From: Brendan Jackman <jackmanb@google.com>
To: Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@kernel.org>
Cc: linux-kernel@vger.kernel.org, Brendan Jackman <jackmanb@google.com>
Subject: [PATCH v2 3/3] x86/mm: drop unused returns from direct map setup functions
Date: Sun, 03 May 2026 13:04:56 +0000 [thread overview]
Message-ID: <20260503-x86-init-cleanup-v2-3-bb690bd2477c@google.com> (raw)
In-Reply-To: <20260503-x86-init-cleanup-v2-0-bb690bd2477c@google.com>
Nothing looks at these return values. Furthermore, as discussed in [0],
it seems like in the case of a pre-existing 4K mapping, the return value
of kernel_physical_mapping_init() is wrong anyway. So, just stop
returning a value.
Signed-off-by: Brendan Jackman <jackmanb@google.com>
---
arch/x86/mm/init_32.c | 5 +--
arch/x86/mm/init_64.c | 96 ++++++++++++++++-------------------------------
arch/x86/mm/mm_internal.h | 11 ++----
3 files changed, 38 insertions(+), 74 deletions(-)
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 0908c44d51e6f..05c456dc9855f 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -245,14 +245,13 @@ static inline int is_x86_32_kernel_text(unsigned long addr)
* of max_low_pfn pages, by creating page tables starting from address
* PAGE_OFFSET:
*/
-unsigned long __init
+void __init
kernel_physical_mapping_init(unsigned long start,
unsigned long end,
unsigned long page_size_mask,
pgprot_t prot)
{
int use_pse = page_size_mask == (1<<PG_LEVEL_2M);
- unsigned long last_map_addr = end;
unsigned long start_pfn, end_pfn;
pgd_t *pgd_base = swapper_pg_dir;
int pgd_idx, pmd_idx, pte_ofs;
@@ -356,7 +355,6 @@ kernel_physical_mapping_init(unsigned long start,
pages_4k++;
if (mapping_iter == 1) {
set_pte(pte, pfn_pte(pfn, init_prot));
- last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE;
} else
set_pte(pte, pfn_pte(pfn, prot));
}
@@ -382,7 +380,6 @@ kernel_physical_mapping_init(unsigned long start,
mapping_iter = 2;
goto repeat;
}
- return last_map_addr;
}
#ifdef CONFIG_HIGHMEM
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index df2261fa4f985..1a22254e9e234 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -464,16 +464,12 @@ void __init cleanup_highmap(void)
}
}
-/*
- * Create PTE level page table mapping for physical addresses.
- * It returns the last physical address mapped.
- */
-static unsigned long __meminit
+/* Create PTE level page table mapping for physical addresses. */
+static void __meminit
phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end,
pgprot_t prot, bool init)
{
unsigned long pages = 0, paddr_next;
- unsigned long paddr_last = paddr_end;
pte_t *pte;
int i;
@@ -506,25 +502,20 @@ phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end,
pages++;
set_pte_init(pte, pfn_pte(paddr >> PAGE_SHIFT, prot), init);
- paddr_last = (paddr & PAGE_MASK) + PAGE_SIZE;
}
update_page_count(PG_LEVEL_4K, pages);
-
- return paddr_last;
}
/*
* Create PMD level page table mapping for physical addresses. The virtual
* and physical address have to be aligned at this level.
- * It returns the last physical address mapped.
*/
-static unsigned long __meminit
+static void __meminit
phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
unsigned long page_size_mask, pgprot_t prot, bool init)
{
unsigned long pages = 0, paddr_next;
- unsigned long paddr_last = paddr_end;
int i = pmd_index(paddr);
@@ -548,9 +539,7 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
if (!pmd_leaf(*pmd)) {
spin_lock(&init_mm.page_table_lock);
pte = (pte_t *)pmd_page_vaddr(*pmd);
- paddr_last = phys_pte_init(pte, paddr,
- paddr_end, prot,
- init);
+ phys_pte_init(pte, paddr, paddr_end, prot, init);
spin_unlock(&init_mm.page_table_lock);
continue;
}
@@ -569,7 +558,6 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
if (page_size_mask & (1 << PG_LEVEL_2M)) {
if (!after_bootmem)
pages++;
- paddr_last = paddr_next;
continue;
}
new_prot = pte_pgprot(pte_clrhuge(*(pte_t *)pmd));
@@ -582,33 +570,29 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
pfn_pmd(paddr >> PAGE_SHIFT, prot_sethuge(prot)),
init);
spin_unlock(&init_mm.page_table_lock);
- paddr_last = paddr_next;
continue;
}
pte = alloc_low_page();
- paddr_last = phys_pte_init(pte, paddr, paddr_end, new_prot, init);
+ phys_pte_init(pte, paddr, paddr_end, new_prot, init);
spin_lock(&init_mm.page_table_lock);
pmd_populate_kernel_init(&init_mm, pmd, pte, init);
spin_unlock(&init_mm.page_table_lock);
}
update_page_count(PG_LEVEL_2M, pages);
- return paddr_last;
}
/*
* Create PUD level page table mapping for physical addresses. The virtual
* and physical address do not have to be aligned at this level. KASLR can
* randomize virtual addresses up to this level.
- * It returns the last physical address mapped.
*/
-static unsigned long __meminit
+static void __meminit
phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
unsigned long page_size_mask, pgprot_t _prot, bool init)
{
unsigned long pages = 0, paddr_next;
- unsigned long paddr_last = paddr_end;
unsigned long vaddr = (unsigned long)__va(paddr);
int i = pud_index(vaddr);
@@ -634,10 +618,8 @@ phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
if (!pud_none(*pud)) {
if (!pud_leaf(*pud)) {
pmd = pmd_offset(pud, 0);
- paddr_last = phys_pmd_init(pmd, paddr,
- paddr_end,
- page_size_mask,
- prot, init);
+ phys_pmd_init(pmd, paddr, paddr_end,
+ page_size_mask, prot, init);
continue;
}
/*
@@ -655,7 +637,6 @@ phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
if (page_size_mask & (1 << PG_LEVEL_1G)) {
if (!after_bootmem)
pages++;
- paddr_last = paddr_next;
continue;
}
prot = pte_pgprot(pte_clrhuge(*(pte_t *)pud));
@@ -668,13 +649,11 @@ phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
pfn_pud(paddr >> PAGE_SHIFT, prot_sethuge(prot)),
init);
spin_unlock(&init_mm.page_table_lock);
- paddr_last = paddr_next;
continue;
}
pmd = alloc_low_page();
- paddr_last = phys_pmd_init(pmd, paddr, paddr_end,
- page_size_mask, prot, init);
+ phys_pmd_init(pmd, paddr, paddr_end, page_size_mask, prot, init);
spin_lock(&init_mm.page_table_lock);
pud_populate_init(&init_mm, pud, pmd, init);
@@ -682,23 +661,22 @@ phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
}
update_page_count(PG_LEVEL_1G, pages);
-
- return paddr_last;
}
-static unsigned long __meminit
+static void __meminit
phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
unsigned long page_size_mask, pgprot_t prot, bool init)
{
- unsigned long vaddr, vaddr_end, vaddr_next, paddr_next, paddr_last;
+ unsigned long vaddr, vaddr_end, vaddr_next, paddr_next;
- paddr_last = paddr_end;
vaddr = (unsigned long)__va(paddr);
vaddr_end = (unsigned long)__va(paddr_end);
- if (!pgtable_l5_enabled())
- return phys_pud_init((pud_t *) p4d_page, paddr, paddr_end,
- page_size_mask, prot, init);
+ if (!pgtable_l5_enabled()) {
+ phys_pud_init((pud_t *) p4d_page, paddr, paddr_end,
+ page_size_mask, prot, init);
+ return;
+ }
for (; vaddr < vaddr_end; vaddr = vaddr_next) {
p4d_t *p4d = p4d_page + p4d_index(vaddr);
@@ -720,33 +698,30 @@ phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
if (!p4d_none(*p4d)) {
pud = pud_offset(p4d, 0);
- paddr_last = phys_pud_init(pud, paddr, __pa(vaddr_end),
- page_size_mask, prot, init);
+ phys_pud_init(pud, paddr, __pa(vaddr_end),
+ page_size_mask, prot, init);
continue;
}
pud = alloc_low_page();
- paddr_last = phys_pud_init(pud, paddr, __pa(vaddr_end),
- page_size_mask, prot, init);
+ phys_pud_init(pud, paddr, __pa(vaddr_end),
+ page_size_mask, prot, init);
spin_lock(&init_mm.page_table_lock);
p4d_populate_init(&init_mm, p4d, pud, init);
spin_unlock(&init_mm.page_table_lock);
}
-
- return paddr_last;
}
-static unsigned long __meminit
+static void __meminit
__kernel_physical_mapping_init(unsigned long paddr_start,
unsigned long paddr_end,
unsigned long page_size_mask,
pgprot_t prot, bool init)
{
bool pgd_changed = false;
- unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last;
+ unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next;
- paddr_last = paddr_end;
vaddr = (unsigned long)__va(paddr_start);
vaddr_end = (unsigned long)__va(paddr_end);
vaddr_start = vaddr;
@@ -759,16 +734,14 @@ __kernel_physical_mapping_init(unsigned long paddr_start,
