[PATCH v5] powerpc/traps: Enhance readability for trap types

From: Xiongwei Song
Date: Wed Apr 14 2021 - 07:07:40 EST


From: Xiongwei Song <sxwjean@xxxxxxxxx>

Define macros to list ppc interrupt types in interttupt.h, replace the
reference of the trap hex values with these macros.

Referred the hex numbers in arch/powerpc/kernel/exceptions-64e.S,
arch/powerpc/kernel/exceptions-64s.S, arch/powerpc/kernel/head_*.S,
arch/powerpc/kernel/head_booke.h and arch/powerpc/include/asm/kvm_asm.h.

v4-v5:
* Delete unnecessary #ifdef.
* Move INTERRUPT_* macros to interttupt.h, classify for different cpu
types. Drop traps.h.
* Directly define INTERRUPT_MACHINE_CHECK with 0x200.

v3-v4:
Fix compile issue:
arch/powerpc/kernel/process.c:1473:14: error: 'INTERRUPT_MACHINE_CHECK' undeclared (first use in this function); did you mean 'TAINT_MACHINE_CHECK'?
Reported-by: kernel test robot <lkp@xxxxxxxxx>

v2-v3:
Correct the prefix of trap macros with INTERRUPT_, the previous prefix
is TRAP_, which is not precise. This is suggested by Segher Boessenkool
and Nicholas Piggin.

v1-v2:
Define more trap macros to replace more trap hexs in code, not just for
the __show_regs function. This is suggested by Christophe Leroy.

Signed-off-by: Xiongwei Song <sxwjean@xxxxxxxxx>
---
arch/powerpc/include/asm/interrupt.h | 48 +++++++++++++++++++++++++--
arch/powerpc/kernel/fadump.c | 2 +-
arch/powerpc/kernel/interrupt.c | 2 +-
arch/powerpc/kernel/process.c | 4 ++-
arch/powerpc/kernel/traps.c | 6 ++--
arch/powerpc/kexec/crash.c | 3 +-
arch/powerpc/mm/book3s64/hash_utils.c | 4 +--
arch/powerpc/mm/fault.c | 16 ++++-----
arch/powerpc/perf/core-book3s.c | 5 +--
arch/powerpc/xmon/xmon.c | 20 +++++++----
10 files changed, 81 insertions(+), 29 deletions(-)

diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h
index 05e7fc4ffb50..86daf1242088 100644
--- a/arch/powerpc/include/asm/interrupt.h
+++ b/arch/powerpc/include/asm/interrupt.h
@@ -9,6 +9,46 @@
#include <asm/kprobes.h>
#include <asm/runlatch.h>

+/* BookE/4xx */
+#define INTERRUPT_CRITICAL_INPUT 0x100
+
+/* BookE */
+#define INTERRUPT_DEBUG 0xd00
+#ifdef CONFIG_BOOKE
+#define INTERRUPT_PERFMON 0x260
+#define INTERRUPT_DOORBELL 0x280
+#endif
+
+/* BookS/4xx/8xx */
+#define INTERRUPT_MACHINE_CHECK 0x200
+
+/* BookS/8xx */
+#define INTERRUPT_SYSTEM_RESET 0x100
+
+/* BookS */
+#define INTERRUPT_DATA_SEGMENT 0x380
+#define INTERRUPT_INST_SEGMENT 0x480
+#define INTERRUPT_TRACE 0xd00
+#define INTERRUPT_H_DATA_STORAGE 0xe00
+#define INTERRUPT_H_FAC_UNAVAIL 0xf80
+#ifdef CONFIG_PPC_BOOK3S
+#define INTERRUPT_DOORBELL 0xa00
+#define INTERRUPT_PERFMON 0xf00
+#endif
+
+/* BookE/BookS/4xx/8xx */
+#define INTERRUPT_DATA_STORAGE 0x300
+#define INTERRUPT_INST_STORAGE 0x400
+#define INTERRUPT_ALIGNMENT 0x600
+#define INTERRUPT_PROGRAM 0x700
+#define INTERRUPT_SYSCALL 0xc00
+
+/* BookE/BookS/44x */
+#define INTERRUPT_FP_UNAVAIL 0x800
+
+/* BookE/BookS/44x/8xx */
+#define INTERRUPT_DECREMENTER 0x900
+
static inline void nap_adjust_return(struct pt_regs *regs)
{
#ifdef CONFIG_PPC_970_NAP
@@ -70,7 +110,7 @@ static inline void interrupt_enter_prepare(struct pt_regs *regs, struct interrup
* CT_WARN_ON comes here via program_check_exception,
* so avoid recursion.
*/
- if (TRAP(regs) != 0x700)
+ if (TRAP(regs) != INTERRUPT_PROGRAM)
CT_WARN_ON(ct_state() != CONTEXT_KERNEL);
}
#endif
@@ -175,7 +215,8 @@ static inline void interrupt_nmi_enter_prepare(struct pt_regs *regs, struct inte
/* Don't do any per-CPU operations until interrupt state is fixed */
#endif
/* Allow DEC and PMI to be traced when they are soft-NMI */
- if (TRAP(regs) != 0x900 && TRAP(regs) != 0xf00 && TRAP(regs) != 0x260) {
+ if (TRAP(regs) != INTERRUPT_DECREMENTER &&
+ TRAP(regs) != INTERRUPT_PERFMON) {
state->ftrace_enabled = this_cpu_get_ftrace_enabled();
this_cpu_set_ftrace_enabled(0);
}
@@ -204,7 +245,8 @@ static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct inter
*/

