diff mbox series

[v5,2/7] drm/msm: adreno: add plumbing to generate bandwidth vote table for GMU

Message ID 20241211-topic-sm8x50-gpu-bw-vote-v5-2-6112f9f785ec@linaro.org
State Superseded
Headers show
Series drm/msm: adreno: add support for DDR bandwidth scaling via GMU | expand

Commit Message

Neil Armstrong Dec. 11, 2024, 8:29 a.m. UTC
The Adreno GPU Management Unit (GMU) can also scale DDR Bandwidth along
the Frequency and Power Domain level, but by default we leave the
OPP core scale the interconnect ddr path.

While scaling via the interconnect path was sufficient, newer GPUs
like the A750 requires specific vote paremeters and bandwidth to
achieve full functionality.

In order to calculate vote values used by the GPU Management
Unit (GMU), we need to parse all the possible OPP Bandwidths and
create a vote value to be sent to the appropriate Bus Control
Modules (BCMs) declared in the GPU info struct.

This vote value is called IB, while on the other side the GMU also
takes another vote called AB which is a 16bit quantized value
of the floor bandwidth against the maximum supported bandwidth.
The AB vote will be calculated later when setting the frequency.

The vote array will then be used to dynamically generate the GMU
bw_table sent during the GMU power-up.

Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 144 ++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  13 +++
 drivers/gpu/drm/msm/adreno/a6xx_gpu.h |   1 +
 3 files changed, 158 insertions(+)

Comments

Konrad Dybcio Dec. 12, 2024, 7:55 p.m. UTC | #1
On 11.12.2024 9:29 AM, Neil Armstrong wrote:
> The Adreno GPU Management Unit (GMU) can also scale DDR Bandwidth along
> the Frequency and Power Domain level, but by default we leave the
> OPP core scale the interconnect ddr path.
> 
> While scaling via the interconnect path was sufficient, newer GPUs
> like the A750 requires specific vote paremeters and bandwidth to
> achieve full functionality.
> 
> In order to calculate vote values used by the GPU Management
> Unit (GMU), we need to parse all the possible OPP Bandwidths and
> create a vote value to be sent to the appropriate Bus Control
> Modules (BCMs) declared in the GPU info struct.
> 
> This vote value is called IB, while on the other side the GMU also
> takes another vote called AB which is a 16bit quantized value
> of the floor bandwidth against the maximum supported bandwidth.
> The AB vote will be calculated later when setting the frequency.
> 
> The vote array will then be used to dynamically generate the GMU
> bw_table sent during the GMU power-up.
> 
> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---
>  drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 144 ++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  13 +++
>  drivers/gpu/drm/msm/adreno/a6xx_gpu.h |   1 +
>  3 files changed, 158 insertions(+)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> index 14db7376c712d19446b38152e480bd5a1e0a5198..36696d372a42a27b26a018b19e73bc6d8a4a5235 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> @@ -9,6 +9,7 @@
>  #include <linux/pm_domain.h>
>  #include <linux/pm_opp.h>
>  #include <soc/qcom/cmd-db.h>
> +#include <soc/qcom/tcs.h>
>  #include <drm/drm_gem.h>
>  
>  #include "a6xx_gpu.h"
> @@ -1287,6 +1288,101 @@ static int a6xx_gmu_memory_probe(struct a6xx_gmu *gmu)
>  	return 0;
>  }
>  
> +/**
> + * struct bcm_db - Auxiliary data pertaining to each Bus Clock Manager (BCM)
> + * @unit: divisor used to convert bytes/sec bw value to an RPMh msg
> + * @width: multiplier used to convert bytes/sec bw value to an RPMh msg
> + * @vcd: virtual clock domain that this bcm belongs to
> + * @reserved: reserved field
> + */
> +struct bcm_db {
> +	__le32 unit;
> +	__le16 width;
> +	u8 vcd;
> +	u8 reserved;
> +};

No. This is a direct copypasta of drivers/interconnect/qcom/icc-rpmh.h
You cannot just randomly duplicate things..

