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arm64: map kernel using large pages when page size is 16K

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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
This commit is contained in:
Alan Cox 2024-05-11 01:09:39 -05:00
parent 47535ba3d3
commit 94b09d388b
1 changed files with 19 additions and 7 deletions
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26
sys/arm64/arm64/locore.S
View file

@ -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]