From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
We want to know out which channels are actually occupied so that
later on we can read the memory timings from the right registers.
To that end convert num_channels into a bitmask.
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_drv.c | 28 +++++++++++++++-------------
drivers/gpu/drm/i915/i915_drv.h | 2 +-
2 files changed, 16 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 9e380cd317dc..8b37ec0e0676 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1209,14 +1209,14 @@ skl_dram_get_channels_info(struct drm_i915_private *dev_priv)
val = I915_READ(SKL_MAD_DIMM_CH0_0_0_0_MCHBAR_MCMAIN);
ret = skl_dram_get_channel_info(dev_priv, &ch0, 0, val);
if (ret == 0)
- dram_info->num_channels++;
+ dram_info->channels |= BIT(0);
val = I915_READ(SKL_MAD_DIMM_CH1_0_0_0_MCHBAR_MCMAIN);
ret = skl_dram_get_channel_info(dev_priv, &ch1, 1, val);
if (ret == 0)
- dram_info->num_channels++;
+ dram_info->channels |= BIT(1);
- if (dram_info->num_channels == 0) {
+ if (dram_info->channels == 0) {
DRM_INFO("Number of memory channels is zero\n");
return -EINVAL;
}
@@ -1285,8 +1285,8 @@ skl_get_dram_info(struct drm_i915_private *dev_priv)
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;
+ dram_info->bandwidth_kbps = mem_freq_khz *
+ hweight8(dram_info->channels) * 8;
if (dram_info->bandwidth_kbps == 0) {
DRM_INFO("Couldn't get system memory bandwidth\n");
@@ -1380,20 +1380,20 @@ static int
bxt_get_dram_info(struct drm_i915_private *dev_priv)
{
struct dram_info *dram_info = &dev_priv->dram_info;
- u32 dram_channels;
u32 mem_freq_khz, val;
- u8 num_active_channels;
+ u8 num_channels = 0;
int i;
val = I915_READ(BXT_P_CR_MC_BIOS_REQ_0_0_0);
mem_freq_khz = DIV_ROUND_UP((val & BXT_REQ_DATA_MASK) *
BXT_MEMORY_FREQ_MULTIPLIER_HZ, 1000);
- dram_channels = val & BXT_DRAM_CHANNEL_ACTIVE_MASK;
- num_active_channels = hweight32(dram_channels);
+ dram_info->channels = (val & BXT_DRAM_CHANNEL_ACTIVE_MASK) >>
+ BXT_DRAM_CHANNEL_ACTIVE_SHIFT;
/* Each active bit represents 4-byte channel */
- dram_info->bandwidth_kbps = (mem_freq_khz * num_active_channels * 4);
+ dram_info->bandwidth_kbps = mem_freq_khz *
+ hweight8(dram_info->channels) * 4;
if (dram_info->bandwidth_kbps == 0) {
DRM_INFO("Couldn't get system memory bandwidth\n");
@@ -1411,7 +1411,7 @@ bxt_get_dram_info(struct drm_i915_private *dev_priv)
if (val == 0xFFFFFFFF)
continue;
- dram_info->num_channels++;
+ num_channels++;
bxt_get_dimm_info(&dimm, val);
type = bxt_get_dimm_type(val);
@@ -1439,6 +1439,8 @@ bxt_get_dram_info(struct drm_i915_private *dev_priv)
dram_info->type = type;
}
+ WARN_ON(num_channels != hweight8(dram_info->channels));
+
if (dram_info->type == INTEL_DRAM_UNKNOWN ||
dram_info->ranks == 0) {
DRM_INFO("couldn't get memory information\n");
@@ -1472,9 +1474,9 @@ intel_get_dram_info(struct drm_i915_private *dev_priv)
if (ret)
return;
- DRM_DEBUG_KMS("DRAM bandwidth: %u kBps, channels: %u\n",
+ DRM_DEBUG_KMS("DRAM bandwidth: %u kBps, channels: 0x%x\n",
dram_info->bandwidth_kbps,
- dram_info->num_channels);
+ dram_info->channels);
DRM_DEBUG_KMS("DRAM ranks: %u, 16Gb DIMMs: %s\n",
dram_info->ranks, yesno(dram_info->is_16gb_dimm));
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 363b2d3e4d50..f638c0c74955 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1832,7 +1832,7 @@ struct drm_i915_private {
struct dram_info {
bool valid;
bool is_16gb_dimm;
- u8 num_channels;
+ u8 channels; /* bitmask */
u8 ranks;
u32 bandwidth_kbps;
bool symmetric_memory;
--
2.19.2
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