Commit graph

634 commits

Author SHA1 Message Date
Simon Glass
c6efee5031 x86: mp: Add more comments to the module
Add a description of how this module works and also some missing function
comments.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-20 09:46:48 +08:00
Simon Glass
8dda2baa97 x86: mtrr: Add support for writing to MTRRs on any CPU
To enable support for the 'mtrr' command, add a way to perform MTRR
operations on selected CPUs.

This works by setting up a little 'operation' structure and sending it
around the CPUs for action.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
2020-07-20 09:46:47 +08:00
Simon Glass
3d734b59c7 x86: Don't enable SMP in SPL
SMP should be set up in U-Boot where possible, not SPL. Disable it in SPL.
For 64-bit U-Boot we should find a way to allow SMP operations in U-Boot,
but this is somewhat more complicated. For now that is disabled too.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
2020-07-20 09:46:46 +08:00
Simon Glass
240752c612 x86: mtrr: Use MP calls to list the MTRRs
Update the mtrr command to use mp_run_on_cpus() to obtain its information.
Since the selected CPU is the boot CPU this does not change the result,
but it sets the stage for supporting other CPUs.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-20 09:46:46 +08:00
Simon Glass
0538d6833c x86: mp: Add iterators for CPUs
It is convenient to iterate through the CPUs performing work on each one
and processing the result. Add a few iterator functions which handle this.
These can be used by any client code. It can call mp_run_on_cpus() on
each CPU that is returned, handling them one at a time.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-20 09:46:46 +08:00
Simon Glass
99a573fb32 x86: mp: Park CPUs before running the OS
With the new MP features the CPUs are no-longer parked when the OS is run.
Fix this by calling a special function to park them, just before the OS is
started.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-20 09:46:46 +08:00
Simon Glass
84d3ed125a x86: mp: Allow running functions on multiple CPUs
Add a way to run a function on a selection of CPUs. This supports either
a single CPU, all CPUs, just the main CPU or just the 'APs', in Intel
terminology.

It works by writing into a mailbox and then waiting for the CPUs to notice
it, take action and indicate they are done.

When SMP is not yet enabled, this just calls the function on the main CPU.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-20 09:46:45 +08:00
Simon Glass
c33aa3527d x86: mp: Support APs waiting for instructions
At present the APs (non-boot CPUs) are inited once and then parked ready
for the OS to use them. However in some cases we want to send new requests
through, such as to change MTRRs and keep them consistent across CPUs.

Change the last state of the flight plan to go into a wait loop, accepting
instructions from the main CPU.

Drop cpu_map since it is not used.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-20 09:46:45 +08:00
Simon Glass
e624858407 x86: mp_init: Avoid declarations in header files
The functions used by the flight plan are declared in the header file but
are not used in any other file.

Move the flight plan steps down to just above where it is used so that we
can make these function static.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-20 09:46:43 +08:00
Simon Glass
78d57d63d7 x86: Move MP code into mp_init
At present the 'flight plan' for CPUs is passed into mp_init. But it is
always the same. Move it into the mp_init file so everything is in one
place. Also drop the SMI function since it does nothing. If we implement
SMIs, more refactoring will be needed anyway.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-20 09:46:42 +08:00
Simon Glass
a308b1fa39 x86: Drop setup_pcat_compatibility()
This function does not exist anymore. Drop it from the header file.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-17 14:32:24 +08:00
Simon Glass
9ef168676c x86: Store the coreboot table address in global_data
At present this information is used to locate and parse the tables but is
not stored. Store it so that we can display it to the user, e.g. with the
'bdinfo' command.

Note that now the GD_FLG_SKIP_LL_INIT flag is set in get_coreboot_info(),
so it is always set when booting from coreboot.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
2020-07-17 14:32:24 +08:00
Simon Glass
b95611f67e x86: apl: Fix save/restore of ITSS priorities
The FSP-S changes the ITSS priorities. The code that tries to save it
before running FSP-S and restore it afterwards does not work as U-Boot
relocates in between the save and restore. This means that the driver
data saved before relocation is lost and the new driver just sees zeroes.

Fix this by allocating space in the relocated memory for the ITSS data.
Save it there and access it from the driver after relocation.

This fixes interrupt handling on coral.

