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Date:   Fri, 5 Jun 2020 17:16:29 -0700
From:   Andrew Morton <akpm@linux-foundation.org>
To:     Wei Yang <richard.weiyang@gmail.com>
Cc:     Geert Uytterhoeven <geert@linux-m68k.org>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Christian Brauner <christian.brauner@ubuntu.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [Patch v2] lib: test get_count_order/long in test_bitops.c
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On Fri, 5 Jun 2020 23:06:10 +0000 Wei Yang <richard.weiyang@gmail.com> wrote:

> On Thu, Jun 04, 2020 at 02:51:40PM +0200, Geert Uytterhoeven wrote:
> >Hi Wei,
> >
> >On Thu, Jun 4, 2020 at 2:28 PM Wei Yang <richard.weiyang@gmail.com> wrote:
> [...]
> >>
> >> You mean
> >>
> >>        {0x0000000000000003,  2},
> >>        {0x0000000000000004,  2},
> >>        {0x0000000000001fff, 13},
> >>        {0x0000000000002000, 13},
> >>        {0x0000000050000000, 31},
> >>        {0x0000000080000000, 31},
> >>        {0x0000000080003000, 32},
> >
> >Yes, those values.  And those should work with get_count_order_long()
> >on both 32-bit and 64-bit.

Geert meant "no, the values in order_comb[]" :)

We have a table of numbers in order_comb[] so we may as well feed them
into get_count_order_long() (as well as get_count_order()) just for a
bit more testing.

So how about the below?  order_comb_long[] just can't be used on 32-bit
machines because their longs are 32-bit.  If we had a
get_count_order_u64() then we could use it.

I haven't runtime tested this - could you please do so?


static unsigned int order_comb[][2] = {
	{0x00000003,  2},
	{0x00000004,  2},
	{0x00001fff, 13},
	{0x00002000, 13},
	{0x50000000, 31},
	{0x80000000, 31},
	{0x80003000, 32},
};

#ifdef CONFIG_64BIT
static unsigned long order_comb_long[][2] = {
	{0x0000000300000000, 34},
	{0x0000000400000000, 34},
	{0x00001fff00000000, 45},
	{0x0000200000000000, 45},
	{0x5000000000000000, 63},
	{0x8000000000000000, 63},
	{0x8000300000000000, 64},
};
#endif

static int __init test_bitops_startup(void)
{
	int i;

	pr_warn("Loaded test module\n");
	set_bit(BITOPS_4, g_bitmap);
	set_bit(BITOPS_7, g_bitmap);
	set_bit(BITOPS_11, g_bitmap);
	set_bit(BITOPS_31, g_bitmap);
	set_bit(BITOPS_88, g_bitmap);

	for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
		if (order_comb[i][1] != get_count_order(order_comb[i][0]))
			pr_warn("get_count_order wrong for %x\n",
				       order_comb[i][0]);
	}

	for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
		if (order_comb[i][1] != get_count_order_long(order_comb[i][0]))
			pr_warn("get_count_order_long wrong for %x\n",
				       order_comb[i][0]);
	}

#ifdef CONFIG_64BIT
	for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
		if (order_comb_long[i][1] !=
			       get_count_order_long(order_comb_long[i][0]))
			pr_warn("get_count_order_long wrong for %lx\n",
				       order_comb_long[i][0]);
	}
#endif
	return 0;
}


From: Andrew Morton <akpm@linux-foundation.org>
Subject: lib-test-get_count_order-long-in-test_bitopsc-fix

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/test_bitops.c |   23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

--- a/lib/test_bitops.c~lib-test-get_count_order-long-in-test_bitopsc-fix
+++ a/lib/test_bitops.c
@@ -28,7 +28,7 @@ enum bitops_fun {
 
 static DECLARE_BITMAP(g_bitmap, BITOPS_LENGTH);
 
-unsigned int order_comb[][2] = {
+static unsigned int order_comb[][2] = {
 	{0x00000003,  2},
 	{0x00000004,  2},
 	{0x00001fff, 13},
@@ -38,7 +38,8 @@ unsigned int order_comb[][2] = {
 	{0x80003000, 32},
 };
 
-unsigned long order_comb_long[][2] = {
+#ifdef CONFIG_64BIT
+static unsigned long order_comb_long[][2] = {
 	{0x0000000300000000, 34},
 	{0x0000000400000000, 34},
 	{0x00001fff00000000, 45},
@@ -47,6 +48,7 @@ unsigned long order_comb_long[][2] = {
 	{0x8000000000000000, 63},
 	{0x8000300000000000, 64},
 };
+#endif
 
 static int __init test_bitops_startup(void)
 {
@@ -62,14 +64,23 @@ static int __init test_bitops_startup(vo
 	for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
 		if (order_comb[i][1] != get_count_order(order_comb[i][0]))
 			pr_warn("get_count_order wrong for %x\n",
-				       order_comb[i][0]); }
+				       order_comb[i][0]);
+	}
 
-	for (i = 0; i < ARRAY_SIZE(order_comb_long); i++) {
+	for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
+		if (order_comb[i][1] != get_count_order_long(order_comb[i][0]))
+			pr_warn("get_count_order_long wrong for %x\n",
+				       order_comb[i][0]);
+	}
+
+#ifdef CONFIG_64BIT
+	for (i = 0; i < ARRAY_SIZE(order_comb); i++) {
 		if (order_comb_long[i][1] !=
 			       get_count_order_long(order_comb_long[i][0]))
 			pr_warn("get_count_order_long wrong for %lx\n",
-				       order_comb_long[i][0]); }
-
+				       order_comb_long[i][0]);
+	}
+#endif
 	return 0;
 }
 
_