u-boot/arch/arm/cpu/armv8/bcmns3/lowlevel.S
Abhishek Shah ef7192e404 board: ns3: add api to save boot parameters passed from BL31
Add API to save boot parameters passed from BL31

Use assembly implementation of save_boot_params instead of c function.
Because generally ATF does not set up SP_EL2 on exiting.
Thus, usage of a C function immediately after exiting with no stack
setup done by ATF explicitly, may cause SP_EL2 to be not sane,
which in turn causes a crash if this boot was not lucky to get
an SP_EL2 in valid range. Replace C implementation with assembly one
which does not use stack this early, and let u-boot to set up its stack
later.

Signed-off-by: Abhishek Shah <abhishek.shah@broadcom.com>
Signed-off-by: Rajesh Ravi <rajesh.ravi@broadcom.com>
Signed-off-by: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com>
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2020-07-29 10:13:41 -04:00

98 lines
1.9 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright 2020 Broadcom.
*
*/
#include <asm/macro.h>
#include <linux/linkage.h>
hnf_pstate_poll:
/* x0 has the desired status, return 0 for success, 1 for timeout
* clobber x1, x2, x3, x4, x6, x7
*/
mov x1, x0
mov x7, #0 /* flag for timeout */
mrs x3, cntpct_el0 /* read timer */
mov w0, #600
mov w6, #1000
mul w0, w0, w6
add x3, x3, x0 /* timeout after 100 microseconds */
mov x0, #0x18
movk x0, #0x6120, lsl #16 /* HNF0_PSTATE_STATUS */
mov w6, #4 /* HN-F node count */
1:
ldr x2, [x0]
cmp x2, x1 /* check status */
b.eq 2f
mrs x4, cntpct_el0
cmp x4, x3
b.ls 1b
mov x7, #1 /* timeout */
b 3f
2:
add x0, x0, #0x10000 /* move to next node */
subs w6, w6, #1
cbnz w6, 1b
3:
mov x0, x7
ret
hnf_set_pstate:
/* x0 has the desired state, clobber x1, x2, x6 */
mov x1, x0
/* power state to SFONLY */
mov w6, #4 /* HN-F node count */
mov x0, #0x10
movk x0, #0x6120, lsl #16 /* HNF0_PSTATE_REQ */
1: /* set pstate to sfonly */
ldr x2, [x0]
and x2, x2, #0xfffffffffffffffc /* & HNFPSTAT_MASK */
orr x2, x2, x1
str x2, [x0]
add x0, x0, #0x10000 /* move to next node */
subs w6, w6, #1
cbnz w6, 1b
ret
ENTRY(__asm_flush_l3_dcache)
/*
* Return status in x0
* success 0
* timeout 1 for setting SFONLY, 2 for FAM, 3 for both
*/
mov x29, lr
mov x8, #0
dsb sy
mov x0, #0x1 /* HNFPSTAT_SFONLY */
bl hnf_set_pstate
mov x0, #0x4 /* SFONLY status */
bl hnf_pstate_poll
cbz x0, 1f
mov x8, #1 /* timeout */
1:
dsb sy
mov x0, #0x3 /* HNFPSTAT_FAM */
bl hnf_set_pstate
mov x0, #0xc /* FAM status */
bl hnf_pstate_poll
cbz x0, 1f
add x8, x8, #0x2
1:
mov x0, x8
mov lr, x29
ret
ENDPROC(__asm_flush_l3_dcache)
ENTRY(save_boot_params)
/*
* void set_boot_params(uint64_t x0, uint64_t x1, uint64_t x2, uint64_t x3)
*/
adr x4, bl33_info
str x0, [x4]
b save_boot_params_ret
ENDPROC(save_boot_params)