[tip: x86/mm] x86/mm: Change cpa_flush() to call flush_kernel_range() directly

From: tip-bot2 for Yu-cheng Yu
Date: Fri Aug 22 2025 - 13:43:34 EST


The following commit has been merged into the x86/mm branch of tip:

Commit-ID: 86e6815b316ec0ea8c4bb3c16a033219a52b6060
Gitweb: https://git.kernel.org/tip/86e6815b316ec0ea8c4bb3c16a033219a52b6060
Author: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
AuthorDate: Fri, 06 Jun 2025 13:10:35 -04:00
Committer: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
CommitterDate: Fri, 22 Aug 2025 07:55:21 -07:00

x86/mm: Change cpa_flush() to call flush_kernel_range() directly

The function cpa_flush() calls __flush_tlb_one_kernel() and
flush_tlb_all().

Replacing that with a call to flush_tlb_kernel_range() allows
cpa_flush() to make use of INVLPGB or RAR without any additional
changes.

Initialize invlpgb_count_max to 1, since flush_tlb_kernel_range()
can now be called before invlpgb_count_max has been initialized
to the value read from CPUID.

[riel: remove now unused __cpa_flush_tlb]

Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
Signed-off-by: Rik van Riel <riel@xxxxxxxxxxx>
Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20250606171112.4013261-4-riel%40surriel.com
---
arch/x86/mm/pat/set_memory.c | 20 +++++++-------------
1 file changed, 7 insertions(+), 13 deletions(-)

diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index 8834c76..d2d54b8 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -399,15 +399,6 @@ static void cpa_flush_all(unsigned long cache)
on_each_cpu(__cpa_flush_all, (void *) cache, 1);
}

-static void __cpa_flush_tlb(void *data)
-{
- struct cpa_data *cpa = data;
- unsigned int i;
-
- for (i = 0; i < cpa->numpages; i++)
- flush_tlb_one_kernel(fix_addr(__cpa_addr(cpa, i)));
-}
-
static int collapse_large_pages(unsigned long addr, struct list_head *pgtables);

static void cpa_collapse_large_pages(struct cpa_data *cpa)
@@ -444,6 +435,7 @@ static void cpa_collapse_large_pages(struct cpa_data *cpa)

static void cpa_flush(struct cpa_data *cpa, int cache)
{
+ unsigned long start, end;
unsigned int i;

BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
@@ -453,10 +445,12 @@ static void cpa_flush(struct cpa_data *cpa, int cache)
goto collapse_large_pages;
}

- if (cpa->force_flush_all || cpa->numpages > tlb_single_page_flush_ceiling)
- flush_tlb_all();
- else
- on_each_cpu(__cpa_flush_tlb, cpa, 1);
+ start = fix_addr(__cpa_addr(cpa, 0));
+ end = fix_addr(__cpa_addr(cpa, cpa->numpages));
+ if (cpa->force_flush_all)
+ end = TLB_FLUSH_ALL;
+
+ flush_tlb_kernel_range(start, end);

if (!cache)
goto collapse_large_pages;