Re: [PATCH v4] drivers: remoteproc: xlnx: add attach detach support

Mathieu Poirier
2024-06-06T21:17:08Z

On Wed, Jun 05, 2024 at 12:45:17PM -0500, Tanmay Shah wrote:
>
>
> On 6/4/24 10:34 AM, Mathieu Poirier wrote:
>
> Hi Mathieu,
>
> Thanks for reviews.
> Please find my comments below.
>
> > Hi Tanmay,
> >
> > On Mon, Jun 03, 2024 at 01:34:38PM -0700, Tanmay Shah wrote:
> >> It is possible that remote processor is already running before
> >> linux boot or remoteproc platform driver probe. Implement required
> >> remoteproc framework ops to provide resource table address and
> >> connect or disconnect with remote processor in such case.
> >>
> >> Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
> >>
> >> ---
> >> Changes in v4:
> >> - Move change log out of commit text
> >>
> >> Changes in v3:
> >>
> >> - Drop SRAM patch from the series
> >> - Change type from "struct resource_table *" to void __iomem *
> >> - Change comment format from /** to /*
> >> - Remove unmap of resource table va address during detach, allowing
> >> attach-detach-reattach use case.
> >> - Unmap rsc_data_va after retrieving resource table data structure.
> >> - Unmap resource table va during driver remove op
> >>
> >> Changes in v2:
> >>
> >> - Fix typecast warnings reported using sparse tool.
> >> - Fix following sparse warnings:
> >>
> >> drivers/remoteproc/xlnx_r5_remoteproc.c:827:21: sparse: warning: incorrect type in assignment (different address spaces)
> >> drivers/remoteproc/xlnx_r5_remoteproc.c:844:18: sparse: warning: incorrect type in assignment (different address spaces)
> >> drivers/remoteproc/xlnx_r5_remoteproc.c:898:24: sparse: warning: incorrect type in argument 1 (different address spaces)
> >> drivers/remoteproc/xlnx_r5_remoteproc.c | 173 +++++++++++++++++++++++-
> >> 1 file changed, 169 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/remoteproc/xlnx_r5_remoteproc.c b/drivers/remoteproc/xlnx_r5_remoteproc.c
> >> index 84243d1dff9f..6898d4761566 100644
> >> --- a/drivers/remoteproc/xlnx_r5_remoteproc.c
> >> +++ b/drivers/remoteproc/xlnx_r5_remoteproc.c
> >> @@ -25,6 +25,10 @@
> >> /* RX mailbox client buffer max length */
> >> #define MBOX_CLIENT_BUF_MAX (IPI_BUF_LEN_MAX + \
> >> sizeof(struct zynqmp_ipi_message))
> >> +
> >> +#define RSC_TBL_XLNX_MAGIC ((uint32_t)'x' << 24 | (uint32_t)'a' << 16 | \
> >> + (uint32_t)'m' << 8 | (uint32_t)'p')
> >> +
> >> /*
> >> * settings for RPU cluster mode which
> >> * reflects possible values of xlnx,cluster-mode dt-property
> >> @@ -73,6 +77,26 @@ struct mbox_info {
> >> struct mbox_chan *rx_chan;
> >> };
> >>
> >> +/**
> >> + * struct rsc_tbl_data
> >> + *
> >> + * Platform specific data structure used to sync resource table address.
> >> + * It's important to maintain order and size of each field on remote side.
> >> + *
> >> + * @version: version of data structure
> >> + * @magic_num: 32-bit magic number.
> >> + * @comp_magic_num: complement of above magic number
> >> + * @rsc_tbl_size: resource table size
> >> + * @rsc_tbl: resource table address
> >> + */
> >> +struct rsc_tbl_data {
> >> + const int version;
> >> + const u32 magic_num;
> >> + const u32 comp_magic_num;
> >
> > I thought we agreed on making the magic number a u64 - did I get this wrong?
> >
>
> Looks like I missed this comment from previous reviews, so didn't address it.
> Thanks for pointing this.
>
> So I think having two 32-bit numbers with proper name, implies what is expected and less chance of errors.
> With 64-bit number, it's easy to create errors when assigning magic number.
>
> However, if 64-bit number is preferred, I will change it and test it.
> Please let me know.

I was under the impression we had agreed on a u64 but that may just be my own
interpretation. Things can stay as they are now.

