It's possible that the length passed to ipa_header_size_encoded()
is larger than what can be represented by the HDR_LEN field alone
(starting with IPA v4.5).  If we attempted that, u32_encode_bits()
would trigger a build-time error.

Avoid this problem by masking off high-order bits of the value
encoded as the lower portion of the header length.

The same sort of problem exists in ipa_metadata_offset_encoded(),
so implement the same fix there.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

IPA v4.5 introduces a new unified timer architecture driven on the
19.2 MHz SoC crystal oscillator (XO).  It is independent of the IPA
core clock and avoids some duplication.

Lower-resolution time stamps are derived from this by using only the
high-order bits of the 19.2 MHz Qtime clock.  And timers are derived
from this based on "pulse generators" configured to fire at a fixed
rate based on the Qtime clock.

This patch introduces ipa_qtime_config(), which configures the Qtime
mechanism for use.  It also adds to the IPA register definitions
related to timers and time stamping.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

IPA v4.5 significantly changes the format of the configuration
register used for endpoint aggregation.  The AGGR_BYTE_LIMIT field
is now larger, and the positions of other fields are shifted.  This
complicates the way we have to access this register because functions
like u32_encode_bits() require their field mask argument to be constant.

A further complication is that we want to know the maximum value
representable by at least one of these fields, and that too requires
a constant field mask.

This patch adds support for IPA v4.5 endpoint aggregation registers
in a way that continues to support "legacy" IPA hardware.  It does
so in a way that keeps field masks constant.

First, for each variable field mask, we define an inline function
whose return value is either the legacy value or the IPA v4.5 value.

Second, we define functions for these fields that encode a value
to use in each field based on the IPA version (this approach is
already used elsewhere).  The field mask provided is supplied by
the function mentioned above.

Finally, for the aggregation byte limit fields where we want to
know the maximum representable value, we define a function that
returns that maximum, computed from the appropriate field mask.

We can no longer verify at build time that our buffer size is
in the range that can be represented by the aggregation byte
limit field.  So remove the test done by a BUILD_BUG_ON() call
in ipa_endpoint_validate_build(), and implement a comparable check
at the top of ipa_endpoint_data_valid().

Doing that makes ipa_endpoint_validate_build() contain a single
line BUILD_BUG_ON() call, so just remove that function and move
the remaining line into ipa_endpoint_data_valid().

One final note:  the aggregation time limit value for IPA v4.5 needs
to be computed differently.  That is handled in an upcoming patch.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Update the IPA code to make use of the updated IPA v4.5 register
definitions.  Generally what this patch does is, if IPA v4.5
hardware is in use:
  - Ensure new registers or fields in IPA v4.5 are updated where
    required
  - Ensure registers or fields not supported in IPA v4.5 are not
    examined when read, or are set to 0 when written
It does this while preserving the existing functionality for IPA
versions lower than v4.5.

The values to program for QSB_MAX_READS and QSB_MAX_WRITES and the
source and destination resource counts are updated to be correct for
all versions through v4.5 as well.

Note that IPA_RESOURCE_GROUP_SRC_MAX and IPA_RESOURCE_GROUP_DST_MAX
already reflect that 5 is an acceptable number of resources (which
IPA v4.5 implements).

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

IPA v4.5 adds a few fields to the endpoint header and extended
header configuration registers that represent new high-order bits
for certain offsets and sizes.  Add code to incorporate these upper
bits into the registers for IPA v4.5.

This includes creating ipa_header_size_encoded(), which handles
encoding the metadata offset field for use in the ENDP_INIT_HDR
register in a way appropriate for the hardware version.  This and
ipa_metadata_offset_encoded() ensure the mask argument passed to
u32_encode_bits() is constant.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Update "ipa_reg.h" so that register definitions support IPA hardware
version 4.5, in addition to versions 3.5.1 through v4.2.  Most of
the register definitions are the same, but in some cases fields are
added, changed, or eliminated.

Updates for a few IPA v4.5 registers are more complex, and adding
those definition will be deferred to separate patches.  This patch
only updates the register offset and field definitions, and adds
informational comments.

The only code change avoids accessing the backward compatibility
register for IPA version 4.5 in ipa_hardware_config().  Other IPA
v4.5-specific code changes will come later.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Some last cleanups for the existing IPA register definitions:
  - Remove the definition of IPA_REG_ENABLED_PIPES_OFFSET, because
    it is not used.
  - Use "IPA_" instead of "BAM_" as the prefix on fields associated
    with the FLAVOR_0 register.  We use GSI (not BAM), but the
    fields apply to both GSI and BAM.
  - Get rid of the definition of IPA_CS_RSVD; it is never used.
  - Add two missing field mask definitions for the INIT_DEAGGR
    endpoint register.
  - Eliminate a few of the defined sequencer types, because they
    are unused.  We can add them back when needed.
  - Add a field mask to indicate which bit causes an interrupt on
    the microcontroller.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Move the definition of the ipa_irq_id enumerated type out of
"ipa_interrupt.h" and into "ipa_reg.h", and flesh out its set of
defined values.  Each interrupt id indicates a particular type of
IPA interrupt that can be signaled.  Their numeric values define bit
positions in the IPA_IRQ_* registers, so should their definitions
should accompany the definition of those register offsets.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Move a few things around in "ipa_reg.h":
  - Move the definition of ipa_reg_state_aggr_active_offset() down
    a bit in the file so definitions are ordered by offset (for
    the lowest supported IPA version) like all other definitions.
  - Move the definition TIMER_FREQUENCY to be immediately above
    the definition of ipa_aggr_granularity_val() where it's used.
  - Move each register field value enumerated type definition to
    immediately follow the definitions of the register and field
    it is associated with.
No code functionality is modified by this patch.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Revise or add comments in "ipa_reg.h" for to provide more
information, and to improve clarity and consistency.
  - Always provide a comment to define when a register or field is
    supported (or not) for certain versions of IPA hardware.
  - Try to be specific about *which* or *how many* definitions
    a comment refers to.
  - Move comments stating that ipa->available defines the valid
    bits in various registers *above* the register offset
    definition, to avoid some checkpatch.pl warnings.
No code is changed by this patch.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>