GICv3: Allow either G1S or G0 interrupts to be configured ...

Currently the GICv3 driver mandates that platform populate
both G1S and G0 interrupts. However, it is possible that a
given platform is not interested in both the groups and
just needs to specify either one of them.

This patch modifies the `gicv3_rdistif_init()` & `gicv3_distif_init()`
functions to allow either G1S or G0 interrupts to be configured.

Fixes ARM-software/tf-issues#400

Change-Id: I43572b0e08ae30bed5af9334f25d35bf439b0d2b

Merge pull request #678 from soby-mathew/sm/PSCI_AArch32 ...

Introduce AArch32 support for PSCI library

gicv3: disable Group1 NonSecure interrupts during core powerdown ...

As per the GICv3 specification, to power down a processor using GICv3
and allow automatic power-on if an interrupt must be sent to a processor,
software must set Enable to zero for all interrupt groups(by writing to
GICC_CTLR or ICC_IGRPEN{0,1}_EL1/3 as appropriate.

Also, NonSecure EL1 software may not be aware of the CPU power state
details and fail to choose right states that require quiescing the CPU
interface. So it's preferred that the PSCI implementation handles it as
it is fully aware of the CPU power states.

This patch adds disabling of Group1 NonSecure interrupts during processor
power down along with Group0 and Group1 Secure interrupts so that all the
interrupt groups are handled at once as per specification.

Change-Id: Ib564d773c9c4c41f2ca9471451c030e3de75e641

AArch32: Enable GIC and TZC support ...

This patch modifies GICv3 and TZC drivers to add AArch32 support.
No modifications are required for the GICv2 driver for AArch32 support.
The TZC driver assumes that the secure world is running in Little-Endian
mode to do 64 bit manipulations. Assertions are present to validate the
assumption.

Note: The legacy GICv3 driver is not supported for AArch32.

Change-Id: Id1bc75a9f5dafb9715c9500ca77b4606eb1e2458

GICv3: Fix the GICD_IROUTER offset ...

This patch fixes the offset of GICD_IROUTER register defined in gicv3.h.
Although the GICv3 documention mentions that the offset for this register
is 0x6100-0x7FD8, the offset calculation for an interrupt id `n` is :

   0x6000 + 8n, where n >= 32

This requires the offset for GICD_IROUTER to be defined as 0x6000.

Fixes ARM-software/tf-issues#410

Change-Id: If9e91e30d946afe7f1f60fea4f065c7567093fa8

Rework type usage in Trusted Firmware ...

This patch reworks type usage in generic code, drivers and ARM platform files
to make it more portable. The major changes done with respect to
type usage are as listed below:

* Use uintptr_t for storing address instead of uint64_t or unsigned long.
* Review usage of unsigned long as it can no longer be assumed to be 64 bit.
* Use u_register_t for register values whose width varies depending on
  whether AArch64 or AArch32.
* Use generic C types where-ever possible.

In addition to the above changes, this patch also modifies format specifiers
in print invocations so that they are AArch64/AArch32 agnostic. Only files
related to upcoming feature development have been reworked.

Change-Id: I9f8c78347c5a52ba7027ff389791f1dad63ee5f8

GIC: Ensure SGIs and PPIs are Group0 before setup ...

The legacy GIC driver assumes that the SGIs and PPIs are Group0 during
initialization. This is true if the driver is the first one to initialize
the GIC hardware after reset. But in some cases, earlier BL stages could
have already initialized the GIC hardware which means that SGI and PPI
configuration are not the expected reset values causing assertion failure
in `gicd_set_ipriorityr()`. This patch explicitly resets the SGI and PPI
to Group0 prior to their initialization in the driver. The same patch is
not done in the GICv2-only driver because unlike in the legacy driver,
`gicd_set_ipriorityr()` of GICv2 driver doesn't enforce this policy and
the appropriate group is set irrespective of the initial value.

Fixes ARM-software/tf-issues#396

Change-Id: I521d35caa37470ce542c796c2ba99716e4763105

Add support for %p in tf_printf() ...

This patch adds support for the `%p` format specifier in tf_printf()
following the example of the printf implementation of the stdlib used
in the trusted firmware.

Fixes ARM-software/tf-issues#292

Change-Id: I0b3230c783f735d3e039be25a9405f00023420da

Move private APIs in gic_common.h to a private header ...

