leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

powerpc: Use a datatype for instructions

Browse Source 
Currently unsigned ints are used to represent instructions on powerpc.
This has worked well as instructions have always been 4 byte words.

However, ISA v3.1 introduces some changes to instructions that mean
this scheme will no longer work as well. This change is Prefixed
Instructions. A prefixed instruction is made up of a word prefix
followed by a word suffix to make an 8 byte double word instruction.
No matter the endianness of the system the prefix always comes first.
Prefixed instructions are only planned for powerpc64.

Introduce a ppc_inst type to represent both prefixed and word
instructions on powerpc64 while keeping it possible to exclusively
have word instructions on powerpc32.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
[mpe: Fix compile error in emulate_spe()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-12-jniethe5@gmail.com
This commit is contained in:
Jordan Niethe
2020-05-06 13:40:31 +10:00
committed by Michael Ellerman
parent 217862d9b9
commit 94afd069d9
26 changed files with 237 additions and 214 deletions
Download Patch File Download Diff File Expand all files Collapse all files

76
arch/powerpc/lib/code-patching.c
View File

@@ -19,12 +19,12 @@
#include <asm/setup.h>
#include <asm/inst.h>
static int __patch_instruction(unsigned int *exec_addr, unsigned int instr,
unsigned int *patch_addr)
static int __patch_instruction(struct ppc_inst *exec_addr, struct ppc_inst instr,
struct ppc_inst *patch_addr)
{
int err = 0;
__put_user_asm(instr, patch_addr, err, "stw");
__put_user_asm(ppc_inst_val(instr), patch_addr, err, "stw");
if (err)
return err;
@@ -34,7 +34,7 @@ static int __patch_instruction(unsigned int *exec_addr, unsigned int instr,
return 0;
}
int raw_patch_instruction(unsigned int *addr, unsigned int instr)
int raw_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr)
{
return __patch_instruction(addr, instr, addr);
}
@@ -137,10 +137,10 @@ static inline int unmap_patch_area(unsigned long addr)
return 0;
}
static int do_patch_instruction(unsigned int *addr, unsigned int instr)
static int do_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr)
{
int err;
unsigned int *patch_addr = NULL;
struct ppc_inst *patch_addr = NULL;
unsigned long flags;
unsigned long text_poke_addr;
unsigned long kaddr = (unsigned long)addr;
@@ -161,8 +161,7 @@ static int do_patch_instruction(unsigned int *addr, unsigned int instr)
goto out;
}
patch_addr = (unsigned int *)(text_poke_addr) +
((kaddr & ~PAGE_MASK) / sizeof(unsigned int));
patch_addr = (struct ppc_inst *)(text_poke_addr + (kaddr & ~PAGE_MASK));
__patch_instruction(addr, instr, patch_addr);
@@ -177,14 +176,14 @@ out:
}
#else /* !CONFIG_STRICT_KERNEL_RWX */
static int do_patch_instruction(unsigned int *addr, unsigned int instr)
static int do_patch_instruction(struct ppc_inst *addr, struct ppc_inst instr)
{
return raw_patch_instruction(addr, instr);
}
#endif /* CONFIG_STRICT_KERNEL_RWX */
int patch_instruction(unsigned int *addr, unsigned int instr)
int patch_instruction(struct ppc_inst *addr, struct ppc_inst instr)
{
/* Make sure we aren't patching a freed init section */
if (init_mem_is_free && init_section_contains(addr, 4)) {
@@ -195,9 +194,9 @@ int patch_instruction(unsigned int *addr, unsigned int instr)
}
NOKPROBE_SYMBOL(patch_instruction);
int patch_branch(unsigned int *addr, unsigned long target, int flags)
int patch_branch(struct ppc_inst *addr, unsigned long target, int flags)
{
unsigned int instr;
struct ppc_inst instr;
create_branch(&instr, addr, target, flags);
return patch_instruction(addr, instr);
@@ -229,7 +228,7 @@ bool is_offset_in_branch_range(long offset)
* Helper to check if a given instruction is a conditional branch
* Derived from the conditional checks in analyse_instr()
*/
bool is_conditional_branch(unsigned int instr)
bool is_conditional_branch(struct ppc_inst instr)
{
unsigned int opcode = ppc_inst_primary_opcode(instr);
@@ -247,13 +246,13 @@ bool is_conditional_branch(unsigned int instr)
}
NOKPROBE_SYMBOL(is_conditional_branch);
int create_branch(unsigned int *instr,
const unsigned int *addr,
int create_branch(struct ppc_inst *instr,
const struct ppc_inst *addr,
unsigned long target, int flags)
{
long offset;
*instr = 0;
*instr = ppc_inst(0);
offset = target;
if (! (flags & BRANCH_ABSOLUTE))
offset = offset - (unsigned long)addr;
@@ -263,12 +262,12 @@ int create_branch(unsigned int *instr,
return 1;
