I am trying to bring up xen suing u-boot that has this patch. Unfortunately as
soon as the code tries to call _nonsec_init through secure_ram_addr in
arm7_init_nonsec function in virt-v7.c I get an undefined instruction
exception. I suspect the CONFIG_ARMV7_SECURE_BASE needs to be defined to a
particular value. What should that be defined to for omap5432?
Surya
On Saturday, February 15, 2014 at 5:36:30 AM UTC-8, Marc Zyngier wrote:
> 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.zyng...@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 68554c8..ecc25f9 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)
> @@ -185,26 +186,16 @@ 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();
> 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
> }
> --
> 1.8.5.1
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