[bootwrapper PATCH v3 11/15] aarch64: move the bulk of EL3 initialization to C
Andre Przywara
andre.przywara at arm.com
Wed Jan 26 08:36:02 PST 2022
On Tue, 25 Jan 2022 15:00:53 +0000
Mark Rutland <mark.rutland at arm.com> wrote:
> The majority of state that we initialize at EL3 is necessary for code at
> lower ELs to function, but isnt' necessary for the boot-wrapper itself.
> Given that, it would be better to write this in C where it can be
> written mode clearly, and where it will be possible to add logging/debug
> logic.
>
> This patch migrates the AArch64 EL3 initialization to C.
>
> There should be no functional change as a result of this patch.
>
> Signed-off-by: Mark Rutland <mark.rutland at arm.com>
With the changes it looks good now, also checked for the BRBE addition.
Reviewed-by: Andre Przywara <andre.przywara at arm.com>
Cheers,
Andre
> ---
> Makefile.am | 2 +-
> arch/aarch64/boot.S | 100 +--------------------------------
> arch/aarch64/include/asm/cpu.h | 35 +++++++++++-
> arch/aarch64/init.c | 72 ++++++++++++++++++++++++
> 4 files changed, 109 insertions(+), 100 deletions(-)
>
> diff --git a/Makefile.am b/Makefile.am
> index 5a0ebd2..a5e8e8b 100644
> --- a/Makefile.am
> +++ b/Makefile.am
> @@ -155,7 +155,7 @@ $(COMMON_SRC):
> %.o: %.S Makefile | $(ARCH_SRC)
> $(CC) $(CPPFLAGS) -D__ASSEMBLY__ $(CFLAGS) $(DEFINES) -c -o $@ $<
>
> -%.o: %.c Makefile | $(COMMON_SRC)
> +%.o: %.c Makefile | $(ARCH_SRC) $(COMMON_SRC)
> $(CC) $(CPPFLAGS) $(CFLAGS) $(DEFINES) -c -o $@ $<
>
> model.lds: $(LD_SCRIPT) Makefile
> diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S
> index 7872daf..c0ec518 100644
> --- a/arch/aarch64/boot.S
> +++ b/arch/aarch64/boot.S
> @@ -45,104 +45,6 @@ reset_at_el3:
> msr sctlr_el3, x0
> isb
>
> - mov x0, #0x30 // RES1
> - orr x0, x0, #(1 << 0) // Non-secure EL1
> - orr x0, x0, #(1 << 8) // HVC enable
> -
> - /* Enable pointer authentication if present */
> - mrs x1, id_aa64isar1_el1
> - /* We check for APA+API and GPA+GPI */
> - ldr x2, =((0xff << 24) | (0xff << 4))
> - and x1, x1, x2
> - cbz x1, 1f
> -
> - orr x0, x0, #(1 << 16) // AP key enable
> - orr x0, x0, #(1 << 17) // AP insn enable
> -1:
> - /* Enable TME if present */
> - mrs x1, id_aa64isar0_el1
> - ubfx x1, x1, #24, #4
> - cbz x1, 1f
> -
> - orr x0, x0, #(1 << 34) // TME enable
> -1:
> - /* Enable FGT if present */
> - mrs x1, id_aa64mmfr0_el1
> - ubfx x1, x1, #56, #4
> - cbz x1, 1f
> -
> - orr x0, x0, #(1 << 27) // FGT enable
> -1:
> - /* Enable ECV2 if present (allows CNTPOFF_EL2) */
> - mrs x1, id_aa64mmfr0_el1
> - ubfx x1, x1, #60, #4
> - cmp x1, #2
> - b.lt 1f
> -
> - orr x0, x0, #(1 << 28) // ECV enable
> -1:
> - /* Enable MTE if present */
> - mrs x10, id_aa64pfr1_el1
> - ubfx x10, x10, #8, #4
> - cmp x10, #2
> - b.lt 1f
> -
> - orr x0, x0, #(1 << 26) // ATA enable
> -1:
> -#ifndef KERNEL_32
> - orr x0, x0, #(1 << 10) // 64-bit EL2
> -#endif
> - msr scr_el3, x0
> -
> - msr cptr_el3, xzr // Disable copro. traps to EL3
> -
> - mov x0, xzr
> - mrs x1, id_aa64dfr0_el1
> - ubfx x1, x1, #32, #4
> - cbz x1, 1f
> -
> - // Enable SPE for the non-secure world.
