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authorJulius Werner <jwerner@chromium.org>2018-08-06 13:50:38 -0700
committerJulius Werner <jwerner@chromium.org>2018-08-10 04:16:46 +0000
commite819c857607bb4a1c2911e2073aa588f74789ee1 (patch)
tree6344dcc7f78397ad89bcc0ae59cdfc0e139cc5c5 /src/arch/arm64/armv8/exception.c
parent0c5f61a01c3ebaa1c19f9a20d20d4b1353648d7c (diff)
downloadcoreboot-e819c857607bb4a1c2911e2073aa588f74789ee1.tar.xz
arm64: Turn architectural register accessors into inline functions
Accesses to architectural registers should be really fast -- they're just registers, after all. In fact, the arm64 architecture uses them for some timing-senstive uses like the architectural timer. A read should be: one instruction, no data dependencies, done. However, our current coreboot framework wraps each of these accesses into a separate function. Suddenly you have to spill registers on a stack, make a function call, move your stack pointer, etc. When running without MMU this adds a significant enough delay to cause timing problems when bitbanging a UART on SDM845. This patch replaces all those existing functions with static inline definitions in the header so they will get reduced to a single instruction as they should be. Also use some macros to condense the code a little since they're all so regular, which should make it easier to add more in the future. This patch also expands all the data types to uint64_t since that's what the actual assembly instruction accesses, even if the register itself only has 32 bits (the others will be ignored by the processor and set to 0 on read). Arm regularly expands registers as they add new bit fields to them with newer iterations of the architecture anyway, so this just prepares us for the inevitable. Change-Id: I2c41cc3ce49ee26bf12cd34e3d0509d8e61ffc63 Signed-off-by: Julius Werner <jwerner@chromium.org> Reviewed-on: https://review.coreboot.org/27881 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net> Reviewed-by: Patrick Rudolph <patrick.rudolph@9elements.com> Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Diffstat (limited to 'src/arch/arm64/armv8/exception.c')
-rw-r--r--src/arch/arm64/armv8/exception.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/src/arch/arm64/armv8/exception.c b/src/arch/arm64/armv8/exception.c
index 924c344e13..e32c79a85a 100644
--- a/src/arch/arm64/armv8/exception.c
+++ b/src/arch/arm64/armv8/exception.c
@@ -78,9 +78,9 @@ static void print_regs(struct exc_state *exc_state)
struct elx_state *elx = &exc_state->elx;
struct regs *regs = &exc_state->regs;
- printk(BIOS_DEBUG, "ELR = 0x%016llx ESR = 0x%08x\n",
+ printk(BIOS_DEBUG, "ELR = 0x%016llx ESR = 0x%08llx\n",
elx->elr, raw_read_esr_el3());
- printk(BIOS_DEBUG, "FAR = 0x%016llx SPSR = 0x%08x\n",
+ printk(BIOS_DEBUG, "FAR = 0x%016llx SPSR = 0x%08llx\n",
raw_read_far_el3(), raw_read_spsr_el3());
for (i = 0; i < 30; i += 2) {
printk(BIOS_DEBUG,