linux/arch/arm/mach-shmobile/headsmp.S
Linus Walleij a9ff696160 ARM: mm: Make virt_to_pfn() a static inline
Making virt_to_pfn() a static inline taking a strongly typed
(const void *) makes the contract of a passing a pointer of that
type to the function explicit and exposes any misuse of the
macro virt_to_pfn() acting polymorphic and accepting many types
such as (void *), (unitptr_t) or (unsigned long) as arguments
without warnings.

Doing this is a bit intrusive: virt_to_pfn() requires
PHYS_PFN_OFFSET and PAGE_SHIFT to be defined, and this is defined in
<asm/page.h>, so this must be included *before* <asm/memory.h>.

The use of macros were obscuring the unclear inclusion order here,
as the macros would eventually be resolved, but a static inline
like this cannot be compiled with unresolved macros.

The naive solution to include <asm/page.h> at the top of
<asm/memory.h> does not work, because <asm/memory.h> sometimes
includes <asm/page.h> at the end of itself, which would create a
confusing inclusion loop. So instead, take the approach to always
unconditionally include <asm/page.h> at the end of <asm/memory.h>

arch/arm uses <asm/memory.h> explicitly in a lot of places,
however it turns out that if we just unconditionally include
<asm/memory.h> into <asm/page.h> and switch all inclusions of
<asm/memory.h> to <asm/page.h> instead, we enforce the right
order and <asm/memory.h> will always have access to the
definitions.

Put an inclusion guard in place making it impossible to include
<asm/memory.h> explicitly.

Link: https://lore.kernel.org/linux-mm/20220701160004.2ffff4e5ab59a55499f4c736@linux-foundation.org/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2023-05-29 11:27:08 +02:00

148 lines
3.0 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0
*
* SMP support for R-Mobile / SH-Mobile
*
* Copyright (C) 2010 Magnus Damm
* Copyright (C) 2010 Takashi Yoshii
*
* Based on vexpress, Copyright (c) 2003 ARM Limited, All Rights Reserved
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <linux/threads.h>
#include <asm/assembler.h>
#include <asm/page.h>
#define SCTLR_MMU 0x01
#define BOOTROM_ADDRESS 0xE6340000
#define RWTCSRA_ADDRESS 0xE6020004
#define RWTCSRA_WOVF 0x10
/*
* Reset vector for secondary CPUs.
* This will be mapped at address 0 by SBAR register.
* We need _long_ jump to the physical address.
*/
.arm
.align 12
ENTRY(shmobile_boot_vector)
ldr r1, 1f
bx r1
ENDPROC(shmobile_boot_vector)
.align 2
.globl shmobile_boot_fn
shmobile_boot_fn:
1: .space 4
.globl shmobile_boot_size
shmobile_boot_size:
.long . - shmobile_boot_vector
#ifdef CONFIG_ARCH_RCAR_GEN2
/*
* Reset vector for R-Car Gen2 and RZ/G1 secondary CPUs.
* This will be mapped at address 0 by SBAR register.
*/
ENTRY(shmobile_boot_vector_gen2)
mrc p15, 0, r0, c0, c0, 5 @ r0 = MPIDR
ldr r1, shmobile_boot_cpu_gen2
cmp r0, r1
bne shmobile_smp_continue_gen2
mrc p15, 0, r1, c1, c0, 0 @ r1 = SCTLR
and r0, r1, #SCTLR_MMU
cmp r0, #SCTLR_MMU
beq shmobile_smp_continue_gen2
ldr r0, rwtcsra
mov r1, #0
ldrb r1, [r0]
and r0, r1, #RWTCSRA_WOVF
cmp r0, #RWTCSRA_WOVF
bne shmobile_smp_continue_gen2
ldr r0, bootrom
bx r0
shmobile_smp_continue_gen2:
ldr r1, shmobile_boot_fn_gen2
bx r1
ENDPROC(shmobile_boot_vector_gen2)
.align 4
rwtcsra:
.word RWTCSRA_ADDRESS
bootrom:
.word BOOTROM_ADDRESS
.globl shmobile_boot_cpu_gen2
shmobile_boot_cpu_gen2:
.word 0x00000000
.align 2
.globl shmobile_boot_fn_gen2
shmobile_boot_fn_gen2:
.space 4
.globl shmobile_boot_size_gen2
shmobile_boot_size_gen2:
.long . - shmobile_boot_vector_gen2
#endif /* CONFIG_ARCH_RCAR_GEN2 */
/*
* Per-CPU SMP boot function/argument selection code based on MPIDR
*/
ENTRY(shmobile_smp_boot)
mrc p15, 0, r1, c0, c0, 5 @ r1 = MPIDR
and r0, r1, #0xffffff @ MPIDR_HWID_BITMASK
@ r0 = cpu_logical_map() value
mov r1, #0 @ r1 = CPU index
adr r2, 1f
ldmia r2, {r5, r6, r7}
add r5, r5, r2 @ array of per-cpu mpidr values
add r6, r6, r2 @ array of per-cpu functions
add r7, r7, r2 @ array of per-cpu arguments
shmobile_smp_boot_find_mpidr:
ldr r8, [r5, r1, lsl #2]
cmp r8, r0
bne shmobile_smp_boot_next
ldr r9, [r6, r1, lsl #2]
cmp r9, #0
bne shmobile_smp_boot_found
shmobile_smp_boot_next:
add r1, r1, #1
cmp r1, #NR_CPUS
blo shmobile_smp_boot_find_mpidr
b shmobile_smp_sleep
shmobile_smp_boot_found:
ldr r0, [r7, r1, lsl #2]
ret r9
ENDPROC(shmobile_smp_boot)
ENTRY(shmobile_smp_sleep)
wfi
b shmobile_smp_boot
ENDPROC(shmobile_smp_sleep)
.align 2
1: .long shmobile_smp_mpidr - .
.long shmobile_smp_fn - 1b
.long shmobile_smp_arg - 1b
.bss
.globl shmobile_smp_mpidr
shmobile_smp_mpidr:
.space NR_CPUS * 4
.globl shmobile_smp_fn
shmobile_smp_fn:
.space NR_CPUS * 4
.globl shmobile_smp_arg
shmobile_smp_arg:
.space NR_CPUS * 4