>
>
> >> + const u32 rsc_tbl_size;
> >> + const uintptr_t rsc_tbl;
> >> +} __packed;
> >> +
> >> /*
> >> * Hardcoded TCM bank values. This will stay in driver to maintain backward
> >> * compatibility with device-tree that does not have TCM information.
> >> @@ -95,20 +119,24 @@ static const struct mem_bank_data zynqmp_tcm_banks_lockstep[] = {
> >> /**
> >> * struct zynqmp_r5_core
> >> *
> >> + * @rsc_tbl_va: resource table virtual address
> >> * @dev: device of RPU instance
> >> * @np: device node of RPU instance
> >> * @tcm_bank_count: number TCM banks accessible to this RPU
> >> * @tcm_banks: array of each TCM bank data
> >> * @rproc: rproc handle
> >> + * @rsc_tbl_size: resource table size retrieved from remote
> >> * @pm_domain_id: RPU CPU power domain id
> >> * @ipi: pointer to mailbox information
> >> */
> >> struct zynqmp_r5_core {
> >> + void __iomem *rsc_tbl_va;
> >> struct device *dev;
> >> struct device_node *np;
> >> int tcm_bank_count;
> >> struct mem_bank_data **tcm_banks;
> >> struct rproc *rproc;
> >> + u32 rsc_tbl_size;
> >> u32 pm_domain_id;
> >> struct mbox_info *ipi;
> >> };
> >> @@ -621,10 +649,19 @@ static int zynqmp_r5_rproc_prepare(struct rproc *rproc)
> >> {
> >> int ret;
> >>
> >> - ret = add_tcm_banks(rproc);
> >> - if (ret) {
> >> - dev_err(&rproc->dev, "failed to get TCM banks, err %d\n", ret);
> >> - return ret;
> >> + /*
> >> + * For attach/detach use case, Firmware is already loaded so
> >> + * TCM isn't really needed at all. Also, for security TCM can be
> >> + * locked in such case and linux may not have access at all.
> >> + * So avoid adding TCM banks. TCM power-domains requested during attach
> >> + * callback.
> >> + */
> >> + if (rproc->state != RPROC_DETACHED) {
> >
> > if (rproc->state == RPROC_DETACHED)
> > return 0;
>
> Actually this will avoid whole prepare function.

You are correct - forget this request.