Also drop the log_msg_ret() in irq_first_device_type() since this function
can be called speculatively in places where we are not sure if there is
an interrupt controller of that type. The resulting log errors are
confusing when there is no error.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
2020-07-17 14:32:24 +08:00
Simon Glass
59cf26480b x86: pinctrl: Drop the acpi_path member
This is in the device tree now, so drop the unnecessary field here.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-17 14:32:24 +08:00
Simon Glass
05516e3d47 x86: pinctrl: Update comment for intel_pinctrl_get_pad()
Add information about what is returned on error.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-17 14:32:24 +08:00
Simon Glass
4916f4586e x86: pinctrl: Add a way to get the pinctrl reg address
At present we can query the offset of a pinctrl register within the p2sb.
For ACPI we need to get the actual address of the register. Add a function
to handle this and rename the old one to more accurately reflect its
purpose.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
2020-07-17 14:32:24 +08:00
Simon Glass
7f926c9648 x86: Add support for building up an NHLT structure
The Intel Non-High-Definition-Audio Link Table (NHLT) table describes the
audio codecs and connections in a system. Various devices can contribute
information to produce the table.

Add functions to allow adding to the structure that is eventually written
to the ACPI tables. Also add the device-tree bindings.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-07-17 14:32:24 +08:00
Simon Glass
8d7ff12e63 acpi: Allow creating the GNVS to fail
In some cases an internal error may prevent this from working. Update the
function return value and report the error. At present the API for writing
tables does not easily support reporting errors, but once it is fully
updated to use a context pointer, this will be easier.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
2020-07-17 14:32:24 +08:00
Simon Glass
0990c894cc x86: fsp: Support a warning message when DRAM init is slow
With DDR4, Intel SOCs take quite a long time to init their memory. During
this time, if the user is watching, it looks like SPL has hung. Add a
message in this case.

This works by adding a return code to fspm_update_config() that indicates
whether MRC data was found and a new property to the device tree.

Also add one more debug message while starting.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Tested-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
2020-07-17 14:32:24 +08:00
Simon Glass
ef5f5f6ca6 x86: Avoid #ifdef with CONFIG_HAVE_ACPI_RESUME
At present this enables a few arch-specific members of the global_data
struct which are otherwise not part of the struct. As a result we have to
use #ifdef in various places.

The cost of always having these in the struct is small. Adjust things so
that we can use compile-time code instead of #ifdefs.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-17 14:32:24 +08:00
Simon Glass
3dada5a1a8 x86: fsp: Reinit the FPU after FSP meminit
The APL FSP appears to leave the FPU in a bad state in that it has
registers in use. This causes an error when the next FPU operation is
performed.

Work around this by re-resetting the FPU after calling FSP-M. This allows
the freetype console to work correctly.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-07-09 12:33:24 +08:00
Tom Rini
897860ebc1 x86: Convert from ACCESS_ONCE to READ/WRITE_ONCE
In order to update our <linux/compiler.h> to a newer version that no
longer provides ACCESS_ONCE() but only READ_ONCE()/WRITE_ONCE() we need
to convert arch/x86/include/asm/atomic.h to the other macros.

Cc: Simon Glass <sjg@chromium.org>
Cc: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2020-07-01 10:11:03 -04:00
Bin Meng
95cfa1d46c x86: quark: acpi: Replace _ADR() by _UID() in description of PCI host bridge
PCI Firmware specification requires _UID() and doesn't require _ADR()
to be set. Replace latter by former. This fixes the following warning
reported by ACPICA 20200430:

  Warning 3073 - Multiple types (Device object requires either a _HID
  or _ADR, but not both)

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-06-02 09:16:13 +08:00
Bin Meng
d8b5f5d436 x86: baytrail: acpi: Replace _ADR() by _UID() in description of PCI host bridge
PCI Firmware specification requires _UID() and doesn't require _ADR()
to be set. Replace latter by former. This fixes the following warning
reported by ACPICA 20200430:

  Warning 3073 - Multiple types (Device object requires either a _HID
  or _ADR, but not both)

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-06-02 09:16:13 +08:00
Bin Meng
319506c7a9 x86: baytrail: acpi: Create buffers outside of the methods
Create buffers outside of the methods as ACPICA 20200430 complains
about this:

  Remark 2173 - Creation of named objects within a method is highly
  inefficient, use globals or method local variables instead
  (\_SB.PCI0.LPCB.IURT._CRS)

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
2020-06-02 09:16:13 +08:00
Andy Shevchenko
b9ce32ec3a x86: tangier: acpi: Drop _HID() where enumerated by _ADR()
ACPICA complains that either _HID() or _ADR() should be used.
For General Purpose DMA we may not drop the _ADR() because
the device is enumerated by PCI. Thus, simple drop _HID().