#ifdef CONFIG_PPC64
- if (TRAP(regs) != 0x900 && TRAP(regs) != 0xf00 && TRAP(regs) != 0x260)
+ if (TRAP(regs) != INTERRUPT_DECREMENTER &&
+ TRAP(regs) != INTERRUPT_PERFMON)
this_cpu_set_ftrace_enabled(state->ftrace_enabled);

#ifdef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index eddf362caedc..b55b4c23f3b6 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -728,7 +728,7 @@ void crash_fadump(struct pt_regs *regs, const char *str)
* If we came in via system reset, wait a while for the secondary
* CPUs to enter.
*/
- if (TRAP(&(fdh->regs)) == 0x100) {
+ if (TRAP(&(fdh->regs)) == INTERRUPT_SYSTEM_RESET) {
msecs = CRASH_TIMEOUT;
while ((atomic_read(&cpus_in_fadump) < ncpus) && (--msecs > 0))
mdelay(1);
diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
index c4dd4b8f9cfa..9e0f02980494 100644
--- a/arch/powerpc/kernel/interrupt.c
+++ b/arch/powerpc/kernel/interrupt.c
@@ -456,7 +456,7 @@ notrace unsigned long interrupt_exit_kernel_prepare(struct pt_regs *regs, unsign
* CT_WARN_ON comes here via program_check_exception,
* so avoid recursion.
*/
- if (TRAP(regs) != 0x700)
+ if (TRAP(regs) != INTERRUPT_PROGRAM)
CT_WARN_ON(ct_state() == CONTEXT_USER);

kuap = kuap_get_and_assert_locked();
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index b966c8e0cead..53792a999cbb 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1469,7 +1469,9 @@ static void __show_regs(struct pt_regs *regs)
trap = TRAP(regs);
if (!trap_is_syscall(regs) && cpu_has_feature(CPU_FTR_CFAR))
pr_cont("CFAR: "REG" ", regs->orig_gpr3);
- if (trap == 0x200 || trap == 0x300 || trap == 0x600) {
+ if (trap == INTERRUPT_MACHINE_CHECK ||
+ trap == INTERRUPT_DATA_STORAGE ||
+ trap == INTERRUPT_ALIGNMENT) {
if (IS_ENABLED(CONFIG_4xx) || IS_ENABLED(CONFIG_BOOKE))
pr_cont("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr);
else
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index efba99870691..a9b11ba77c4d 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -221,7 +221,7 @@ static void oops_end(unsigned long flags, struct pt_regs *regs,
/*
* system_reset_excption handles debugger, crash dump, panic, for 0x100
*/
- if (TRAP(regs) == 0x100)
+ if (TRAP(regs) == INTERRUPT_SYSTEM_RESET)
return;

crash_fadump(regs, "die oops");
@@ -289,7 +289,7 @@ void die(const char *str, struct pt_regs *regs, long err)
/*
* system_reset_excption handles debugger, crash dump, panic, for 0x100
*/
- if (TRAP(regs) != 0x100) {
+ if (TRAP(regs) != INTERRUPT_SYSTEM_RESET) {
if (debugger(regs))
return;
}
@@ -1682,7 +1682,7 @@ DEFINE_INTERRUPT_HANDLER(facility_unavailable_exception)
u8 status;
bool hv;

