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-rw-r--r--arch/arm64/kernel/head.S25
1 files changed, 17 insertions, 8 deletions
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index 23cfc08fc8ba..917d98108b3f 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -415,15 +415,17 @@ ENDPROC(__create_page_tables)
*/
.set initial_sp, init_thread_union + THREAD_START_SP
__mmap_switched:
- adr_l x6, __bss_start
- adr_l x7, __bss_stop
-
-1: cmp x6, x7
- b.hs 2f
- str xzr, [x6], #8 // Clear BSS
- b 1b
-2:
+ // Clear BSS
+ adr_l x0, __bss_start
+ mov x1, xzr
+ adr_l x2, __bss_stop
+ sub x2, x2, x0
+ bl __pi_memset
+
adr_l sp, initial_sp, x4
+ mov x4, sp
+ and x4, x4, #~(THREAD_SIZE - 1)
+ msr sp_el0, x4 // Save thread_info
str_l x21, __fdt_pointer, x5 // Save FDT pointer
str_l x24, memstart_addr, x6 // Save PHYS_OFFSET
mov x29, #0
@@ -512,9 +514,14 @@ CPU_LE( movk x0, #0x30d0, lsl #16 ) // Clear EE and E0E on LE systems
#endif
/* EL2 debug */
+ mrs x0, id_aa64dfr0_el1 // Check ID_AA64DFR0_EL1 PMUVer
+ sbfx x0, x0, #8, #4
+ cmp x0, #1
+ b.lt 4f // Skip if no PMU present
mrs x0, pmcr_el0 // Disable debug access traps
ubfx x0, x0, #11, #5 // to EL2 and allow access to
msr mdcr_el2, x0 // all PMU counters from EL1
+4:
/* Stage-2 translation */
msr vttbr_el2, xzr
@@ -606,6 +613,8 @@ ENDPROC(secondary_startup)
ENTRY(__secondary_switched)
ldr x0, [x21] // get secondary_data.stack
mov sp, x0
+ and x0, x0, #~(THREAD_SIZE - 1)
+ msr sp_el0, x0 // save thread_info
mov x29, #0
b secondary_start_kernel
ENDPROC(__secondary_switched)