The branch main has been updated by alc:
URL:
https://cgit.FreeBSD.org/src/commit/?id=94b09d388b81eb724769e506cdf0f51bba9b73fb
commit 94b09d388b81eb724769e506cdf0f51bba9b73fb
Author: Alan Cox <a...@freebsd.org>
AuthorDate: 2024-05-11 06:09:39 +0000
Commit: Alan Cox <a...@freebsd.org>
CommitDate: 2024-05-12 23:22:38 +0000
arm64: map kernel using large pages when page size is 16K
When the page size is 16K, use ATTR_CONTIGUOUS to map the kernel code
and data sections using 2M pages. Previously, they were mapped using
16K pages.
Reviewed by: markj
Tested by: markj
Differential Revision: https://reviews.freebsd.org/D45162
---
sys/arm64/arm64/locore.S | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/sys/arm64/arm64/locore.S b/sys/arm64/arm64/locore.S
index f53cd365de55..fffebe8f2b02 100644
--- a/sys/arm64/arm64/locore.S
+++ b/sys/arm64/arm64/locore.S
@@ -516,11 +516,10 @@ booti_no_fdt:
common:
#if PAGE_SIZE != PAGE_SIZE_4K
/*
- * Create L3 pages. The kernel will be loaded at a 2M aligned
- * address, however L2 blocks are too large when the page size is
- * not 4k to map the kernel with such an aligned address. However,
- * when the page size is larger than 4k, L2 blocks are too large to
- * map the kernel with such an alignment.
+ * Create L3 and L3C pages. The kernel will be loaded at a 2M aligned
+ * address, enabling the creation of L3C pages. However, when the page
+ * size is larger than 4k, L2 blocks are too large to map the kernel
+ * with 2M alignment.
*/
#define PTE_SHIFT L3_SHIFT
#define BUILD_PTE_FUNC build_l3_page_pagetable
@@ -784,13 +783,17 @@ LENTRY(link_l2_pagetable)
LEND(link_l2_pagetable)
/*
- * Builds count level 3 page table entries
+ * Builds count level 3 page table entries. Uses ATTR_CONTIGUOUS to create
+ * large page (L3C) mappings when the current VA and remaining count allow
+ * it.
* x6 = L3 table
* x7 = Block attributes
* x8 = VA start
* x9 = PA start (trashed)
* x10 = Entry count (trashed)
* x11, x12 and x13 are trashed
+ *
+ * VA start (x8) modulo L3C_SIZE must equal PA start (x9) modulo L3C_SIZE.
*/
LENTRY(build_l3_page_pagetable)
/*
@@ -811,8 +814,17 @@ LENTRY(build_l3_page_pagetable)
/* Only use the output address bits */
lsr x9, x9, #L3_SHIFT
+ /* Check if an ATTR_CONTIGUOUS mapping is possible */
+1: tst x11, #(L3C_ENTRIES - 1)
+ b.ne 2f
+ cmp x10, #L3C_ENTRIES
+ b.lo 3f
+ orr x12, x12, #(ATTR_CONTIGUOUS)
+ b 2f
+3: and x12, x12, #(~ATTR_CONTIGUOUS)
+
/* Set the physical address for this virtual address */
-1: orr x13, x12, x9, lsl #L3_SHIFT
+2: orr x13, x12, x9, lsl #L3_SHIFT
/* Store the entry */
str x13, [x6, x11, lsl #3]