Reported-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
2020-06-02 09:16:13 +08:00
Andy Shevchenko
10a428ed15 x86: tangier: acpi: Drop _ADR() where _HID() is present
ACPICA complains that either _HID() or _ADR() should be used.
Drop _ADR() where _HID() is present.

Reported-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
2020-06-02 09:16:13 +08:00
Andy Shevchenko
55f54538f8 x86: tangier: acpi: Replace _ADR() by _UID() in description of PCI host bridge
PCI Firmware specification requires _UID() and doesn't require _ADR()
to be set. Replace latter by former.

Reported-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
2020-06-02 09:16:13 +08:00
Andy Shevchenko
d8177a94ca x86: tangier: acpi: Create buffers outside of the methods
Create buffers outside of the methods as ACPICA 20200214 complains about this:

	Remark 2173 - Creation of named objects within a method is
	highly inefficient, use globals or method local variables
	instead

Reported-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
2020-06-02 09:16:13 +08:00
Simon Glass
4711c1f548 x86: apl: Add hex offsets for registers in FSP-S
When comparing hex dumps it is useful to see the offsets of the registers.
Add them in where they correspond to a multiple of 16.

Possibly it would be useful to have a a command to output the FSP values
in human-readable form, making use of the fsp_bindings implementation.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-06-02 09:16:13 +08:00
Simon Glass
6e5ac59ec3 x86: apl: Add hex offsets for registers in FSP-M
When comparing hex dumps it is useful to see the offsets of the registers.
Add them in where they correspond to a multiple of 16.

Possibly it would be useful to have a a command to output the FSP values
in human-readable form, making use of the fsp_bindings implementation.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-06-02 09:16:13 +08:00
Simon Glass
70c3c911cc x86: mrccache: Allow use before driver model is active
The change to avoid searching the device tree does not work on boards
wich don't have driver model set up this early, for example minnowmax.
Put back the old code (converted to livetree) as a fallback for these
devices. Also update the documentation.

This is tested on minnowmax, link, samus and coral.

Fixes: 87f1084a63 (x86: Adjust mrccache_get_region() to use livetree)
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com> (on Intel minnowmax)
2020-06-02 09:16:13 +08:00
Simon Glass
8e2922e357 x86: spi: Add a way to access the SPI mapping via registers
At present the PCI BDF (bus/device/function) is needed to access the SPI
mapping, since the registers are at BAR0. This doesn't work when PCI
auto-config has not been done yet, since BARs are unassigned.

Add another way to find the mapping, using the MMIO base, if the caller
knows this.

Also add a missing function comment.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-06-02 09:16:13 +08:00
Christian Gmeiner
53942b9658 x86: coreboot: add SMBIOS cbmem entry parsing
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-05-27 14:40:09 +08:00
Bernhard Messerklinger
d9e7efe10a x86: apl: Use devicetree for FSP-S configuration
A the moment the FSP-S configuration is a mix of hard coded values and
devicetree properties.

This patch makes FSP-S full configurable from devicetree by
adding binding properties for all FSP-S parameters.

Co-developed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Signed-off-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Signed-off-by: Bernhard Messerklinger <bernhard.messerklinger@br-automation.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org> (Tested on coral)
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
2020-05-27 14:40:09 +08:00
Bernhard Messerklinger
1fa6305fd6 x86: apl: Use devicetree for FSP-M configuration
A the moment the FSP-M configuration is a mix of hard coded values and
devicetree properties.

This patch makes FSP-M full configurable from devicetree by adding
binding properties for all FSP-M parameters.

