Rename ESP_CMDBUF_SZ to ESP_CMDFIFO_SZ and cmdbuf_cdb_offset to cmdfifo_cdb_offset
to indicate that the command buffer type has changed from an array to a Fifo8.

This also enables us to remove the ESPState field cmdlen since the command length
is now simply the number of elements used in cmdfifo.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-40-mark.cave-ayland@ilande.co.uk>

Rename TI_BUFSZ to ESP_FIFO_SZ since this constant is really describing the size
of the FIFO and is not directly related to the TI size.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-39-mark.cave-ayland@ilande.co.uk>

The SCSI bus should remain in the message out phase after the SATN and stop
command rather than transitioning to the command phase. A new ESPState variable
cmdbuf_cdb_offset is added which stores the offset of the CDB from the start
of cmdbuf when accumulating extended message out phase data.

Currently any extended message out data is discarded in do_cmd() before the CDB
is processed in do_busid_cmd().

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-38-mark.cave-ayland@ilande.co.uk>

Some guests use a mixture of DMA and non-DMA transfers in combination with the
SATN and stop command to transfer message out phase and command phase bytes to
the target. Prepare for the next commit by adding a maxlen parameter to
get_cmd() to allow partial transfers.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-37-mark.cave-ayland@ilande.co.uk>

This matches the description in the datasheet and is required as support for
non-DMA transfers is added.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-36-mark.cave-ayland@ilande.co.uk>

Commit ea84a442 "scsi: esp: Defer command completion until previous interrupts
have been handled" provided a mechanism to delay the command completion interrupt
until ESP_RINTR is read after the command has completed.

With the previous fixes for latching the ESP_RINTR bits and deferring the setting
of the command completion interrupt for incoming data to the SCSI callback, this
workaround is no longer required and can be removed.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-35-mark.cave-ayland@ilande.co.uk>

The MacOS toolbox ROM issues a command to the ESP controller as part of its
"FAST" SCSI routines and then proceeds to read the incoming data soon after
receiving the command completion interrupt.

Unfortunately due to SCSI block transfers being asynchronous the incoming data
may not yet be present causing an underflow error. Resolve this by waiting for
the SCSI subsystem transfer_data callback before raising the command completion
interrupt.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-34-mark.cave-ayland@ilande.co.uk>

Currently the ESP_RINTR register is set to a specific value as required within
the ESP state machine. In order to implement the upcoming deferred interrupt
functionality it is necessary to set individual bits within ESP_RINTR so that
a deferred interrupt will not overwrite the value of any other interrupt bits.

This also requires fixing up a few locations where the ESP_RINTR and ESP_RSEQ
registers are set/reset unexpectedly.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-33-mark.cave-ayland@ilande.co.uk>

At this point it is now possible to properly implement the FIFO flush command
without causing guest errors.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-32-mark.cave-ayland@ilande.co.uk>

The MacOS toolbox ROM performs 4 byte reads/writes when transferring data to
and from the target. Since the SCSI bus is 16-bits wide, use the memory API
to split a 4 byte access into 2 x 2 byte accesses.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-31-mark.cave-ayland@ilande.co.uk>

Now that all data is transferred via the FIFO (ti_buf) there is no need to track
the source buffer being used for the data transfer. This also eliminates the
need for a separate subsection for PDMA state migration.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-30-mark.cave-ayland@ilande.co.uk>

PDMA as implemented on the Quadra 800 uses DREQ to load data into the FIFO
up to a maximum of 16 bytes at a time. The MacOS toolbox ROM requires this
because it mixes FIFO and PDMA transfers whilst checking the FIFO status
and counter registers to ensure success.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-29-mark.cave-ayland@ilande.co.uk>

Currently the target selection for PDMA is done after the SCSI command has been
delivered which is not correct. Perform target selection as part of the initial
get_cmd() call when the command is submitted: if no target is present, don't
raise DRQ.

