[PATCH v2 2/2] sunxi: A133: dram: Add NSI arbiter configuration support
Paul Kocialkowski
paulk at sys-base.io
Fri May 8 14:25:40 CEST 2026
Hi Andre,
On Thu 30 Apr 26, 15:58, Andre Przywara wrote:
> From: Paul Kocialkowski <contact at paulk.fr>
Actually I made a mistake when sending this initially and this should
be my work email instead:
From: Paul Kocialkowski <paulk at sys-base.io>
All the best,
Paul
>
> The Allwinner DRAM controllers contains logic to assign priorities to
> various DRAM DMA masters. Configuring this DRAM port arbitration priority
> correctly is important to make sure that critical masters are not starved
> by other less important ones. This is especially the case with the display
> engine that needs to be able to fetch pixels in time for scanout and can
> easily be starved by CPU or GPU access.
>
> Add support for configuring the NSI arbiter in the A133 DRAM init code,
> using the recently refactored NSI code already used on the A523.
> The list and order of available ports are highly SoC-specific and the
> default config values are set to match the BSP's defaults.
>
> Signed-off-by: Paul Kocialkowski <paulk at sys-base.io>
> [Andre: using new generic NSI function]
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> Sponsored-by: MEC Electronics GmbH <https://www.mec.at/>
> ---
> .../include/asm/arch-sunxi/cpu_sun50i_h6.h | 4 ++
> .../include/asm/arch-sunxi/dram_sun50i_a133.h | 23 ++++++++++
> arch/arm/mach-sunxi/Makefile | 2 +-
> arch/arm/mach-sunxi/dram_sun50i_a133.c | 43 ++++++++++++++++++-
> 4 files changed, 70 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm/include/asm/arch-sunxi/cpu_sun50i_h6.h b/arch/arm/include/asm/arch-sunxi/cpu_sun50i_h6.h
> index b0f2d3f4656..c31437f9acc 100644
> --- a/arch/arm/include/asm/arch-sunxi/cpu_sun50i_h6.h
> +++ b/arch/arm/include/asm/arch-sunxi/cpu_sun50i_h6.h
> @@ -17,6 +17,10 @@
>
> #define SUNXI_GIC400_BASE 0x03020000
>
> +#ifdef CONFIG_MACH_SUN50I_A133
> +#define SUNXI_NSI_BASE 0x03100000
> +#endif
> +
> #ifdef CONFIG_MACH_SUN50I_H6
> #define SUNXI_DRAM_COM_BASE 0x04002000
> #define SUNXI_DRAM_CTL0_BASE 0x04003000
> diff --git a/arch/arm/include/asm/arch-sunxi/dram_sun50i_a133.h b/arch/arm/include/asm/arch-sunxi/dram_sun50i_a133.h
> index 01f2214cd15..1e8e0f7ab96 100644
> --- a/arch/arm/include/asm/arch-sunxi/dram_sun50i_a133.h
> +++ b/arch/arm/include/asm/arch-sunxi/dram_sun50i_a133.h
> @@ -24,6 +24,29 @@ static inline int ns_to_t(int nanoseconds)
> return DIV_ROUND_UP(ctrl_freq * nanoseconds, 1000);
> }
>
> +enum sunxi_nsi_port {
> + SUNXI_NSI_PORT_CPU = 0,
> + SUNXI_NSI_PORT_GPU,
> + SUNXI_NSI_PORT_SD1,
> + SUNXI_NSI_PORT_MSTG,
> + SUNXI_NSI_PORT_GMAC0,
> + SUNXI_NSI_PORT_GMAC1,
> + SUNXI_NSI_PORT_USB0,
> + SUNXI_NSI_PORT_USB1,
> + SUNXI_NSI_PORT_NDFC,
> + SUNXI_NSI_PORT_DMAC,
> + SUNXI_NSI_PORT_CE,
> + SUNXI_NSI_PORT_DE0,
> + SUNXI_NSI_PORT_DE1,
> + SUNXI_NSI_PORT_VE,
> + SUNXI_NSI_PORT_CSI,
> + SUNXI_NSI_PORT_ISP,
> + SUNXI_NSI_PORT_G2D,
> + SUNXI_NSI_PORT_EINK,
> + SUNXI_NSI_PORT_IOMMU,
> + SUNXI_NSI_PORT_CPUS,
> +};
> +
> /* MBUS part is largely the same as in H6, except for one special register */
> #define MCTL_COM_UNK_008 0x008
