This is a note to let you know that I've just added the patch titled
powerpc/32: Remove 'noltlbs' kernel parameter
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-32-remove-noltlbs-kernel-parameter.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3076184eae4c674b945867376083d7279b9e2f81
Author: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Date: Tue Jun 14 12:32:24 2022 +0200
powerpc/32: Remove 'noltlbs' kernel parameter
[ Upstream commit 56e54b4e6c477b2a7df43f9a320ae5f9a5bfb16c ]
Mapping without large TLBs has no added value on the 8xx.
Mapping without large TLBs is still necessary on 40x when
selecting CONFIG_KFENCE or CONFIG_DEBUG_PAGEALLOC or
CONFIG_STRICT_KERNEL_RWX, but this is done automatically
and doesn't require user selection.
Remove 'noltlbs' kernel parameter, the user has no reason
to use it.
Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/80ca17bd39cf608a8ebd0764d7064a498e131199.1655202721.git.christophe.leroy@xxxxxxxxxx
Stable-dep-of: f9f2bff64c2f ("powerpc/8xx: Fix initial memory mapping")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index e2c2ccba6e388..c22a8ee02e73b 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3626,9 +3626,6 @@
nolapic_timer [X86-32,APIC] Do not use the local APIC timer.
- noltlbs [PPC] Do not use large page/tlb entries for kernel
- lowmem mapping on PPC40x and PPC8xx
-
nomca [IA-64] Disable machine check abort handling
nomce [X86-32] Disable Machine Check Exception
diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
index b702f2b642957..967432d1b6c78 100644
--- a/arch/powerpc/mm/init_32.c
+++ b/arch/powerpc/mm/init_32.c
@@ -80,9 +80,6 @@ unsigned long __max_low_memory = MAX_LOW_MEM;
*/
static void __init MMU_setup(void)
{
- if (strstr(boot_command_line, "noltlbs")) {
- __map_without_ltlbs = 1;
- }
if (IS_ENABLED(CONFIG_PPC_8xx))
return;
diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index 5348e1f9eb940..94efd4fa6e768 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -18,8 +18,6 @@
#define IMMR_SIZE (FIX_IMMR_SIZE << PAGE_SHIFT)
-extern int __map_without_ltlbs;
-
static unsigned long block_mapped_ram;
/*
@@ -32,8 +30,6 @@ phys_addr_t v_block_mapped(unsigned long va)
if (va >= VIRT_IMMR_BASE && va < VIRT_IMMR_BASE + IMMR_SIZE)
return p + va - VIRT_IMMR_BASE;
- if (__map_without_ltlbs)
- return 0;
if (va >= PAGE_OFFSET && va < PAGE_OFFSET + block_mapped_ram)
return __pa(va);
return 0;
@@ -49,8 +45,6 @@ unsigned long p_block_mapped(phys_addr_t pa)
if (pa >= p && pa < p + IMMR_SIZE)
return VIRT_IMMR_BASE + pa - p;
- if (__map_without_ltlbs)
- return 0;
if (pa < block_mapped_ram)
return (unsigned long)__va(pa);
return 0;
@@ -157,9 +151,6 @@ unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
mmu_mapin_immr();
- if (__map_without_ltlbs)
- return 0;
-
mmu_mapin_ram_chunk(0, boundary, PAGE_KERNEL_TEXT, true);
if (debug_pagealloc_enabled_or_kfence()) {
top = boundary;