> - orr x0, x0, #(0x3 << 12)
> -
> - // Do not trap PMSNEVFR_EL1 if present
> - cmp x1, #3
> - b.lt 1f
> - orr x0, x0, #(1 << 36)
> -
> -1: mrs x1, id_aa64dfr0_el1
> - ubfx x1, x1, #44, #4
> - cbz x1, 1f
> -
> - // Enable TRBE for the non-secure world.
> - ldr x1, =(0x3 << 24)
> - orr x0, x0, x1
> -
> -1: mrs x1, id_aa64dfr0_el1
> - ubfx x1, x1, #52, #4
> - cbz x1, 1f
> -
> - // Enable BRBE for the non-secure world.
> - ldr x1, =(0x3 << 32)
> - orr x0, x0, x1
> -
> -1: msr mdcr_el3, x0 // Disable traps to EL3
> -
> - mrs x0, id_aa64pfr0_el1
> - ubfx x0, x0, #32, #4 // SVE present?
> - cbz x0, 1f // Skip SVE init if not
> -
> - mrs x0, cptr_el3
> - orr x0, x0, #CPTR_EL3_EZ // enable SVE
> - msr cptr_el3, x0
> - isb
> -
> - mov x0, #ZCR_EL3_LEN_MAX // SVE: Enable full vector len
> - msr ZCR_EL3, x0 // for EL2.
> -
> -1:
> - ldr x0, =COUNTER_FREQ
> - msr cntfrq_el0, x0
> -
> cpuid x0, x1
> bl find_logical_id
> cmp x0, #MPIDR_INVALID
> @@ -151,6 +53,8 @@ reset_at_el3:
>
> bl cpu_init_bootwrapper
>
> + bl cpu_init_el3
> +
> bl gic_secure_init
>
> b start_el3
> diff --git a/arch/aarch64/include/asm/cpu.h b/arch/aarch64/include/asm/cpu.h
> index 0a4085b..1be2d54 100644
> --- a/arch/aarch64/include/asm/cpu.h
> +++ b/arch/aarch64/include/asm/cpu.h
> @@ -34,7 +34,40 @@
> (BIT(29) | BIT(28) | BIT(23) | BIT(22) | BIT(20) | BIT(11) | \
> BIT(8) | BIT(7) | BIT(4))
>
> -#define HCR_EL2_RES1 (BIT(1))
> +#define MDCR_EL3_NSPB_NS_NOTRAP (UL(3) << 12)
> +#define MDCR_EL3_NSTB_NS_NOTRAP (UL(3) << 24)
> +#define MDCR_EL3_SBRBE_NOTRAP_NOPROHIBIT (UL(3) << 32)
> +#define MDCR_EL3_ENPMSN BIT(36)
> +
> +#define SCR_EL3_RES1 BITS(5, 4)
> +#define SCR_EL3_NS BIT(0)
> +#define SCR_EL3_HCE BIT(8)
> +#define SCR_EL3_RW BIT(10)
> +#define SCR_EL3_APK BIT(16)
> +#define SCR_EL3_API BIT(17)
> +#define SCR_EL3_ATA BIT(26)
> +#define SCR_EL3_FGTEN BIT(27)
> +#define SCR_EL3_ECVEN BIT(28)
> +#define SCR_EL3_TME BIT(34)
> +
> +#define HCR_EL2_RES1 BIT(1)
> +
> +#define ID_AA64DFR0_EL1_PMSVER BITS(35, 32)
> +#define ID_AA64DFR0_EL1_TRACEBUFFER BITS(47, 44)
> +#define ID_AA64DFR0_EL1_BRBE BITS(55, 52)
> +
> +#define ID_AA64ISAR0_EL1_TME BITS(27, 24)
> +
> +#define ID_AA64ISAR1_EL1_APA BITS(7, 4)
> +#define ID_AA64ISAR1_EL1_API BITS(11, 8)
> +#define ID_AA64ISAR1_EL1_GPA BITS(27, 24)
> +#define ID_AA64ISAR1_EL1_GPI BITS(31, 28)
> +
> +#define ID_AA64MMFR0_EL1_FGT BITS(59, 56)
> +#define ID_AA64MMFR0_EL1_ECV BITS(63, 60)
> +
> +#define ID_AA64PFR1_EL1_MTE BITS(11, 8)
> +#define ID_AA64PFR0_EL1_SVE BITS(35, 32)
>
> /*
> * Initial register values required for the boot-wrapper to run out-of-reset.