- hv = (TRAP(regs) == 0xf80);
+ hv = (TRAP(regs) == INTERRUPT_H_FAC_UNAVAIL);
if (hv)
value = mfspr(SPRN_HFSCR);
else
diff --git a/arch/powerpc/kexec/crash.c b/arch/powerpc/kexec/crash.c
index c9a889880214..0196d0c211ac 100644
--- a/arch/powerpc/kexec/crash.c
+++ b/arch/powerpc/kexec/crash.c
@@ -24,6 +24,7 @@
#include <asm/smp.h>
#include <asm/setjmp.h>
#include <asm/debug.h>
+#include <asm/interrupt.h>

/*
* The primary CPU waits a while for all secondary CPUs to enter. This is to
@@ -336,7 +337,7 @@ void default_machine_crash_shutdown(struct pt_regs *regs)
* If we came in via system reset, wait a while for the secondary
* CPUs to enter.
*/
- if (TRAP(regs) == 0x100)
+ if (TRAP(regs) == INTERRUPT_SYSTEM_RESET)
mdelay(PRIMARY_TIMEOUT);

crash_kexec_prepare_cpus(crashing_cpu);
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index 7719995323c3..ab49216c0ef3 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -1145,7 +1145,7 @@ unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap)

/* page is dirty */
if (!test_bit(PG_dcache_clean, &page->flags) && !PageReserved(page)) {
- if (trap == 0x400) {
+ if (trap == INTERRUPT_INST_STORAGE) {
flush_dcache_icache_page(page);
set_bit(PG_dcache_clean, &page->flags);
} else
@@ -1545,7 +1545,7 @@ DEFINE_INTERRUPT_HANDLER_RET(__do_hash_fault)
if (user_mode(regs) || (region_id == USER_REGION_ID))
access &= ~_PAGE_PRIVILEGED;

- if (TRAP(regs) == 0x400)
+ if (TRAP(regs) == INTERRUPT_INST_STORAGE)
access |= _PAGE_EXEC;

err = hash_page_mm(mm, ea, access, TRAP(regs), flags);
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c
index 0c0b1c2cfb49..25523f371c79 100644
--- a/arch/powerpc/mm/fault.c
+++ b/arch/powerpc/mm/fault.c
@@ -197,7 +197,7 @@ static int mm_fault_error(struct pt_regs *regs, unsigned long addr,
static bool bad_kernel_fault(struct pt_regs *regs, unsigned long error_code,
unsigned long address, bool is_write)
{
- int is_exec = TRAP(regs) == 0x400;
+ int is_exec = TRAP(regs) == INTERRUPT_INST_STORAGE;

/* NX faults set DSISR_PROTFAULT on the 8xx, DSISR_NOEXEC_OR_G on others */
if (is_exec && (error_code & (DSISR_NOEXEC_OR_G | DSISR_KEYFAULT |
@@ -391,7 +391,7 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address,
struct vm_area_struct * vma;
struct mm_struct *mm = current->mm;
unsigned int flags = FAULT_FLAG_DEFAULT;
- int is_exec = TRAP(regs) == 0x400;
+ int is_exec = TRAP(regs) == INTERRUPT_INST_STORAGE;
int is_user = user_mode(regs);
int is_write = page_fault_is_write(error_code);
vm_fault_t fault, major = 0;
@@ -588,20 +588,20 @@ void __bad_page_fault(struct pt_regs *regs, int sig)
/* kernel has accessed a bad area */

switch (TRAP(regs)) {
- case 0x300:
- case 0x380:
- case 0xe00:
+ case INTERRUPT_DATA_STORAGE:
+ case INTERRUPT_DATA_SEGMENT:
+ case INTERRUPT_H_DATA_STORAGE:
pr_alert("BUG: %s on %s at 0x%08lx\n",
regs->dar < PAGE_SIZE ? "Kernel NULL pointer dereference" :
"Unable to handle kernel data access",
is_write ? "write" : "read", regs->dar);
break;
- case 0x400:
- case 0x480:
+ case INTERRUPT_INST_STORAGE:
+ case INTERRUPT_INST_SEGMENT:
pr_alert("BUG: Unable to handle kernel instruction fetch%s",
regs->nip < PAGE_SIZE ? " (NULL pointer?)\n" : "\n");
break;
- case 0x600:
+ case INTERRUPT_ALIGNMENT:
pr_alert("BUG: Unable to handle kernel unaligned access at 0x%08lx\n",
regs->dar);
break;
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 766f064f00fb..2ae6126ac8f2 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -17,6 +17,7 @@
#include <asm/firmware.h>
#include <asm/ptrace.h>
#include <asm/code-patching.h>
+#include <asm/interrupt.h>

