Access system registers directly in assembler
Instead of using the system register helper functions to read
or write system registers, assembler coded functions should
use MRS/MSR instructions. This results in faster and more
compact code.
This change replaces all usage of the helper functions with
direct register accesses.
Change-Id: I791d5f11f257010bb3e6a72c6c5ab8779f1982b3
diff --git a/bl1/aarch64/bl1_entrypoint.S b/bl1/aarch64/bl1_entrypoint.S
index e25386f..c081af4 100644
--- a/bl1/aarch64/bl1_entrypoint.S
+++ b/bl1/aarch64/bl1_entrypoint.S
@@ -97,10 +97,10 @@
* their turn to be woken up
* ---------------------------------------------
*/
- bl read_mpidr
+ mrs x0, mpidr_el1
bl platform_get_entrypoint
cbnz x0, _do_warm_boot
- bl read_mpidr
+ mrs x0, mpidr_el1
bl platform_is_primary_cpu
cbnz x0, _do_cold_boot
diff --git a/bl1/aarch64/bl1_exceptions.S b/bl1/aarch64/bl1_exceptions.S
index 71fd4cd..a87b20f 100644
--- a/bl1/aarch64/bl1_exceptions.S
+++ b/bl1/aarch64/bl1_exceptions.S
@@ -189,7 +189,7 @@
mov x0, #SYNC_EXCEPTION_AARCH64
bl plat_report_exception
- bl read_esr_el3
+ mrs x0, esr_el3
ubfx x1, x0, #ESR_EC_SHIFT, #ESR_EC_LENGTH
cmp x1, #EC_AARCH64_SMC
b.ne panic
@@ -201,10 +201,8 @@
mov x2, x3
mov x3, x4
bl display_boot_progress
- mov x0, x20
- bl write_elr
- mov x0, x21
- bl write_spsr
+ msr elr_el3, x20
+ msr spsr_el3, x21
ubfx x0, x21, #MODE_EL_SHIFT, #2
cmp x0, #MODE_EL3
b.ne skip_mmu_teardown
@@ -216,7 +214,7 @@
* ---------------------------------------------
*/
bl disable_mmu_icache_el3
- bl tlbialle3
+ tlbi alle3
skip_mmu_teardown:
ldp x6, x7, [sp, #0x30]
ldp x4, x5, [sp, #0x20]
diff --git a/bl2/aarch64/bl2_entrypoint.S b/bl2/aarch64/bl2_entrypoint.S
index cd07aa9..4f7565f 100644
--- a/bl2/aarch64/bl2_entrypoint.S
+++ b/bl2/aarch64/bl2_entrypoint.S
@@ -54,8 +54,7 @@
* So, make sure no secondary has lost its way.
* ---------------------------------------------
*/
- bl read_mpidr
- mov x19, x0
+ mrs x0, mpidr_el1
bl platform_is_primary_cpu
cbz x0, _panic
@@ -102,7 +101,7 @@
* ease the pain of initializing the MMU
* --------------------------------------------
*/
- mov x0, x19
+ mrs x0, mpidr_el1
bl platform_set_coherent_stack
/* ---------------------------------------------
@@ -120,7 +119,7 @@
* -IS-WBWA memory
* ---------------------------------------------
*/
- mov x0, x19
+ mrs x0, mpidr_el1
bl platform_set_stack
/* ---------------------------------------------
diff --git a/bl31/aarch64/bl31_entrypoint.S b/bl31/aarch64/bl31_entrypoint.S
index 1b79421..13bd5b8 100644
--- a/bl31/aarch64/bl31_entrypoint.S
+++ b/bl31/aarch64/bl31_entrypoint.S
@@ -107,8 +107,7 @@
* So, make sure no secondary has lost its way.
* ---------------------------------------------
*/
- bl read_mpidr
- mov x19, x0
+ mrs x0, mpidr_el1
bl platform_is_primary_cpu
cbz x0, _panic
@@ -137,7 +136,7 @@
* ease the pain of initializing the MMU
* --------------------------------------------
*/
- mov x0, x19
+ mrs x0, mpidr_el1
bl platform_set_coherent_stack
/* ---------------------------------------------
@@ -154,7 +153,7 @@
* -IS-WBWA memory
* ---------------------------------------------
*/
- mov x0, x19
+ mrs x0, mpidr_el1
bl platform_set_stack
/* ---------------------------------------------
diff --git a/include/common/asm_macros.S b/include/common/asm_macros.S
index 6cf1a19..a41b729 100644
--- a/include/common/asm_macros.S
+++ b/include/common/asm_macros.S
@@ -58,7 +58,7 @@
.macro smc_check label
- bl read_esr
+ mrs x0, esr_el3
ubfx x0, x0, #ESR_EC_SHIFT, #ESR_EC_LENGTH
cmp x0, #EC_AARCH64_SMC
b.ne $label
diff --git a/lib/aarch64/cpu_helpers.S b/lib/aarch64/cpu_helpers.S
index 4e5eb5b..abb996d 100644
--- a/lib/aarch64/cpu_helpers.S
+++ b/lib/aarch64/cpu_helpers.S
@@ -35,13 +35,11 @@
func cpu_reset_handler
- mov x19, x30 // lr
-
/* ---------------------------------------------
* As a bare minimal enable the SMP bit.
* ---------------------------------------------
*/
- bl read_midr
+ mrs x0, midr_el1
lsr x0, x0, #MIDR_PN_SHIFT
and x0, x0, #MIDR_PN_MASK
cmp x0, #MIDR_PN_A57
@@ -49,9 +47,9 @@
cmp x0, #MIDR_PN_A53
b.ne smp_setup_end
smp_setup_begin:
- bl read_cpuectlr
+ mrs x0, CPUECTLR_EL1
orr x0, x0, #CPUECTLR_SMP_BIT
- bl write_cpuectlr
+ msr CPUECTLR_EL1, x0
isb
smp_setup_end:
- ret x19
+ ret
diff --git a/plat/fvp/aarch64/bl1_plat_helpers.S b/plat/fvp/aarch64/bl1_plat_helpers.S
index 92075ea..b4d4458 100644
--- a/plat/fvp/aarch64/bl1_plat_helpers.S
+++ b/plat/fvp/aarch64/bl1_plat_helpers.S
@@ -67,7 +67,7 @@
* loader zeroes out the zi section.
* ---------------------------------------------
*/
- bl read_mpidr
+ mrs x0, mpidr_el1
ldr x1, =PWRC_BASE
str w0, [x1, #PPOFFR_OFF]
@@ -173,8 +173,6 @@
func platform_cold_boot_init
mov x20, x0
bl platform_mem_init
- bl read_mpidr
- mov x19, x0
/* ---------------------------------------------
* Give ourselves a small coherent stack to
@@ -182,6 +180,7 @@
* CCI in assembler
* ---------------------------------------------
*/
+ mrs x0, mpidr_el1
bl platform_set_coherent_stack
/* ---------------------------------------------
@@ -200,7 +199,7 @@
* -IS-WBWA memory
* ---------------------------------------------
*/
- mov x0, x19
+ mrs x0, mpidr_el1
bl platform_set_stack
/* ---------------------------------------------
diff --git a/services/std_svc/psci/psci_entry.S b/services/std_svc/psci/psci_entry.S
index ec55a81..25adaa1 100644
--- a/services/std_svc/psci/psci_entry.S
+++ b/services/std_svc/psci/psci_entry.S
@@ -76,8 +76,7 @@
*/
msr spsel, #0
- bl read_mpidr
- mov x19, x0
+ mrs x0, mpidr_el1
bl platform_set_coherent_stack
/* ---------------------------------------------
@@ -85,14 +84,14 @@
* level 0.
* ---------------------------------------------
*/
- mov x0, x19
+ mrs x0, mpidr_el1
bl get_power_on_target_afflvl
cmp x0, xzr
b.lt _panic
mov x3, x23
mov x2, x0
- mov x0, x19
mov x1, #MPIDR_AFFLVL0
+ mrs x0, mpidr_el1
blr x22
/* --------------------------------------------
@@ -100,7 +99,7 @@
* -IS-WBWA memory
* --------------------------------------------
*/
- mov x0, x19
+ mrs x0, mpidr_el1
bl platform_set_stack
zero_callee_saved_regs
@@ -119,7 +118,7 @@
sub sp, sp, #0x10
stp x19, x20, [sp, #0]
mov x19, sp
- bl read_mpidr
+ mrs x0, mpidr_el1
bl platform_set_coherent_stack
bl psci_cpu_off
mov x1, #PSCI_E_SUCCESS
@@ -140,7 +139,7 @@
mov x20, x0
mov x21, x1
mov x22, x2
- bl read_mpidr
+ mrs x0, mpidr_el1
bl platform_set_coherent_stack
mov x0, x20
mov x1, x21