[PATCH net] nfp: use full 40 bits of the NSP buffer address

[PATCH net] nfp: use full 40 bits of the NSP buffer address

[Jakub Kicinski]

From: Dirk van der Merwe <dirk.vandermerwe@netronome.com>

The NSP default buffer is a piece of NFP memory where additional
command data can be placed.  Its format has been copied from
host buffer, but the PCIe selection bits do not make sense in
this case.  If those get masked out from a NFP address - writes
to random place in the chip memory may be issued and crash the
device.

This has never been an issue because the buffer used to be
allocated in memory with less-than-38-bit-long address but that
is about to change.

Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c
index 39abac678b71..b54ab02f5b33 100644
--- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c
+++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c
@@ -71,8 +71,7 @@
 /* CPP address to retrieve the data from */
 #define NSP_BUFFER		0x10
 #define   NSP_BUFFER_CPP	GENMASK_ULL(63, 40)
-#define   NSP_BUFFER_PCIE	GENMASK_ULL(39, 38)
-#define   NSP_BUFFER_ADDRESS	GENMASK_ULL(37, 0)
+#define   NSP_BUFFER_ADDRESS	GENMASK_ULL(39, 0)
 
 #define NSP_DFLT_BUFFER		0x18
 
-- 
2.16.2

Re: [PATCH net] nfp: use full 40 bits of the NSP buffer address

[Jakub Kicinski]

On Fri, 23 Mar 2018 19:42:22 -0700, Jakub Kicinski wrote:
> From: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
> 
> The NSP default buffer is a piece of NFP memory where additional
> command data can be placed.  Its format has been copied from
> host buffer, but the PCIe selection bits do not make sense in
> this case.  If those get masked out from a NFP address - writes
> to random place in the chip memory may be issued and crash the
> device.
> 
> This has never been an issue because the buffer used to be
> allocated in memory with less-than-38-bit-long address but that
> is about to change.
> 
> Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
> Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
> ---
>  drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c
> index 39abac678b71..b54ab02f5b33 100644
> --- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c
> +++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c
> @@ -71,8 +71,7 @@
>  /* CPP address to retrieve the data from */
>  #define NSP_BUFFER		0x10
>  #define   NSP_BUFFER_CPP	GENMASK_ULL(63, 40)
> -#define   NSP_BUFFER_PCIE	GENMASK_ULL(39, 38)
> -#define   NSP_BUFFER_ADDRESS	GENMASK_ULL(37, 0)
> +#define   NSP_BUFFER_ADDRESS	GENMASK_ULL(39, 0)

self-nack, this is changing a shared define for all bufs, adding a new
define of NFP buf will be cleaner.

Re: [PATCH net] nfp: use full 40 bits of the NSP buffer address

[David Miller]

From: Jakub Kicinski <jakub.kicinski@netronome.com>
Date: Tue,  3 Apr 2018 17:24:23 -0700

> From: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
> 
> The NSP default buffer is a piece of NFP memory where additional
> command data can be placed.  Its format has been copied from
> host buffer, but the PCIe selection bits do not make sense in
> this case.  If those get masked out from a NFP address - writes
> to random place in the chip memory may be issued and crash the
> device.
> 
> Even in the general NSP buffer case, it doesn't make sense to have the
> PCIe selection bits there anymore. These are unused at the moment, and
> when it becomes necessary, the PCIe selection bits should rather be
> moved to another register to utilise more bits for the buffer address.
> 
> This has never been an issue because the buffer used to be
> allocated in memory with less-than-38-bit-long address but that
> is about to change.
> 
> Fixes: 1a64821c6af7 ("nfp: add support for service processor access")
> Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>

Applied and queued up for -stable, thanks.

[PATCH net] nfp: use full 40 bits of the NSP buffer address

[Jakub Kicinski]

From: Dirk van der Merwe <dirk.vandermerwe@netronome.com>

The NSP default buffer is a piece of NFP memory where additional
command data can be placed.  Its format has been copied from
host buffer, but the PCIe selection bits do not make sense in
this case.  If those get masked out from a NFP address - writes
to random place in the chip memory may be issued and crash the
device.

Even in the general NSP buffer case, it doesn't make sense to have the
PCIe selection bits there anymore. These are unused at the moment, and
when it becomes necessary, the PCIe selection bits should rather be
moved to another register to utilise more bits for the buffer address.

This has never been an issue because the buffer used to be
allocated in memory with less-than-38-bit-long address but that
is about to change.

Fixes: 1a64821c6af7 ("nfp: add support for service processor access")
Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c
index 39abac678b71..99bb679a9801 100644
--- a/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c
+++ b/drivers/net/ethernet/netronome/nfp/nfpcore/nfp_nsp.c
@@ -71,10 +71,11 @@
 /* CPP address to retrieve the data from */
 #define NSP_BUFFER		0x10
 #define   NSP_BUFFER_CPP	GENMASK_ULL(63, 40)
-#define   NSP_BUFFER_PCIE	GENMASK_ULL(39, 38)
-#define   NSP_BUFFER_ADDRESS	GENMASK_ULL(37, 0)
+#define   NSP_BUFFER_ADDRESS	GENMASK_ULL(39, 0)
 
 #define NSP_DFLT_BUFFER		0x18
+#define   NSP_DFLT_BUFFER_CPP	GENMASK_ULL(63, 40)
+#define   NSP_DFLT_BUFFER_ADDRESS	GENMASK_ULL(39, 0)
 
 #define NSP_DFLT_BUFFER_CONFIG	0x20
 #define   NSP_DFLT_BUFFER_SIZE_MB	GENMASK_ULL(7, 0)
@@ -427,8 +428,8 @@ __nfp_nsp_command_buf(struct nfp_nsp *nsp, u16 code, u32 option,
 	if (err < 0)
 		return err;
 
-	cpp_id = FIELD_GET(NSP_BUFFER_CPP, reg) << 8;
-	cpp_buf = FIELD_GET(NSP_BUFFER_ADDRESS, reg);
+	cpp_id = FIELD_GET(NSP_DFLT_BUFFER_CPP, reg) << 8;
+	cpp_buf = FIELD_GET(NSP_DFLT_BUFFER_ADDRESS, reg);
 
 	if (in_buf && in_size) {
 		err = nfp_cpp_write(cpp, cpp_id, cpp_buf, in_buf, in_size);
-- 
2.16.2