#ifdef CONFIG_PPC64
#include "internal.h"
@@ -168,7 +169,7 @@ static bool regs_use_siar(struct pt_regs *regs)
* they have not been setup using perf_read_regs() and so regs->result
* is something random.
*/
- return ((TRAP(regs) == 0xf00) && regs->result);
+ return ((TRAP(regs) == INTERRUPT_PERFMON) && regs->result);
}

/*
@@ -347,7 +348,7 @@ static inline void perf_read_regs(struct pt_regs *regs)
* hypervisor samples as well as samples in the kernel with
* interrupts off hence the userspace check.
*/
- if (TRAP(regs) != 0xf00)
+ if (TRAP(regs) != INTERRUPT_PERFMON)
use_siar = 0;
else if ((ppmu->flags & PPMU_NO_SIAR))
use_siar = 0;
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 3fe37495f63d..62544a7ab437 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -54,6 +54,7 @@
#include <asm/code-patching.h>
#include <asm/sections.h>
#include <asm/inst.h>
+#include <asm/interrupt.h>

#ifdef CONFIG_PPC64
#include <asm/hvcall.h>
@@ -605,7 +606,7 @@ static int xmon_core(struct pt_regs *regs, int fromipi)
* debugger break (IPI). This is similar to
* crash_kexec_secondary().
*/
- if (TRAP(regs) != 0x100 || !wait_for_other_cpus(ncpus))
+ if (TRAP(regs) != INTERRUPT_SYSTEM_RESET || !wait_for_other_cpus(ncpus))
smp_send_debugger_break();

wait_for_other_cpus(ncpus);
@@ -615,7 +616,7 @@ static int xmon_core(struct pt_regs *regs, int fromipi)

if (!locked_down) {
/* for breakpoint or single step, print curr insn */
- if (bp || TRAP(regs) == 0xd00)
+ if (bp || TRAP(regs) == INTERRUPT_TRACE)
ppc_inst_dump(regs->nip, 1, 0);
printf("enter ? for help\n");
}
@@ -684,7 +685,7 @@ static int xmon_core(struct pt_regs *regs, int fromipi)
disable_surveillance();
if (!locked_down) {
/* for breakpoint or single step, print current insn */
- if (bp || TRAP(regs) == 0xd00)
+ if (bp || TRAP(regs) == INTERRUPT_TRACE)
ppc_inst_dump(regs->nip, 1, 0);
printf("enter ? for help\n");
}
@@ -1769,9 +1770,12 @@ static void excprint(struct pt_regs *fp)
printf(" sp: %lx\n", fp->gpr[1]);
printf(" msr: %lx\n", fp->msr);

- if (trap == 0x300 || trap == 0x380 || trap == 0x600 || trap == 0x200) {
+ if (trap == INTERRUPT_DATA_STORAGE ||
+ trap == INTERRUPT_DATA_SEGMENT ||
+ trap == INTERRUPT_ALIGNMENT ||
+ trap == INTERRUPT_MACHINE_CHECK) {
printf(" dar: %lx\n", fp->dar);
- if (trap != 0x380)
+ if (trap != INTERRUPT_DATA_SEGMENT)
printf(" dsisr: %lx\n", fp->dsisr);
}

@@ -1785,7 +1789,7 @@ static void excprint(struct pt_regs *fp)
current->pid, current->comm);
}

- if (trap == 0x700)
+ if (trap == INTERRUPT_PROGRAM)
print_bug_trap(fp);

printf(linux_banner);
@@ -1846,7 +1850,9 @@ static void prregs(struct pt_regs *fp)
printf("ctr = "REG" xer = "REG" trap = %4lx\n",
fp->ctr, fp->xer, fp->trap);
trap = TRAP(fp);
- if (trap == 0x300 || trap == 0x380 || trap == 0x600)
+ if (trap == INTERRUPT_DATA_STORAGE ||
+ trap == INTERRUPT_DATA_SEGMENT ||
+ trap == INTERRUPT_ALIGNMENT)
printf("dar = "REG" dsisr = %.8lx\n", fp->dar, fp->dsisr);
}

--
2.26.1