[PATCH v4 01/18] remoteproc: st_xp70_rproc: add a xp70 slimcore rproc driver

[Peter Griffin]

Hi Bjorn,

Thanks for reviewing.

On Wed, 25 May 2016, Bjorn Andersson wrote:

> On Wed 25 May 09:06 PDT 2016, Peter Griffin wrote:
> 
> > XP70 slim core is used as a basis for many IPs in the STi
> > chipsets such as fdma, display, and demux. To avoid
> > duplicating the elf loading code in each device driver
> > an xp70 rproc driver has been created.
> > 
> I like this approach.
> 
> [..]
> 
> > diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
> [..]
> >  
> > +config ST_XP70_REMOTEPROC
> > +	tristate "XP70 slim remoteproc support"
> 
> As this "driver" in itself doesn't do anything I don't think it makes
> sense to have it user selectable. Please make the "clients" select it
> instead.

Good point, will fix in v5.

> 
> > +	depends on ARCH_STI
> > +	select REMOTEPROC
> > +	help
> > +	  Say y here to support xp70 slim core.
> > +	  If unsure say N.
> > +
> >  endmenu
> > diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
> [..]
> > +#include <linux/clk.h>
> > +#include <linux/elf.h>
> 
> You should be able to drop inclusion of elf.h now.

Will fix in v5.

> 
> [..]
> > +static int xp70_clk_get(struct st_xp70_rproc *xp70_rproc, struct device *dev)
> > +{
> > +	int clk, err = 0;
> 
> No need to initialize err.

Will fix in v5.

> 
> > +
> > +	for (clk = 0; clk < XP70_MAX_CLK; clk++) {
> > +		xp70_rproc->clks[clk] = of_clk_get(dev->of_node, clk);
> > +		if (IS_ERR(xp70_rproc->clks[clk])) {
> > +			err = PTR_ERR(xp70_rproc->clks[clk]);
> > +			if (err == -EPROBE_DEFER)
> > +				goto err_put_clks;
> > +			xp70_rproc->clks[clk] = NULL;
> > +			break;
> > +		}
> > +	}
> > +
> > +	return 0;
> > +
> > +err_put_clks:
> > +	while (--clk >= 0)
> > +		clk_put(xp70_rproc->clks[clk]);
> > +
> > +	return err;
> > +}
> > +
> [..]
> > +/**
> > + * Remoteproc xp70 specific device handlers
> > + */
> > +static int xp70_rproc_start(struct rproc *rproc)
> > +{
> > +	struct device *dev = &rproc->dev;
> > +	struct st_xp70_rproc *xp70_rproc = rproc->priv;
> > +	unsigned long hw_id, hw_ver, fw_rev;
> > +	u32 val, ret = 0;
> 
> ret should be signed and there's no need to initialize it.

Will fix in v5.

> 
> > +
> > +	ret = xp70_clk_enable(xp70_rproc);
> > +	if (ret) {
> > +		dev_err(dev, "Failed to enable clocks\n");
> > +		goto err_clk;
> > +	}
> [..]
> > +
> > +	dev_dbg(dev, "XP70 started\n");
> > +
> > +err_clk:
> > +	return ret;
> > +}
> > +
> > +static int xp70_rproc_stop(struct rproc *rproc)
> > +{
> > +	struct st_xp70_rproc *xp70_rproc = rproc->priv;
> > +	u32 val;
> > +
> > +	/* mask all (cmd & int) channels */
> > +	writel_relaxed(0UL, xp70_rproc->peri + XP70_INT_MASK_OFST);
> > +	writel_relaxed(0UL, xp70_rproc->peri + XP70_CMD_MASK_OFST);
> > +
> > +	/* disable cpu pipeline clock */
> > +	writel_relaxed(XP70_CLK_GATE_DIS
> > +		, xp70_rproc->slimcore + XP70_CLK_GATE_OFST);
> > +
> > +	writel_relaxed(!XP70_EN_RUN, xp70_rproc->slimcore + XP70_EN_OFST);
> 
> Don't you want to ensure ordering of these writes? Perhaps making this
> last one a writel()?

That is a good point. In the past these writes were all part of the same
mapping. But now it is split between several mappings
(slimcore, peri, dmem) ordering of the writes could be an issue.

Will change to writel / readl in v5.

> 
> > +
> > +	val = readl_relaxed(xp70_rproc->slimcore + XP70_EN_OFST);
> > +	if (val & XP70_EN_RUN)
> > +		dev_warn(&rproc->dev, "Failed to disable XP70");
> > +
> > +	xp70_clk_disable(xp70_rproc);
> > +
> > +	dev_dbg(&rproc->dev, "xp70 stopped\n");
> > +
> > +	return 0;
> > +}
> > +
> > +static void *xp70_rproc_da_to_va(struct rproc *rproc, u64 da, int len)
> > +{
> > +	struct st_xp70_rproc *xp70_rproc = rproc->priv;
> > +	void *va = NULL;
> > +	int i;
> > +
> > +	for (i = 0; i < XP70_MEM_MAX; i++) {
> > +
> > +		if (da != xp70_rproc->mem[i].bus_addr)
> > +			continue;
> > +
> > +		va = xp70_rproc->mem[i].cpu_addr;
> > +			break;
> > +	}
> 
> Please clean up the indentation and drop the extra newline at the
> beginning in this loop.

Will fix in v5

> 
> > +
> > +	dev_dbg(&rproc->dev, "%s: da = 0x%llx len = 0x%x va = 0x%p\n"
> > +		, __func__, da, len, va);
> > +
> > +	return va;
> > +}
> > +
> > +static struct rproc_ops xp70_rproc_ops = {
> > +	.start		= xp70_rproc_start,
> > +	.stop		= xp70_rproc_stop,
> > +	.da_to_va       = xp70_rproc_da_to_va,
> > +};
> > +
> > +/**
> > + * Firmware handler operations: sanity, boot address, load ...
> > + */
> > +
> > +static struct resource_table empty_rsc_tbl = {
> > +	.ver = 1,
> > +	.num = 0,
> > +};
> 
> 
> I'm looking at making the resource table optional, good to see another
> vote for that. Looks good for now though.
> 
> [..]
> 
> > +
> > +/**
> > +  * xp70_rproc_alloc - allocate and initialise xp70 rproc
> 
> Drop one of the two spaces indenting this block and add () after then
> function name.

Will fix in v5

> 
> > +  * @pdev: Pointer to the platform_device struct
> > +  * @fw_name: Name of firmware for rproc to use
> > +  *
> > +  * Function for allocating and initialising a xp70 rproc for use by
> > +  * device drivers whose IP is based around the xp70 slim core. It
> > +  * obtains and enables any clocks required by the xp70 core and also
> > +  * ioremaps the various IO.
> > +  *
> > +  * Returns rproc pointer or PTR_ERR() on error.
> > +  */
> > +
> > +struct rproc *xp70_rproc_alloc(struct platform_device *pdev, char *fw_name)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	struct st_xp70_rproc *xp70_rproc;
> > +	struct device_node *np = dev->of_node;
> > +	struct rproc *rproc;
> > +	struct resource *res;
> > +	int err, i;
> > +	const struct rproc_fw_ops *elf_ops;
> > +
> > +	if (!np || !fw_name)
> > +		return ERR_PTR(-EINVAL);
> 
> This should, I believe, only ever happen in development. So if you want
> to keep it to aid developers feel free to throw in a WARN_ON() in the
> condition.

Will add WARN_ON in v5.

> 
> > +
> > +	if (!of_device_is_compatible(np, "st,xp70-rproc"))
> > +		return ERR_PTR(-EINVAL);
> > +
> > +	rproc = rproc_alloc(dev, np->name, &xp70_rproc_ops,
> > +			fw_name, sizeof(*xp70_rproc));
> > +	if (!rproc)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	rproc->has_iommu = false;
> > +
> > +	xp70_rproc = rproc->priv;
> > +	xp70_rproc->rproc = rproc;
> > +
> > +	/* Get standard ELF ops */
> > +	elf_ops = rproc_get_elf_ops();
> > +
> > +	/* Use some generic elf ops */
> > +	xp70_rproc_fw_ops.load = elf_ops->load;
> > +	xp70_rproc_fw_ops.sanity_check = elf_ops->sanity_check;
> > +
> > +	rproc->fw_ops = &xp70_rproc_fw_ops;
> > +
> > +	/* get imem and dmem */
> > +	for (i = 0; i < ARRAY_SIZE(mem_names); i++) {
> > +		res = xp70_rproc->mem[i].io_res;
> > +
> 
> io_res is NULL here, and res is directly assigned again. So drop this
> and io_res from the struct.

Good point. Will fix in v5.

> 
> > +		res = platform_get_resource_byname
> > +			(pdev, IORESOURCE_MEM, mem_names[i]);
> > +
> > +		xp70_rproc->mem[i].cpu_addr = devm_ioremap_resource(dev, res);
> > +		if (IS_ERR(xp70_rproc->mem[i].cpu_addr)) {
> > +			dev_err(&pdev->dev, "devm_ioremap_resource failed\n");
> > +			err = PTR_ERR(xp70_rproc->mem[i].cpu_addr);
> > +			goto err;
> > +		}
> > +		xp70_rproc->mem[i].bus_addr = res->start;
> > +		xp70_rproc->mem[i].size = resource_size(res);
> > +	}
> > +
> > +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "slimcore");
> > +
> > +	xp70_rproc->slimcore = devm_ioremap_resource(dev, res);
> > +	if (IS_ERR(xp70_rproc->slimcore)) {
> > +		dev_err(&pdev->dev, "devm_ioremap_resource failed for slimcore\n");
> > +		err = PTR_ERR(xp70_rproc->slimcore);
> > +		goto err;
> > +	}
> > +
> > +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "peripherals");
> > +
> > +	xp70_rproc->peri = devm_ioremap_resource(dev, res);
> > +	if (IS_ERR(xp70_rproc->peri)) {
> > +		dev_err(&pdev->dev, "devm_ioremap_resource failed for peri\n");
> > +		err = PTR_ERR(xp70_rproc->peri);
> > +		goto err;
> > +	}
> > +
> > +	err = xp70_clk_get(xp70_rproc, dev);
> > +	if (err)
> > +		goto err;
> > +
> > +	/* Register as a remoteproc device */
> > +	err = rproc_add(rproc);
> > +	if (err) {
> > +		dev_err(dev, "registration of xp70 remoteproc failed\n");
> > +		goto err;
> 
> In this case you should also put the clocks.