Co-developed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Signed-off-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Signed-off-by: Bernhard Messerklinger <bernhard.messerklinger@br-automation.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org> (Tested on coral)
[sjg: Fix a build error for coral]
Signed-off-by: Simon Glass <sjg@chromium.org>
[bmeng: Add __maybe_unused to fsp_update_config_from_dtb()]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
2020-05-27 14:40:09 +08:00
Simon Glass
cd93d625fd common: Drop linux/bitops.h from common header
Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-05-18 21:19:23 -04:00
Simon Glass
f09f1ecbe7 Use __ASSEMBLY__ as the assembly macros
Some places use __ASSEMBLER__ instead which does not work since the
Makefile does not define it. Fix them.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-05-18 21:19:23 -04:00
Simon Glass
0914011310 command: Remove the cmd_tbl_t typedef
We should not use typedefs in U-Boot. They cannot be used as forward
declarations which means that header files must include the full header to
access them.

Drop the typedef and rename the struct to remove the _s suffix which is
now not useful.

This requires quite a few header-file additions.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-05-18 18:36:55 -04:00
Simon Glass
e6f6f9e648 common: Drop part.h from common header
Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-05-18 17:33:33 -04:00
Simon Glass
90526e9fba common: Drop net.h from common header
Move this header out of the common header. Network support is used in
quite a few places but it still does not warrant blanket inclusion.

Note that this net.h header itself has quite a lot in it. It could be
split into the driver-mode support, functions, structures, checksumming,
etc.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-05-18 17:33:31 -04:00
Simon Glass
33139a0bc7 x86: Move coreboot-table detection into common code
To support detecting booting from coreboot, move the code which locates
the coreboot tables into a common place. Adjust the algorithm slightly to
use a word comparison instead of string, since it is faster.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
[bmeng: correct the comments to 960KB]
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
2020-04-30 17:47:06 +08:00
Simon Glass
0b885bcfd9 acpi: Add an acpi command
It is useful to dump ACPI tables in U-Boot to see what has been generated.
Add a command to handle this.

To allow the command to find the tables, add a position into the global
data.

Support subcommands to list and dump the tables.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
2020-04-30 17:16:12 +08:00
Simon Glass
776cc20194 x86: Move acpi_table header to main include/ directory
This file is potentially useful to other architectures saddled with ACPI
so move most of its contents to a common location.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
2020-04-16 14:36:28 +08:00
Simon Glass
b2c3868463 x86: apl: Add Global NVS table header
Add the C version of this header. It includes a few Chrome OS bits which
are disabled for a normal build.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolgang.wallner@br-automation.com>
2020-04-16 14:36:28 +08:00
Simon Glass
2831405447 x86: Correct wording of coreboot source code
Some files are taken or modified from coreboot, but the files are
no-longer part of the coreboot project. Fix the wording in a few places.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
2020-04-16 14:36:28 +08:00
Andy Shevchenko
4d073fa83b x86: acpi: Describe USB 3 host controller found on Intel Tangier
USB 3 host controller may be described in ACPI to allow users alter
the properties or other features. Describe it for Intel Tangier SoC.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-04-04 22:08:44 +08:00
Andy Shevchenko
d0f7ab5310 x86: acpi: Add I²C timings to Intel Merrifield platform
There is established way to provide I²C timings, or actually counters,
to the OS via ACPI. Fill them for Intel Merrifield platform.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2020-04-04 22:08:44 +08:00
Wolfgang Wallner
fc35d7e1b1 x86: cpu_x86: Make cpu_x86_get_count() non-static
The function cpu_x86_get_count() is also useful for other modules.
Make it non-static and add a prototype + description.

Signed-off-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2020-03-05 18:25:22 +08:00
Masahiro Yamada
9d86b89c59 dma-mapping: move dma_map_(un)single() to <linux/dma-mapping.h>
The implementation of dma_map_single() and dma_unmap_single() is
exactly the same for all the architectures that support them.

Factor them out to <linux/dma-mapping.h>, and make all drivers to
include <linux/dma-mapping.h> instead of <asm/dma-mapping.h>.

If we need to differentiate them for some architectures, we can
move the generic definitions to <asm-generic/dma-mapping.h>.

Add some comments to the helpers. The concept is quite similar to
the DMA-API of Linux kernel. Drivers are agnostic about what is
going on behind the scene. Just call dma_map_single() before the
DMA, and dma_unmap_single() after it.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2020-02-19 21:27:30 +08:00