[PATCH 3/3] powerpc/mm: Update the memory limit based on direct mapping restrictions
memory limit value specified by the user are further updated such that
the value is 16MB aligned. This is because hash translation mode use
16MB as direct mapping page size. Make sure we update the global
variable 'memory_limit' with the 16MB aligned value such that all kernel
components will see the new aligned value of the memory limit.
Signed-off-by: Aneesh Kumar K.V (IBM)
---
arch/powerpc/kernel/prom.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 7451bedad1f4..b8f764453eaa 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -779,7 +779,6 @@ static inline void save_fscr_to_task(void) {}
void __init early_init_devtree(void *params)
{
- phys_addr_t limit;
DBG(" -> early_init_devtree(%px)\n", params);
@@ -850,8 +849,8 @@ void __init early_init_devtree(void *params)
memory_limit = 0;
/* Align down to 16 MB which is large page size with hash page
translation */
- limit = ALIGN_DOWN(memory_limit ?: memblock_phys_mem_size(), SZ_16M);
- memblock_enforce_memory_limit(limit);
+ memory_limit = ALIGN_DOWN(memory_limit ?: memblock_phys_mem_size(),
SZ_16M);
+ memblock_enforce_memory_limit(memory_limit);
#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_4K_PAGES)
if (!early_radix_enabled())
--
2.44.0
[PATCH 2/3] powerpc/fadump: Don't update the user-specified memory limit
If the user specifies the memory limit, the kernel should honor it such
that all allocation and reservations are made within the memory limit
specified. fadump was breaking that rule. Remove the code which updates
the memory limit such that fadump reservations are done within the
limit specified.
Cc: Mahesh Salgaonkar
Signed-off-by: Aneesh Kumar K.V (IBM)
---
arch/powerpc/kernel/fadump.c | 16
1 file changed, 16 deletions(-)
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index d14eda1e8589..4e768d93c6d4 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -573,22 +573,6 @@ int __init fadump_reserve_mem(void)
}
}
- /*
-* Calculate the memory boundary.
-* If memory_limit is less than actual memory boundary then reserve
-* the memory for fadump beyond the memory_limit and adjust the
-* memory_limit accordingly, so that the running kernel can run with
-* specified memory_limit.
-*/
- if (memory_limit && memory_limit < memblock_end_of_DRAM()) {
- size = get_fadump_area_size();
- if ((memory_limit + size) < memblock_end_of_DRAM())
- memory_limit += size;
- else
- memory_limit = memblock_end_of_DRAM();
- printk(KERN_INFO "Adjusted memory_limit for firmware-assisted"
- " dump, now %#016llx\n", memory_limit);
- }
if (memory_limit)
mem_boundary = memory_limit;
else
--
2.44.0
[PATCH 1/3] powerpc/mm: Align memory_limit value specified using mem= kernel parameter
The value specified for the memory limit is used to set a restriction on memory usage. It is important to ensure that this restriction is within the linear map kernel address space range. The hash page table translation uses a 16MB page size to map the kernel linear map address space. htab_bolt_mapping() function aligns down the size of the range while mapping kernel linear address space. Since the memblock limit is enforced very early during boot, before we can detect the type of memory translation (radix vs hash), we align the memory limit value specified as a kernel parameter to 16MB. This alignment value will work for both hash and radix translations. Signed-off-by: Aneesh Kumar K.V (IBM) --- arch/powerpc/kernel/prom.c | 7 +-- arch/powerpc/kernel/prom_init.c | 4 ++-- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index cd8d8883de90..7451bedad1f4 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -846,8 +846,11 @@ void __init early_init_devtree(void *params) reserve_crashkernel(); early_reserve_mem(); - /* Ensure that total memory size is page-aligned. */ - limit = ALIGN(memory_limit ?: memblock_phys_mem_size(), PAGE_SIZE); + if (memory_limit > memblock_phys_mem_size()) + memory_limit = 0; + + /* Align down to 16 MB which is large page size with hash page translation */ + limit = ALIGN_DOWN(memory_limit ?: memblock_phys_mem_size(), SZ_16M); memblock_enforce_memory_limit(limit); #if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_4K_PAGES) diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c index 0ef358285337..fbb68fc28ed3 100644 --- a/arch/powerpc/kernel/prom_init.c +++ b/arch/powerpc/kernel/prom_init.c @@ -817,8 +817,8 @@ static void __init early_cmdline_parse(void) opt += 4; prom_memory_limit = prom_memparse(opt, (const char **)&opt); #ifdef CONFIG_PPC64 - /* Align to 16 MB == size of ppc64 large page */ - prom_memory_limit = ALIGN(prom_memory_limit, 0x100); + /* Align down to 16 MB which is large page size with hash page translation */ + prom_memory_limit = ALIGN_DOWN(prom_memory_limit, SZ_16M); #endif } base-commit: 3e92c1e6cd876754b64d1998ec0a01800ed954a6 -- 2.44.0
[PATCH] mm/debug_vm_pgtable: Fix BUG_ON with pud advanced test
Architectures like powerpc add debug checks to ensure we find only devmap
PUD pte entries. These debug checks are only done with CONFIG_DEBUG_VM.