> diff --git a/arch/aarch64/init.c b/arch/aarch64/init.c
> index 82816e7..74190be 100644
> --- a/arch/aarch64/init.c
> +++ b/arch/aarch64/init.c
> @@ -8,6 +8,7 @@
> */
> #include <cpu.h>
> #include <platform.h>
> +#include <stdbool.h>
>
> void announce_arch(void)
> {
> @@ -17,3 +18,74 @@ void announce_arch(void)
> print_char('0' + el);
> print_string("\r\n");
> }
> +
> +static inline bool kernel_is_32bit(void)
> +{
> +#ifdef KERNEL_32
> + return true;
> +#else
> + return false;
> +#endif
> +}
> +
> +static inline bool cpu_has_pauth(void)
> +{
> + const unsigned long id_pauth = ID_AA64ISAR1_EL1_APA |
> + ID_AA64ISAR1_EL1_API |
> + ID_AA64ISAR1_EL1_GPA |
> + ID_AA64ISAR1_EL1_GPI;
> +
> + return mrs(ID_AA64ISAR1_EL1) & id_pauth;
> +}
> +
> +void cpu_init_el3(void)
> +{
> + unsigned long scr = SCR_EL3_RES1 | SCR_EL3_NS | SCR_EL3_HCE;
> + unsigned long mdcr = 0;
> + unsigned long cptr = 0;
> +
> + if (cpu_has_pauth())
> + scr |= SCR_EL3_APK | SCR_EL3_API;
> +
> + if (mrs_field(ID_AA64ISAR0_EL1, TME))
> + scr |= SCR_EL3_TME;
> +
> + if (mrs_field(ID_AA64MMFR0_EL1, FGT))
> + scr |= SCR_EL3_FGTEN;
> +
> + if (mrs_field(ID_AA64MMFR0_EL1, ECV) >= 2)
> + scr |= SCR_EL3_ECVEN;
> +
> + if (mrs_field(ID_AA64PFR1_EL1, MTE) >= 2)
> + scr |= SCR_EL3_ATA;
> +
> + if (!kernel_is_32bit())
> + scr |= SCR_EL3_RW;
> +
> + msr(SCR_EL3, scr);
> +
> + msr(CPTR_EL3, cptr);
> +
> + if (mrs_field(ID_AA64DFR0_EL1, PMSVER))
> + mdcr |= MDCR_EL3_NSPB_NS_NOTRAP;
> +
> + if (mrs_field(ID_AA64DFR0_EL1, PMSVER) >= 3)
> + mdcr |= MDCR_EL3_ENPMSN;
> +
> + if (mrs_field(ID_AA64DFR0_EL1, TRACEBUFFER))
> + mdcr |= MDCR_EL3_NSTB_NS_NOTRAP;
> +
> + if (mrs_field(ID_AA64DFR0_EL1, BRBE))
> + mdcr |= MDCR_EL3_SBRBE_NOTRAP_NOPROHIBIT;
> +
> + msr(MDCR_EL3, mdcr);
> +
> + if (mrs_field(ID_AA64PFR0_EL1, SVE)) {
> + cptr |= CPTR_EL3_EZ;
> + msr(CPTR_EL3, cptr);
> + isb();
> + msr(ZCR_EL3, ZCR_EL3_LEN_MAX);
> + }
> +
> + msr(CNTFRQ_EL0, COUNTER_FREQ);
> +}
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