This patch moves the private GIC common accessors from `gic_common.h` to
a new private header file `gic_common_private.h`. This patch also adds
additional comments to GIC register accessors to highlight the fact
that some of them access register values that correspond to multiple
interrupt IDs. The convention used is that the `set`, `get` and `clr`
accessors access and modify the values corresponding to a single interrupt
ID whereas the `read` and `write` GIC register accessors access the raw
GIC registers and it could correspond to multiple interrupt IDs depending
on the register accessed.

Change-Id: I2643ecb2533f01e3d3219fcedfb5f80c120622f9

Fix GIC_IPRIORITYR setting in new drivers ...

The code to set the interrupt priority for secure interrupts in the
new GICv2 and GICv3 drivers is incorrect. The setup code to configure
interrupt priorities of secure interrupts, one interrupt at a time, used
gicd_write_ipriorityr()/gicr_write_ipriority() function affecting
4 interrupts at a time. This bug did not manifest itself because all the
secure interrupts were configured to the highest secure priority(0) during
cold boot and the adjacent non secure interrupt priority would be configured
later by the normal world. This patch introduces new accessors,
gicd_set_ipriorityr() and gicr_set_ipriorityr(), for configuring priority
one interrupt at a time and fixes the the setup code to use the new
accessors.

Fixes ARM-software/tf-issues#344

Change-Id: I470fd74d2b7fce7058b55d83f604be05a27e1341

Fix race in GIC IPRIORITY and ITARGET accessors ...

GICD_IPRIORITYR and GICD_ITARGETSR specifically support byte addressing
so that individual interrupt priorities can be atomically updated by
issuing a single byte write. The previous implementation of
gicd_set_ipriority() and gicd_set_itargetsr() used 32-bit register
accesses, modifying values for 4 interrupts at a time, using a
read-modify-write approach. This potentially may cause concurrent changes
by other CPUs to the adjacent interrupts to be corrupted. This patch fixes
the issue by modifying these accessors to use byte addressing.

Fixes ARM-software/tf-issues#343

Change-Id: Iec28b5f5074045b00dfb8d5f5339b685f9425915

Rename GICv3 interrupt group macros ...

This patch renames the GICv3 interrupt group macros from
INT_TYPE_G0, INT_TYPE_G1S and INT_TYPE_G1NS to INTR_GROUP0,
INTR_GROUP1S and INTR_GROUP1NS respectively.

Change-Id: I40c66f589ce6234fa42205adcd91f7d6ad8f33d4

Add ARM GICv2 driver ...

This patch adds a driver for ARM GICv2 systems, example GIC-400. Unlike
the existing GIC driver in `include/drivers/arm/arm_gic.h`, this driver
is optimised for GICv2 and does not support GICv3 systems in GICv2
compatibility mode. The driver interface has been implemented in
`drivers/arm/gic/v2/gicv2_main.c`. The corresponding header is in
`include/drivers/arm/gicv2.h`. Helper functions are implemented in
`drivers/arm/gic/v2/gicv2_helpers.c` and are accessible through the
`drivers/arm/gic/v2/gicv2_private.h` header.

Change-Id: I09fffa4e621fb99ba3c01204839894816cd89a2a

Add ARM GICv3 driver without support for legacy operation ...

This patch adds a driver for ARM GICv3 systems that need to run software
stacks where affinity routing is enabled across all privileged exception
levels for both security states. This driver is a partial implementation
of the ARM Generic Interrupt Controller Architecture Specification, GIC
architecture version 3.0 and version 4.0 (ARM IHI 0069A). The driver does
not cater for legacy support of interrupts and asymmetric configurations.

The existing GIC driver has been preserved unchanged. The common code for
GICv2 and GICv3 systems has been refactored into a new file,
`drivers/arm/gic/common/gic_common.c`. The corresponding header is in
`include/drivers/arm/gic_common.h`.

The driver interface is implemented in `drivers/arm/gic/v3/gicv3_main.c`.
The corresponding header is in `include/drivers/arm/gicv3.h`. Helper
functions are implemented in `drivers/arm/gic/v3/arm_gicv3_helpers.c`
and are accessible through the `drivers/arm/gic/v3/gicv3_private.h`
header.

Change-Id: I8c3c834a1d049d05b776b4dcb76b18ccb927444a

Remove EL2/EL1 GICv3 register updates ...

