Messages in this thread |  | | Subject | Re: [PATCHv4 11/14] remoteproc/omap: add support for system suspend/resume | From | Tero Kristo <> | Date | Wed, 15 Jan 2020 15:20:48 +0200 |
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On 08/01/2020 23:42, Suman Anna wrote: > On 1/8/20 1:57 PM, Suman Anna wrote: >> On 1/2/20 7:18 AM, Tero Kristo wrote: >>> From: Suman Anna <s-anna@ti.com> >>> >>> This patch adds the support for system suspend/resume to the >>> OMAP remoteproc driver so that the OMAP remoteproc devices can >>> be suspended/resumed during a system suspend/resume. The support >>> is added through the driver PM .suspend/.resume callbacks, and >>> requires appropriate support from the OS running on the remote >>> processors. >>> >>> The IPU & DSP remote processors typically have their own private >>> modules like registers, internal memories, caches etc. The context >>> of these modules need to be saved and restored properly for a >>> suspend/resume to work. These are in general not accessible from >>> the MPU, so the remote processors themselves have to implement >>> the logic for the context save & restore of these modules. >>> >>> The OMAP remoteproc driver initiates a suspend by sending a mailbox >>> message requesting the remote processor to save its context and >>> enter into an idle/standby state. The remote processor should >>> usually stop whatever processing it is doing to switch to a context >>> save mode. The OMAP remoteproc driver detects the completion of >>> the context save by checking the module standby status for the >>> remoteproc device. It also stops any resources used by the remote >>> processors like the timers. The timers need to be running only >>> when the processor is active and executing, and need to be stopped >>> otherwise to allow the timer driver to reach low-power states. The >>> IOMMUs are automatically suspended by the PM core during the late >>> suspend stage, after the remoteproc suspend process is completed by >>> putting the remote processor cores into reset. Thereafter, the Linux >>> kernel can put the domain into further lower power states as possible. >>> >>> The resume sequence undoes the operations performed in the PM suspend >>> callback, by starting the timers and finally releasing the processors >>> from reset. This requires that the remote processor side OS be able to >>> distinguish a power-resume boot from a power-on/cold boot, restore the >>> context of its private modules saved during the suspend phase, and >>> resume executing code from where it was suspended. The IOMMUs would >>> have been resumed by the PM core during early resume, so they are >>> already enabled by the time remoteproc resume callback gets invoked. >>> >>> The remote processors should save their context into System RAM (DDR), >>> as any internal memories are not guaranteed to retain context as it >>> depends on the lowest power domain that the remote processor device >>> is put into. The management of the DDR contents will be managed by >>> the Linux kernel. >>> >>> Signed-off-by: Suman Anna <s-anna@ti.com> >>> [t-kristo@ti.com: converted to use ti-sysc instead of hwmod] >>> Signed-off-by: Tero Kristo <t-kristo@ti.com> >>> --- >>> v4: >>> - include headers sorted by name >> >>> - using #ifdef CONFIG_PM_SLEEP for suspend/resume ops >> >> Yeah, guess you missed my response comment on this on v3. This is >> actually old-style, so original code in v3 is good on this one.
Ok, will revert it back to v3 way of doing things.