> /* NOTE: This register has the same importance as mctl_ctl->clken in H616 */
> diff --git a/arch/arm/mach-sunxi/Makefile b/arch/arm/mach-sunxi/Makefile
> index 3ef0113ea43..30cce7d1784 100644
> --- a/arch/arm/mach-sunxi/Makefile
> +++ b/arch/arm/mach-sunxi/Makefile
> @@ -48,7 +48,7 @@ obj-$(CONFIG_DRAM_SUN50I_H6) += dram_sun50i_h6.o dram_dw_helpers.o
> obj-$(CONFIG_DRAM_SUN50I_H6) += dram_timings/
> obj-$(CONFIG_DRAM_SUN50I_H616) += dram_sun50i_h616.o dram_dw_helpers.o
> obj-$(CONFIG_DRAM_SUN50I_H616) += dram_timings/
> -obj-$(CONFIG_DRAM_SUN50I_A133) += dram_sun50i_a133.o
> +obj-$(CONFIG_DRAM_SUN50I_A133) += dram_sun50i_a133.o sunxi_nsi.o
> obj-$(CONFIG_DRAM_SUN50I_A133) += dram_timings/
> obj-$(CONFIG_MACH_SUN55I_A523) += dram_sun55i_a523.o dram_dw_helpers.o sunxi_nsi.o
> obj-$(CONFIG_DRAM_SUN55I_A523) += dram_timings/
> diff --git a/arch/arm/mach-sunxi/dram_sun50i_a133.c b/arch/arm/mach-sunxi/dram_sun50i_a133.c
> index ca3e2513c69..433044e1e2b 100644
> --- a/arch/arm/mach-sunxi/dram_sun50i_a133.c
> +++ b/arch/arm/mach-sunxi/dram_sun50i_a133.c
> @@ -21,6 +21,7 @@
> #include <asm/arch/cpu.h>
> #include <asm/arch/dram.h>
> #include <asm/arch/prcm.h>
> +#include <asm/arch/sunxi_nsi.h>
> #include <asm/io.h>
> #include <init.h>
> #include <linux/bitops.h>
> @@ -69,6 +70,41 @@ static const u8 phy_init[] = {
> };
> #endif
>
> +static void nsi_set_master_priority(void)
> +{
> + struct {
> + unsigned int port;
> + u8 pri;
> + u8 qos_sel;
> + } ports[] = {
> + NSI_CONF(CPU, LOWEST, INPUT),
> + NSI_CONF(GPU, LOWEST, INPUT),
> + NSI_CONF(SD1, LOWEST, OUTPUT),
> + NSI_CONF(MSTG, LOWEST, OUTPUT),
> + NSI_CONF(GMAC0, LOWEST, OUTPUT),
> + NSI_CONF(GMAC1, LOWEST, OUTPUT),
> + NSI_CONF(USB0, LOWEST, OUTPUT),
> + NSI_CONF(USB1, LOWEST, OUTPUT),
> + NSI_CONF(NDFC, LOWEST, OUTPUT),
> + NSI_CONF(DMAC, LOWEST, OUTPUT),
> + NSI_CONF(CE, LOWEST, OUTPUT),
> + NSI_CONF(DE0, HIGH, INPUT),
> + NSI_CONF(DE1, HIGH, INPUT),
> + NSI_CONF(VE, LOWEST, INPUT),
> + NSI_CONF(CSI, HIGH, INPUT),
> + NSI_CONF(ISP, HIGH, INPUT),
> + NSI_CONF(G2D, LOWEST, INPUT),
> + NSI_CONF(EINK, LOWEST, OUTPUT),
> + NSI_CONF(IOMMU, HIGHEST, INPUT),
> + NSI_CONF(CPUS, LOWEST, OUTPUT),
> + };
> + unsigned int i;
> +
> + for (i = 0; i < ARRAY_SIZE(ports); i++)
> + nsi_configure_port(ports[i].port, ports[i].pri,
> + ports[i].qos_sel);
> +}
> +
> static void mctl_clk_init(u32 clk)
> {
> void * const ccm = (void *)SUNXI_CCM_BASE;
> @@ -1205,6 +1241,7 @@ static const struct dram_para para = {
> unsigned long sunxi_dram_init(void)
> {
> struct dram_config config;
> + unsigned long size;
>
> /* Writing to undocumented SYS_CFG area, according to user manual. */
> setbits_le32(0x03000160, BIT(8));
> @@ -1221,5 +1258,9 @@ unsigned long sunxi_dram_init(void)
> 1U << config.bankgrps, 1U << config.ranks,
> 16U << config.bus_full_width);
>
> - return calculate_dram_size(&config);
> + size = calculate_dram_size(&config);
> +
> + nsi_set_master_priority();
> +
> + return size;
> }
> --
> 2.43.0
>
--
Paul Kocialkowski,
Independent contractor - sys-base - https://www.sys-base.io/
Free software developer - https://www.paulk.fr/
Expert in multimedia, graphics and embedded hardware support with Linux.
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