refactor(el3_runtime): introduce save_x30 macro
Most of the macros/routine in vector entry need a free scratch register.
Introduce a macro "save_x30" and call it right at the begining of vector
entries where x30 is used. It is more exlicit and less error prone
Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I617f3d41a120739e5e3fe1c421c79ceb70c1188e
diff --git a/bl31/aarch64/runtime_exceptions.S b/bl31/aarch64/runtime_exceptions.S
index 0c60859..7cdde55 100644
--- a/bl31/aarch64/runtime_exceptions.S
+++ b/bl31/aarch64/runtime_exceptions.S
@@ -40,6 +40,14 @@
.globl serror_aarch32
/*
+ * Save LR and make x30 available as most of the routines in vector entry
+ * need a free register
+ */
+ .macro save_x30
+ str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
+ .endm
+
+ /*
* Macro that prepares entry to EL3 upon taking an exception.
*
* With RAS_EXTENSION, this macro synchronizes pending errors with an ESB
@@ -58,12 +66,6 @@
/* Unmask the SError interrupt */
msr daifclr, #DAIF_ABT_BIT
- /*
- * Explicitly save x30 so as to free up a register and to enable
- * branching
- */
- str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
-
/* Check for SErrors synchronized by the ESB instruction */
mrs x30, DISR_EL1
tbz x30, #DISR_A_BIT, 1f
@@ -108,11 +110,7 @@
/* Use ISB for the above unmask operation to take effect immediately */
isb
- /*
- * Refer Note 1.
- * No need to restore X30 as macros following this modify x30 anyway.
- */
- str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
+ /* Refer Note 1. */
mov x30, #1
str x30, [sp, #CTX_EL3STATE_OFFSET + CTX_IS_IN_EL3]
dmb sy
@@ -316,7 +314,7 @@
* triggered due to explicit synchronization in EL3. Refer Note 1.
*/
/* Assumes SP_EL3 on entry */
- str x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR]
+ save_x30
ldr x30, [sp, #CTX_EL3STATE_OFFSET + CTX_IS_IN_EL3]
cbnz x30, 1f
@@ -338,24 +336,28 @@
* to a valid cpu context where the general purpose and system register
* state can be saved.
*/
+ save_x30
apply_at_speculative_wa
check_and_unmask_ea
handle_sync_exception
end_vector_entry sync_exception_aarch64
vector_entry irq_aarch64
+ save_x30
apply_at_speculative_wa
check_and_unmask_ea
handle_interrupt_exception irq_aarch64
end_vector_entry irq_aarch64
vector_entry fiq_aarch64
+ save_x30
apply_at_speculative_wa
check_and_unmask_ea
handle_interrupt_exception fiq_aarch64
end_vector_entry fiq_aarch64
vector_entry serror_aarch64
+ save_x30
apply_at_speculative_wa
#if RAS_EXTENSION
msr daifclr, #DAIF_ABT_BIT
@@ -377,24 +379,28 @@
* to a valid cpu context where the general purpose and system register
* state can be saved.
*/
+ save_x30
apply_at_speculative_wa
check_and_unmask_ea
handle_sync_exception
end_vector_entry sync_exception_aarch32
vector_entry irq_aarch32
+ save_x30
apply_at_speculative_wa
check_and_unmask_ea
handle_interrupt_exception irq_aarch32
end_vector_entry irq_aarch32
vector_entry fiq_aarch32
+ save_x30
apply_at_speculative_wa
check_and_unmask_ea
handle_interrupt_exception fiq_aarch32
end_vector_entry fiq_aarch32
vector_entry serror_aarch32
+ save_x30
apply_at_speculative_wa
#if RAS_EXTENSION
msr daifclr, #DAIF_ABT_BIT
diff --git a/include/arch/aarch64/el2_common_macros.S b/include/arch/aarch64/el2_common_macros.S
index 7bf4806..b3b85e6 100644
--- a/include/arch/aarch64/el2_common_macros.S
+++ b/include/arch/aarch64/el2_common_macros.S
@@ -384,13 +384,12 @@
.macro apply_at_speculative_wa
#if ERRATA_SPECULATIVE_AT
/*
- * Explicitly save x30 so as to free up a register and to enable
- * branching and also, save x29 which will be used in the called
- * function
+ * This function expects x30 has been saved.
+ * Also, save x29 which will be used in the called function.
*/
- stp x29, x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X29]
+ str x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X29]
bl save_and_update_ptw_el1_sys_regs
- ldp x29, x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X29]
+ ldr x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X29]
#endif
.endm
diff --git a/include/arch/aarch64/el3_common_macros.S b/include/arch/aarch64/el3_common_macros.S
index de2b931..40ff056 100644
--- a/include/arch/aarch64/el3_common_macros.S
+++ b/include/arch/aarch64/el3_common_macros.S
@@ -532,13 +532,12 @@
.macro apply_at_speculative_wa
#if ERRATA_SPECULATIVE_AT
/*
- * Explicitly save x30 so as to free up a register and to enable
- * branching and also, save x29 which will be used in the called
- * function
+ * This function expects x30 has been saved.
+ * Also, save x29 which will be used in the called function.
*/
- stp x29, x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X29]
+ str x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X29]
bl save_and_update_ptw_el1_sys_regs
- ldp x29, x30, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X29]
+ ldr x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X29]
#endif
.endm