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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - arch/parisc/kernel/alternative.c
1 // SPDX-License-Identifier: GPL-2.0
3 * Alternative live-patching for parisc.
4 * Copyright (C) 2018 Helge Deller <deller@gmx.de>
8 #include <asm/processor.h>
9 #include <asm/sections.h>
10 #include <asm/alternative.h>
12 #include <linux/module.h>
14 static int no_alternatives
;
15 static int __init
setup_no_alternatives(char *str
)
20 __setup("no-alternatives", setup_no_alternatives
);
22 void __init_or_module
apply_alternatives(struct alt_instr
*start
,
23 struct alt_instr
*end
, const char *module_name
)
25 struct alt_instr
*entry
;
26 int index
= 0, applied
= 0;
27 int num_cpus
= num_online_cpus();
29 for (entry
= start
; entry
< end
; entry
++, index
++) {
31 u32
*from
, len
, cond
, replacement
;
33 from
= (u32
*)((ulong
)&entry
->orig_offset
+ entry
->orig_offset
);
36 replacement
= entry
->replacement
;
40 if (cond
!= ALT_COND_ALWAYS
&& no_alternatives
)
43 pr_debug("Check %d: Cond 0x%x, Replace %02d instructions @ 0x%px with 0x%08x\n",
44 index
, cond
, len
, from
, replacement
);
46 if ((cond
& ALT_COND_NO_SMP
) && (num_cpus
!= 1))
48 if ((cond
& ALT_COND_NO_DCACHE
) && (cache_info
.dc_size
!= 0))
50 if ((cond
& ALT_COND_NO_ICACHE
) && (cache_info
.ic_size
!= 0))
54 * If the PDC_MODEL capabilities has Non-coherent IO-PDIR bit
55 * set (bit #61, big endian), we have to flush and sync every
56 * time IO-PDIR is changed in Ike/Astro.
58 if ((cond
& ALT_COND_NO_IOC_FDC
) &&
59 (boot_cpu_data
.pdc
.capabilities
& PDC_MODEL_IOPDIR_FDC
))
62 /* Want to replace pdtlb by a pdtlb,l instruction? */
63 if (replacement
== INSN_PxTLB
) {
65 if (boot_cpu_data
.cpu_type
>= pcxu
) /* >= pa2.0 ? */
66 replacement
|= (1 << 10); /* set el bit */
70 * Replace instruction with NOPs?
71 * For long distance insert a branch instruction instead.
73 if (replacement
== INSN_NOP
&& len
> 1)
74 replacement
= 0xe8000002 + (len
-2)*8; /* "b,n .+8" */
76 pr_debug("Do %d: Cond 0x%x, Replace %02d instructions @ 0x%px with 0x%08x\n",
77 index
, cond
, len
, from
, replacement
);
79 /* Replace instruction */
84 pr_info("%s%salternatives: applied %d out of %d patches\n",
85 module_name
? : "", module_name
? " " : "",
90 void __init
apply_alternatives_all(void)
92 set_kernel_text_rw(1);
94 apply_alternatives((struct alt_instr
*) &__alt_instructions
,
95 (struct alt_instr
*) &__alt_instructions_end
, NULL
);
97 set_kernel_text_rw(0);