diff mbox series

[v4,05/16] powerpc: Use a function for masking instructions

Message ID 20200320051809.24332-6-jniethe5@gmail.com (mailing list archive)
State Superseded
Headers show
Series Initial Prefixed Instruction support | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch powerpc/merge (8a445cbcb9f5090cb07ec6cbb89a8a1fc99a0ff7)
snowpatch_ozlabs/checkpatch warning total: 0 errors, 0 warnings, 1 checks, 96 lines checked
snowpatch_ozlabs/needsstable success Patch has no Fixes tags

Commit Message

Jordan Niethe March 20, 2020, 5:17 a.m. UTC 
In preparation for using an instruction data type that can not be used
directly with the '&' operator, use a function to mask instructions.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
---
v4: New to series
---
 arch/powerpc/include/asm/sstep.h   |  6 +++---
 arch/powerpc/kernel/align.c        |  2 +-
 arch/powerpc/kernel/trace/ftrace.c |  8 ++++----
 arch/powerpc/lib/code-patching.c   | 12 ++++++------
 4 files changed, 14 insertions(+), 14 deletions(-)

Comments

Nicholas Piggin March 23, 2020, 6:37 a.m. UTC | #1 
Jordan Niethe's on March 20, 2020 3:17 pm:
> In preparation for using an instruction data type that can not be used
> directly with the '&' operator, use a function to mask instructions.

Hmm. ppc_inst_mask isn't such a good interface I think. It takes a
ppc_inst and a mask, you would expect it to return a ppc_inst, probably
with some part of its value anded with your mask value but not entirely
clear.

I would have a ppc_inst_val that is a more mechanical replacement and
lets you do more things with it, although I like the other helpers you
add later. Oh you've added ppc_inst_word further down. Why not use that
here intead of ppc_inst_mask()?

Thanks,
Nick
Jordan Niethe March 23, 2020, 9:31 a.m. UTC | #2 
On Mon, Mar 23, 2020 at 5:40 PM Nicholas Piggin <npiggin@gmail.com> wrote:
>
> Jordan Niethe's on March 20, 2020 3:17 pm:
> > In preparation for using an instruction data type that can not be used
> > directly with the '&' operator, use a function to mask instructions.
>
> Hmm. ppc_inst_mask isn't such a good interface I think. It takes a
> ppc_inst and a mask, you would expect it to return a ppc_inst, probably
> with some part of its value anded with your mask value but not entirely
> clear.
>
> I would have a ppc_inst_val that is a more mechanical replacement and
> lets you do more things with it, although I like the other helpers you
> add later. Oh you've added ppc_inst_word further down. Why not use that
> here intead of ppc_inst_mask()?
ppc_inst_word() was what I started using first, but I started seeing a
whole lot of them immediately being &'d so I made ppc_inst_mask().
The ppc_inst_word() patch can come first, and I will just get rid of
the ppc_inst_mask() function - it is not very clear.
>
> Thanks,
> Nick
>
diff mbox series

Patch

diff --git a/arch/powerpc/include/asm/sstep.h b/arch/powerpc/include/asm/sstep.h
index 9353916fcba7..ef5483288920 100644
--- a/arch/powerpc/include/asm/sstep.h
+++ b/arch/powerpc/include/asm/sstep.h
@@ -16,9 +16,9 @@  struct pt_regs;
  * Note that IS_MTMSRD returns true for both an mtmsr (32-bit)
  * and an mtmsrd (64-bit).
  */
-#define IS_MTMSRD(instr)	(((instr) & 0xfc0007be) == 0x7c000124)
-#define IS_RFID(instr)		(((instr) & 0xfc0007fe) == 0x4c000024)
-#define IS_RFI(instr)		(((instr) & 0xfc0007fe) == 0x4c000064)
+#define IS_MTMSRD(instr)	((ppc_inst_mask((instr), 0xfc0007be) == 0x7c000124))
+#define IS_RFID(instr)		((ppc_inst_mask((instr), 0xfc0007fe) == 0x4c000024))
+#define IS_RFI(instr)		((ppc_inst_mask((instr), 0xfc0007fe) == 0x4c000064))
 