From Linux 3.17 onwards, the mainline kernel has support for GICv3
systems and if EL3 exists, it only needs to initialise ICC_SRE_EL3.SRE
and ICC_SRE_EL3.Enable to 1. Hence, this patch removes the redundant
updates of ICC_SRE_EL2 and ICC_PMR_EL1.

NOTE: For partner software's which enter kernel in EL1,
ICC_SRE_EL2.Enable and ICC_SRE_EL2.SRE bit needs to be set to 1
in EL2 before jumping to linux.

Change-Id: I09ed47869351b08a3b034735f532bc677eaa6917

Use uintptr_t as base address type in ARM driver APIs ...

This patch changes the type of the base address parameter in the
ARM device driver APIs to uintptr_t (GIC, CCI, TZC400, PL011). The
uintptr_t type allows coverage of the whole memory space and to
perform arithmetic operations on the addresses. ARM platform code
has also been updated to use uintptr_t as GIC base address in the
configuration.

Fixes ARM-software/tf-issues#214

Change-Id: I1b87daedadcc8b63e8f113477979675e07d788f1

Fix reporting of interrupt ID in ARM GIC driver ...

The ARM GIC driver treats the entire contents of the GICC_HPPIR as the interrupt
ID instead of just bits[9:0]. This could result in an SGI being treated as a
Group 1 interrupt on a GICv2 system.

This patch introduces a mask to retrieve only the ID from a read of GICC_HPPIR,
GICC_IAR and similar registers. The value read from these registers is masked
with this constant prior to use as an interrupt ID.

Fixes ARM-software/tf-issues#306

Change-Id: Ie3885157de33b71df9781a41f6ef015a30c4608d

Set group status of PPIs and SGIs correctly on GICv3 systems ...

On a GICv2 system, the group status of PPIs and SGIs is set in the GICD_IGROUPR0
register. On a GICv3 system, if affinity routing is enabled for the non-secure
state, then the group status of PPIs and SGIs should be set in the GICR_IGROUPR0
register. ARM Trusted firmware sets the group status using the GICv2
sequence. On a GICv3 system, if the group status of an interrupt is set to Group
1 through a write to the GICD_IGROUPR0, then the GICR_IGROUPR0 is updated as
well.

The current sequence is incorrect since it first marks all PPIs and SGIs as
Group 1. It then clears the bits in GICD_IGROUPR0 corresponding to secure
interrupts to set their group status to Group 0. This operation is a no-op. It
leaves the secure generic timer interrupt (#29) used by the TSP marked as Group
1. This causes the interrupt to interfere with the execution of non-secure
software. Once an interrupt has been marked as Group 1, the GICR_IGROUPR0 should
be programmed to change its group status.

This patch rectifies this issue by setting the group status of only the
non-secure PPI and SGIs to Group 1 in the first place. GICD_IGROUPR0 resets to
0. So secure interrupts are marked as Group 0 by default.

Change-Id: I958b4b15f3e2b2444ce4c17764def36216498d00

Improvements to ARM GIC driver ...

This patch introduces several improvements to the ARM GIC driver:

* In function gicd_set_itargetsr(), target CPU is specified using
  the same bit mask detailed in the GICD_ITARGETSRn register instead
  of the CPU linear ID, removing the dependency between bit position
  and linear ID in the platform porting. The current CPU bit mask
  may be obtained by reading GICD_ITARGETSR0.

* PPIs and SGIs are initialized in arm_gic_pcpu_distif_setup().
  SPIs are initialized in arm_gic_distif_setup().

* By default, non secure interrupts are assigned the maximum
  priority allowed to a non secure interrupt (defined by
  GIC_HIGHEST_NS_PRIORITY).

* GICR base address is allowed to be NULL for GICv1 and GICv2.

Change-Id: Ie2837fe860d43b2282e582dfdb13c39c6186f232

Rework incorrect use of assert() and panic() in codebase ...

Assert a valid security state using the macro sec_state_is_valid().
Replace assert() with panic() in those cases that might arise
because of runtime errors and not programming errors.
Replace panic() with assert() in those cases that might arise
because of programming errors.

Fixes ARM-software/tf-issues#96

Change-Id: I51e9ef0439fd5ff5e0edfef49050b69804bf14d5

Refactor fvp gic code to be a generic driver ...

Refactor the FVP gic code in plat/fvp/fvp_gic.c to be a generic ARM
GIC driver in drivers/arm/gic/arm_gic.c. Provide the platform
specific inputs in the arm_gic_setup() function so that the driver
has no explicit dependency on platform code.

