diff options
| author | Yen Lin <yelin@nvidia.com> | 2015-03-24 11:15:10 -0700 |
|---|---|---|
| committer | Patrick Georgi <pgeorgi@google.com> | 2015-04-22 08:48:10 +0200 |
| commit | 900059a2236424ca70cb29cc4af3ac5cf47712fd (patch) | |
| tree | 1d53444b2823ba2d19e1a68ad905725e6ed46464 /src/arch | |
| parent | f7c5c610a2563971461bbc066117d185022df0f5 (diff) | |
arch/arm64: allow floating-point registers access
BRANCH=None
BUG=None
TEST=build coreboot, make sure there are fmov instructions
generated by the compiler, and boot to kernel
Change-Id: Ia99c710be77d5baec7a743a726257ef3ec782635
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: f770a436a0692c8e57a8c80860a180330b71e82c
Original-Change-Id: Iab4ba979b483d19fe92b8a75d9b881a57985eed7
Original-Signed-off-by: Yen Lin <yelin@nvidia.com>
Original-Signed-off-by: Furquan Shaikh <furquan@google.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/262242
Original-Tested-by: Furquan Shaikh <furquan@chromium.org>
Original-Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Original-Commit-Queue: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: http://review.coreboot.org/9884
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/arch')
| -rw-r--r-- | src/arch/arm64/cpu_ramstage.c | 19 | ||||
| -rw-r--r-- | src/arch/arm64/include/armv8/arch/lib_helpers.h | 22 |
2 files changed, 41 insertions, 0 deletions
diff --git a/src/arch/arm64/cpu_ramstage.c b/src/arch/arm64/cpu_ramstage.c index 466ca0124f..369bae3c11 100644 --- a/src/arch/arm64/cpu_ramstage.c +++ b/src/arch/arm64/cpu_ramstage.c @@ -117,6 +117,25 @@ static void init_this_cpu(void *arg) printk(BIOS_DEBUG, "%s init\n", dev_path(dev)); dev->ops->init(dev); } + + /* + * Disable coprocessor traps to EL3: + * TCPAC [20] = 0, disable traps for EL2 accesses to CPTR_EL2 or HCPTR + * and EL2/EL1 access to CPACR_EL1. + * TTA [20] = 0, disable traps for trace register access from any EL. + * TFP [10] = 0, disable traps for floating-point instructions from any + * EL. + */ + raw_write_cptr_el3(CPTR_EL3_TCPAC_DISABLE | CPTR_EL3_TTA_DISABLE | + CPTR_EL3_TFP_DISABLE); + + /* + * Allow FPU accesses: + * FPEN [21:20] = 3, disable traps for floating-point instructions from + * EL0/EL1. + * TTA [28] = 0, disable traps for trace register access from EL0/EL1. + */ + raw_write_cpacr_el1(CPACR_TRAP_FP_DISABLE | CPACR_TTA_DISABLE); } /* Fill in cpu_info structures according to device tree. */ diff --git a/src/arch/arm64/include/armv8/arch/lib_helpers.h b/src/arch/arm64/include/armv8/arch/lib_helpers.h index ba41f45440..1e04d48cfa 100644 --- a/src/arch/arm64/include/armv8/arch/lib_helpers.h +++ b/src/arch/arm64/include/armv8/arch/lib_helpers.h @@ -126,6 +126,28 @@ #define SCTLR_LITTLE_END (0 << SCTLR_ENDIAN_SHIFT) #define SCTLR_BIG_END (1 << SCTLR_ENDIAN_SHIFT) +#define CPTR_EL3_TCPAC_SHIFT (31) +#define CPTR_EL3_TTA_SHIFT (20) +#define CPTR_EL3_TFP_SHIFT (10) +#define CPTR_EL3_TCPAC_DISABLE (0 << CPTR_EL3_TCPAC_SHIFT) +#define CPTR_EL3_TCPAC_ENABLE (1 << CPTR_EL3_TCPAC_SHIFT) +#define CPTR_EL3_TTA_DISABLE (0 << CPTR_EL3_TTA_SHIFT) +#define CPTR_EL3_TTA_ENABLE (1 << CPTR_EL3_TTA_SHIFT) +#define CPTR_EL3_TFP_DISABLE (0 << CPTR_EL3_TFP_SHIFT) +#define CPTR_EL3_TFP_ENABLE (1 << CPTR_EL3_TFP_SHIFT) + +#define CPACR_TTA_SHIFT (28) +#define CPACR_TTA_ENABLE (1 << CPACR_TTA_SHIFT) +#define CPACR_TTA_DISABLE (0 << CPACR_TTA_SHIFT) +#define CPACR_FPEN_SHIFT (20) +/* + * ARMv8-A spec: Values 0b00 and 0b10 both seem to enable traps from el0 and el1 + * for fp reg access. + */ +#define CPACR_TRAP_FP_EL0_EL1 (0 << CPACR_FPEN_SHIFT) +#define CPACR_TRAP_FP_EL0 (1 << CPACR_FPEN_SHIFT) +#define CPACR_TRAP_FP_DISABLE (3 << CPACR_FPEN_SHIFT) + #ifdef __ASSEMBLY__ /* Macro to switch to label based on current el */ |