[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Xen-devel] [PATCH v2 3/3] xen/arm: fix mask calculation in pdx_init_mask
- To: Stefano Stabellini <sstabellini@xxxxxxxxxx>, Jan Beulich <JBeulich@xxxxxxxx>
- From: Julien Grall <julien.grall@xxxxxxx>
- Date: Mon, 3 Jun 2019 23:02:35 +0100
- Cc: Stefano Stabellini <stefanos@xxxxxxxxxx>, Wei Liu <wei.liu2@xxxxxxxxxx>, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>, George Dunlap <George.Dunlap@xxxxxxxxxxxxx>, Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>, Tim Deegan <tim@xxxxxxx>, xen-devel <xen-devel@xxxxxxxxxxxxxxxxxxxx>
- Delivery-date: Mon, 03 Jun 2019 22:02:43 +0000
- List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
Hi Stefano,
On 6/3/19 10:56 PM, Stefano Stabellini wrote:
On Thu, 9 May 2019, Jan Beulich wrote:
On 09.05.19 at 00:47, <sstabellini@xxxxxxxxxx> wrote:
--- a/xen/common/pdx.c
+++ b/xen/common/pdx.c
@@ -50,9 +50,13 @@ static u64 __init fill_mask(u64 mask)
return mask;
}
+/*
+ * We always map the first 1<<MAX_ORDER pages of RAM, hence, they
+ * are left uncompressed.
+ */
u64 __init pdx_init_mask(u64 base_addr)
{
- return fill_mask(base_addr - 1);
+ return fill_mask(max(base_addr, (u64)1 << (MAX_ORDER + PAGE_SHIFT)) - 1);
Personally I think that despite the surrounding u64 this should be
uint64_t. You could avoid this altogether by using 1ULL.
I cannot use 1ULL because it would break the build: the reason is that
u64 is defined as unsigned long on some architectures and unsigned long
long on others. The pointers comparison in the max macro will fail to
compile.
I could use uint64_t, that works, but I think is not a good idea to use
potentially different types between the arguments passed to max. If you
still would like me to change (u64)1 to (uint64_t)1 please explain why
in more details.
We are phasing out uXX in favor of uintXX_t so I agree with Jan that we
want to avoid introducing more here.
Except the way they are defined, u64 and uint64_t will always be equal
to 64-bits. So you can easily update the interface to use uint64_t
instead of u64 without worrying about type issue.
Cheers,
--
Julien Grall
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel
|