>> >> regards >> Suman >> >>> >>> drivers/remoteproc/omap_remoteproc.c | 181 +++++++++++++++++++++++++++ >>> drivers/remoteproc/omap_remoteproc.h | 18 ++- >>> 2 files changed, 197 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/remoteproc/omap_remoteproc.c b/drivers/remoteproc/omap_remoteproc.c >>> index fd4700861a14..2a333565a9c1 100644 >>> --- a/drivers/remoteproc/omap_remoteproc.c >>> +++ b/drivers/remoteproc/omap_remoteproc.c >>> @@ -15,13 +15,17 @@ >>> >>> #include <linux/kernel.h> >>> #include <linux/module.h> >>> +#include <linux/clk.h> >>> +#include <linux/clk/ti.h> >>> #include <linux/err.h> >>> +#include <linux/io.h> >>> #include <linux/of_device.h> >>> #include <linux/of_reserved_mem.h> >>> #include <linux/platform_device.h> >>> #include <linux/dma-mapping.h> >>> #include <linux/remoteproc.h> >>> #include <linux/mailbox_client.h> >>> +#include <linux/omap-iommu.h> >>> #include <linux/omap-mailbox.h> >>> #include <linux/regmap.h> >>> #include <linux/mfd/syscon.h> >>> @@ -81,6 +85,9 @@ struct omap_rproc_timer { >>> * @timers: timer(s) info used by rproc >>> * @rproc: rproc handle >>> * @reset: reset handle >>> + * @pm_comp: completion primitive to sync for suspend response >>> + * @fck: functional clock for the remoteproc >>> + * @suspend_acked: state machine flag to store the suspend request ack >>> */ >>> struct omap_rproc { >>> struct mbox_chan *mbox; >>> @@ -92,6 +99,9 @@ struct omap_rproc { >>> struct omap_rproc_timer *timers; >>> struct rproc *rproc; >>> struct reset_control *reset; >>> + struct completion pm_comp; >>> + struct clk *fck; >>> + bool suspend_acked; >>> }; >>> >>> /** >>> @@ -366,6 +376,12 @@ static void omap_rproc_mbox_callback(struct mbox_client *client, void *data) >>> case RP_MBOX_ECHO_REPLY: >>> dev_info(dev, "received echo reply from %s\n", name); >>> break; >>> + case RP_MBOX_SUSPEND_ACK: >>> + /* Fall through */ >>> + case RP_MBOX_SUSPEND_CANCEL: >>> + oproc->suspend_acked = msg == RP_MBOX_SUSPEND_ACK; >>> + complete(&oproc->pm_comp); >>> + break; >>> default: >>> if (msg >= RP_MBOX_READY && msg < RP_MBOX_END_MSG) >>> return; >>> @@ -554,6 +570,158 @@ static const struct rproc_ops omap_rproc_ops = { >>> .da_to_va = omap_rproc_da_to_va, >>> }; >>> >>> +#ifdef CONFIG_PM >>> +static bool _is_rproc_in_standby(struct omap_rproc *oproc) >>> +{ >>> + return ti_clk_is_in_standby(oproc->fck); >>> +} >>> + >>> +/* 1 sec is long enough time to let the remoteproc side suspend the device */ >>> +#define DEF_SUSPEND_TIMEOUT 1000 >>> +static int _omap_rproc_suspend(struct rproc *rproc) >>> +{ >>> + struct device *dev = rproc->dev.parent; >>> + struct omap_rproc *oproc = rproc->priv; >>> + unsigned long to = msecs_to_jiffies(DEF_SUSPEND_TIMEOUT); >>> + unsigned long ta = jiffies + to; >>> + int ret; >>> + >>> + reinit_completion(&oproc->pm_comp); >>> + oproc->suspend_acked = false; >>> + ret = mbox_send_message(oproc->mbox, (void *)RP_MBOX_SUSPEND_SYSTEM); >>> + if (ret < 0) { >>> + dev_err(dev, "PM mbox_send_message failed: %d\n", ret); >>> + return ret; >>> + } >>> + >>> + ret = wait_for_completion_timeout(&oproc->pm_comp, to); >>> + if (!oproc->suspend_acked) >>> + return -EBUSY; >>> + >>> + /* >>> + * The remoteproc side is returning the ACK message before saving the >>> + * context, because the context saving is performed within a SYS/BIOS >>> + * function, and it cannot have any inter-dependencies against the IPC >>> + * layer. Also, as the SYS/BIOS needs to preserve properly the processor >>> + * register set, sending this ACK or signalling the completion of the >>> + * context save through a shared memory variable can never be the >>> + * absolute last thing to be executed on the remoteproc side, and the >>> + * MPU cannot use the ACK message as a sync point to put the remoteproc >>> + * into reset. The only way to ensure that the remote processor has >>> + * completed saving the context is to check that the module has reached >>> + * STANDBY state (after saving the context, the SYS/BIOS executes the >>> + * appropriate target-specific WFI instruction causing the module to >>> + * enter STANDBY). >>> + */ >>> + while (!_is_rproc_in_standby(oproc)) { >>> + if (time_after(jiffies, ta)) >>> + return -ETIME; >>> + schedule(); >>> + } >>> + >>> + reset_control_assert(oproc->reset); >>> + >>> + ret = omap_rproc_disable_timers(rproc, false); >>> + if (ret) { >>> + dev_err(dev, "disabling timers during suspend failed %d\n", >>> + ret); >>> + goto enable_device; >>> + } >>> + >>> + return 0; >>> + >>> +enable_device: >>> + reset_control_deassert(oproc->reset); >>> + return ret; >>> +} >>> + >>> +static int _omap_rproc_resume(struct rproc *rproc) >>> +{ >>> + struct device *dev = rproc->dev.parent; >>> + struct omap_rproc *oproc = rproc->priv; >>> + int ret; >>> + >>> + /* boot address could be lost after suspend, so restore it */ >>> + if (oproc->boot_data) { >>> + ret = omap_rproc_write_dsp_boot_addr(rproc); >>> + if (ret) { >>> + dev_err(dev, "boot address restore failed %d\n", ret); >>> + goto out; >>> + } >>> + } >>> + >>> + ret = omap_rproc_enable_timers(rproc, false); >>> + if (ret) { >>> + dev_err(dev, "enabling timers during resume failed %d\n", ret); >>> + goto out; >>> + } >>> + >>> + reset_control_deassert(oproc->reset); > > So, I actually did not comment specifically on this on v3 hoping that my > comment on the lack of error checking in v3 Patch 2 would have been > taken care of here as well.
Ok, will add error handling on this one.
-Tero
> > Please do compare the overall code against our current downstream > release code as well. I still see some deltas, I have to double-check > the behavior as well once with the auto-suspend patch. Probably will do > that on the next version. > > regards > Suman > >>> + >>> +out: >>> + return ret; >>> +} >>> + >>> +#ifdef CONFIG_PM_SLEEP >>> +static int omap_rproc_suspend(struct device *dev) >>> +{ >>> + struct platform_device *pdev = to_platform_device(dev); >>> + struct rproc *rproc = platform_get_drvdata(pdev); >>> + int ret = 0; >>> + >>> + mutex_lock(&rproc->lock); >>> + if (rproc->state == RPROC_OFFLINE) >>> + goto out; >>> + >>> + if (rproc->state == RPROC_SUSPENDED) >>> + goto out; >>> + >>> + if (rproc->state != RPROC_RUNNING) { >>> + ret = -EBUSY; >>> + goto out; >>> + } >>> + >>> + ret = _omap_rproc_suspend(rproc); >>> + if (ret) { >>> + dev_err(dev, "suspend failed %d\n", ret); >>> + goto out; >>> + } >>> + >>> + rproc->state = RPROC_SUSPENDED; >>> +out: >>> + mutex_unlock(&rproc->lock); >>> + return ret; >>> +} >>> + >>> +static int omap_rproc_resume(struct device *dev) >>> +{ >>> + struct platform_device *pdev = to_platform_device(dev); >>> + struct