| Message ID | 1466437295-30553-1-git-send-email-sudeep.holla@arm.com |
|---|---|
| State | Accepted |
| Commit | 71ee68a8e7a37a020433a11388ef8e86310662f2 |
| Headers | show |
On Mon, 2016-06-20 at 16:41 +0100, Sudeep Holla wrote: > Most of the ARM SoCs have small SRAM memory used for various purposes > that require faster access to data compared to normal DDR. > > This patch enables the Generic on-chip SRAM driver on ARM64. Would this cause things in the kernel to automatically start using SRAM found in device-tree, or would each use need to be added explicitly? I'm just wondering if we might start seeing new bugs caused by firmware using SRAM for special purposes but that memory not being properly reserved or hidden from the kernel. -- Tixy _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On 20/06/16 17:34, Jon Medhurst (Tixy) wrote: > On Mon, 2016-06-20 at 16:41 +0100, Sudeep Holla wrote: >> Most of the ARM SoCs have small SRAM memory used for various purposes >> that require faster access to data compared to normal DDR. >> >> This patch enables the Generic on-chip SRAM driver on ARM64. > > Would this cause things in the kernel to automatically start using SRAM > found in device-tree, or would each use need to be added explicitly? > I'm just wondering if we might start seeing new bugs caused by firmware > using SRAM for special purposes but that memory not being properly > reserved or hidden from the kernel. > No only the unreserved part of SRAM will be used by generic allocator and the users/drivers needing this have to explicitly request for the same(my understanding based on some usage I have seen on ARM32 platforms). The reserved part is not touched by the generic allocator. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig index d9e914aec081..bf0b0d258246 100644 --- a/arch/arm64/configs/defconfig +++ b/arch/arm64/configs/defconfig @@ -101,6 +101,7 @@ CONFIG_MTD_M25P80=y CONFIG_MTD_SPI_NOR=y CONFIG_BLK_DEV_LOOP=y CONFIG_VIRTIO_BLK=y +CONFIG_SRAM=y # CONFIG_SCSI_PROC_FS is not set CONFIG_BLK_DEV_SD=y # CONFIG_SCSI_LOWLEVEL is not set
Most of the ARM SoCs have small SRAM memory used for various purposes that require faster access to data compared to normal DDR. This patch enables the Generic on-chip SRAM driver on ARM64. Cc: Kevin Hilman <khilman@kernel.org> Cc: Olof Johansson <olof@lixom.net> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> --- arch/arm64/configs/defconfig | 1 + 1 file changed, 1 insertion(+) -- 2.7.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel