick_all_cpus();
+#endif
/* call the non-sec switching code on this CPU also */
- _nonsec_init();
-
+ relocate_secure_section();
+ secure_ram_addr(_nonsec_init)();
return 0;
}
diff --git a/arch/arm/include/asm/armv7.h b/arch/arm/include/asm/armv7.h
index 395444e..11476dd 100644
--- a/arch/arm/include/asm/armv7.h
+++ b/arch/arm/include/asm/armv7.h
@@ -78,13 +78,17 @@ void v7_outer_cache_inval_range(u32 start, u32 end);
#if defined(CONFIG_ARMV7_NONSEC) || defined(CONFIG_ARMV7_VIRT)
-int armv7_switch_nonsec(void);
-int armv7_switch_hyp(void);
+int armv7_init_nonsec(void);
/* defined in assembly file */
unsigned int _nonsec_init(void);
+void _do_nonsec_entry(void *target_pc, unsigned long r0,
+ unsigned long r1, unsigned long r2);
void _smp_pen(void);
-void _switch_to_hyp(void);
+
+extern char __secure_start[];
+extern char __secure_end[];
+
#endif /* CONFIG_ARMV7_NONSEC || CONFIG_ARMV7_VIRT */
#endif /* ! __ASSEMBLY__ */
diff --git a/arch/arm/include/asm/secure.h b/arch/arm/include/asm/secure.h
new file mode 100644
index 0000000..effdb18
--- /dev/null
+++ b/arch/arm/include/asm/secure.h
@@ -0,0 +1,26 @@
+#ifndef __ASM_SECURE_H
+#define __ASM_SECURE_H
+
+#include <config.h>
+
+#ifdef CONFIG_ARMV7_SECURE_BASE
+/*
+ * Warning, horror ahead.
+ *
+ * The target code lives in our "secure ram", but u-boot doesn't know
+ * that, and has blindly added reloc_off to every relocation
+ * entry. Gahh. Do the opposite conversion. This hack also prevents
+ * GCC from generating code veeners, which u-boot doesn't relocate at
+ * all...
+ */
+#define secure_ram_addr(_fn) ({ \
+ DECLARE_GLOBAL_DATA_PTR; \
+ void *__fn = _fn; \
+ typeof(_fn) *__tmp = (__fn - gd->reloc_off); \
+ __tmp; \
+ })
+#else
+#define secure_ram_addr(_fn) (_fn)
+#endif
+
+#endif
diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index 10634a4..61aa14e 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -20,6 +20,7 @@
#include <libfdt.h>
#include <fdt_support.h>
#include <asm/bootm.h>
+#include <asm/secure.h>
#include <linux/compiler.h>
#if defined(CONFIG_ARMV7_NONSEC) || defined(CONFIG_ARMV7_VIRT)
@@ -184,27 +185,17 @@ static void setup_end_tag(bd_t *bd)
__weak void setup_board_tags(struct tag **in_params) {}
+#ifdef CONFIG_ARM64
static void do_nonsec_virt_switch(void)
{
-#if defined(CONFIG_ARMV7_NONSEC) || defined(CONFIG_ARMV7_VIRT)
- if (armv7_switch_nonsec() == 0)
-#ifdef CONFIG_ARMV7_VIRT
- if (armv7_switch_hyp() == 0)
- debug("entered HYP mode\n");
-#else
- debug("entered non-secure state\n");
-#endif
-#endif
-
-#ifdef CONFIG_ARM64
smp_kick_all_cpus();
flush_dcache_all(); /* flush cache before swtiching to EL2 */
armv8_switch_to_el2();
#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
armv8_switch_to_el1();
#endif
-#endif
}
+#endif
/* Subcommand: PREP */
static void boot_prep_linux(bootm_headers_t *images)
@@ -287,8 +278,13 @@ static void boot_jump_linux(bootm_headers_t *images, int flag)
r2 = gd->bd->bi_boot_params;
if (!fake) {
- do_nonsec_virt_switch();
+#if defined(CONFIG_ARMV7_NONSEC) || defined(CONFIG_ARMV7_VIRT)
+ armv7_init_nonsec();
+ secure_ram_addr(_do_nonsec_entry)(kernel_entry,
+ 0, machid, r2);
+#else
kernel_entry(0, machid, r2);
+#endif
}
#endif
}
--
1.9.2
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