Move it out to a shared header in include/ (and remove the duplicate from
clk-rpmh.c while at it)


I'd also really prefer if you took

drivers/interconnect/qcom/bcm-voter.c : tcs_list_gen()

and abstracted it to operate on struct bcm_db with any additional
required parameters passed as arguments.. Still left some comments
on this version if you decide to go with it

> +
> +static int a6xx_gmu_rpmh_bw_votes_init(const struct a6xx_info *info,
> +				       struct a6xx_gmu *gmu)
> +{
> +	const struct bcm_db *bcm_data[GMU_MAX_BCMS] = { 0 };
> +	unsigned int bcm_index, bw_index, bcm_count = 0;
> +
> +	if (!info->bcms)
> +		return 0;

You already checked that from the caller

> +
> +	/* Retrieve BCM data from cmd-db */
> +	for (bcm_index = 0; bcm_index < GMU_MAX_BCMS; bcm_index++) {
> +		size_t count;
> +
> +		/* Stop at first unconfigured bcm */
> +		if (!info->bcms[bcm_index].name)
> +			break;

Unconfigured doesn't really fit here.. Maybe just mention the list is NULL
-terminated

> +
> +		bcm_data[bcm_index] = cmd_db_read_aux_data(
> +						info->bcms[bcm_index].name,
> +						&count);
> +		if (IS_ERR(bcm_data[bcm_index]))
> +			return PTR_ERR(bcm_data[bcm_index]);
> +
> +		if (!count)
> +			return -EINVAL;

If this condition ever happens, it'll be impossible to track down,
please add an err message

> +
> +		++bcm_count;

I've heard somewhere that prefixed increments are discouraged for
"reasons" and my OCD would like to support that

> +	}
> +
> +	/* Generate BCM votes values for each bandwidth & BCM */
> +	for (bw_index = 0; bw_index < gmu->nr_gpu_bws; bw_index++) {
> +		u32 *data = gmu->gpu_ib_votes[bw_index];
> +		u32 bw = gmu->gpu_bw_table[bw_index];
> +
> +		/* Calculations loosely copied from bcm_aggregate() & tcs_cmd_gen() */
> +		for (bcm_index = 0; bcm_index < bcm_count; bcm_index++) {
> +			bool commit = false;
> +			u64 peak;
> +			u32 vote;
> +
> +			/* Skip unconfigured BCM */
> +			if (!bcm_data[bcm_index])
> +				continue;

I don't see how this is useful here

> +
> +			if (bcm_index == bcm_count - 1 ||
> +			    (bcm_data[bcm_index + 1] &&
> +			     bcm_data[bcm_index]->vcd != bcm_data[bcm_index + 1]->vcd))
> +				commit = true;
> +
> +			if (!bw) {
> +				data[bcm_index] = BCM_TCS_CMD(commit, false, 0, 0);
> +				continue;
> +			}
> +
> +			if (info->bcms[bcm_index].fixed) {

You may want to take a pointer to info->bcms[bcm_index]

> +				u32 perfmode = 0;
> +
> +				if (bw >= info->bcms[bcm_index].perfmode_bw)
> +					perfmode = info->bcms[bcm_index].perfmode;
> +
> +				data[bcm_index] = BCM_TCS_CMD(commit, true, 0, perfmode);
> +				continue;
> +			}
> +
> +			/* Multiply the bandwidth by the width of the connection */
> +			peak = (u64)bw * le16_to_cpu(bcm_data[bcm_index]->width);
> +			do_div(peak, info->bcms[bcm_index].buswidth);
> +
> +			/* Input bandwidth value is in KBps, scale the value to BCM unit */
> +			peak *= 1000ULL;

I don't think this needs to be ULL since the other argument is an u64

> +			do_div(peak, le32_to_cpu(bcm_data[bcm_index]->unit));
> +
> +			vote = clamp(peak, 1, BCM_TCS_CMD_VOTE_MASK);
> +
> +			data[bcm_index] = BCM_TCS_CMD(commit, true, vote, vote);

x is the avg vote, y is the peak vote

Just noting down for my future self I guess, a6xx sets ab=0,
a7xx sets ab=ib like you did here

Konrad
Neil Armstrong Dec. 12, 2024, 9:45 p.m. UTC | #2
On 12/12/2024 20:55, Konrad Dybcio wrote:
> On 11.12.2024 9:29 AM, Neil Armstrong wrote:
>> The Adreno GPU Management Unit (GMU) can also scale DDR Bandwidth along
>> the Frequency and Power Domain level, but by default we leave the
>> OPP core scale the interconnect ddr path.
>>
>> While scaling via the interconnect path was sufficient, newer GPUs
>> like the A750 requires specific vote paremeters and bandwidth to
>> achieve full functionality.
>>
>> In order to calculate vote values used by the GPU Management
>> Unit (GMU), we need to parse all the possible OPP Bandwidths and
>> create a vote value to be sent to the appropriate Bus Control
>> Modules (BCMs) declared in the GPU info struct.
>>
>> This vote value is called IB, while on the other side the GMU also
>> takes another vote called AB which is a 16bit quantized value
>> of the floor bandwidth against the maximum supported bandwidth.
>> The AB vote will be calculated later when setting the frequency.
>>
>> The vote array will then be used to dynamically generate the GMU
>> bw_table sent during the GMU power-up.
>>
>> Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
>>   drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 144 ++++++++++++++++++++++++++++++++++
>>   drivers/gpu/drm/msm/adreno/a6xx_gmu.h |  13 +++
>>   drivers/gpu/drm/msm/adreno/a6xx_gpu.h |   1 +
>>   3 files changed, 158 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>> index 14db7376c712d19446b38152e480bd5a1e0a5198..36696d372a42a27b26a018b19e73bc6d8a4a5235 100644
>> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
>> @@ -9,6 +9,7 @@
>>   #include <linux/pm_domain.h>
>>   #include <linux/pm_opp.h>
>>   #include <soc/qcom/cmd-db.h>
>> +#include <soc/qcom/tcs.h>
>>   #include <drm/drm_gem.h>
>>   
>>   #include "a6xx_gpu.h"
>> @@ -1287,6 +1288,101 @@ static int a6xx_gmu_memory_probe(struct a6xx_gmu *gmu)
>>   	return 0;
>>   }
>>   
>> +/**
>> + * struct bcm_db - Auxiliary data pertaining to each Bus Clock Manager (BCM)
>> + * @unit: divisor used to convert bytes/sec bw value to an RPMh msg
>> + * @width: multiplier used to convert bytes/sec bw value to an RPMh msg
>> + * @vcd: virtual clock domain that this bcm belongs to
>> + * @reserved: reserved field
>> + */
>> +struct bcm_db {
>> +	__le32 unit;
>> +	__le16 width;
>> +	u8 vcd;
>> +	u8 reserved;
>> +};
> 
> No. This is a direct copypasta of drivers/interconnect/qcom/icc-rpmh.h
> You cannot just randomly duplicate things..
> 
> Move it out to a shared header in include/ (and remove the duplicate from
> clk-rpmh.c while at it)
> 

Not sure if this a good idea

> 
> I'd also really prefer if you took
> 
> drivers/interconnect/qcom/bcm-voter.c : tcs_list_gen()
> 
> and abstracted it to operate on struct bcm_db with any additional
> required parameters passed as arguments.. Still left some comments
> on this version if you decide to go with it

They are still very different, look closely, tcs_list_gen is designed to
operate on BW aggregations + scsaling, it would make no sense to unify them.

The calculation is simple enough, I made it explicitely easy to read and
maintain, but honestly there's nothing special.

> 
>> +
>> +static int a6xx_gmu_rpmh_bw_votes_init(const struct a6xx_info *info,
>> +				       struct a6xx_gmu *gmu)
>> +{
>> +	const struct bcm_db *bcm_data[GMU_MAX_BCMS] = { 0 };
>> +	unsigned int bcm_index, bw_index, bcm_count = 0;
>> +
>> +	if (!info->bcms)
>> +		return 0;
> 
> You already checked that from the caller

Good catch

> 
>> +
>> +	/* Retrieve BCM data from cmd-db */
>> +	for (bcm_index = 0; bcm_index < GMU_MAX_BCMS; bcm_index++) {
>> +		size_t count;
>> +
>> +		/* Stop at first unconfigured bcm */
>> +		if (!info->bcms[bcm_index].name)
>> +			break;
> 
> Unconfigured doesn't really fit here.. Maybe just mention the list is NULL
> -terminated

Ack

> 
>> +
>> +		bcm_data[bcm_index] = cmd_db_read_aux_data(
>> +						info->bcms[bcm_index].name,
>> +						&count);
>> +		if (IS_ERR(bcm_data[bcm_index]))
>> +			return PTR_ERR(bcm_data[bcm_index]);
>> +
>> +		if (!count)
>> +			return -EINVAL;
> 
> If this condition ever happens, it'll be impossible to track down,
> please add an err message

Hmm sure

> 
>> +
>> +		++bcm_count;
> 
> I've heard somewhere that prefixed increments are discouraged for
> "reasons" and my OCD would like to support that

Never got this memo...