> I am still adding "memory-region" property carveouts for vrings, vdevbuffer.
> Instead I can move above check to add_tcm_banks function, and can avoid
> modification in prepare callback.
>
>
> >
> > ret = add_tcm_banks(rproc);
> > if (ret) {
> > dev_err(&rproc->dev, "failed to get TCM banks, err %d\n", ret);
> > return ret;
> > }
> >
> >> + ret = add_tcm_banks(rproc);
> >> + if (ret) {
> >> + dev_err(&rproc->dev, "failed to get TCM banks, err %d\n", ret);
> >> + return ret;
> >> + }
> >> }
> >>
> >> ret = add_mem_regions_carveout(rproc);
> >> @@ -662,6 +699,120 @@ static int zynqmp_r5_rproc_unprepare(struct rproc *rproc)
> >> return 0;
> >> }
> >>
> >> +static struct resource_table *zynqmp_r5_get_loaded_rsc_table(struct rproc *rproc,
> >> + size_t *size)
> >> +{
> >> + struct zynqmp_r5_core *r5_core;
> >> +
> >> + r5_core = rproc->priv;
> >> +
> >> + *size = r5_core->rsc_tbl_size;
> >> +
> >> + return (struct resource_table *)r5_core->rsc_tbl_va;
> >> +}
> >> +
> >> +static int zynqmp_r5_get_rsc_table_va(struct zynqmp_r5_core *r5_core)
> >> +{
> >> + struct resource_table *rsc_tbl_addr;
> >> + struct device *dev = r5_core->dev;
> >> + struct rsc_tbl_data *rsc_data_va;
> >> + struct resource res_mem;
> >> + struct device_node *np;
> >> + int ret;
> >> +
> >> + /*
> >> + * It is expected from remote processor firmware to provide resource
> >> + * table address via struct rsc_tbl_data data structure.
> >> + * Start address of first entry under "memory-region" property list
> >> + * contains that data structure which holds resource table address, size
> >> + * and some magic number to validate correct resource table entry.
> >> + */
> >> + np = of_parse_phandle(r5_core->np, "memory-region", 0);
> >> + if (!np) {
> >> + dev_err(dev, "failed to get memory region dev node\n");
> >> + return -EINVAL;
> >> + }
> >> +
> >> + ret = of_address_to_resource(np, 0, &res_mem);
> >> + if (ret) {
> >> + dev_err(dev, "failed to get memory-region resource addr\n");
> >> + return -EINVAL;
> >> + }
> >> +
> >> + rsc_data_va = (struct rsc_tbl_data *)ioremap_wc(res_mem.start,
> >> + sizeof(struct rsc_tbl_data));
> >> + if (!rsc_data_va) {
> >> + dev_err(dev, "failed to map resource table data address\n");
> >> + return -EIO;
> >> + }
> >> +
> >> + /*
> >> + * If RSC_TBL_XLNX_MAGIC number and its complement isn't found then
> >> + * do not consider resource table address valid and don't attach
> >> + */
> >> + if (rsc_data_va->magic_num != RSC_TBL_XLNX_MAGIC ||
> >> + rsc_data_va->comp_magic_num != ~RSC_TBL_XLNX_MAGIC) {
> >> + dev_dbg(dev, "invalid magic number, won't attach\n");
> >> + return -EINVAL;
> >> + }
> >> +
> >> + r5_core->rsc_tbl_va = ioremap_wc(rsc_data_va->rsc_tbl,
> >> + rsc_data_va->rsc_tbl_size);
> >> + if (!r5_core->rsc_tbl_va) {
> >> + dev_err(dev, "failed to get resource table va\n");
> >> + return -EINVAL;
> >> + }
> >> +
> >> + rsc_tbl_addr = (struct resource_table *)r5_core->rsc_tbl_va;
> >> +
> >> + /*
> >> + * As of now resource table version 1 is expected. Don't fail to attach
> >> + * but warn users about it.
> >> + */
> >> + if (rsc_tbl_addr->ver != 1)
> >> + dev_warn(dev, "unexpected resource table version %d\n",
> >> + rsc_tbl_addr->ver);
> >> +
> >> + iounmap((void __iomem *)rsc_data_va);
> >> + r5_core->rsc_tbl_size = rsc_data_va->rsc_tbl_size;
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static int zynqmp_r5_attach(struct rproc *rproc)
> >> +{
> >> + struct zynqmp_r5_core *r5_core = rproc->priv;
> >> + int i, pm_domain_id, ret;
> >> +
> >> + /*
> >> + * Firmware is loaded in TCM. Request TCM power domains to notify
> >> + * platform management controller that TCM is in use. This will be
> >> + * released during unprepare callback.
> >> + */
> >> + for (i = 0; i < r5_core->tcm_bank_count; i++) {
> >> + pm_domain_id = r5_core->tcm_banks[i]->pm_domain_id;
> >> + ret = zynqmp_pm_request_node(pm_domain_id,
> >> + ZYNQMP_PM_CAPABILITY_ACCESS, 0,
> >> + ZYNQMP_PM_REQUEST_ACK_BLOCKING);
> >> + if (ret < 0)
> >> + pr_warn("TCM %d can't be requested\n", i);
> >> + }
> >> +
> >> + return 0;
> >> +}
> >> +
> >> +static int zynqmp_r5_detach(struct rproc *rproc)
> >> +{
> >> + /*
> >> + * Generate last notification to remote after clearing virtio flag.
> >> + * Remote can avoid polling on virtio reset flag if kick is generated
> >> + * during detach by host and check virtio reset flag on kick interrupt.
> >> + */
> >> + zynqmp_r5_rproc_kick(rproc, 0);
> >> +
> >> + return 0;
> >> +}
> >> +
> >> static const struct rproc_ops zynqmp_r5_rproc_ops = {
> >> .prepare = zynqmp_r5_rproc_prepare,
> >> .unprepare = zynqmp_r5_rproc_unprepare,
> >> @@ -673,6 +824,9 @@ static const struct rproc_ops zynqmp_r5_rproc_ops = {
> >> .sanity_check = rproc_elf_sanity_check,
> >> .get_boot_addr = rproc_elf_get_boot_addr,
> >> .kick = zynqmp_r5_rproc_kick,
> >> + .get_loaded_rsc_table = zynqmp_r5_get_loaded_rsc_table,
> >> + .attach = zynqmp_r5_attach,
> >> + .detach = zynqmp_r5_detach,
> >> };
> >>
> >> /**
> >> @@ -723,6 +877,16 @@ static struct zynqmp_r5_core *zynqmp_r5_add_rproc_core(struct device *cdev)
> >> goto free_rproc;
> >> }
> >>
> >> + /*
> >> + * Move rproc state to DETACHED to give one time opportunity to attach
> >
> >
> > "one time opportunity" ?
> >
>
> Ack, not one-time anymore. Will be fixed.
>
> > Other than the above this patch is sound. That said I reviewed your work from
> > the airport, which is not optimal.
>
> Okay. I willl wait for your comments on above, then will move forward with v5.
>
> Thanks.
>
> We'll what turns up with the next revision.
> >
> > Thanks, Mathieu
> >
> >> + * if firmware is already available in the memory. This can happen if
> >> + * firmware is loaded via debugger or by any other agent in the system.
> >> + * If firmware isn't available in the memory and resource table isn't found,
> >> + * then rproc state stay OFFLINE.
> >> + */
> >> + if (!zynqmp_r5_get_rsc_table_va(r5_core))
> >> + r5_rproc->state = RPROC_DETACHED;
> >> +
> >> r5_core->rproc = r5_rproc;
> >> return r5_core;
> >>
> >> @@ -1134,6 +1298,7 @@ static void zynqmp_r5_cluster_exit(void *data)
> >> for (i = 0; i < cluster->core_count; i++) {
> >> r5_core = cluster->r5_cores[i];
> >> zynqmp_r5_free_mbox(r5_core->ipi);
> >> + iounmap(r5_core->rsc_tbl_va);
> >> of_reserved_mem_device_release(r5_core->dev);
> >> put_device(r5_core->dev);
> >> rproc_del(r5_core->rproc);
> >>
> >> base-commit: d7faf9a16886a748c9dd4063ea897f1e68b412f2
> >> --
> >> 2.37.6
> >>
>