am43xx: Tune the system to avoid DSS underflows

* This is done by limiting the ARM's bandwidth and setting DSS priority in
  the EMIF controller to ensure underflows do not occur.

4 files changed, 49 insertions, 4 deletions

diff --git a/arch/arm/cpu/armv7/am33xx/ddr.c b/arch/arm/cpu/armv7/am33xx/ddr.c
index bbe9d1a8dea..fc66872a317 100644
--- a/arch/arm/cpu/armv7/am33xx/ddr.c
+++ b/arch/arm/cpu/armv7/am33xx/ddr.c
@@ -94,6 +94,18 @@ void config_sdram_emif4d5(const struct emif_regs *regs, int nr)
 	writel(regs->emif_rd_wr_exec_thresh,
 	       &emif_reg[nr]->emif_rd_wr_exec_thresh);
 
+	/*
+	 * for most SOCs these registers won't need to be changed so only
+	 * write to these registers if someone explicitly has set the
+	 * register's value.
+	 */
+	if(regs->emif_cos_config) {
+		writel(regs->emif_prio_class_serv_map, &emif_reg[nr]->emif_prio_class_serv_map);
+		writel(regs->emif_connect_id_serv_1_map, &emif_reg[nr]->emif_connect_id_serv_1_map);
+		writel(regs->emif_connect_id_serv_2_map, &emif_reg[nr]->emif_connect_id_serv_2_map);
+		writel(regs->emif_cos_config, &emif_reg[nr]->emif_cos_config);
+	}
+
 	writel(regs->ref_ctrl, &emif_reg[nr]->emif_sdram_ref_ctrl);
 	writel(regs->ref_ctrl, &emif_reg[nr]->emif_sdram_ref_ctrl_shdw);
 	writel(regs->sdram_config, &emif_reg[nr]->emif_sdram_config);
diff --git a/arch/arm/include/asm/arch-am33xx/cpu.h b/arch/arm/include/asm/arch-am33xx/cpu.h
index aa10fab4dd8..8dd69b3c80e 100644
--- a/arch/arm/include/asm/arch-am33xx/cpu.h
+++ b/arch/arm/include/asm/arch-am33xx/cpu.h
@@ -489,6 +489,12 @@ struct ctrl_stat {
 #define OMAP_GPIO_SETDATAOUT		0x0194
 
 /* Control Device Register */
+
+ /* Control Device Register */
+#define MREQPRIO_0_SAB_INIT1_MASK	0xFFFFFF8F
+#define MREQPRIO_0_SAB_INIT0_MASK	0xFFFFFFF8
+#define MREQPRIO_1_DSS_MASK		0xFFFFFF8F
+
 struct ctrl_dev {
 	unsigned int deviceid;		/* offset 0x00 */
 	unsigned int resv1[7];
@@ -502,10 +508,25 @@ struct ctrl_dev {
 	unsigned int macid1h;		/* offset 0x3c */
 	unsigned int resv4[4];
 	unsigned int miisel;		/* offset 0x50 */
-	unsigned int resv5[106];
+	unsigned int resv5[7];
+	unsigned int mreqprio_0;	/* offset 0x70 */
+	unsigned int mreqprio_1;	/* offset 0x74 */
+	unsigned int resv6[97];
 	unsigned int efuse_sma;		/* offset 0x1FC */
 };
 
+/* Bandwidth Limiter Portion of the L3Fast Configuration Register */
+#define BW_LIMITER_BW_FRAC_MASK         0xFFFFFFE0
+#define BW_LIMITER_BW_INT_MASK          0xFFFFFFF0
+#define BW_LIMITER_BW_WATERMARK_MASK    0xFFFFF800
+
+struct l3f_cfg_bwlimiter {
+	u32 padding0[2];
+	u32 modena_init0_bw_fractional;
+	u32 modena_init0_bw_integer;
+	u32 modena_init0_watermark_0;
+};
+
 /* gmii_sel register defines */
 #define GMII1_SEL_MII		0x0
 #define GMII1_SEL_RMII		0x1
diff --git a/arch/arm/include/asm/arch-am33xx/hardware_am43xx.h b/arch/arm/include/asm/arch-am33xx/hardware_am43xx.h
index 15399dcc747..b4703192499 100644
--- a/arch/arm/include/asm/arch-am33xx/hardware_am43xx.h
+++ b/arch/arm/include/asm/arch-am33xx/hardware_am43xx.h
@@ -13,6 +13,9 @@
 
 /* Module base addresses */
 
+/* L3 Fast Configuration Bandwidth Limiter Base Address */
+#define L3F_CFG_BWLIMITER		0x44005200
+
 /* UART Base Address */
 #define UART0_BASE			0x44E09000
 
diff --git a/arch/arm/include/asm/emif.h b/arch/arm/include/asm/emif.h
index 45668ca4dd7..b8d6bdca9b1 100644
--- a/arch/arm/include/asm/emif.h
+++ b/arch/arm/include/asm/emif.h
@@ -642,11 +642,16 @@ struct emif_reg_struct {
 	u32 emif_ddr_phy_ctrl_1;
 	u32 emif_ddr_phy_ctrl_1_shdw;
 	u32 emif_ddr_phy_ctrl_2;
-	u32 padding7[12];
+	u32 padding7[4];
+	u32 emif_prio_class_serv_map;
+	u32 emif_connect_id_serv_1_map;
+	u32 emif_connect_id_serv_2_map;
+	u32 padding8[5];
 	u32 emif_rd_wr_exec_thresh;
-	u32 padding8[7];
+	u32 emif_cos_config;
+	u32 padding9[6];
 	u32 emif_ddr_phy_status[21];
-	u32 padding9[27];
+	u32 padding10[27];
 	u32 emif_ddr_ext_phy_ctrl_1;
 	u32 emif_ddr_ext_phy_ctrl_1_shdw;
 	u32 emif_ddr_ext_phy_ctrl_2;
@@ -1137,6 +1142,10 @@ struct emif_regs {
 	u32 emif_rd_wr_lvl_rmp_ctl;
 	u32 emif_rd_wr_lvl_ctl;
 	u32 emif_rd_wr_exec_thresh;
+	u32 emif_prio_class_serv_map;
+	u32 emif_connect_id_serv_1_map;
+	u32 emif_connect_id_serv_2_map;
+	u32 emif_cos_config;
 };
 
 struct lpddr2_mr_regs {