Re: [PATCH 3/4] sunxi: DRAM: H6: split struct dram_para

On Saturday, October 21, 2023 3:10:24 AM CEST Andre Przywara wrote:

Currently there is one DRAM parameter struct for the Allwinner H6 DRAM "driver". It contains many fields that are compile time constants (set by Kconfig variables), though there are also some fields that are probed and changed over the runtime of the DRAM initialisation.

Because of this mixture, the compiler cannot properly optimise the code for size, as it does not consider constant propagation in its full potential.

Help the compiler out by splitting that structure into two: one that only contains values known at compile time, and another one where the values will actually change. The former can then be declared "const", which will let the compiler fold its values directly into the code using it. To facilitate this, the definition of the struct has to become "static const" outside of any functions, so move that part out of sunxi_dram_init().

That results in code savings around 500 bytes, which helps the notorously tight H6 SPL to stay within it current limit.

Signed-off-by: Andre Przywara andre.przywara@arm.com

Reviewed-by: Jernej Skrabec jernej.skrabec@gmail.com

Best regards, Jernej

---

.../include/asm/arch-sunxi/dram_sun50i_h6.h | 12 +- arch/arm/mach-sunxi/dram_sun50i_h6.c | 134 +++++++++--------- 2 files changed, 77 insertions(+), 69 deletions(-)

diff --git a/arch/arm/include/asm/arch-sunxi/dram_sun50i_h6.h b/arch/arm/include/asm/arch-sunxi/dram_sun50i_h6.h index a7c6435220f..058f2cabb6e 100644 --- a/arch/arm/include/asm/arch-sunxi/dram_sun50i_h6.h +++ b/arch/arm/include/asm/arch-sunxi/dram_sun50i_h6.h @@ -313,17 +313,19 @@ check_member(sunxi_mctl_phy_reg, dx[3].reserved_0xf0, 0xaf0); */ #define RD_LINES_PER_BYTE_LANE (BITS_PER_BYTE + 6) struct dram_para {

• const u32 clk;
• const enum sunxi_dram_type type;

• u32 clk;
• enum sunxi_dram_type type;
• u8 dx_read_delays[NR_OF_BYTE_LANES][RD_LINES_PER_BYTE_LANE];
• u8 dx_write_delays[NR_OF_BYTE_LANES][WR_LINES_PER_BYTE_LANE];

+};

+struct dram_config { u8 cols; u8 rows; u8 ranks; u8 bus_full_width;

• const u8 dx_read_delays[NR_OF_BYTE_LANES][RD_LINES_PER_BYTE_LANE];
• const u8 dx_write_delays[NR_OF_BYTE_LANES]

[WR_LINES_PER_BYTE_LANE];

};

static inline int ns_to_t(int nanoseconds) { const unsigned int ctrl_freq = CONFIG_DRAM_CLK / 2; diff --git a/arch/arm/mach-sunxi/dram_sun50i_h6.c b/arch/arm/mach-sunxi/dram_sun50i_h6.c index 1187f1960a0..8e959f4c600 100644 --- a/arch/arm/mach-sunxi/dram_sun50i_h6.c +++ b/arch/arm/mach-sunxi/dram_sun50i_h6.c @@ -179,15 +179,15 @@ static void mctl_sys_init(u32 clk_rate) writel(0x8000, &mctl_ctl->unk_0x00c); }

-static void mctl_set_addrmap(const struct dram_para *para) +static void mctl_set_addrmap(const struct dram_config *config) { struct sunxi_mctl_ctl_reg * const mctl_ctl = (struct sunxi_mctl_ctl_reg

*)SUNXI_DRAM_CTL0_BASE;

• u8 cols = para->cols;
• u8 rows = para->rows;
• u8 ranks = para->ranks;

• u8 cols = config->cols;
• u8 rows = config->rows;
• u8 ranks = config->ranks;

• if (!para->bus_full_width)

• if (!config->bus_full_width) cols -= 1;

  /* Ranks */

@@ -265,7 +265,8 @@ static void mctl_set_addrmap(const struct dram_para *para) mctl_ctl->addrmap[8] = 0x3F3F; }

-static void mctl_com_init(const struct dram_para *para) +static void mctl_com_init(const struct dram_para *para,

• 	  const struct dram_config *config)
  

{ struct sunxi_mctl_com_reg * const mctl_com = (struct sunxi_mctl_com_reg

*)SUNXI_DRAM_COM_BASE;

@@ -275,7 +276,7 @@ static void mctl_com_init(const struct dram_para *para) (struct sunxi_mctl_phy_reg

*)SUNXI_DRAM_PHY0_BASE;

u32 reg_val, tmp;

• mctl_set_addrmap(para);

• mctl_set_addrmap(config);

  setbits_le32(&mctl_com->cr, BIT(31));

@@ -294,12 +295,12 @@ static void mctl_com_init(const struct dram_para *para) clrsetbits_le32(&mctl_com->unk_0x008, 0x3f00, reg_val);

