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Commit 5771caf8 authored by Mahesh Kumar's avatar Mahesh Kumar Committed by Rodrigo Vivi
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drm/i915/skl+: Decode memory bandwidth and parameters 



This patch adds support to decode system memory bandwidth and other
parameters for skylake and Gen9+ platforms, which will be used for
arbitrated display memory bandwidth calculation in GEN9 based
platforms and WM latency level-0 Work-around calculation on GEN9+.

Changes Since V1:
 - s/memdev_info/dram_info
 - create a struct to hold channel info
Changes Since V2:
 - rewrite code to adhere i915 coding style
 - not valid for GLK

Signed-off-by: default avatarMahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180824093225.12598-3-mahesh1.kumar@intel.com
parent cbfa59d4

drivers/gpu/drm/i915/i915_drv.c

+141 −4
Original line number Diff line number Diff line
@@ -1063,6 +1063,132 @@ static void intel_sanitize_options(struct drm_i915_private *dev_priv) 
	intel_gvt_sanitize_options(dev_priv);

}



static enum dram_rank skl_get_dimm_rank(u8 size, u32 rank)

{

	if (size == 0)

		return I915_DRAM_RANK_INVALID;

	if (rank == SKL_DRAM_RANK_SINGLE)

		return I915_DRAM_RANK_SINGLE;

	else if (rank == SKL_DRAM_RANK_DUAL)

		return I915_DRAM_RANK_DUAL;



	return I915_DRAM_RANK_INVALID;

}



static int

skl_dram_get_channel_info(struct dram_channel_info *ch, u32 val)

{

	u32 tmp_l, tmp_s;

	u32 s_val = val >> SKL_DRAM_S_SHIFT;



	if (!val)

		return -EINVAL;



	tmp_l = val & SKL_DRAM_SIZE_MASK;

	tmp_s = s_val & SKL_DRAM_SIZE_MASK;



	if (tmp_l == 0 && tmp_s == 0)

		return -EINVAL;



	ch->l_info.size = tmp_l;

	ch->s_info.size = tmp_s;



	tmp_l = (val & SKL_DRAM_WIDTH_MASK) >> SKL_DRAM_WIDTH_SHIFT;

	tmp_s = (s_val & SKL_DRAM_WIDTH_MASK) >> SKL_DRAM_WIDTH_SHIFT;

	ch->l_info.width = (1 << tmp_l) * 8;

	ch->s_info.width = (1 << tmp_s) * 8;



	tmp_l = val & SKL_DRAM_RANK_MASK;

	tmp_s = s_val & SKL_DRAM_RANK_MASK;

	ch->l_info.rank = skl_get_dimm_rank(ch->l_info.size, tmp_l);

	ch->s_info.rank = skl_get_dimm_rank(ch->s_info.size, tmp_s);



	if (ch->l_info.rank == I915_DRAM_RANK_DUAL ||

	    ch->s_info.rank == I915_DRAM_RANK_DUAL)

		ch->rank = I915_DRAM_RANK_DUAL;

	else if (ch->l_info.rank == I915_DRAM_RANK_SINGLE &&

		 ch->s_info.rank == I915_DRAM_RANK_SINGLE)

		ch->rank = I915_DRAM_RANK_DUAL;

	else

		ch->rank = I915_DRAM_RANK_SINGLE;



	DRM_DEBUG_KMS("(size:width:rank) L(%dGB:X%d:%s) S(%dGB:X%d:%s)\n",

		      ch->l_info.size, ch->l_info.width,

		      ch->l_info.rank ? "dual" : "single",

		      ch->s_info.size, ch->s_info.width,

		      ch->s_info.rank ? "dual" : "single");



	return 0;

}



static int

skl_dram_get_channels_info(struct drm_i915_private *dev_priv)

{

	struct dram_info *dram_info = &dev_priv->dram_info;

	struct dram_channel_info ch0, ch1;

	u32 val;

	int ret;



	val = I915_READ(SKL_MAD_DIMM_CH0_0_0_0_MCHBAR_MCMAIN);

	ret = skl_dram_get_channel_info(&ch0, val);

	if (ret == 0)

		dram_info->num_channels++;



	val = I915_READ(SKL_MAD_DIMM_CH1_0_0_0_MCHBAR_MCMAIN);

	ret = skl_dram_get_channel_info(&ch1, val);

	if (ret == 0)

		dram_info->num_channels++;



	if (dram_info->num_channels == 0) {

		DRM_INFO("Number of memory channels is zero\n");

		return -EINVAL;

	}



	/*

	 * If any of the channel is single rank channel, worst case output

	 * will be same as if single rank memory, so consider single rank

	 * memory.

