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[1/2] MIPS: Introduce CAVIUM_RESERVE32 Kconfig option

Message ID 20220725091740.28188-2-alexander.sverdlin@nokia.com (mailing list archive)
State Accepted
Commit 3e3114ac460e94825e34d1fed6a48a9ce4b07689
Headers show
Series MIPS: Restore CONFIG_CAVIUM_RESERVE32 | expand

Commit Message

Alexander Sverdlin July 25, 2022, 9:17 a.m. UTC 
From: Alexander Sverdlin <alexander.sverdlin@nokia.com>

This options is used to reserve a shared memory region for user processes
to use for hardware memory buffers. The actual code to support the option
comes in the following patch.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
---
 arch/mips/cavium-octeon/Kconfig | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Comments

Yu Zhao Aug. 30, 2022, 3:02 a.m. UTC | #1 
Hi,

This commit produces a bogus error message on systems that use the
default value. Please take a look.

Thanks.

  Linux version 6.0.0-rc1 (builder@buildhost) (mips64-openwrt-linux-musl-gcc (OpenWrt GCC 11.2.0 r19590-042d558536) 11.2.0, GNU ld (GNU Binutils) 2.37) #0 SMP Sun Jul 31 15:12:47 2022
  Failed to allocate CAVIUM_RESERVE32 memory area  <<<===
  Skipping L2 locking due to reduced L2 cache size
  CVMSEG size: 0 cache lines (0 bytes)
  printk: bootconsole [early0] enabled
  CPU0 revision is: 000d9301 (Cavium Octeon II)
Yu Zhao Sept. 5, 2022, 6:50 p.m. UTC | #2 
Hi Alexander,

On Mon, Aug 29, 2022 at 9:03 PM Yu Zhao <yuzhao@google.com> wrote:
>
> Hi,
>
> This commit produces a bogus error message on systems that use the
> default value. Please take a look.
>
> Thanks.
>
>   Linux version 6.0.0-rc1 (builder@buildhost) (mips64-openwrt-linux-musl-gcc (OpenWrt GCC 11.2.0 r19590-042d558536) 11.2.0, GNU ld (GNU Binutils) 2.37) #0 SMP Sun Jul 31 15:12:47 2022
>   Failed to allocate CAVIUM_RESERVE32 memory area  <<<===
>   Skipping L2 locking due to reduced L2 cache size
>   CVMSEG size: 0 cache lines (0 bytes)
>   printk: bootconsole [early0] enabled
>   CPU0 revision is: 000d9301 (Cavium Octeon II)

Following up on this. Please take a look. Thanks.
Alexander Sverdlin Sept. 6, 2022, 7:55 a.m. UTC | #3 
Hello Yu,

On 05/09/2022 20:50, Yu Zhao wrote:
>> This commit produces a bogus error message on systems that use the
>> default value. Please take a look.
>>
>> Thanks.
>>
>>   Linux version 6.0.0-rc1 (builder@buildhost) (mips64-openwrt-linux-musl-gcc (OpenWrt GCC 11.2.0 r19590-042d558536) 11.2.0, GNU ld (GNU Binutils) 2.37) #0 SMP Sun Jul 31 15:12:47 2022
>>   Failed to allocate CAVIUM_RESERVE32 memory area  <<<===
>>   Skipping L2 locking due to reduced L2 cache size
>>   CVMSEG size: 0 cache lines (0 bytes)
>>   printk: bootconsole [early0] enabled
>>   CPU0 revision is: 000d9301 (Cavium Octeon II)
> Following up on this. Please take a look. Thanks.

thanks for following this up! I thought I've sent the patch a week ago, but seems something
went wrong... Nevertheless:
https://lore.kernel.org/linux-mips/20220906075253.28491-1-alexander.sverdlin@nokia.com/T/#u
diff mbox series

Patch

diff --git a/arch/mips/cavium-octeon/Kconfig b/arch/mips/cavium-octeon/Kconfig
index 4984e46..c1899f1 100644
--- a/arch/mips/cavium-octeon/Kconfig
+++ b/arch/mips/cavium-octeon/Kconfig
@@ -67,6 +67,18 @@  config CAVIUM_OCTEON_LOCK_L2_MEMCPY
 	help
 	  Lock the kernel's implementation of memcpy() into L2.
 
+config CAVIUM_RESERVE32
+	int "Memory to reserve for user processes shared region (MB)"
+	range 0 1536
+	default "0"
+	help
+	  Reserve a shared memory region for user processes to use for hardware
+	  memory buffers. This is required for 32bit applications to be able to
+	  send and receive packets directly. Applications access this memory by
+	  memory mapping /dev/mem for the addresses in /proc/octeon_info. For
+	  optimal performance with HugeTLBs, keep this size an even number of
+	  megabytes.
+
 config OCTEON_ILM
 	tristate "Module to measure interrupt latency using Octeon CIU Timer"
 	help