/* TODO: DDR4 */

• reg_val = MSTR_BURST_LENGTH(8) | MSTR_ACTIVE_RANKS(para->ranks);

• reg_val = MSTR_BURST_LENGTH(8) | MSTR_ACTIVE_RANKS(config->ranks); if (para->type == SUNXI_DRAM_TYPE_LPDDR3) reg_val |= MSTR_DEVICETYPE_LPDDR3; if (para->type == SUNXI_DRAM_TYPE_DDR3) reg_val |= MSTR_DEVICETYPE_DDR3 | MSTR_2TMODE;

• if (para->bus_full_width)

• if (config->bus_full_width) reg_val |= MSTR_BUSWIDTH_FULL; else reg_val |= MSTR_BUSWIDTH_HALF;

@@ -311,7 +312,7 @@ static void mctl_com_init(const struct dram_para *para) reg_val = DCR_DDR3 | DCR_DDR8BANK | DCR_DDR2T; writel(reg_val | 0x400, &mctl_phy->dcr);

• if (para->ranks == 2)

• if (config->ranks == 2) writel(0x0303, &mctl_ctl->odtmap); else writel(0x0201, &mctl_ctl->odtmap);

@@ -329,7 +330,7 @@ static void mctl_com_init(const struct dram_para *para) } writel(reg_val, &mctl_ctl->odtcfg);

• if (!para->bus_full_width) {

• if (!config->bus_full_width) { writel(0x0, &mctl_phy->dx[2].gcr[0]); writel(0x0, &mctl_phy->dx[3].gcr[0]); }

@@ -394,7 +395,8 @@ static void mctl_bit_delay_set(const struct dram_para *para) } }

-static bool mctl_channel_init(const struct dram_para *para) +static bool mctl_channel_init(const struct dram_para *para,

• 	      const struct dram_config *config)
  

{ struct sunxi_mctl_com_reg * const mctl_com = (struct sunxi_mctl_com_reg

*)SUNXI_DRAM_COM_BASE;

@@ -429,14 +431,14 @@ static bool mctl_channel_init(const struct dram_para *para)

udelay(100);

• if (para->ranks == 2)

• if (config->ranks == 2) setbits_le32(&mctl_phy->dtcr[1], 0x30000); else clrsetbits_le32(&mctl_phy->dtcr[1], 0x30000, 0x10000);

  if (sunxi_dram_is_lpddr(para->type)) clrbits_le32(&mctl_phy->dtcr[1], BIT(1));

• if (para->ranks == 2) {

• if (config->ranks == 2) { writel(0x00010001, &mctl_phy->rankidr); writel(0x20000, &mctl_phy->odtcr); } else {

@@ -544,10 +546,11 @@ static bool mctl_channel_init(const struct dram_para *para) return true; }

-static bool mctl_core_init(const struct dram_para *para) +static bool mctl_core_init(const struct dram_para *para,

• 	   const struct dram_config *config)
  

{ mctl_sys_init(para->clk);

• mctl_com_init(para);

• mctl_com_init(para, config); switch (para->type) { case SUNXI_DRAM_TYPE_LPDDR3: case SUNXI_DRAM_TYPE_DDR3:

@@ -556,14 +559,15 @@ static bool mctl_core_init(const struct dram_para *para) default: panic("Unsupported DRAM type!"); };

• return mctl_channel_init(para);

• return mctl_channel_init(para, config);

}

-static void mctl_auto_detect_rank_width(struct dram_para *para) +static void mctl_auto_detect_rank_width(const struct dram_para *para,

• 			struct dram_config 
  

*config)

{ /* this is minimum size that it's supported */

• para->cols = 8;
• para->rows = 13;

• config->cols = 8;

• config->rows = 13;

  /*

  • Previous versions of this driver tried to auto detect the rank

@@ -579,68 +583,69 @@ static void mctl_auto_detect_rank_width(struct dram_para *para) */

debug("testing 32-bit width, rank = 2\n");

• para->bus_full_width = 1;
• para->ranks = 2;
• if (mctl_core_init(para))

• config->bus_full_width = 1;

• config->ranks = 2;

• if (mctl_core_init(para, config)) return;

  debug("testing 32-bit width, rank = 1\n");

• para->bus_full_width = 1;
• para->ranks = 1;
• if (mctl_core_init(para))

• config->bus_full_width = 1;

• config->ranks = 1;

• if (mctl_core_init(para, config)) return;

  debug("testing 16-bit width, rank = 2\n");

• para->bus_full_width = 0;
• para->ranks = 2;
• if (mctl_core_init(para))

• config->bus_full_width = 0;

• config->ranks = 2;

• if (mctl_core_init(para, config)) return;

  debug("testing 16-bit width, rank = 1\n");

• para->bus_full_width = 0;
• para->ranks = 1;
• if (mctl_core_init(para))

• config->bus_full_width = 0;

• config->ranks = 1;

