Re: [PATCH RFC v2 15/27] arm64: mte: Check that tag storage blocks are in the same zone

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 19.11.23 17:57, Alexandru Elisei wrote:
alloc_contig_range() requires that the requested pages are in the same
zone. Check that this is indeed the case before initializing the tag
storage blocks.

Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
---
  arch/arm64/kernel/mte_tag_storage.c | 33 +++++++++++++++++++++++++++++
  1 file changed, 33 insertions(+)

diff --git a/arch/arm64/kernel/mte_tag_storage.c b/arch/arm64/kernel/mte_tag_storage.c
index 8b9bedf7575d..fd63430d4dc0 100644
--- a/arch/arm64/kernel/mte_tag_storage.c
+++ b/arch/arm64/kernel/mte_tag_storage.c
@@ -265,6 +265,35 @@ void __init mte_tag_storage_init(void)
  	}
  }
+/* alloc_contig_range() requires all pages to be in the same zone. */
+static int __init mte_tag_storage_check_zone(void)
+{
+	struct range *tag_range;
+	struct zone *zone;
+	unsigned long pfn;
+	u32 block_size;
+	int i, j;
+
+	for (i = 0; i < num_tag_regions; i++) {
+		block_size = tag_regions[i].block_size;
+		if (block_size == 1)
+			continue;
+
+		tag_range = &tag_regions[i].tag_range;
+		for (pfn = tag_range->start; pfn <= tag_range->end; pfn += block_size) {
+			zone = page_zone(pfn_to_page(pfn));
+			for (j = 1; j < block_size; j++) {
+				if (page_zone(pfn_to_page(pfn + j)) != zone) {
+					pr_err("Tag storage block pages in different zones");
+					return -EINVAL;
+				}
+			}
+		}
+	}
+
+	 return 0;
+}
+

Looks like something that ordinary CMA provides. See cma_activate_area().

Can't we find a way to let CMA do CMA thingies and only be a user of that? What would be required to make the performance issue you spelled out in the cover letter be gone and not have to open-code that in arch code?

--
Cheers,

David / dhildenb





[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [IETF Annouce]     [Bugtraq]     [Linux OMAP]     [Linux MIPS]     [eCos]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux