Re: [PATCH v2] remoteproc: xlnx: add sram support

From: Mathieu Poirier
Date: Thu Jul 25 2024 - 10:43:10 EST


On Wed, 24 Jul 2024 at 16:04, Tanmay Shah <tanmay.shah@xxxxxxx> wrote:
>
> Hello Mathieu,
>
> Thanks for reviews.
>
> All the comments looks good, I will send next revision addressing them all.
>
> On 7/22/24 11:39 AM, Mathieu Poirier wrote:
> > Good morning,
> >
> > On Mon, Jul 15, 2024 at 06:39:54PM -0700, Tanmay Shah wrote:
> >> AMD-Xilinx zynqmp platform contains on-chip sram memory (OCM).
> >> R5 cores can access OCM and access is faster than DDR memory but slower
> >> than TCM memories available. Sram region can have optional multiple
> >> power-domains. Platform management firmware is responsible
> >> to operate these power-domains.
> >>
> >> Signed-off-by: Tanmay Shah <tanmay.shah@xxxxxxx>
> >> ---
> >>
> >> Changes in v2:
> >> - Expand commit message with power-domains related information.
> >>
> >> drivers/remoteproc/xlnx_r5_remoteproc.c | 131 ++++++++++++++++++++++++
> >> 1 file changed, 131 insertions(+)
> >>
> >> diff --git a/drivers/remoteproc/xlnx_r5_remoteproc.c b/drivers/remoteproc/xlnx_r5_remoteproc.c
> >> index 596f3ffb8935..52ddd42b09e0 100644
> >> --- a/drivers/remoteproc/xlnx_r5_remoteproc.c
> >> +++ b/drivers/remoteproc/xlnx_r5_remoteproc.c
> >> @@ -56,6 +56,17 @@ struct mem_bank_data {
> >> char *bank_name;
> >> };
> >>
> >> +/**
> >> + * struct zynqmp_sram_bank - sram bank description
> >> + *
> >> + * @sram_res: sram address region information
> >> + * @da: device address of sram
> >> + */
> >> +struct zynqmp_sram_bank {
> >> + struct resource sram_res;
> >> + u32 da;
> >> +};
> >> +
> >> /**
> >> * struct mbox_info
> >> *
> >> @@ -120,6 +131,8 @@ static const struct mem_bank_data zynqmp_tcm_banks_lockstep[] = {
> >> * struct zynqmp_r5_core
> >> *
> >> * @rsc_tbl_va: resource table virtual address
> >> + * @sram: Array of sram memories assigned to this core
> >> + * @num_sram: number of sram for this core
> >> * @dev: device of RPU instance
> >> * @np: device node of RPU instance
> >> * @tcm_bank_count: number TCM banks accessible to this RPU
> >> @@ -131,6 +144,8 @@ static const struct mem_bank_data zynqmp_tcm_banks_lockstep[] = {
> >> */
> >> struct zynqmp_r5_core {
> >> void __iomem *rsc_tbl_va;
> >> + struct zynqmp_sram_bank **sram;
> >
> > I suggest making @sram an array rather than an array of pointers - it would
> > simplify function zynqmp_r5_get_sram_banks().
> >
>
> Ack.
>
> >> + int num_sram;
> >> struct device *dev;
> >> struct device_node *np;
> >> int tcm_bank_count;
> >> @@ -494,6 +509,40 @@ static int add_mem_regions_carveout(struct rproc *rproc)
> >> return 0;
> >> }
> >>
> >> +static int add_sram_carveouts(struct rproc *rproc)
> >> +{
> >> + struct zynqmp_r5_core *r5_core = rproc->priv;
> >> + struct rproc_mem_entry *rproc_mem;
> >> + struct zynqmp_sram_bank *sram;
> >> + dma_addr_t dma_addr;
> >> + size_t len;
> >> + int da, i;
> >> +
> >> + for (i = 0; i < r5_core->num_sram; i++) {
> >> + sram = r5_core->sram[i];
> >> +
> >> + dma_addr = (dma_addr_t)sram->sram_res.start;
> >> + len = resource_size(&sram->sram_res);
> >> + da = sram->da;
> >> +
> >> + /* Register associated reserved memory regions */
> >> + rproc_mem = rproc_mem_entry_init(&rproc->dev, NULL,
> >> + (dma_addr_t)dma_addr,
> >> + len, da,
> >> + zynqmp_r5_mem_region_map,
> >> + zynqmp_r5_mem_region_unmap,
> >> + sram->sram_res.name);
> >> +
> >> + rproc_add_carveout(rproc, rproc_mem);
> >> + rproc_coredump_add_segment(rproc, da, len);
> >> +
> >> + dev_dbg(&rproc->dev, "sram carveout %s addr=%llx, da=0x%x, size=0x%lx",
> >> + sram->sram_res.name, dma_addr, da, len);
> >> + }
> >> +
> >> + return 0;
> >> +}
> >> +
> >> /*
> >> * tcm_mem_unmap()
> >> * @rproc: single R5 core's corresponding rproc instance
> >> @@ -669,6 +718,12 @@ static int zynqmp_r5_rproc_prepare(struct rproc *rproc)
> >> return ret;
> >> }
> >>
> >> + ret = add_sram_carveouts(rproc);
> >> + if (ret) {
> >> + dev_err(&rproc->dev, "failed to get sram carveout %d\n", ret);
> >> + return ret;
> >> + }
> >> +
> >> return 0;
> >> }
> >>
> >> @@ -881,6 +936,78 @@ static struct zynqmp_r5_core *zynqmp_r5_add_rproc_core(struct device *cdev)
> >> return ERR_PTR(ret);
> >> }
> >>
> >> +static int zynqmp_r5_get_sram_banks(struct zynqmp_r5_core *r5_core)
> >> +{
> >> + struct zynqmp_sram_bank **sram, *sram_data;
> >> + struct device_node *np = r5_core->np;
> >> + struct device *dev = r5_core->dev;
> >> + struct device_node *sram_np;
> >> + int num_sram, i, ret;
> >> + u64 abs_addr, size;
> >> +
> >> + /* "sram" is optional proprty. Do not fail, if unavailable. */
> >
> > s/proprty/property
>
> Ack.
>
> >
> >> + if (!of_find_property(r5_core->np, "sram", NULL))
> >> + return 0;
> >> +
> >> + num_sram = of_property_count_elems_of_size(np, "sram", sizeof(phandle));
> >> + if (num_sram <= 0) {
> >
> > Any reason this is "<" rather than "<=" ?
>
> I will make it < 1.
>

I had another read at the documentation of function
of_property_count_elems_of_size() - what you had will work just fine.
You can disregard this comment.

> >
> >> + dev_err(dev, "Invalid sram property, ret = %d\n",
> >> + num_sram);
> >> + return -EINVAL;
> >> + }
> >> +
> >> + sram = devm_kcalloc(dev, num_sram,
> >> + sizeof(struct zynqmp_sram_bank *), GFP_KERNEL);
> >> + if (!sram)
> >> + return -ENOMEM;
> >> +
> >> + for (i = 0; i < num_sram; i++) {
> >> + sram_data = devm_kzalloc(dev, sizeof(struct zynqmp_sram_bank),
> >> + GFP_KERNEL);
> >> + if (!sram_data)
> >> + return -ENOMEM;
> >> +
> >> + sram_np = of_parse_phandle(np, "sram", i);
> >> + if (!sram_np) {
> >> + dev_err(dev, "failed to get sram %d phandle\n", i);
> >> + return -EINVAL;
> >> + }
> >> +
> >> + if (!of_device_is_available(sram_np)) {
> >> + of_node_put(sram_np);
> >> + dev_err(dev, "sram device not available\n");
> >> + return -EINVAL;
> >> + }
> >> +
> >> + ret = of_address_to_resource(sram_np, 0, &sram_data->sram_res);
> >> + of_node_put(sram_np);
> >
> > Why calling this here when sram_np is used below?
> >
>
> Ack.
> I wanted to keep of_node_put as close as of_node_get.
> But, I think within same function I can move of_node_put after all use of sram_np.
>
> I didn't face any runtime errors though, so I am wondering is it required ?

It is required to keep a proper reference count of the node.

>
> I will move it anyway as suggested.
>
> >> + if (ret) {
> >> + dev_err(dev, "addr to res failed\n");
> >> + return ret;
> >> + }
> >> +
> >> + /* Get SRAM device address */
> >> + ret = of_property_read_reg(sram_np, i, &abs_addr, &size);
> >> + if (ret) {
> >> + dev_err(dev, "failed to get reg property\n");
> >> + return ret;
> >> + }
> >> +
> >> + sram_data->da = (u32)abs_addr;
> >> +
> >> + sram[i] = sram_data;
> >> +
> >> + dev_dbg(dev, "sram %d: name=%s, addr=0x%llx, da=0x%x, size=0x%llx\n",
> >> + i, sram[i]->sram_res.name, sram[i]->sram_res.start,
> >> + sram[i]->da, resource_size(&sram[i]->sram_res));
> >> + }
> >> +
> >> + r5_core->sram = sram;
> >> + r5_core->num_sram = num_sram;
> >> +
> >> + return 0;
> >> +}
> >> +
> >> static int zynqmp_r5_get_tcm_node_from_dt(struct zynqmp_r5_cluster *cluster)
> >> {
> >> int i, j, tcm_bank_count, ret, tcm_pd_idx, pd_count;
> >> @@ -1095,6 +1222,10 @@ static int zynqmp_r5_core_init(struct zynqmp_r5_cluster *cluster,
> >> return ret;
> >> }
> >> }
> >> +
> >> + ret = zynqmp_r5_get_sram_banks(r5_core);
> >> + if (ret)
> >> + return ret;
> >> }
> >
> > Thanks,
> > Mathieu
> >
> >>
> >> return 0;
> >>
> >> base-commit: d87dbfd31796f810ed777aee4919f211b4a6c7fb
> >> --
> >> 2.25.1
> >>
>