• if (mctl_core_init(para, config)) return;

  panic("This DRAM setup is currently not supported.\n");

}

-static void mctl_auto_detect_dram_size(struct dram_para *para) +static void mctl_auto_detect_dram_size(const struct dram_para *para,

• 		       struct dram_config *config)
  

{ /* TODO: non-(LP)DDR3 */

/* detect row address bits */

• para->cols = 8;
• para->rows = 18;
• mctl_core_init(para);

• config->cols = 8;
• config->rows = 18;
• mctl_core_init(para, config);

• for (para->rows = 13; para->rows < 18; para->rows++) {

• for (config->rows = 13; config->rows < 18; config->rows++) { /* 8 banks, 8 bit per byte and 16/32 bit width */

• if (mctl_mem_matches((1 << (para->rows + para->cols +
  

• 			    4 + para-
  

bus_full_width))))

• if (mctl_mem_matches((1 << (config->rows + config->cols +
  

• 			    4 + config-
  

bus_full_width)))) break; }

/* detect column address bits */

• para->cols = 11;
• mctl_core_init(para);

• config->cols = 11;
• mctl_core_init(para, config);

• for (para->cols = 8; para->cols < 11; para->cols++) {

• for (config->cols = 8; config->cols < 11; config->cols++) { /* 8 bits per byte and 16/32 bit width */

• if (mctl_mem_matches(1 << (para->cols + 1 +
  

• 			   para-
  

bus_full_width)))

• if (mctl_mem_matches(1 << (config->cols + 1 +
  

• 			   config-
  

bus_full_width))) break; } }

-unsigned long mctl_calc_size(const struct dram_para *para) +unsigned long mctl_calc_size(const struct dram_config *config) {

• u8 width = para->bus_full_width ? 4 : 2;

• u8 width = config->bus_full_width ? 4 : 2;

  /* TODO: non-(LP)DDR3 */

  /* 8 banks */

• return (1ULL << (para->cols + para->rows + 3)) * width * para-

ranks;

• return (1ULL << (config->cols + config->rows + 3)) * width *

config->ranks; }

#define SUN50I_H6_LPDDR3_DX_WRITE_DELAYS \ @@ -665,36 +670,37 @@ unsigned long mctl_calc_size(const struct dram_para *para) { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, \ { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }}

+static const struct dram_para para = {

• .clk = CONFIG_DRAM_CLK,

+#ifdef CONFIG_SUNXI_DRAM_H6_LPDDR3

• .type = SUNXI_DRAM_TYPE_LPDDR3,
• .dx_read_delays = SUN50I_H6_LPDDR3_DX_READ_DELAYS,
• .dx_write_delays = SUN50I_H6_LPDDR3_DX_WRITE_DELAYS,

+#elif defined(CONFIG_SUNXI_DRAM_H6_DDR3_1333)

• .type = SUNXI_DRAM_TYPE_DDR3,
• .dx_read_delays = SUN50I_H6_DDR3_DX_READ_DELAYS,
• .dx_write_delays = SUN50I_H6_DDR3_DX_WRITE_DELAYS,

+#endif +};

unsigned long sunxi_dram_init(void) { struct sunxi_mctl_com_reg * const mctl_com = (struct sunxi_mctl_com_reg

*)SUNXI_DRAM_COM_BASE;

struct sunxi_prcm_reg *const prcm = (struct sunxi_prcm_reg *)SUNXI_PRCM_BASE;

• struct dram_para para = {

• .clk = CONFIG_DRAM_CLK,
  

-#ifdef CONFIG_SUNXI_DRAM_H6_LPDDR3

• .type = SUNXI_DRAM_TYPE_LPDDR3,
  

• .dx_read_delays  = SUN50I_H6_LPDDR3_DX_READ_DELAYS,
  

• .dx_write_delays = SUN50I_H6_LPDDR3_DX_WRITE_DELAYS,
  

-#elif defined(CONFIG_SUNXI_DRAM_H6_DDR3_1333)

• .type = SUNXI_DRAM_TYPE_DDR3,
  

• .dx_read_delays  = SUN50I_H6_DDR3_DX_READ_DELAYS,
  

• .dx_write_delays = SUN50I_H6_DDR3_DX_WRITE_DELAYS,
  

-#endif

• };

• struct dram_config config; unsigned long size;

  setbits_le32(&prcm->res_cal_ctrl, BIT(8)); clrbits_le32(&prcm->ohms240, 0x3f);

• mctl_auto_detect_rank_width(&para);
• mctl_auto_detect_dram_size(&para);

• mctl_auto_detect_rank_width(&para, &config);
• mctl_auto_detect_dram_size(&para, &config);

• mctl_core_init(&para);

• mctl_core_init(&para, &config);

• size = mctl_calc_size(&para);

• size = mctl_calc_size(&config);

  clrsetbits_le32(&mctl_com->cr, 0xf0, (size >> (10 + 10 + 4)) &

0xf0);