[PATCH 4.18 004/171] powerpc/mm: fix always true/false warning in slice.c

Greg Kroah-Hartman
2018-11-19T16:40:51Z

From: Christophe Leroy <christophe.leroy@c-s.fr>

[ Upstream commit 37e9c674e7e6f445e12cb1151017bd4bacdd1e2d ]

This patch fixes the following warnings (obtained with make W=1).

arch/powerpc/mm/slice.c: In function 'slice_range_to_mask':
arch/powerpc/mm/slice.c:73:12: error: comparison is always true due to limited range of data type [-Werror=type-limits]
if (start < SLICE_LOW_TOP) {
^
arch/powerpc/mm/slice.c:81:20: error: comparison is always false due to limited range of data type [-Werror=type-limits]
if ((start + len) > SLICE_LOW_TOP) {
^
arch/powerpc/mm/slice.c: In function 'slice_mask_for_free':
arch/powerpc/mm/slice.c:136:17: error: comparison is always true due to limited range of data type [-Werror=type-limits]
if (high_limit <= SLICE_LOW_TOP)
^
arch/powerpc/mm/slice.c: In function 'slice_check_range_fits':
arch/powerpc/mm/slice.c:185:12: error: comparison is always true due to limited range of data type [-Werror=type-limits]
if (start < SLICE_LOW_TOP) {
^
arch/powerpc/mm/slice.c:195:39: error: comparison is always false due to limited range of data type [-Werror=type-limits]
if (SLICE_NUM_HIGH && ((start + len) > SLICE_LOW_TOP)) {
^
arch/powerpc/mm/slice.c: In function 'slice_scan_available':
arch/powerpc/mm/slice.c:306:11: error: comparison is always true due to limited range of data type [-Werror=type-limits]
if (addr < SLICE_LOW_TOP) {
^
arch/powerpc/mm/slice.c: In function 'get_slice_psize':
arch/powerpc/mm/slice.c:709:11: error: comparison is always true due to limited range of data type [-Werror=type-limits]
if (addr < SLICE_LOW_TOP) {
^

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/powerpc/mm/slice.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)

--- a/arch/powerpc/mm/slice.c
+++ b/arch/powerpc/mm/slice.c
@@ -61,6 +61,13 @@ static void slice_print_mask(const char

#endif

+static inline bool slice_addr_is_low(unsigned long addr)
+{
+ u64 tmp = (u64)addr;
+
+ return tmp < SLICE_LOW_TOP;
+}
+
static void slice_range_to_mask(unsigned long start, unsigned long len,
struct slice_mask *ret)
{
@@ -70,7 +77,7 @@ static void slice_range_to_mask(unsigned
if (SLICE_NUM_HIGH)
bitmap_zero(ret->high_slices, SLICE_NUM_HIGH);

- if (start < SLICE_LOW_TOP) {
+ if (slice_addr_is_low(start)) {
unsigned long mend = min(end,
(unsigned long)(SLICE_LOW_TOP - 1));

@@ -78,7 +85,7 @@ static void slice_range_to_mask(unsigned
- (1u << GET_LOW_SLICE_INDEX(start));
}

- if ((start + len) > SLICE_LOW_TOP) {
+ if (SLICE_NUM_HIGH && !slice_addr_is_low(end)) {
unsigned long start_index = GET_HIGH_SLICE_INDEX(start);
unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT));
unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index;
@@ -133,7 +140,7 @@ static void slice_mask_for_free(struct m
if (!slice_low_has_vma(mm, i))
ret->low_slices |= 1u << i;

- if (high_limit <= SLICE_LOW_TOP)
+ if (slice_addr_is_low(high_limit - 1))
return;

for (i = 0; i < GET_HIGH_SLICE_INDEX(high_limit); i++)
@@ -182,7 +189,7 @@ static bool slice_check_range_fits(struc
unsigned long end = start + len - 1;
u64 low_slices = 0;

- if (start < SLICE_LOW_TOP) {
+ if (slice_addr_is_low(start)) {
unsigned long mend = min(end,
(unsigned long)(SLICE_LOW_TOP - 1));

@@ -192,7 +199,7 @@ static bool slice_check_range_fits(struc
if ((low_slices & available->low_slices) != low_slices)
return false;

- if (SLICE_NUM_HIGH && ((start + len) > SLICE_LOW_TOP)) {
+ if (SLICE_NUM_HIGH && !slice_addr_is_low(end)) {
unsigned long start_index = GET_HIGH_SLICE_INDEX(start);
unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT));
unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index;
@@ -303,7 +310,7 @@ static bool slice_scan_available(unsigne
int end, unsigned long *boundary_addr)
{
unsigned long slice;
- if (addr < SLICE_LOW_TOP) {
+ if (slice_addr_is_low(addr)) {
slice = GET_LOW_SLICE_INDEX(addr);
*boundary_addr = (slice + end) << SLICE_LOW_SHIFT;
return !!(available->low_slices & (1u << slice));
@@ -706,7 +713,7 @@ unsigned int get_slice_psize(struct mm_s

VM_BUG_ON(radix_enabled());

- if (addr < SLICE_LOW_TOP) {
+ if (slice_addr_is_low(addr)) {
psizes = mm->context.low_slices_psize;
index = GET_LOW_SLICE_INDEX(addr);
} else {