rproc *rproc = platform_get_drvdata(pdev); >>> + int ret = 0; >>> + >>> + mutex_lock(&rproc->lock); >>> + if (rproc->state == RPROC_OFFLINE) >>> + goto out; >>> + >>> + if (rproc->state != RPROC_SUSPENDED) { >>> + ret = -EBUSY; >>> + goto out; >>> + } >>> + >>> + ret = _omap_rproc_resume(rproc); >>> + if (ret) { >>> + dev_err(dev, "resume failed %d\n", ret); >>> + goto out; >>> + } >>> + >>> + rproc->state = RPROC_RUNNING; >>> +out: >>> + mutex_unlock(&rproc->lock); >>> + return ret; >>> +} >>> +#endif /* CONFIG_PM_SLEEP */ >>> +#endif /* CONFIG_PM */ >>> + >>> static const struct omap_rproc_mem_data ipu_mems[] = { >>> { .name = "l2ram", .dev_addr = 0x20000000 }, >>> { }, >>> @@ -796,6 +964,14 @@ static int omap_rproc_probe(struct platform_device *pdev) >>> oproc->num_timers); >>> } >>> >>> + init_completion(&oproc->pm_comp); >>> + >>> + oproc->fck = devm_clk_get(&pdev->dev, 0); >>> + if (IS_ERR(oproc->fck)) { >>> + ret = PTR_ERR(oproc->fck); >>> + goto free_rproc; >>> + } >>> + >>> ret = of_reserved_mem_device_init(&pdev->dev); >>> if (ret) { >>> dev_err(&pdev->dev, "device does not have specific CMA pool\n"); >>> @@ -828,11 +1004,16 @@ static int omap_rproc_remove(struct platform_device *pdev) >>> return 0; >>> } >>> >>> +static const struct dev_pm_ops omap_rproc_pm_ops = { >>> + SET_SYSTEM_SLEEP_PM_OPS(omap_rproc_suspend, omap_rproc_resume) >>> +}; >>> + >>> static struct platform_driver omap_rproc_driver = { >>> .probe = omap_rproc_probe, >>> .remove = omap_rproc_remove, >>> .driver = { >>> .name = "omap-rproc", >>> + .pm = &omap_rproc_pm_ops, >>> .of_match_table = omap_rproc_of_match, >>> }, >>> }; >>> diff --git a/drivers/remoteproc/omap_remoteproc.h b/drivers/remoteproc/omap_remoteproc.h >>> index 72f656c93caa..8af37e46aa73 100644 >>> --- a/drivers/remoteproc/omap_remoteproc.h >>> +++ b/drivers/remoteproc/omap_remoteproc.h >>> @@ -1,7 +1,7 @@ >>> /* >>> * Remote processor messaging >>> * >>> - * Copyright (C) 2011 Texas Instruments, Inc. >>> + * Copyright (C) 2011-2020 Texas Instruments, Inc. >>> * Copyright (C) 2011 Google, Inc. >>> * All rights reserved. >>> * >>> @@ -57,6 +57,16 @@ >>> * @RP_MBOX_ABORT_REQUEST: a "please crash" request, used for testing the >>> * recovery mechanism (to some extent). >>> * >>> + * @RP_MBOX_SUSPEND_AUTO: auto suspend request for the remote processor >>> + * >>> + * @RP_MBOX_SUSPEND_SYSTEM: system suspend request for the remote processor >>> + * >>> + * @RP_MBOX_SUSPEND_ACK: successful response from remote processor for a >>> + * suspend request >>> + * >>> + * @RP_MBOX_SUSPEND_CANCEL: a cancel suspend response from a remote processor >>> + * on a suspend request >>> + * >>> * Introduce new message definitions if any here. >>> * >>> * @RP_MBOX_END_MSG: Indicates end of known/defined messages from remote core >>> @@ -70,7 +80,11 @@ enum omap_rp_mbox_messages { >>> RP_MBOX_ECHO_REQUEST = 0xFFFFFF03, >>> RP_MBOX_ECHO_REPLY = 0xFFFFFF04, >>> RP_MBOX_ABORT_REQUEST = 0xFFFFFF05, >>> - RP_MBOX_END_MSG = 0xFFFFFF06, >>> + RP_MBOX_SUSPEND_AUTO = 0xFFFFFF10, >>> + RP_MBOX_SUSPEND_SYSTEM = 0xFFFFFF11, >>> + RP_MBOX_SUSPEND_ACK = 0xFFFFFF12, >>> + RP_MBOX_SUSPEND_CANCEL = 0xFFFFFF13, >>> + RP_MBOX_END_MSG = 0xFFFFFF14, >>> }; >>> >>> #endif /* _OMAP_RPMSG_H */ >>> >> >
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