> 
>> +	}
>> +
>> +	/* Generate BCM votes values for each bandwidth & BCM */
>> +	for (bw_index = 0; bw_index < gmu->nr_gpu_bws; bw_index++) {
>> +		u32 *data = gmu->gpu_ib_votes[bw_index];
>> +		u32 bw = gmu->gpu_bw_table[bw_index];
>> +
>> +		/* Calculations loosely copied from bcm_aggregate() & tcs_cmd_gen() */
>> +		for (bcm_index = 0; bcm_index < bcm_count; bcm_index++) {
>> +			bool commit = false;
>> +			u64 peak;
>> +			u32 vote;
>> +
>> +			/* Skip unconfigured BCM */
>> +			if (!bcm_data[bcm_index])
>> +				continue;
> 
> I don't see how this is useful here

It's a leftover, will drop

> 
>> +
>> +			if (bcm_index == bcm_count - 1 ||
>> +			    (bcm_data[bcm_index + 1] &&
>> +			     bcm_data[bcm_index]->vcd != bcm_data[bcm_index + 1]->vcd))
>> +				commit = true;
>> +
>> +			if (!bw) {
>> +				data[bcm_index] = BCM_TCS_CMD(commit, false, 0, 0);
>> +				continue;
>> +			}
>> +
>> +			if (info->bcms[bcm_index].fixed) {
> 
> You may want to take a pointer to info->bcms[bcm_index]

Sure, will help

> 
>> +				u32 perfmode = 0;
>> +
>> +				if (bw >= info->bcms[bcm_index].perfmode_bw)
>> +					perfmode = info->bcms[bcm_index].perfmode;
>> +
>> +				data[bcm_index] = BCM_TCS_CMD(commit, true, 0, perfmode);
>> +				continue;
>> +			}
>> +
>> +			/* Multiply the bandwidth by the width of the connection */
>> +			peak = (u64)bw * le16_to_cpu(bcm_data[bcm_index]->width);
>> +			do_div(peak, info->bcms[bcm_index].buswidth);
>> +
>> +			/* Input bandwidth value is in KBps, scale the value to BCM unit */
>> +			peak *= 1000ULL;
> 
> I don't think this needs to be ULL since the other argument is an u64
> 
>> +			do_div(peak, le32_to_cpu(bcm_data[bcm_index]->unit));
>> +
>> +			vote = clamp(peak, 1, BCM_TCS_CMD_VOTE_MASK);
>> +
>> +			data[bcm_index] = BCM_TCS_CMD(commit, true, vote, vote);
> 
> x is the avg vote, y is the peak vote

downstream sets both calculated from the exact same value and the same way...

> 
> Just noting down for my future self I guess, a6xx sets ab=0,
> a7xx sets ab=ib like you did here

Probably, I'll need to check on that, but it can be done in a second step when enabling it on a6xx

> 
> Konrad
diff mbox series

Patch

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
index 14db7376c712d19446b38152e480bd5a1e0a5198..36696d372a42a27b26a018b19e73bc6d8a4a5235 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -9,6 +9,7 @@ 
 #include <linux/pm_domain.h>
 #include <linux/pm_opp.h>
 #include <soc/qcom/cmd-db.h>
+#include <soc/qcom/tcs.h>
 #include <drm/drm_gem.h>
 
 #include "a6xx_gpu.h"
@@ -1287,6 +1288,101 @@  static int a6xx_gmu_memory_probe(struct a6xx_gmu *gmu)
 	return 0;
 }
 
+/**
+ * struct bcm_db - Auxiliary data pertaining to each Bus Clock Manager (BCM)
+ * @unit: divisor used to convert bytes/sec bw value to an RPMh msg
+ * @width: multiplier used to convert bytes/sec bw value to an RPMh msg
+ * @vcd: virtual clock domain that this bcm belongs to
+ * @reserved: reserved field
+ */
+struct bcm_db {
+	__le32 unit;
+	__le16 width;
+	u8 vcd;
+	u8 reserved;
+};
+
+static int a6xx_gmu_rpmh_bw_votes_init(const struct a6xx_info *info,
+				       struct a6xx_gmu *gmu)
+{
+	const struct bcm_db *bcm_data[GMU_MAX_BCMS] = { 0 };
+	unsigned int bcm_index, bw_index, bcm_count = 0;
+
+	if (!info->bcms)
+		return 0;
+
+	/* Retrieve BCM data from cmd-db */
+	for (bcm_index = 0; bcm_index < GMU_MAX_BCMS; bcm_index++) {
+		size_t count;
+
+		/* Stop at first unconfigured bcm */
+		if (!info->bcms[bcm_index].name)
+			break;
+
+		bcm_data[bcm_index] = cmd_db_read_aux_data(
+						info->bcms[bcm_index].name,
+						&count);
+		if (IS_ERR(bcm_data[bcm_index]))
+			return PTR_ERR(bcm_data[bcm_index]);
+
+		if (!count)
+			return -EINVAL;
+
+		++bcm_count;
+	}
+
+	/* Generate BCM votes values for each bandwidth & BCM */
+	for (bw_index = 0; bw_index < gmu->nr_gpu_bws; bw_index++) {
+		u32 *data = gmu->gpu_ib_votes[bw_index];
+		u32 bw = gmu->gpu_bw_table[bw_index];
+
+		/* Calculations loosely copied from bcm_aggregate() & tcs_cmd_gen() */
+		for (bcm_index = 0; bcm_index < bcm_count; bcm_index++) {
+			bool commit = false;
+			u64 peak;
+			u32 vote;
+
+			/* Skip unconfigured BCM */
+			if (!bcm_data[bcm_index])
+				continue;
+
+			if (bcm_index == bcm_count - 1 ||
+			    (bcm_data[bcm_index + 1] &&
+			     bcm_data[bcm_index]->vcd != bcm_data[bcm_index + 1]->vcd))
+				commit = true;
+
+			if (!bw) {
+				data[bcm_index] = BCM_TCS_CMD(commit, false, 0, 0);
+				continue;
+			}
+
+			if (info->bcms[bcm_index].fixed) {
+				u32 perfmode = 0;
+
+				if (bw >= info->bcms[bcm_index].perfmode_bw)
+					perfmode = info->bcms[bcm_index].perfmode;
+
+				data[bcm_index] = BCM_TCS_CMD(commit, true, 0, perfmode);
+				continue;
+			}
+
+			/* Multiply the bandwidth by the width of the connection */
+			peak = (u64)bw * le16_to_cpu(bcm_data[bcm_index]->width);
+			do_div(peak, info->bcms[bcm_index].buswidth);
+
+			/* Input bandwidth value is in KBps, scale the value to BCM unit */
+			peak *= 1000ULL;
+			do_div(peak, le32_to_cpu(bcm_data[bcm_index]->unit));
+
+			vote = clamp(peak, 1, BCM_TCS_CMD_VOTE_MASK);
+
+			data[bcm_index] = BCM_TCS_CMD(commit, true, vote, vote);
+		}
+	}
+
+	return 0;
+}
+
 /* Return the 'arc-level' for the given frequency */
 static unsigned int a6xx_gmu_get_arc_level(struct device *dev,
 					   unsigned long freq)
@@ -1390,12 +1486,15 @@  static int a6xx_gmu_rpmh_arc_votes_init(struct device *dev, u32 *votes,
  * The GMU votes with the RPMh for itself and on behalf of the GPU but we need
  * to construct the list of votes on the CPU and send it over. Query the RPMh
  * voltage levels and build the votes
+ * The GMU can also vote for DDR interconnects, use the OPP bandwidth entries
+ * and BCM parameters to build the votes.
  */
 
 static int a6xx_gmu_rpmh_votes_init(struct a6xx_gmu *gmu)
 {
 	struct a6xx_gpu *a6xx_gpu = container_of(gmu, struct a6xx_gpu, gmu);
 	struct adreno_gpu *adreno_gpu = &a6xx_gpu->base;
+	const struct a6xx_info *info = adreno_gpu->info->a6xx;
 	struct msm_gpu *gpu = &adreno_gpu->base;
 	int ret;
 
@@ -1407,6 +1506,10 @@  static int a6xx_gmu_rpmh_votes_init(struct a6xx_gmu *gmu)
 	ret |= a6xx_gmu_rpmh_arc_votes_init(gmu->dev, gmu->cx_arc_votes,
 		gmu->gmu_freqs, gmu->nr_gmu_freqs, "cx.lvl");
 
+	/* Build the interconnect votes */
+	if (info->bcms && gmu->nr_gpu_bws > 1)
+		ret |= a6xx_gmu_rpmh_bw_votes_init(info, gmu);
+
 	return ret;
 }
 
@@ -1442,10 +1545,43 @@  static int a6xx_gmu_build_freq_table(struct device *dev, unsigned long *freqs,
 	return index;
 }
 
+static int a6xx_gmu_build_bw_table(struct device *dev, unsigned long *bandwidths,
+		u32 size)
+{
+	int count = dev_pm_opp_get_opp_count(dev);
+	struct dev_pm_opp *opp;
+	int i, index = 0;
+	unsigned int bandwidth = 1;
+
+	/*
+	 * The OPP table doesn't contain the "off" bandwidth level so we need to
+	 * add 1 to the table size to account for it
+	 */
+
+	if (WARN(count + 1 > size,
+		"The GMU bandwidth table is being truncated\n"))
+		count = size - 1;
+
+	/* Set the "off" bandwidth */
+	bandwidths[index++] = 0;
+
+	for (i = 0; i < count; i++) {
+		opp = dev_pm_opp_find_bw_ceil(dev, &bandwidth, 0);
+		if (IS_ERR(opp))
+			break;
+
+		dev_pm_opp_put(opp);
+		bandwidths[index++] = bandwidth++;
+	}
+
+	return index;
+}
+
 static int a6xx_gmu_pwrlevels_probe(struct a6xx_gmu *gmu)
 {
 	struct a6xx_gpu *a6xx_gpu = container_of(gmu, struct a6xx_gpu, gmu);
 	struct adreno_gpu *adreno_gpu = &a6xx_gpu->base;
+	const struct a6xx_info *info = adreno_gpu->info->a6xx;
 	struct msm_gpu *gpu = &adreno_gpu->base;
 
 	int ret = 0;
@@ -1472,6 +1608,14 @@  static int a6xx_gmu_pwrlevels_probe(struct a6xx_gmu *gmu)
 
 	gmu->current_perf_index = gmu->nr_gpu_freqs - 1;
 
+	/*
+	 * The GMU also handles GPU Interconnect Votes so build a list
+	 * of DDR bandwidths from the GPU OPP table
+	 */
+	if (info->bcms)
+		gmu->nr_gpu_bws = a6xx_gmu_build_bw_table(&gpu->pdev->dev,
+			gmu->gpu_bw_table, ARRAY_SIZE(gmu->gpu_bw_table));
+
 	/* Build the list of RPMh votes that we'll send to the GMU */
 	return a6xx_gmu_rpmh_votes_init(gmu);
 }
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
index 88f18ea6a38a08b5b171709e5020010947a5d347..2062a2be224768c1937d7768f7b8439920e9e127 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
@@ -21,6 +21,15 @@  struct a6xx_gmu_bo {
 
 #define GMU_MAX_GX_FREQS	16
 #define GMU_MAX_CX_FREQS	4
+#define GMU_MAX_BCMS		3
+
+struct a6xx_bcm {
+	char *name;
+	unsigned int buswidth;
+	bool fixed;
+	unsigned int perfmode;
+	unsigned int perfmode_bw;
+};
 
 /*
  * These define the different GMU wake up options - these define how both the
@@ -85,6 +94,10 @@  struct a6xx_gmu {
 	unsigned long gpu_freqs[GMU_MAX_GX_FREQS];
 	u32 gx_arc_votes[GMU_MAX_GX_FREQS];
 
+	int nr_gpu_bws;
+	unsigned long gpu_bw_table[GMU_MAX_GX_FREQS];
+	u32 gpu_ib_votes[GMU_MAX_GX_FREQS][GMU_MAX_BCMS];
+
 	int nr_gmu_freqs;
 	unsigned long gmu_freqs[GMU_MAX_CX_FREQS];
 	u32 cx_arc_votes[GMU_MAX_CX_FREQS];
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.h b/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
index 4aceffb6aae89c781facc2a6e4a82b20b341b6cb..9201a53dd341bf432923ffb44947e015208a3d02 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.h
@@ -44,6 +44,7 @@  struct a6xx_info {
 	u32 gmu_chipid;
 	u32 gmu_cgc_mode;
 	u32 prim_fifo_threshold;
+	const struct a6xx_bcm *bcms;
 };
 
 struct a6xx_gpu {