diff options
| author | Chen-Yu Tsai <wens@csie.org> | 2016-06-19 12:38:37 +0800 |
|---|---|---|
| committer | Hans de Goede <hdegoede@redhat.com> | 2016-07-15 15:54:57 +0200 |
| commit | 8c0ef7fad676827125ad91060361d05ab4b16f44 (patch) | |
| tree | b6a9f0062be1655fc290a80728ce7f84f131417d /arch/arm/cpu/armv7/psci.S | |
| parent | 980d6a55119f757ade4abed88bf4b2b7494c68e6 (diff) | |
ARM: PSCI: Allocate PSCI stack in secure stack section
Now that we have a secure stack section that guarantees usable memory,
allocate the PSCI stacks in that section.
Also add a diagram detailing how the stacks are placed in memory.
Reserved space for the target PC remains unchanged. This should be
moved to global variables within a secure data section in the future.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Diffstat (limited to 'arch/arm/cpu/armv7/psci.S')
| -rw-r--r-- | arch/arm/cpu/armv7/psci.S | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/arch/arm/cpu/armv7/psci.S b/arch/arm/cpu/armv7/psci.S index 46fcf770c2..bfc4475e36 100644 --- a/arch/arm/cpu/armv7/psci.S +++ b/arch/arm/cpu/armv7/psci.S @@ -196,18 +196,28 @@ ENTRY(psci_cpu_off_common) bx lr ENDPROC(psci_cpu_off_common) -@ expects CPU ID in r0 and returns stack top in r0 +@ The stacks are allocated in reverse order, i.e. +@ the stack for CPU0 has the highest memory address. +@ +@ -------------------- __secure_stack_end +@ | CPU0 target PC | +@ |------------------| +@ | | +@ | CPU0 stack | +@ | | +@ |------------------| __secure_stack_end - 1KB +@ | . | +@ | . | +@ | . | +@ | . | +@ -------------------- __secure_stack_start +@ +@ This expects CPU ID in r0 and returns stack top in r0 ENTRY(psci_get_cpu_stack_top) - mov r3, #0x400 @ 1kB of stack per CPU - mul r0, r0, r3 - - ldr r3, =psci_text_end @ end of monitor text - add r3, r3, #0x2000 @ Skip two pages - lsr r3, r3, #12 @ Align to start of page - lsl r3, r3, #12 - sub r3, r3, #4 @ reserve 1 word for target PC - sub r0, r3, r0 @ here's our stack! - + @ stack top = __secure_stack_end - (cpuid << ARM_PSCI_STACK_SHIFT) + ldr r3, =__secure_stack_end + sub r0, r3, r0, LSL #ARM_PSCI_STACK_SHIFT + sub r0, r0, #4 @ Save space for target PC bx lr ENDPROC(psci_get_cpu_stack_top) |