At the moment the nvme_get_features() and nvme_set_features() functions
carry a (somewhat misleading) comment about missing cache maintenance.

As it turns out, nvme_get_features() has no caller at all in the tree,
and nvme_set_features' only user doesn't use a DMA buffer.

Mention that in the comment, and leave some breadcrumbs for the future,
should those functions attract more users.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

At the moment nvme_read_completion_status() tries to invalidate a single
member of the cqes[] array, which is shady as just a single entry is
not cache line aligned.
The structure is dictated by hardware, and with 16 bytes is smaller than
any cache line we usually deal with. Also multiple entries need to be
consecutive in memory, so we can't pad them to cover a whole cache line.

As a consequence we can only always invalidate all of them - U-Boot just
uses two of them anyway. This is fine, as they are only ever read by the
CPU (apart from the initial zeroing), so they can't become dirty.

Make this obvious by always invalidating the whole array, regardless of
the entry number we are about to read.
Also blow up the allocation size to cover whole cache lines, to avoid
other heap allocations to sneak in.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Michael Trimarchi <michael@amarulasolutions.com>
Tested-by: Neil Armstrong <narmstrong@baylibre.com>

Prepare v2021.01-rc5

Signed-off-by: Tom Rini <trini@konsulko.com>

There might be hardware configurations where 64-bit data accesses
to NVMe registers are not supported properly.  This patch removes
the readq/writeq so always two 32-bit accesses are used to read/write
64-bit NVMe registers, similarly as it is done in Linux kernel.

This patch fixes operation of NVMe devices on RPi4 Broadcom BCM2711 SoC
based board, where the PCIe Root Complex, which is attached to the
system through the SCB bridge.

Even though the architecture is 64-bit the PCIe BAR is 32-bit and likely
the 64-bit wide register accesses initiated by the CPU are not properly
translated to a sequence of 32-bit PCIe accesses.
nvme_readq(), for example, always returns same value in upper and lower
32-bits, e.g. 0x3c033fff3c033fff which lead to NVMe devices to fail
probing.

This fix is analogous to commit 8e2ab05000ab ("usb: xhci: Use only
32-bit accesses in xhci_writeq/xhci_readq").

Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc: Matthias Brugger <mbrugger@suse.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>

Try to maintain some consistency between these variables by using _plat as
a suffix for them.

Signed-off-by: Simon Glass <sjg@chromium.org>

We use 'priv' for private data but often use 'platdata' for platform data.
We can't really use 'pdata' since that is ambiguous (it could mean private
or platform data).

Rename some of the latter variables to end with 'plat' for consistency.

Signed-off-by: Simon Glass <sjg@chromium.org>

This construct is quite long-winded. In earlier days it made some sense
since auto-allocation was a strange concept. But with driver model now
used pretty universally, we can shorten this to 'auto'. This reduces
verbosity and makes it easier to read.

Coincidentally it also ensures that every declaration is on one line,
thus making dtoc's job easier.

Signed-off-by: Simon Glass <sjg@chromium.org>

This patch try to avoids eviction of dirty lines during DMA
transfer. The code right now execute the following step:

- allocate the buffer
- start a dma operation using the non-coherent dma buffer
- invalidate cache lines associated with the buffer
- read the buffer

This can lead to reading back not valid information, because the cache
controller could evict dirty cache lines belonging to the buffer *after*
the DMA operation has started to fill the DRAM.
In order to avoid this, a new invalidation is required *before* starting
the DMA operation. The patch just adds an invalidation before submitting
the DMA command.

Example below shows the nvme disk scan result without the following
patch

=> nvme scan
nvme_get_info_from_identify: nn = 544502629, vwc = 100,
sn = dev_0T, mn = `�\�, fr = t_part, mdts = 105

So, invalidating the cache before submitting the admin command,
fix the cpu read.

Cc: André Przywara <andre.przywara@arm.com>
Reported-by: Suniel Mahesh <sunil@amarulasolutions.com>
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Suniel Mahesh <sunil@amarulasolutions.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

Move this header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>

Move this uncommon header out of the common header.

Signed-off-by: Simon Glass <sjg@chromium.org>