kernel_optimize_test/arch/arm/kernel/sleep.S
Ard Biesheuvel d0776aff9a ARM: 8324/1: move cpu_resume() to .text section
Move cpu_resume() to the .text section where it belongs. Change
the adr reference to sleep_save_sp to an explicit PC relative
reference so sleep_save_sp itself can remain in .data.

This helps prevent linker failure on large kernels, as the code
in the .data section may be too far away to be in range for normal
b/bl instructions.

Reviewed-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-03-29 23:11:57 +01:00

163 lines
4.5 KiB
ArmAsm

#include <linux/linkage.h>
#include <linux/threads.h>
#include <asm/asm-offsets.h>
#include <asm/assembler.h>
#include <asm/glue-cache.h>
#include <asm/glue-proc.h>
.text
/*
* Implementation of MPIDR hash algorithm through shifting
* and OR'ing.
*
* @dst: register containing hash result
* @rs0: register containing affinity level 0 bit shift
* @rs1: register containing affinity level 1 bit shift
* @rs2: register containing affinity level 2 bit shift
* @mpidr: register containing MPIDR value
* @mask: register containing MPIDR mask
*
* Pseudo C-code:
*
*u32 dst;
*
*compute_mpidr_hash(u32 rs0, u32 rs1, u32 rs2, u32 mpidr, u32 mask) {
* u32 aff0, aff1, aff2;
* u32 mpidr_masked = mpidr & mask;
* aff0 = mpidr_masked & 0xff;
* aff1 = mpidr_masked & 0xff00;
* aff2 = mpidr_masked & 0xff0000;
* dst = (aff0 >> rs0 | aff1 >> rs1 | aff2 >> rs2);
*}
* Input registers: rs0, rs1, rs2, mpidr, mask
* Output register: dst
* Note: input and output registers must be disjoint register sets
(eg: a macro instance with mpidr = r1 and dst = r1 is invalid)
*/
.macro compute_mpidr_hash dst, rs0, rs1, rs2, mpidr, mask
and \mpidr, \mpidr, \mask @ mask out MPIDR bits
and \dst, \mpidr, #0xff @ mask=aff0
ARM( mov \dst, \dst, lsr \rs0 ) @ dst=aff0>>rs0
THUMB( lsr \dst, \dst, \rs0 )
and \mask, \mpidr, #0xff00 @ mask = aff1
ARM( orr \dst, \dst, \mask, lsr \rs1 ) @ dst|=(aff1>>rs1)
THUMB( lsr \mask, \mask, \rs1 )
THUMB( orr \dst, \dst, \mask )
and \mask, \mpidr, #0xff0000 @ mask = aff2
ARM( orr \dst, \dst, \mask, lsr \rs2 ) @ dst|=(aff2>>rs2)
THUMB( lsr \mask, \mask, \rs2 )
THUMB( orr \dst, \dst, \mask )
.endm
/*
* Save CPU state for a suspend. This saves the CPU general purpose
* registers, and allocates space on the kernel stack to save the CPU
* specific registers and some other data for resume.
* r0 = suspend function arg0
* r1 = suspend function
* r2 = MPIDR value the resuming CPU will use
*/
ENTRY(__cpu_suspend)
stmfd sp!, {r4 - r11, lr}
#ifdef MULTI_CPU
ldr r10, =processor
ldr r4, [r10, #CPU_SLEEP_SIZE] @ size of CPU sleep state
#else
ldr r4, =cpu_suspend_size
#endif
mov r5, sp @ current virtual SP
add r4, r4, #12 @ Space for pgd, virt sp, phys resume fn
sub sp, sp, r4 @ allocate CPU state on stack
ldr r3, =sleep_save_sp
stmfd sp!, {r0, r1} @ save suspend func arg and pointer
ldr r3, [r3, #SLEEP_SAVE_SP_VIRT]
ALT_SMP(ldr r0, =mpidr_hash)
ALT_UP_B(1f)
/* This ldmia relies on the memory layout of the mpidr_hash struct */
ldmia r0, {r1, r6-r8} @ r1 = mpidr mask (r6,r7,r8) = l[0,1,2] shifts
compute_mpidr_hash r0, r6, r7, r8, r2, r1
add r3, r3, r0, lsl #2
1: mov r2, r5 @ virtual SP
mov r1, r4 @ size of save block
add r0, sp, #8 @ pointer to save block
bl __cpu_suspend_save
adr lr, BSYM(cpu_suspend_abort)
ldmfd sp!, {r0, pc} @ call suspend fn
ENDPROC(__cpu_suspend)
.ltorg
cpu_suspend_abort:
ldmia sp!, {r1 - r3} @ pop phys pgd, virt SP, phys resume fn
teq r0, #0
moveq r0, #1 @ force non-zero value
mov sp, r2
ldmfd sp!, {r4 - r11, pc}
ENDPROC(cpu_suspend_abort)
/*
* r0 = control register value
*/
.align 5
.pushsection .idmap.text,"ax"
ENTRY(cpu_resume_mmu)
ldr r3, =cpu_resume_after_mmu
instr_sync
mcr p15, 0, r0, c1, c0, 0 @ turn on MMU, I-cache, etc
mrc p15, 0, r0, c0, c0, 0 @ read id reg
instr_sync
mov r0, r0
mov r0, r0
ret r3 @ jump to virtual address
ENDPROC(cpu_resume_mmu)
.popsection
cpu_resume_after_mmu:
bl cpu_init @ restore the und/abt/irq banked regs
mov r0, #0 @ return zero on success
ldmfd sp!, {r4 - r11, pc}
ENDPROC(cpu_resume_after_mmu)
.text
.align
ENTRY(cpu_resume)
ARM_BE8(setend be) @ ensure we are in BE mode
#ifdef CONFIG_ARM_VIRT_EXT
bl __hyp_stub_install_secondary
#endif
safe_svcmode_maskall r1
mov r1, #0
ALT_SMP(mrc p15, 0, r0, c0, c0, 5)
ALT_UP_B(1f)
adr r2, mpidr_hash_ptr
ldr r3, [r2]
add r2, r2, r3 @ r2 = struct mpidr_hash phys address
/*
* This ldmia relies on the memory layout of the mpidr_hash
* struct mpidr_hash.
*/
ldmia r2, { r3-r6 } @ r3 = mpidr mask (r4,r5,r6) = l[0,1,2] shifts
compute_mpidr_hash r1, r4, r5, r6, r0, r3
1:
adr r0, _sleep_save_sp
ldr r2, [r0]
add r0, r0, r2
ldr r0, [r0, #SLEEP_SAVE_SP_PHYS]
ldr r0, [r0, r1, lsl #2]
@ load phys pgd, stack, resume fn
ARM( ldmia r0!, {r1, sp, pc} )
THUMB( ldmia r0!, {r1, r2, r3} )
THUMB( mov sp, r2 )
THUMB( bx r3 )
ENDPROC(cpu_resume)
.align 2
_sleep_save_sp:
.long sleep_save_sp - .
mpidr_hash_ptr:
.long mpidr_hash - . @ mpidr_hash struct offset
.data
.type sleep_save_sp, #object
ENTRY(sleep_save_sp)
.space SLEEP_SAVE_SP_SZ @ struct sleep_save_sp