From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
x86@kernel.org, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Andy Lutomirski <luto@amacapital.net>,
Dmitry Safonov <dsafonov@virtuozzo.com>,
Cyrill Gorcunov <gorcunov@openvz.org>,
Borislav Petkov <bp@suse.de>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCHv5 13/19] x86/mm: Make early boot code support boot-time switching of paging modes
Date: Mon, 21 Aug 2017 18:29:10 +0300 [thread overview]
Message-ID: <20170821152916.40124-14-kirill.shutemov@linux.intel.com> (raw)
In-Reply-To: <20170821152916.40124-1-kirill.shutemov@linux.intel.com>
Early boot code, that setup page table should be able to initialize page
tables for both 4- and 5-level paging modes.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
arch/x86/kernel/head64.c | 33 +++++++++++++++++++++------------
arch/x86/kernel/head_64.S | 10 ++++------
2 files changed, 25 insertions(+), 18 deletions(-)
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index f013b0732c96..8a44b3d06261 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -74,13 +74,13 @@ static unsigned int __head *fixup_int(void *ptr, unsigned long physaddr)
return fixup_pointer(ptr, physaddr);
}
-static void __head check_la57_support(unsigned long physaddr)
+static bool __head check_la57_support(unsigned long physaddr)
{
if (native_cpuid_eax(0) < 7)
- return;
+ return false;
if (!(native_cpuid_ecx(7) & (1 << (X86_FEATURE_LA57 & 31))))
- return;
+ return false;
*fixup_int(&pgtable_l5_enabled, physaddr) = 1;
*fixup_int(&pgdir_shift, physaddr) = 48;
@@ -89,24 +89,28 @@ static void __head check_la57_support(unsigned long physaddr)
*fixup_long(&vmalloc_base, physaddr) = __VMALLOC_BASE57;
*fixup_long(&vmemmap_base, physaddr) = __VMEMMAP_BASE57;
- return;
+ return true;
}
#else
-static void __head check_la57_support(unsigned long physaddr) {}
+static bool __head check_la57_support(unsigned long physaddr)
+{
+ return false;
+}
#endif
unsigned long __head __startup_64(unsigned long physaddr,
struct boot_params *bp)
{
- unsigned long load_delta;
+ unsigned long load_delta, *p;
unsigned long pgtable_flags;
pgdval_t *pgd;
p4dval_t *p4d;
pudval_t *pud;
pmdval_t *pmd, pmd_entry;
+ bool la57;
int i;
- check_la57_support(physaddr);
+ la57 = check_la57_support(physaddr);
/* Is the address too large? */
if (physaddr >> MAX_PHYSMEM_BITS)
@@ -131,9 +135,14 @@ unsigned long __head __startup_64(unsigned long physaddr,
/* Fixup the physical addresses in the page table */
pgd = fixup_pointer(&early_top_pgt, physaddr);
- pgd[pgd_index(__START_KERNEL_map)] += load_delta;
-
- if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+ p = pgd + pgd_index(__START_KERNEL_map);
+ if (la57)
+ *p = (unsigned long)level4_kernel_pgt;
+ else
+ *p = (unsigned long)level3_kernel_pgt;
+ *p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
+
+ if (la57) {
p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
p4d[511] += load_delta;
}
@@ -156,7 +165,7 @@ unsigned long __head __startup_64(unsigned long physaddr,
pmd = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr);
pgtable_flags = _KERNPG_TABLE_NOENC + sme_get_me_mask();
- if (IS_ENABLED(CONFIG_X86_5LEVEL)) {
+ if (la57) {
p4d = fixup_pointer(early_dynamic_pgts[next_early_pgt++], physaddr);
i = (physaddr >> PGDIR_SHIFT) % PTRS_PER_PGD;
@@ -253,7 +262,7 @@ int __init __early_make_pgtable(unsigned long address, pmdval_t pmd)
* critical -- __PAGE_OFFSET would point us back into the dynamic
* range and we might end up looping forever...
*/
- if (!IS_ENABLED(CONFIG_X86_5LEVEL))
+ if (!pgtable_l5_enabled)
p4d_p = pgd_p;
else if (pgd)
p4d_p = (p4dval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index a8409cd23b35..49f8bb43d107 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -121,7 +121,10 @@ ENTRY(secondary_startup_64)
/* Enable PAE mode, PGE and LA57 */
movl $(X86_CR4_PAE | X86_CR4_PGE), %ecx
#ifdef CONFIG_X86_5LEVEL
+ testl $1, pgtable_l5_enabled(%rip)
+ jz 1f
orl $X86_CR4_LA57, %ecx
+1:
#endif
movq %rcx, %cr4
@@ -350,12 +353,7 @@ GLOBAL(name)
__INITDATA
NEXT_PAGE(early_top_pgt)
- .fill 511,8,0
-#ifdef CONFIG_X86_5LEVEL
- .quad level4_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
-#else
- .quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE_NOENC
-#endif
+ .fill 512,8,0
NEXT_PAGE(early_dynamic_pgts)
.fill 512*EARLY_DYNAMIC_PAGE_TABLES,8,0
--
2.14.1
--
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next prev parent reply other threads:[~2017-08-21 15:29 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-21 15:28 [PATCHv5 00/19] Boot-time switching between 4- and 5-level paging Kirill A. Shutemov
2017-08-21 15:28 ` [PATCHv5 01/19] mm/sparsemem: Allocate mem_section at runtime for SPARSEMEM_EXTREME Kirill A. Shutemov
2017-08-22 16:28 ` Borislav Petkov
2017-08-22 17:50 ` Kirill A. Shutemov
2017-08-21 15:28 ` [PATCHv5 02/19] mm/zsmalloc: Prepare to variable MAX_PHYSMEM_BITS Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 03/19] x86/kasan: Use the same shadow offset for 4- and 5-level paging Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 04/19] x86/xen: Provide pre-built page tables only for XEN_PV and XEN_PVH Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 05/19] x86/xen: Drop 5-level paging support code from XEN_PV code Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 06/19] x86/boot/compressed/64: Detect and handle 5-level paging at boot-time Kirill A. Shutemov
2017-08-27 11:29 ` Cyrill Gorcunov
2017-09-04 13:02 ` Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 07/19] x86/mm: Make virtual memory layout movable for CONFIG_X86_5LEVEL Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 08/19] x86/mm: Make PGDIR_SHIFT and PTRS_PER_P4D variable Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 09/19] x86/mm: Make MAX_PHYSADDR_BITS and MAX_PHYSMEM_BITS dynamic Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 10/19] x86/mm: Make __PHYSICAL_MASK_SHIFT and __VIRTUAL_MASK_SHIFT dynamic Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 11/19] x86/mm: Make STACK_TOP_MAX dynamic Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 12/19] x86/mm: Adjust virtual address space layout in early boot Kirill A. Shutemov
2017-08-21 15:29 ` Kirill A. Shutemov [this message]
2017-08-21 15:29 ` [PATCHv5 14/19] x86/mm: Fold p4d page table layer at runtime Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 15/19] x86/mm: Replace compile-time checks for 5-level with runtime-time Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 16/19] x86/mm: Allow to boot without la57 if CONFIG_X86_5LEVEL=y Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 17/19] x86/xen: Allow XEN_PV and XEN_PVH to be enabled with X86_5LEVEL Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 18/19] x86/mm: Redefine some of page table helpers as macros Kirill A. Shutemov
2017-08-21 15:29 ` [PATCHv5 19/19] x86/mm: Offset boot-time paging mode switching cost Kirill A. Shutemov
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