This patch adds arm64 helpers to write protect pmds/ptes and retrieve
permissions while logging dirty pages. Also adds prototype to write protect
a memory slot and adds a pmd define to check for read-only pmds.
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMario Smarduch <m.smarduch@samsung.com>

The macros in these files can easily be computed based on PAGE_SHIFT and
VA_BITS, so just remove them and add the corresponding macros to
asm/pgtable-hwdef.h
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NJungseok Lee <jungseoklee85@gmail.com>

Rather than having several Kconfig options, define int
ARM64_PGTABLE_LEVELS which will be also useful in converting some of the
pgtable macros.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NJungseok Lee <jungseoklee85@gmail.com>

This patch implements 4 levels of translation tables since 3 levels
of page tables with 4KB pages cannot support 40-bit physical address
space described in [1] due to the following issue.

It is a restriction that kernel logical memory map with 4KB + 3 levels
(0xffffffc000000000-0xffffffffffffffff) cannot cover RAM region from
544GB to 1024GB in [1]. Specifically, ARM64 kernel fails to create
mapping for this region in map_mem function since __phys_to_virt for
this region reaches to address overflow.

If SoC design follows the document, [1], over 32GB RAM would be placed
from 544GB. Even 64GB system is supposed to use the region from 544GB
to 576GB for only 32GB RAM. Naturally, it would reach to enable 4 levels
of page tables to avoid hacking __virt_to_phys and __phys_to_virt.

However, it is recommended 4 levels of page table should be only enabled
if memory map is too sparse or there is about 512GB RAM.

References
----------
[1]: Principles of ARM Memory Maps, White Paper, Issue C
Signed-off-by: NJungseok Lee <jays.lee@samsung.com>
Reviewed-by: NSungjinn Chung <sungjinn.chung@samsung.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: NSteve Capper <steve.capper@linaro.org>
[catalin.marinas@arm.com: MEMBLOCK_INITIAL_LIMIT removed, same as PUD_SIZE]
[catalin.marinas@arm.com: early_ioremap_init() updated for 4 levels]
[catalin.marinas@arm.com: 48-bit VA depends on BROKEN until KVM is fixed]
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NJungseok Lee <jungseoklee85@gmail.com>

This patch adds virtual address space size and a level of translation
tables to kernel configuration. It facilicates introduction of
different MMU options, such as 4KB + 4 levels, 16KB + 4 levels and
64KB + 3 levels, easily.

The idea is based on the discussion with Catalin Marinas:
http://www.spinics.net/linux/lists/arm-kernel/msg319552.htmlSigned-off-by: NJungseok Lee <jays.lee@samsung.com>
Reviewed-by: NSungjinn Chung <sungjinn.chung@samsung.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NJungseok Lee <jungseoklee85@gmail.com>

We have the capability to map 1GB level 1 blocks when using a 4K
granule.

This patch adjusts the create_mapping logic s.t. when mapping physical
memory on boot, we attempt to use a 1GB block if both the VA and PA
start and end are 1GB aligned. This both reduces the levels of lookup
required to resolve a kernel logical address, as well as reduces TLB
pressure on cores that support 1GB TLB entries.
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
Tested-by: NJungseok Lee <jays.lee@samsung.com>
[catalin.marinas@arm.com: s/prot_sect_kernel/PROT_SECT_NORMAL_EXEC/]
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The current TCR register setting in arch/arm64/mm/proc.S assumes that
TCR_EL1.TG* fields are one bit wide and bit 31 is RES1 (reserved, set to
1). With the addition of 16K pages (currently unsupported in the
kernel), the TCR_EL1.TG* fields have been extended to two bits. This
patch updates the corresponding Linux definitions and drops the bit 31
setting in proc.S in favour of the new macros.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Reported-by: NJoe Sylve <joe.sylve@gmail.com>

ARMv8 supports a range of physical address bit sizes. The PARange bits
from ID_AA64MMFR0_EL1 register are read during boot-time and the
intermediate physical address size bits are written in the translation
control registers (TCR_EL1 and VTCR_EL2).

There is no change in the VA bits and levels of translation.
Signed-off-by: NRadha Mohan Chintakuntla <rchintakuntla@cavium.com>
Reviewed-by: NWill Deacon <Will.deacon@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Modify the value of PMD_SECT_PROT_NONE to match that of PTE_NONE. This
should have been in commit 3676f9ef (Move PTE_PROT_NONE higher up).
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
Cc: <stable@vger.kernel.org> # 3.11+: 3676f9ef: arm64: Move PTE_PROT_NONE higher up
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Support huge pages in KVM/ARM and KVM/ARM64.  The pud_huge checking on
the unmap path may feel a bit silly as the pud_huge check is always
defined to false, but the compiler should be smart about this.

Note: This deals only with VMAs marked as huge which are allocated by
users through hugetlbfs only.  Transparent huge pages can only be
detected by looking at the underlying pages (or the page tables
themselves) and this patch so far simply maps these on a page-by-page
level in the Stage-2 page tables.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

TCR.TBI0 can be used to cause hardware address translation to ignore the
top byte of userspace virtual addresses. Whilst not especially useful in
standard C programs, this can be used by JITs to `tag' pointers with
various pieces of metadata.

This patch enables this bit for AArch64 Linux, and adds a new file to
Documentation/arm64/ which describes some potential caveats when using
tagged virtual addresses.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Bring Transparent HugePage support to ARM. The size of a
transparent huge page depends on the normal page size. A
transparent huge page is always represented as a pmd.

If PAGE_SIZE is 4KB, THPs are 2MB.
If PAGE_SIZE is 64KB, THPs are 512MB.
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>

Add huge page support to ARM64, different huge page sizes are
supported depending on the size of normal pages:

PAGE_SIZE is 4KB:
   2MB - (pmds) these can be allocated at any time.
1024MB - (puds) usually allocated on bootup with the command line
         with something like: hugepagesz=1G hugepages=6

PAGE_SIZE is 64KB:
 512MB - (pmds) usually allocated on bootup via command line.
Signed-off-by: NSteve Capper <steve.capper@linaro.org>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>

Add HYP and S2 page flags, for both normal and device memory.
Reviewed-by: NChristopher Covington <cov@codeaurora.org>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

On AArch64, the meaning of the XN bit has changed to UXN (user). The PXN
(privileged) bit must be set to prevent kernel execution. Without the
PXN bit set, the CPU may speculatively access device memory. This patch
ensures that all the mappings that the kernel must not execute from
(including user mappings) have the PXN bit set.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The virtual memory layout is described in
Documentation/arm64/memory.txt. This patch adds the MMU definitions for
the 4KB and 64KB translation table configurations. The SECTION_SIZE is
2MB with 4KB page and 512MB with 64KB page configuration.

PHYS_OFFSET is calculated at run-time and stored in a variable (no
run-time code patching at this stage).

On the current implementation, both user and kernel address spaces are
512G (39-bit) each with a maximum of 256G for the RAM linear mapping.
Linux uses 3 levels of translation tables with the 4K page configuration
and 2 levels with the 64K configuration. Extending the memory space
beyond 39-bit with the 4K pages or 42-bit with 64K pages requires an
additional level of translation tables.

The SPARSEMEM configuration is global to all AArch64 platforms and
allows for 1GB sections with SPARSEMEM_VMEMMAP enabled by default.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Acked-by: NNicolas Pitre <nico@linaro.org>
Acked-by: NOlof Johansson <olof@lixom.net>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>