/* Mask out the flags and target, so they don't step on each other. */
*instr = 0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC);
*instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC));
return 0;
}
int create_cond_branch(unsigned int *instr, const unsigned int *addr,
int create_cond_branch(struct ppc_inst *instr, const struct ppc_inst *addr,
unsigned long target, int flags)
{
long offset;
@@ -282,27 +281,27 @@ int create_cond_branch(unsigned int *instr, const unsigned int *addr,
return 1;
/* Mask out the flags and target, so they don't step on each other. */
*instr = 0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC);
*instr = ppc_inst(0x40000000 | (flags & 0x3FF0003) | (offset & 0xFFFC));
return 0;
}
static unsigned int branch_opcode(unsigned int instr)
static unsigned int branch_opcode(struct ppc_inst instr)
{
return ppc_inst_primary_opcode(instr) & 0x3F;
}
static int instr_is_branch_iform(unsigned int instr)
static int instr_is_branch_iform(struct ppc_inst instr)
{
return branch_opcode(instr) == 18;
}
static int instr_is_branch_bform(unsigned int instr)
static int instr_is_branch_bform(struct ppc_inst instr)
{
return branch_opcode(instr) == 16;
}
int instr_is_relative_branch(unsigned int instr)
int instr_is_relative_branch(struct ppc_inst instr)
{
if (ppc_inst_val(instr) & BRANCH_ABSOLUTE)
return 0;
@@ -310,12 +309,12 @@ int instr_is_relative_branch(unsigned int instr)
return instr_is_branch_iform(instr) || instr_is_branch_bform(instr);
}
int instr_is_relative_link_branch(unsigned int instr)
int instr_is_relative_link_branch(struct ppc_inst instr)
{
return instr_is_relative_branch(instr) && (ppc_inst_val(instr) & BRANCH_SET_LINK);
}
static unsigned long branch_iform_target(const unsigned int *instr)
static unsigned long branch_iform_target(const struct ppc_inst *instr)
{
signed long imm;
@@ -331,7 +330,7 @@ static unsigned long branch_iform_target(const unsigned int *instr)
return (unsigned long)imm;
}
static unsigned long branch_bform_target(const unsigned int *instr)
static unsigned long branch_bform_target(const struct ppc_inst *instr)
{
signed long imm;
@@ -347,7 +346,7 @@ static unsigned long branch_bform_target(const unsigned int *instr)
return (unsigned long)imm;
}
unsigned long branch_target(const unsigned int *instr)
unsigned long branch_target(const struct ppc_inst *instr)
{
if (instr_is_branch_iform(*instr))
return branch_iform_target(instr);
@@ -357,7 +356,7 @@ unsigned long branch_target(const unsigned int *instr)
return 0;
}
int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr)
int instr_is_branch_to_addr(const struct ppc_inst *instr, unsigned long addr)
{
if (instr_is_branch_iform(*instr) || instr_is_branch_bform(*instr))
return branch_target(instr) == addr;
@@ -365,8 +364,8 @@ int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr)
return 0;
}
int translate_branch(unsigned int *instr, const unsigned int *dest,
const unsigned int *src)
int translate_branch(struct ppc_inst *instr, const struct ppc_inst *dest,
const struct ppc_inst *src)
{
unsigned long target;
@@ -392,7 +391,7 @@ void __patch_exception(int exc, unsigned long addr)
* instruction of the exception, not the first one
*/
patch_branch(ibase + (exc / 4) + 1, addr, 0);
patch_branch((struct ppc_inst *)(ibase + (exc / 4) + 1), addr, 0);
}
#endif
@@ -409,7 +408,7 @@ static void __init test_trampoline(void)
static void __init test_branch_iform(void)
{
int err;
unsigned int instr;
struct ppc_inst instr;
unsigned long addr;
addr = (unsigned long)&instr;
@@ -484,12 +483,12 @@ static void __init test_branch_iform(void)
static void __init test_create_function_call(void)
{
unsigned int *iptr;
struct ppc_inst *iptr;
unsigned long dest;
unsigned int instr;
struct ppc_inst instr;
/* Check we can create a function call */
iptr = (unsigned int *)ppc_function_entry(test_trampoline);
iptr = (struct ppc_inst *)ppc_function_entry(test_trampoline);
dest = ppc_function_entry(test_create_function_call);
create_branch(&instr, iptr, dest, BRANCH_SET_LINK);
patch_instruction(iptr, instr);
@@ -500,7 +499,8 @@ static void __init test_branch_bform(void)
{
int err;
unsigned long addr;
unsigned int *iptr, instr, flags;
struct ppc_inst *iptr, instr;
unsigned int flags;
iptr = &instr;
addr = (unsigned long)iptr;
@@ -570,8 +570,8 @@ static void __init test_branch_bform(void)
static void __init test_translate_branch(void)
{
unsigned long addr;
unsigned int *p, *q;
unsigned int instr;
struct ppc_inst *p, *q;
struct ppc_inst instr;
void *buf;
buf = vmalloc(PAGE_ALIGN(0x2000000 + 1));