This patch marks the ptes used for PUD advanced test devmap pte entries
so that we don't hit on debug checks on architecture like ppc64 as
below.
WARNING: CPU: 2 PID: 1 at arch/powerpc/mm/book3s64/radix_pgtable.c:1382
radix__pud_hugepage_update+0x38/0x138
NIP [c00a7004] radix__pud_hugepage_update+0x38/0x138
LR [c00a77a8] radix__pudp_huge_get_and_clear+0x28/0x60
Call Trace:
[c4a2f950] [c4a2f9a0] 0xc4a2f9a0 (unreliable)
[c4a2f980] [000d34c1] 0xd34c1
[c4a2f9a0] [c206ba98] pud_advanced_tests+0x118/0x334
[c4a2fa40] [c206db34] debug_vm_pgtable+0xcbc/0x1c48
[c4a2fc10] [c000fd28] do_one_initcall+0x60/0x388
Also
kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:202!
NIP [c0096510] pudp_huge_get_and_clear_full+0x98/0x174
LR [c206bb34] pud_advanced_tests+0x1b4/0x334
Call Trace:
[c4a2f950] [000d34c1] 0xd34c1 (unreliable)
[c4a2f9a0] [c206bb34] pud_advanced_tests+0x1b4/0x334
[c4a2fa40] [c206db34] debug_vm_pgtable+0xcbc/0x1c48
[c4a2fc10] [c000fd28] do_one_initcall+0x60/0x388
Fixes: 27af67f35631 ("powerpc/book3s64/mm: enable transparent pud hugepage")
Signed-off-by: Aneesh Kumar K.V (IBM)
---
mm/debug_vm_pgtable.c | 8
1 file changed, 8 insertions(+)
diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
index 5662e29fe253..65c19025da3d 100644
--- a/mm/debug_vm_pgtable.c
+++ b/mm/debug_vm_pgtable.c
@@ -362,6 +362,12 @@ static void __init pud_advanced_tests(struct
pgtable_debug_args *args)
vaddr &= HPAGE_PUD_MASK;
pud = pfn_pud(args->pud_pfn, args->page_prot);
+ /*
+* Some architectures have debug checks to make sure
+* huge pud mapping are only found with devmap entries
+* For now test with only devmap entries.
+*/
+ pud = pud_mkdevmap(pud);
set_pud_at(args->mm, vaddr, args->pudp, pud);
flush_dcache_page(page);
pudp_set_wrprotect(args->mm, vaddr, args->pudp);
@@ -374,6 +380,7 @@ static void __init pud_advanced_tests(struct
pgtable_debug_args *args)
WARN_ON(!pud_none(pud));
#endif /* __PAGETABLE_PMD_FOLDED */
pud = pfn_pud(args->pud_pfn, args->page_prot);
+ pud = pud_mkdevmap(pud);
pud = pud_wrprotect(pud);
pud = pud_mkclean(pud);
set_pud_at(args->mm, vaddr, args->pudp, pud);
@@ -391,6 +398,7 @@ static void __init pud_advanced_tests(struct
pgtable_debug_args *args)
#endif /* __PAGETABLE_PMD_FOLDED */
pud = pfn_pud(args->pud_pfn, args->page_prot);
+ pud = pud_mkdevmap(pud);
pud = pud_mkyoung(pud);
set_pud_at(args->mm, vaddr, args->pudp, pud);
flush_dcache_page(page);
--
2.43.0