Provide weak implementations of the platform interrupt controller
API in a new file, plat/common/plat_gic.c. These simply call through
to the ARM GIC driver.

Move the only remaining FVP GIC function, fvp_gic_init() to
plat/fvp/aarch64/fvp_common.c and remove plat/fvp/fvp_gic.c

Fixes ARM-software/tf-issues#182

Change-Id: Iea82fe095fad62dd33ba9efbddd48c57717edd21

Make system register functions inline assembly ...

Replace the current out-of-line assembler implementations of
the system register and system instruction operations with
inline assembler.

This enables better compiler optimisation and code generation
when accessing system registers.

Fixes ARM-software/tf-issues#91

Change-Id: I149af3a94e1e5e5140a3e44b9abfc37ba2324476

Introduce interrupt registration framework in BL3-1 ...

This patch introduces a framework for registering interrupts routed to
EL3. The interrupt routing model is governed by the SCR_EL3.IRQ and
FIQ bits and the security state an interrupt is generated in. The
framework recognizes three type of interrupts depending upon which
exception level and security state they should be handled in
i.e. Secure EL1 interrupts, Non-secure interrupts and EL3
interrupts. It provides an API and macros that allow a runtime service
to register an handler for a type of interrupt and specify the routing
model. The framework validates the routing model and uses the context
management framework to ensure that it is applied to the SCR_EL3 prior
to entry into the target security state. It saves the handler in
internal data structures. An API is provided to retrieve the handler
when an interrupt of a particular type is asserted. Registration is
expected to be done once by the primary CPU. The same handler and
routing model is used for all CPUs.

Support for EL3 interrupts will be added to the framework in the
future. A makefile flag has been added to allow the FVP port choose
between ARM GIC v2 and v3 support in EL3. The latter version is
currently unsupported.

A framework for handling interrupts in BL3-1 will be introduced in
subsequent patches. The default routing model in the absence of any
handlers expects no interrupts to be routed to EL3.

Change-Id: Idf7c023b34fcd4800a5980f2bef85e4b5c29e649

Fix C accessors to GIC distributor registers with set/clear semantics ...

This patch fixes C accessors to GIC registers that follow a set/clear
semantic to change the state of an interrupt, instead of read/write/modify.
These registers are:
  Set-Enable
  Clear-Enable
  Set-Pending
  Clear-Pending
  Set-Active
  Clear-Active
For instance, to enable an interrupt we write a one to the corresponding bit
in the Set-Enable register, whereas to disable it we write a one to the
corresponding bit in the Clear-Enable register.

Fixes ARM-software/tf-issues#137

Change-Id: I3b66bad94d0b28e0fe08c9042bac0bf5ffa07944

Correct usage of data and instruction barriers ...

The current code does not always use data and instruction
barriers as required by the architecture and frequently uses
barriers excessively due to their inclusion in all of the
write_*() helper functions.

Barriers should be used explicitly in assembler or C code
when modifying processor state that requires the barriers in
order to enable review of correctness of the code.

This patch removes the barriers from the helper functions and
introduces them as necessary elsewhere in the code.

PORTING NOTE: check any port of Trusted Firmware for use of
system register helper functions for reliance on the previous
barrier behaviour and add explicit barriers as necessary.

Fixes ARM-software/tf-issues#92

Change-Id: Ie63e187404ff10e0bdcb39292dd9066cb84c53bf

Reduce deep nesting of header files ...

Reduce the number of header files included from other header
files as much as possible without splitting the files. Use forward
declarations where possible. This allows removal of some unnecessary
"#ifndef __ASSEMBLY__" statements.

Also, review the .c and .S files for which header files really need
including and reorder the #include statements alphabetically.

Fixes ARM-software/tf-issues#31

Change-Id: Iec92fb976334c77453e010b60bcf56f3be72bd3e

Refactor GIC header files ...

Move the function prototypes from gic.h into either gic_v2.h or
gic_v3.h as appropriate. Update the source files to include the
correct headers.

Change-Id: I368cfda175cdcbd3a68f46e2332738ec49048e19

Move include and source files to logical locations ...

Move almost all system include files to a logical sub-directory
under ./include. The only remaining system include directories
not under ./include are specific to the platform. Move the
corresponding source files to match the include directory
structure.

Also remove pm.h as it is no longer used.

Change-Id: Ie5ea6368ec5fad459f3e8a802ad129135527f0b3