Hi Evan,

On 12/1/18 02:39, Evan Green wrote:

On Tue, Nov 27, 2018 at 10:04 AM Georgi Djakov [off-list ref] wrote:

quoted

From: David Dai <redacted>

Introduce Qualcomm SDM845 specific provider driver using the
interconnect framework.

Signed-off-by: David Dai <redacted>
Signed-off-by: Georgi Djakov <redacted>
---
 .../bindings/interconnect/qcom,sdm845.txt     |  24 +
 drivers/interconnect/Kconfig                  |   5 +
 drivers/interconnect/Makefile                 |   1 +
 drivers/interconnect/qcom/Kconfig             |  13 +
 drivers/interconnect/qcom/Makefile            |   5 +
 drivers/interconnect/qcom/sdm845.c            | 836 ++++++++++++++++++
 .../dt-bindings/interconnect/qcom,sdm845.h    | 143 +++
 7 files changed, 1027 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interconnect/qcom,sdm845.txt
 create mode 100644 drivers/interconnect/qcom/Kconfig
 create mode 100644 drivers/interconnect/qcom/Makefile
 create mode 100644 drivers/interconnect/qcom/sdm845.c
 create mode 100644 include/dt-bindings/interconnect/qcom,sdm845.h

diff --git a/Documentation/devicetree/bindings/interconnect/qcom,sdm845.txt b/Documentation/devicetree/bindings/interconnect/qcom,sdm845.txt
new file mode 100644
index 000000000000..d45150e99665
--- /dev/null
+++ b/Documentation/devicetree/bindings/interconnect/qcom,sdm845.txt

@@ -0,0 +1,24 @@
+Qualcomm SDM845 Network-On-Chip interconnect driver binding
+-----------------------------------------------------------
+
+SDM845 interconnect providers support system bandwidth requirements through
+RPMh hardware accelerators known as Bus Clock Manager(BCM). The provider is able
+to communicate with the BCM through the Resource State Coordinator(RSC)
+associated with each execution environment. Provider nodes must reside within
+an RPMh device node pertaining to their RSC and each provider maps to
+a single RPMh resource.
+
+Required properties :
+- compatible : shall contain only one of the following:
+                       "qcom,sdm845-rsc-hlos"

I wonder if maybe hlos isn't necessary. Unless you somehow imagine
secure mode would have a device tree entry in here as well? Probably
not.

Ok, will remove it. David, please chime in if you have any concerns with
this.

quoted

+- #interconnect-cells : should contain 1
+
+Examples:
+
+apps_rsc: rsc {
+               qnoc: qnoc-rsc-hlos {
+                       compatible = "qcom,sdm845-rsc-hlos";
+                       #interconnect-cells = <1>;
+               };
+};
+

...

quoted

diff --git a/drivers/interconnect/qcom/sdm845.c b/drivers/interconnect/qcom/sdm845.c
new file mode 100644
index 000000000000..1678de91ca52
--- /dev/null
+++ b/drivers/interconnect/qcom/sdm845.c

@@ -0,0 +1,836 @@

...

quoted

+
+static void tcs_list_gen(struct list_head *bcm_list,
+                        struct tcs_cmd *tcs_list, int *n)

We could make the prototype of this function be:

static void tcs_list_gen(struct list_head *bcm_list,
        struct tcs_cmd tcs_list[SDM845_MAX_VCD], int n[SDM845_MAX_VCD])

which would catch errors if somebody later passed in an array that
wasn't the right size, since we blindly memset below.

Yes, sounds good. I will try to optimize it.

Thanks,
Georgi

quoted

+{
+       struct qcom_icc_bcm *bcm;
+       bool commit;
+       size_t idx = 0, batch = 0, cur_vcd_size = 0;
+
+       memset(n, 0, sizeof(int) * SDM845_MAX_VCD);
+
+       list_for_each_entry(bcm, bcm_list, list) {
+               commit = false;
+               cur_vcd_size++;
+               if ((list_is_last(&bcm->list, bcm_list)) ||
+                   bcm->aux_data.vcd != list_next_entry(bcm, list)->aux_data.vcd) {
+                       commit = true;
+                       cur_vcd_size = 0;
+               }
+               tcs_cmd_gen(&tcs_list[idx], bcm->vote_x, bcm->vote_y,
+                           bcm->addr, commit);
+               idx++;
+               n[batch]++;
+               /*
+                * Batch the BCMs in such a way that we do not split them in
+                * multiple payloads when they are under the same VCD. This is
+                * to ensure that every BCM is committed since we only set the
+                * commit bit on the last BCM request of every VCD.
+                */
+               if (n[batch] >= MAX_RPMH_PAYLOAD) {
+                       if (!commit) {
+                               n[batch] -= cur_vcd_size;
+                               n[batch + 1] = cur_vcd_size;
+                       }
+                       batch++;
+               }
+       }
+}
+

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