Will fix in v5.

> 
> > +	}
> > +
> > +	dev_dbg(dev, "XP70 rproc init successful\n");
> > +	return rproc;
> > +
> > +err:
> > +	rproc_put(rproc);
> > +	return ERR_PTR(err);
> > +}
> > +EXPORT_SYMBOL(xp70_rproc_alloc);
> > +
> > +/**
> > +  * xp70_rproc_put - put xp70 rproc resources
> > +  * @xp70_rproc: Pointer to the st_xp70_rproc struct
> > +  *
> > +  * Function for calling respective _put() functions on
> > +  * xp70_rproc resources.
> > +  *
> > +  * Returns rproc pointer or PTR_ERR() on error.
> > +  */
> > +void xp70_rproc_put(struct st_xp70_rproc *xp70_rproc)
> > +{
> > +	int clk;
> > +
> > +	if (!xp70_rproc)
> > +		return;
> > +
> > +	rproc_put(xp70_rproc->rproc);
> > +
> > +	for (clk = 0; clk < XP70_MAX_CLK && xp70_rproc->clks[clk]; clk++)
> > +		clk_put(xp70_rproc->clks[clk]);
> 
> rproc_put() will free your private data, i.e. xp70_rproc, so you must
> put your clocks before that.

Good spot. Will fix in v5.

> 
> > +
> > +}
> > +EXPORT_SYMBOL(xp70_rproc_put);
> > +
> > +MODULE_AUTHOR("Peter Griffin");
> > +MODULE_DESCRIPTION("STMicroelectronics XP70 rproc driver");
> > +MODULE_LICENSE("GPL v2");
> > diff --git a/include/linux/remoteproc/st_xp70_rproc.h b/include/linux/remoteproc/st_xp70_rproc.h
> [..]
> > +
> > +#define XP70_MEM_MAX 2
> > +#define XP70_MAX_CLK 4
> > +#define NAME_SZ 10
> 
> NAME_SZ seems unused and would be too generic.

Will fix in v5.

> 
> > +
> > +enum {
> > +	DMEM,
> > +	IMEM,
> 
> These are too generic for a header file.

Changed to XP70_DMEM in v5.

> 
> > +};
> > +
> > +/**
> > + * struct xp70_mem - xp70 internal memory structure
> > + * @cpu_addr: MPU virtual address of the memory region
> > + * @bus_addr: Bus address used to access the memory region
> > + * @dev_addr: Device address from Wakeup M3 view
> > + * @size: Size of the memory region
> > + */
> > +struct xp70_mem {
> > +	void __iomem *cpu_addr;
> > +	phys_addr_t bus_addr;
> > +	u32 dev_addr;
> 
> dev_addr is unused.

Will fix in v5.


> 
> > +	size_t size;
> > +	struct resource *io_res;
> 
> io_res is unused.

Will fix in v5.

> 
> > +};
> > +
> > +/**
> > + * struct st_xp70_rproc - XP70 slim core
> > + * @rproc: rproc handle
> > + * @pdev: pointer to platform device
> > + * @mem: xp70 memory information
> > + * @slimcore: xp70 slimcore regs
> > + * @peri: xp70 peripheral regs
> > + * @clks: xp70 clocks
> > + */
> > +struct st_xp70_rproc {
> > +	struct rproc *rproc;
> > +	struct platform_device *pdev;
> 
> pdev is unused.

Will fix in v5.

> 
> > +	struct xp70_mem mem[XP70_MEM_MAX];
> > +	void __iomem *slimcore;
> > +	void __iomem *peri;
> > +	struct clk *clks[XP70_MAX_CLK];
> > +};
> 
> I generally don't like sharing a struct like this between two
> implementations, but I don't think it's worth working around it in this
> case.
> 
> Perhaps you can group the members into a section of "public" and a
> section of "private" members; with a /* st_xp70_rproc private */ heading
> the latter?

Heading added in v5.

> 
> > +
> > +struct rproc *xp70_rproc_alloc(struct platform_device *pdev, char *fw_name);
> 
> For consistency I think xp70_rproc_alloc() should return a st_xp70_rproc
> reference, rather than forcing the clients pull that pointer out of
> rproc->priv.

Good idea, have changed like you suggest in v5.

> 
> > +void xp70_rproc_put(struct st_xp70_rproc *xp70_rproc);
> > +
> > +#endif

Regards,

Peter.