...instead of open coding file operations followed by custom ->open()
callbacks per each attribute.

While here, replace permissions by explicit octal value.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180214154317.52290-2-andriy.shevchenko@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Isolated Memory Regions support a lock bit. The lock bit in an IMR prevents
modification of the IMR until the core goes through a warm or cold reset.
The lock bit feature is not useful in the context of the kernel API and is
not really necessary since modification of IMRs is possible only from
ring-zero anyway. This patch drops support for IMR locks bits, it
simplifies the kernel API and removes an unnecessary and needlessly complex
feature.
Suggested-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: andriy.shevchenko@linux.intel.com
Cc: boon.leong.ong@intel.com
Cc: paul.gortmaker@windriver.com
Link: http://lkml.kernel.org/r/1456190999-12685-3-git-send-email-pure.logic@nexus-software.ieSigned-off-by: NIngo Molnar <mingo@kernel.org>

Currently when setting up an IMR around the kernel's .text section we lock
that IMR, preventing further modification. While superficially this appears
to be the right thing to do, in fact this doesn't account for a legitimate
change in the memory map such as when executing a new kernel via kexec.

In such a scenario a second kernel can have a different size and location
to it's predecessor and can view some of the memory occupied by it's
predecessor as legitimately usable DMA RAM. If this RAM were then
subsequently allocated to DMA agents within the system it could conceivably
trigger an IMR violation.

This patch fixes the this potential situation by keeping the kernel's .text
section IMR lock bit false by default.
Suggested-by: NIngo Molnar <mingo@kernel.org>
Reported-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: boon.leong.ong@intel.com
Cc: paul.gortmaker@windriver.com
Link: http://lkml.kernel.org/r/1456190999-12685-2-git-send-email-pure.logic@nexus-software.ieSigned-off-by: NIngo Molnar <mingo@kernel.org>

The Kconfig currently controlling compilation of this code is:

  drivers/platform/x86/Kconfig:config INTEL_IMR
  drivers/platform/x86/Kconfig:   bool "Intel Isolated Memory Region support"

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Reviewed-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1455491396-30977-2-git-send-email-paul.gortmaker@windriver.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

When we print values, such as @size, we have to understand that
it's derived from [begin .. end] as:

	size = end - begin + 1

On the opposite the @end is derived from the rest as:

	end = begin + size - 1

Correct the IMR code to print values correctly.

Note that @__end_rodata actually points to the next address
after the aligned .rodata section.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ong, Boon Leong <boon.leong.ong@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1453320821-64328-1-git-send-email-andriy.shevchenko@linux.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The read and write opcodes are global for all units on SoC and even across
Intel SoCs. Remove duplication of corresponding constants. At the same time
convert all current users.

No functional change.
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NBoon Leong Ong <boon.leong.ong@intel.com>
Acked-by: NJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

arch/x86/platform/intel-quark/imr.c:129:1-4: WARNING: end returns can be simpified

 Simplify a trivial if-return sequence.  Possibly combine with a preceding function call.

Generated by: scripts/coccinelle/misc/simple_return.cocci
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Andy Shevchenko <andy.schevchenko@gmail.com>
Cc: Ong, Boon Leong <boon.leong.ong@intel.com>
Cc: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: kbuild-all@01.org
Link: http://lkml.kernel.org/r/20150219081432.GA21996@waimeaSigned-off-by: NIngo Molnar <mingo@kernel.org>

arch/x86/platform/intel-quark/imr.c:280:1-3: WARNING: PTR_ERR_OR_ZERO can be used

 Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Andy Shevchenko <andy.schevchenko@gmail.com>
Cc: Ong, Boon Leong <boon.leong.ong@intel.com>
Cc: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: kbuild-all@01.org
Link: http://lkml.kernel.org/r/20150219081432.GA21983@waimeaSigned-off-by: NIngo Molnar <mingo@kernel.org>

Intel's Quark X1000 SoC contains a set of registers called
Isolated Memory Regions. IMRs are accessed over the IOSF mailbox
interface. IMRs are areas carved out of memory that define
read/write access rights to the various system agents within the
Quark system. For a given agent in the system it is possible to
specify if that agent may read or write an area of memory
defined by an IMR with a granularity of 1 KiB.

Quark_SecureBootPRM_330234_001.pdf section 4.5 details the
concept of IMRs quark-x1000-datasheet.pdf section 12.7.4 details
the implementation of IMRs in silicon.

eSRAM flush, CPU Snoop write-only, CPU SMM Mode, CPU non-SMM
mode, RMU and PCIe Virtual Channels (VC0 and VC1) can have
individual read/write access masks applied to them for a given
memory region in Quark X1000. This enables IMRs to treat each
memory transaction type listed above on an individual basis and
to filter appropriately based on the IMR access mask for the
memory region. Quark supports eight IMRs.

Since all of the DMA capable SoC components in the X1000 are
mapped to VC0 it is possible to define sections of memory as
invalid for DMA write operations originating from Ethernet, USB,
SD and any other DMA capable south-cluster component on VC0.
Similarly it is possible to mark kernel memory as non-SMM mode
read/write only or to mark BIOS runtime memory as SMM mode
accessible only depending on the particular memory footprint on
a given system.

On an IMR violation Quark SoC X1000 systems are configured to
reset the system, so ensuring that the IMR memory map is
consistent with the EFI provided memory map is critical to
ensure no IMR violations reset the system.

The API for accessing IMRs is based on MTRR code but doesn't
provide a /proc or /sys interface to manipulate IMRs. Defining
the size and extent of IMRs is exclusively the domain of
in-kernel code.

Quark firmware sets up a series of locked IMRs around pieces of
memory that firmware owns such as ACPI runtime data. During boot
a series of unlocked IMRs are placed around items in memory to
guarantee no DMA modification of those items can take place.
Grub also places an unlocked IMR around the kernel boot params
data structure and compressed kernel image. It is necessary for
the kernel to tear down all unlocked IMRs in order to ensure
that the kernel's view of memory passed via the EFI memory map
is consistent with the IMR memory map. Without tearing down all
unlocked IMRs on boot transitory IMRs such as those used to
protect the compressed kernel image will cause IMR violations and system reboots.

The IMR init code tears down all unlocked IMRs and sets a
protective IMR around the kernel .text and .rodata as one
contiguous block. This sanitizes the IMR memory map with respect
to the EFI memory map and protects the read-only portions of the
kernel from unwarranted DMA access.
Tested-by: NOng, Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: NBryan O'Donoghue <pure.logic@nexus-software.ie>
Reviewed-by: NAndy Shevchenko <andy.schevchenko@gmail.com>
Reviewed-by: NDarren Hart <dvhart@linux.intel.com>
Reviewed-by: NOng, Boon Leong <boon.leong.ong@intel.com>
Cc: andy.shevchenko@gmail.com
Cc: dvhart@infradead.org
Link: http://lkml.kernel.org/r/1422635379-12476-2-git-send-email-pure.logic@nexus-software.ieSigned-off-by: NIngo Molnar <mingo@kernel.org>