If the target is present then switch to the command phase since the MacOS toolbox
ROM checks for this before attempting to submit the SCSI command.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-28-mark.cave-ayland@ilande.co.uk>

This better describes the purpose of the function.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-27-mark.cave-ayland@ilande.co.uk>

The cmdbuf is really just a copy of FIFO data (including extra message phase
bytes) so its pdma_origin is effectively TI. Fortunately we already know when
we are receiving a SCSI command since do_cmd == 1 which enables us to
distinguish between the two cases in esp_pdma_read()/esp_pdma_write().

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-26-mark.cave-ayland@ilande.co.uk>

Real hardware simply counts down using the in-built TC to determine when the
the PDMA request is complete. Use the TC to determine the PDMA transfer length
which then enables us to remove the redundant pdma_len variable.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-25-mark.cave-ayland@ilande.co.uk>

This eliminates the last user of the PDMA-specific pdma_cur variable which can
now be removed.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-24-mark.cave-ayland@ilande.co.uk>

Here the updates to async_len and ti_size are moved into the corresponding
esp_pdma_read()/esp_pdma_write() function to eliminate the reference to
pdma_cur in do_dma_pdma_cb().

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-23-mark.cave-ayland@ilande.co.uk>

Now that PDMA SCSI commands are accumulated in cmdbuf in the same way as normal
commands, the existing logic for locating the start of the SCSI command in
cmdbuf via cmdlen can be used. This enables the PDMA-specific pdma_start and
also get_pdma_buf() to be removed.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-22-mark.cave-ayland@ilande.co.uk>

Now that all SCSI commands are accumulated in cmdbuf, remove the buf and buflen
parameters from get_cmd() since these always reference cmdbuf and ESP_CMDBUF_SZ
respectively.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-21-mark.cave-ayland@ilande.co.uk>

Now that all SCSI commands are accumulated in cmdbuf, remove the buf parameter
from do_cmd() since this always points to cmdbuf.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-20-mark.cave-ayland@ilande.co.uk>

ESP SCSI commands are already accumulated in cmdbuf and so there is no need to
keep a separate pdma_buf buffer. Accumulate SCSI commands for PDMA transfers in
cmdbuf instead of pdma_buf so update cmdlen accordingly and change pdma_origin
for PDMA transfers to CMD which allows the PDMA origin to be removed.

This commit also removes a stray memcpy() from get_cmd() which is a no-op because
cmdlen is always zero at the start of a command.

Notionally the removal of pdma_buf from vmstate_esp_pdma also breaks migration
compatibility for the PDMA subsection until its complete removal by the end of
the series.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-19-mark.cave-ayland@ilande.co.uk>

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-18-mark.cave-ayland@ilande.co.uk>

This is the first step in removing get_pdma_buf() from esp.c.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-17-mark.cave-ayland@ilande.co.uk>

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-16-mark.cave-ayland@ilande.co.uk>

The limiting of DMA transfers to the maximum size of the available data is already
handled by esp_do_dma() and do_dma_pdma_cb().

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-15-mark.cave-ayland@ilande.co.uk>

The ESP device already keeps track of the remaining bytes left to transfer via
its TC (transfer counter) register which is decremented for each byte that
is transferred across the SCSI bus.

Switch the transfer logic to use the value of TC instead of dma_left and then
remove dma_left completely, adding logic to the vmstate_esp post_load() function
to transfer the old dma_left value to the TC register during migration from
older versions.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-14-mark.cave-ayland@ilande.co.uk>

The value of dma_counter is set once at the start of the transfer and remains
the same until the transfer is complete. This allows the check in esp_transfer_data
to be simplified since dma_left will always be non-zero until the transfer is
completed.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-13-mark.cave-ayland@ilande.co.uk>

Perform the length adjustment whereby a value of 0 in the STC represents
a transfer length of 0x10000 at the point where the TC is loaded at the
start of a DMA command rather than just when a TI (Transfer Information)
command is executed. This better matches the description as given in the
datasheet.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-12-mark.cave-ayland@ilande.co.uk>

This function simplifies reading the STC register value without having to manually
shift each individual 8-bit value.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-11-mark.cave-ayland@ilande.co.uk>

These functions simplify reading and writing the TC register value without having to
manually shift each individual 8-bit value.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-10-mark.cave-ayland@ilande.co.uk>

The transfer direction is currently determined by checking the sign of ti_size
but as this series progresses ti_size can be zero at the end of the transfer.