if (pgd_val(*pgd)) {
p4d = (p4d_t *)pgd_page_vaddr(*pgd);
- paddr_last = phys_p4d_init(p4d, __pa(vaddr),
- __pa(vaddr_end),
- page_size_mask,
- prot, init);
+ phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
+ page_size_mask, prot, init);
continue;
}
p4d = alloc_low_page();
- paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
- page_size_mask, prot, init);
+ phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end),
+ page_size_mask, prot, init);
spin_lock(&init_mm.page_table_lock);
if (pgtable_l5_enabled())
@@ -783,8 +756,6 @@ __kernel_physical_mapping_init(unsigned long paddr_start,
if (pgd_changed)
sync_global_pgds(vaddr_start, vaddr_end - 1);
-
- return paddr_last;
}
@@ -792,15 +763,15 @@ __kernel_physical_mapping_init(unsigned long paddr_start,
* Create page table mapping for the physical memory for specific physical
* addresses. Note that it can only be used to populate non-present entries.
* The virtual and physical addresses have to be aligned on PMD level
- * down. It returns the last physical address mapped.
+ * down.
*/
-unsigned long __meminit
+void __meminit
kernel_physical_mapping_init(unsigned long paddr_start,
unsigned long paddr_end,
unsigned long page_size_mask, pgprot_t prot)
{
- return __kernel_physical_mapping_init(paddr_start, paddr_end,
- page_size_mask, prot, true);
+ __kernel_physical_mapping_init(paddr_start, paddr_end,
+ page_size_mask, prot, true);
}
/*
@@ -809,14 +780,13 @@ kernel_physical_mapping_init(unsigned long paddr_start,
* when updating the mapping. The caller is responsible to flush the TLBs after
* the function returns.
*/
-unsigned long __meminit
+void __meminit
kernel_physical_mapping_change(unsigned long paddr_start,
unsigned long paddr_end,
unsigned long page_size_mask)
{
- return __kernel_physical_mapping_init(paddr_start, paddr_end,
- page_size_mask, PAGE_KERNEL,
- false);
+ __kernel_physical_mapping_init(paddr_start, paddr_end,
+ page_size_mask, PAGE_KERNEL, false);
}
#ifndef CONFIG_NUMA
diff --git a/arch/x86/mm/mm_internal.h b/arch/x86/mm/mm_internal.h
index 7c4a41235323b..dad8abe65ed03 100644
--- a/arch/x86/mm/mm_internal.h
+++ b/arch/x86/mm/mm_internal.h
@@ -10,13 +10,10 @@ static inline void *alloc_low_page(void)
void early_ioremap_page_table_range_init(void);
-unsigned long kernel_physical_mapping_init(unsigned long start,
- unsigned long end,
- unsigned long page_size_mask,
- pgprot_t prot);
-unsigned long kernel_physical_mapping_change(unsigned long start,
- unsigned long end,
- unsigned long page_size_mask);
+void kernel_physical_mapping_init(unsigned long start, unsigned long end,
+ unsigned long page_size_mask, pgprot_t prot);
+void kernel_physical_mapping_change(unsigned long start, unsigned long end,
+ unsigned long page_size_mask);
extern int after_bootmem;
--
2.51.2
prev parent reply other threads:[~2026-05-03 13:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-03 13:04 [PATCH v2 0/3] x86/mm: some cleanups for pagetable setup code Brendan Jackman
2026-05-03 13:04 ` [PATCH v2 1/3] x86/mm: drop unused return from init_memory_mapping() Brendan Jackman
2026-05-03 13:04 ` [PATCH v2 2/3] x86/mm: simplify calculation of max_pfn_mapped Brendan Jackman
2026-05-03 13:04 ` Brendan Jackman [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260503-x86-init-cleanup-v2-3-bb690bd2477c@google.com \
--to=jackmanb@google.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=tglx@kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox