Messages in this thread | | | Date | Wed, 11 Apr 2018 10:33:34 -0600 | From | Lina Iyer <> | Subject | Re: [PATCH v5 05/10] drivers: qcom: rpmh-rsc: write sleep/wake requests to TCS |
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On Tue, Apr 10 2018 at 18:31 -0600, Bjorn Andersson wrote: >On Thu 05 Apr 09:18 PDT 2018, Lina Iyer wrote: >> diff --git a/drivers/soc/qcom/rpmh-internal.h b/drivers/soc/qcom/rpmh-internal.h >[..] >> @@ -439,6 +445,107 @@ int rpmh_rsc_send_data(struct rsc_drv *drv, const struct tcs_request *msg) >> } >> EXPORT_SYMBOL(rpmh_rsc_send_data); >> >> +static int find_match(const struct tcs_group *tcs, const struct tcs_cmd *cmd, >> + int len) >> +{ >> + int i, j; >> + >> + /* Check for already cached commands */ >> + for_each_set_bit(i, tcs->slots, MAX_TCS_SLOTS) { > >Wouldn't it be good if this cared about TCS boundaries? > A sequence would never cross a TCS boundary. So it doesn't need to be checked.
>> + for (j = 0; j < len; j++) { >> + if (tcs->cmd_cache[i] != cmd[0].addr) { >> + if (j == 0) >> + break; >> + WARN(tcs->cmd_cache[i + j] != cmd[j].addr, >> + "Message does not match previous sequence.\n"); >> + return -EINVAL; >> + } else if (j == len - 1) { >> + return i; >> + } >> + } >> + } >> + >> + return -ENODATA; >> +} >> + >> +static int find_slots(struct tcs_group *tcs, const struct tcs_request *msg, >> + int *m, int *n) >> +{ >> + int slot, offset; >> + int i = 0; >> + >> + /* Find if we already have the msg in our TCS */ > >"Search for the sequence of addresses in our tcs group" > OK >> + slot = find_match(tcs, msg->cmds, msg->num_cmds); >> + if (slot >= 0) >> + goto copy_data; >> + >> + /* Do over, until we can fit the full payload in a TCS */ >> + do { >> + slot = bitmap_find_next_zero_area(tcs->slots, MAX_TCS_SLOTS, >> + i, msg->num_cmds, 0); >> + if (slot == MAX_TCS_SLOTS) >> + return -ENOMEM; >> + i += tcs->ncpt; >> + } while (slot + msg->num_cmds - 1 >= i); > >Does this conditional check that the sequence of free slots that we >found doesn't extend past the boundary of a TCS? > Yes, it does.
>I'm sorry, but this code is hard to understand. I would find this much >easier to read if there was one bitmap per TCS and you just looped over >them to find free regions. > Hmm, its too many bitmaps otherwise.
>> + >> +copy_data: >> + bitmap_set(tcs->slots, slot, msg->num_cmds); >> + /* Copy the addresses of the resources over to the slots */ >> + for (i = 0; i < msg->num_cmds; i++) >> + tcs->cmd_cache[slot + i] = msg->cmds[i].addr; >> + >> + offset = slot / tcs->ncpt; >> + *m = offset + tcs->offset; >> + *n = slot % tcs->ncpt; >> + >> + return 0; >> +} >> + >> +static int tcs_ctrl_write(struct rsc_drv *drv, const struct tcs_request *msg) >> +{ >> + struct tcs_group *tcs; >> + int m = 0, n = 0; >> + unsigned long flags; >> + int ret; >> + >> + tcs = get_tcs_for_msg(drv, msg); >> + if (IS_ERR(tcs)) >> + return PTR_ERR(tcs); >> + >> + spin_lock_irqsave(&tcs->lock, flags); >> + /* find the m-th TCS and the n-th position in the TCS to write to */ >> + ret = find_slots(tcs, msg, &m, &n); >> + if (!ret) >> + __tcs_buffer_write(drv, m, n, msg); >> + spin_unlock_irqrestore(&tcs->lock, flags); >> + >> + return ret; >> +} >> + >> +/** >> + * rpmh_rsc_write_ctrl_data: Write request to the controller >> + * >> + * @drv: the controller >> + * @msg: the data to be written to the controller >> + * >> + * There is no response returned for writing the request to the controller. >> + */ >> +int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv, const struct tcs_request *msg) > >So this is exactly the same thing as rpmh_rsc_send_data() but for one of >the non-active TCSs? > Yes. >Can't we have a single API for writing msg to the hardware and if it's >active we "send" it as well? > Hmm.. It can be done.
>> +{ >> + if (!msg || !msg->cmds || !msg->num_cmds || >> + msg->num_cmds > MAX_RPMH_PAYLOAD) { >> + pr_err("Payload error\n"); >> + return -EINVAL; >> + } >> + >> + /* Data sent to this API will not be sent immediately */ >> + if (msg->state == RPMH_ACTIVE_ONLY_STATE) >> + return -EINVAL; > >If you're concerned about this then the API isn't clear enough. > >> + >> + return tcs_ctrl_write(drv, msg); >> +} >> +EXPORT_SYMBOL(rpmh_rsc_write_ctrl_data); >> + >> static int rpmh_probe_tcs_config(struct platform_device *pdev, >> struct rsc_drv *drv) >> { >> @@ -512,6 +619,19 @@ static int rpmh_probe_tcs_config(struct platform_device *pdev, >> tcs->mask = ((1 << tcs->num_tcs) - 1) << st; >> tcs->offset = st; >> st += tcs->num_tcs; >> + >> + /* >> + * Allocate memory to cache sleep and wake requests to >> + * avoid reading TCS register memory. >> + */ >> + if (tcs->type == ACTIVE_TCS) >> + continue; > >Rather than "the rest of this loop shouldn't be done for the active tcs >group" just make another loop... Or at least make the comment relate >directly to the code it's adjacent. > Will move the comment out. >> + >> + tcs->cmd_cache = devm_kcalloc(&pdev->dev, >> + tcs->num_tcs * ncpt, sizeof(u32), >> + GFP_KERNEL); >> + if (!tcs->cmd_cache) >> + return -ENOMEM; >
Thanks for the review Bjorn.
-- Lina
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