Use the SCSI phase to determine the transfer direction as used in other SCSI
controller implementations.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-9-mark.cave-ayland@ilande.co.uk>

This will become more useful later when trying to debug mixed FIFO and PDMA
requests.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-8-mark.cave-ayland@ilande.co.uk>

Move the trace event to the end of the function so that it correctly reports
the returned value if it doesn't come directly from the rregs array.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-7-mark.cave-ayland@ilande.co.uk>

This enables us to determine whether the command being issued is for a DMA or a
non-DMA transfer.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-6-mark.cave-ayland@ilande.co.uk>

The QOM object representing ESPState is currently embedded within both the
SYSBUS_ESP and PCI_ESP devices with migration state handled by embedding
vmstate_esp within each device using VMSTATE_STRUCT.

Since the vmstate_esp fields are embedded directly within the migration
stream, the incoming vmstate_esp version_id is lost. The only version information
available is that from vmstate_sysbus_esp_scsi and vmstate_esp_pci_scsi, but
those versions represent their respective devices and not that of the underlying
ESPState.

Resolve this by adding a new version-dependent field in vmstate_sysbus_esp_scsi
and vmstate_esp_pci_scsi which stores the vmstate_esp version_id field within
ESPState to be used to allow migration from older QEMU versions.

Finally bump the vmstate_esp version to 5 to cover the upcoming ESPState changes
within this patch series.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-5-mark.cave-ayland@ilande.co.uk>

Make this new QOM device state a child device of both the sysbus-esp and esp-pci
implementations.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-4-mark.cave-ayland@ilande.co.uk>

The existing ESP QOM type currently represents a sysbus device with an embedded
ESP state. Rename the type to SYSBUS_ESP accordingly.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-3-mark.cave-ayland@ilande.co.uk>

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20210304221103.6369-2-mark.cave-ayland@ilande.co.uk>

some accumulated s390x fixes

# gpg: Signature made Fri 05 Mar 2021 15:50:00 GMT
# gpg:                using RSA key C3D0D66DC3624FF6A8C018CEDECF6B93C6F02FAF
# gpg:                issuer "cohuck@redhat.com"
# gpg: Good signature from "Cornelia Huck <conny@cornelia-huck.de>" [unknown]
# gpg:                 aka "Cornelia Huck <huckc@linux.vnet.ibm.com>" [full]
# gpg:                 aka "Cornelia Huck <cornelia.huck@de.ibm.com>" [full]
# gpg:                 aka "Cornelia Huck <cohuck@kernel.org>" [unknown]
# gpg:                 aka "Cornelia Huck <cohuck@redhat.com>" [unknown]
# Primary key fingerprint: C3D0 D66D C362 4FF6 A8C0  18CE DECF 6B93 C6F0 2FAF

* remotes/cohuck-gitlab/tags/s390x-20210305:
  target/s390x/kvm: Simplify debug code
  vfio-ccw: Do not read region ret_code after write
  css: SCHIB measurement block origin must be aligned
  virtio-ccw: commands on revision-less devices
  s390x/pci: restore missing Query PCI Function CLP data
  hw/s390x: fix build for virtio-9p-ccw
  target/s390x/arch_dump: Fix warning for the name field in the PT_NOTE section
  s390x/cpu_model: disallow unpack for --only-migratable

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>