 enum instruction_type {
 	COMPUTE,		/* arith/logical/CR op, etc. */
diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c
index 6008f14a145b..38542fffa179 100644
--- a/arch/powerpc/kernel/align.c
+++ b/arch/powerpc/kernel/align.c
@@ -331,7 +331,7 @@  int fix_alignment(struct pt_regs *regs)
 	 * when pasting to a co-processor. Furthermore, paste_last is the
 	 * synchronisation point for preceding copy/paste sequences.
 	 */
-	if ((instr & 0xfc0006fe) == (PPC_INST_COPY & 0xfc0006fe))
+	if (ppc_inst_mask(instr, 0xfc0006fe) == (PPC_INST_COPY & 0xfc0006fe))
 		return -EIO;
 
 	r = analyse_instr(&op, regs, instr);
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
index 380f1ce77715..b189a34baaa2 100644
--- a/arch/powerpc/kernel/trace/ftrace.c
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -98,19 +98,19 @@  static ppc_inst test_24bit_addr(unsigned long ip, unsigned long addr)
 
 static int is_bl_op(ppc_inst op)
 {
-	return (op & 0xfc000003) == 0x48000001;
+	return ppc_inst_mask(op, 0xfc000003) == 0x48000001;
 }
 
 static int is_b_op(ppc_inst op)
 {
-	return (op & 0xfc000003) == 0x48000000;
+	return ppc_inst_mask(op, 0xfc000003) == 0x48000000;
 }
 
 static unsigned long find_bl_target(unsigned long ip, ppc_inst op)
 {
 	int offset;
 
-	offset = (op & 0x03fffffc);
+	offset = ppc_inst_mask(op, 0x03fffffc);
 	/* make it signed */
 	if (offset & 0x02000000)
 		offset |= 0xfe000000;
@@ -494,7 +494,7 @@  expected_nop_sequence(void *ip, ppc_inst op0, ppc_inst op1)
 	 * The load offset is different depending on the ABI. For simplicity
 	 * just mask it out when doing the compare.
 	 */
-	if ((op0 != 0x48000008) || ((op1 & 0xffff0000) != 0xe8410000))
+	if ((op0 != 0x48000008) || (ppc_inst_mask(op1, 0xffff0000) != 0xe8410000))
 		return 0;
 	return 1;
 }
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 5d69e836337d..e2ba23fd6f4d 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -301,7 +301,7 @@  static int instr_is_branch_bform(ppc_inst instr)
 
 int instr_is_relative_branch(ppc_inst instr)
 {
-	if (instr & BRANCH_ABSOLUTE)
+	if (ppc_inst_mask(instr, BRANCH_ABSOLUTE))
 		return 0;
 
 	return instr_is_branch_iform(instr) || instr_is_branch_bform(instr);
@@ -309,20 +309,20 @@  int instr_is_relative_branch(ppc_inst instr)
 
 int instr_is_relative_link_branch(ppc_inst instr)
 {
-	return instr_is_relative_branch(instr) && (instr & BRANCH_SET_LINK);
+	return instr_is_relative_branch(instr) && ppc_inst_mask(instr, BRANCH_SET_LINK);
 }
 
 static unsigned long branch_iform_target(const ppc_inst *instr)
 {
 	signed long imm;
 
-	imm = *instr & 0x3FFFFFC;
+	imm = ppc_inst_mask(*instr, 0x3FFFFFC);
 
 	/* If the top bit of the immediate value is set this is negative */
 	if (imm & 0x2000000)
 		imm -= 0x4000000;
 
-	if ((*instr & BRANCH_ABSOLUTE) == 0)
+	if ((ppc_inst_mask(*instr, BRANCH_ABSOLUTE)) == 0)
 		imm += (unsigned long)instr;
 
 	return (unsigned long)imm;
@@ -332,13 +332,13 @@  static unsigned long branch_bform_target(const ppc_inst *instr)
 {
 	signed long imm;
 
-	imm = *instr & 0xFFFC;
+	imm = ppc_inst_mask(*instr, 0xFFFC);
 
 	/* If the top bit of the immediate value is set this is negative */
 	if (imm & 0x8000)
 		imm -= 0x10000;
 
-	if ((*instr & BRANCH_ABSOLUTE) == 0)
+	if ((ppc_inst_mask(*instr, BRANCH_ABSOLUTE)) == 0)
 		imm += (unsigned long)instr;
 
 	return (unsigned long)imm;