	 */

	if (ch0.rank == I915_DRAM_RANK_SINGLE ||

	    ch1.rank == I915_DRAM_RANK_SINGLE)

		dram_info->rank = I915_DRAM_RANK_SINGLE;

	else

		dram_info->rank = max(ch0.rank, ch1.rank);



	if (dram_info->rank == I915_DRAM_RANK_INVALID) {

		DRM_INFO("couldn't get memory rank information\n");

		return -EINVAL;

	}

	return 0;

}



static int

skl_get_dram_info(struct drm_i915_private *dev_priv)

{

	struct dram_info *dram_info = &dev_priv->dram_info;

	u32 mem_freq_khz, val;

	int ret;



	ret = skl_dram_get_channels_info(dev_priv);

	if (ret)

		return ret;



	val = I915_READ(SKL_MC_BIOS_DATA_0_0_0_MCHBAR_PCU);

	mem_freq_khz = DIV_ROUND_UP((val & SKL_REQ_DATA_MASK) *

				    SKL_MEMORY_FREQ_MULTIPLIER_HZ, 1000);



	dram_info->bandwidth_kbps = dram_info->num_channels *

							mem_freq_khz * 8;



	if (dram_info->bandwidth_kbps == 0) {

		DRM_INFO("Couldn't get system memory bandwidth\n");

		return -EINVAL;

	}



	dram_info->valid = true;

	return 0;

}



static int

bxt_get_dram_info(struct drm_i915_private *dev_priv)

{
@@ -1153,6 +1279,7 @@ static void 
intel_get_dram_info(struct drm_i915_private *dev_priv)

{

	struct dram_info *dram_info = &dev_priv->dram_info;

	char bandwidth_str[32];

	int ret;



	dram_info->valid = false;
@@ -1160,15 +1287,25 @@ intel_get_dram_info(struct drm_i915_private *dev_priv) 
	dram_info->bandwidth_kbps = 0;

	dram_info->num_channels = 0;



	if (!IS_BROXTON(dev_priv))

	if (INTEL_GEN(dev_priv) < 9 || IS_GEMINILAKE(dev_priv))

		return;



	/* Need to calculate bandwidth only for Gen9 */

	if (IS_BROXTON(dev_priv))

		ret = bxt_get_dram_info(dev_priv);

	else if (INTEL_GEN(dev_priv) == 9)

		ret = skl_get_dram_info(dev_priv);

	else

		ret = skl_dram_get_channels_info(dev_priv);

	if (ret)

		return;



	DRM_DEBUG_KMS("DRAM bandwidth:%d KBps, total-channels: %u\n",

		      dram_info->bandwidth_kbps, dram_info->num_channels);

	if (dram_info->bandwidth_kbps)

		sprintf(bandwidth_str, "%d KBps", dram_info->bandwidth_kbps);

	else

		sprintf(bandwidth_str, "unknown");

	DRM_DEBUG_KMS("DRAM bandwidth:%s, total-channels: %u\n",

		      bandwidth_str, dram_info->num_channels);

	DRM_DEBUG_KMS("DRAM rank: %s rank\n",

		      (dram_info->rank == I915_DRAM_RANK_DUAL) ?

		      "dual" : "single");

drivers/gpu/drm/i915/i915_drv.h

+8 −0
Original line number Diff line number Diff line
@@ -2169,6 +2169,14 @@ struct drm_i915_private { 
	 */

};



struct dram_channel_info {

	struct info {

		u8 size, width;

		enum dram_rank rank;

	} l_info, s_info;

	enum dram_rank rank;

};



static inline struct drm_i915_private *to_i915(const struct drm_device *dev)

{

	return container_of(dev, struct drm_i915_private, drm);

drivers/gpu/drm/i915/i915_reg.h

+18 −0
Original line number Diff line number Diff line
@@ -9613,6 +9613,24 @@ enum skl_power_gate { 
#define  BXT_DRAM_SIZE_12GB			(0x3 << 6)

#define  BXT_DRAM_SIZE_16GB			(0x4 << 6)



#define SKL_MEMORY_FREQ_MULTIPLIER_HZ		266666666

#define SKL_MC_BIOS_DATA_0_0_0_MCHBAR_PCU	_MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5E04)

#define  SKL_REQ_DATA_MASK			(0xF << 0)



#define SKL_MAD_DIMM_CH0_0_0_0_MCHBAR_MCMAIN	_MMIO(MCHBAR_MIRROR_BASE_SNB + 0x500C)

#define SKL_MAD_DIMM_CH1_0_0_0_MCHBAR_MCMAIN	_MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5010)

#define  SKL_DRAM_S_SHIFT			16

#define  SKL_DRAM_SIZE_MASK			0x3F

#define  SKL_DRAM_WIDTH_MASK			(0x3 << 8)

#define  SKL_DRAM_WIDTH_SHIFT			8

#define  SKL_DRAM_WIDTH_X8			(0x0 << 8)

#define  SKL_DRAM_WIDTH_X16			(0x1 << 8)

#define  SKL_DRAM_WIDTH_X32			(0x2 << 8)

#define  SKL_DRAM_RANK_MASK			(0x1 << 10)

#define  SKL_DRAM_RANK_SHIFT			10

#define  SKL_DRAM_RANK_SINGLE			(0x0 << 10)

#define  SKL_DRAM_RANK_DUAL			(0x1 << 10)



/* Please see hsw_read_dcomp() and hsw_write_dcomp() before using this register,

 * since on HSW we can't write to it using I915_WRITE. */

#define D_COMP_HSW			_MMIO(MCHBAR_MIRROR_BASE_SNB + 0x5F0C)