[PATCH 5.19 03/72] firmware: tegra: bpmp: Do only aligned access to IPC memory area

Greg Kroah-Hartman
2022-09-02T12:52:38Z

From: Timo Alho <talho@nvidia.com>

commit a4740b148a04dc60e14fe6a1dfe216d3bae214fd upstream.

Use memcpy_toio and memcpy_fromio variants of memcpy to guarantee no
unaligned access to IPC memory area. This is to allow the IPC memory to
be mapped as Device memory to further suppress speculative reads from
happening within the 64 kB memory area above the IPC memory when 64 kB
memory pages are used.

Signed-off-by: Timo Alho <talho@nvidia.com>
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/firmware/tegra/bpmp.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/firmware/tegra/bpmp.c
+++ b/drivers/firmware/tegra/bpmp.c
@@ -201,7 +201,7 @@ static ssize_t __tegra_bpmp_channel_read
int err;

if (data && size > 0)
- memcpy(data, channel->ib->data, size);
+ memcpy_fromio(data, channel->ib->data, size);

err = tegra_bpmp_ack_response(channel);
if (err < 0)
@@ -245,7 +245,7 @@ static ssize_t __tegra_bpmp_channel_writ
channel->ob->flags = flags;

if (data && size > 0)
- memcpy(channel->ob->data, data, size);
+ memcpy_toio(channel->ob->data, data, size);

return tegra_bpmp_post_request(channel);
}
@@ -420,7 +420,7 @@ void tegra_bpmp_mrq_return(struct tegra_
channel->ob->code = code;

if (data && size > 0)
- memcpy(channel->ob->data, data, size);
+ memcpy_toio(channel->ob->data, data, size);

err = tegra_bpmp_post_response(channel);
if (WARN_ON(err < 0))