#define CurrentEL_EL1 (1 << 2)
#define CurrentEL_EL2 (2 << 2)
+#define INIT_PSTATE_EL1 \
+ (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL1h)
+#define INIT_PSTATE_EL2 \
+ (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT | PSR_MODE_EL2h)
+
/*
* PMR values used to mask/unmask interrupts.
*
* reachable EL supported by the kernel in a chosen default state. If dropping
* from EL2 to EL1, configure EL2 before configuring EL1.
*
+ * Since we cannot always rely on ERET synchronizing writes to sysregs (e.g. if
+ * SCTLR_ELx.EOS is clear), we place an ISB prior to ERET.
+ *
* Returns either BOOT_CPU_MODE_EL1 or BOOT_CPU_MODE_EL2 in w0 if
* booted in EL1 or EL2 respectively.
*/
SYM_FUNC_START(init_kernel_el)
- msr SPsel, #1 // We want to use SP_EL{1,2}
mrs x0, CurrentEL
cmp x0, #CurrentEL_EL2
- b.eq 1f
+ b.eq init_el2
+
+SYM_INNER_LABEL(init_el1, SYM_L_LOCAL)
mov_q x0, INIT_SCTLR_EL1_MMU_OFF
msr sctlr_el1, x0
- mov w0, #BOOT_CPU_MODE_EL1 // This cpu booted in EL1
isb
- ret
+ mov_q x0, INIT_PSTATE_EL1
+ msr spsr_el1, x0
+ msr elr_el1, lr
+ mov w0, #BOOT_CPU_MODE_EL1
+ eret
-1: mov_q x0, INIT_SCTLR_EL2_MMU_OFF
+SYM_INNER_LABEL(init_el2, SYM_L_LOCAL)
+ mov_q x0, INIT_SCTLR_EL2_MMU_OFF
msr sctlr_el2, x0
#ifdef CONFIG_ARM64_VHE
cbz x2, install_el2_stub
- mov w0, #BOOT_CPU_MODE_EL2 // This CPU booted in EL2
isb
- ret
+ mov_q x0, INIT_PSTATE_EL2
+ msr spsr_el2, x0
+ msr elr_el2, lr
+ mov w0, #BOOT_CPU_MODE_EL2
+ eret
SYM_INNER_LABEL(install_el2_stub, SYM_L_LOCAL)
/*
7: adr_l x0, __hyp_stub_vectors
msr vbar_el2, x0
- /* spsr */
- mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
- PSR_MODE_EL1h)
+ isb
+ mov x0, #INIT_PSTATE_EL1
msr spsr_el2, x0
msr elr_el2, lr
- mov w0, #BOOT_CPU_MODE_EL2 // This CPU booted in EL2
+ mov w0, #BOOT_CPU_MODE_EL2
eret
SYM_FUNC_END(init_kernel_el)