RE: [PATCH v14 06/21] PCI: dwc: Change arguments of dw_pcie_prog_ep_outbound_atu()

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Hi Serge,

> From: Serge Semin, Sent: Tuesday, May 2, 2023 3:59 AM
> 
> On Wed, Apr 26, 2023 at 01:55:42PM +0900, Yoshihiro Shimoda wrote:
> > To add more arguments to the dw_pcie_prog_ep_outbound_atu() in
> > the future, introduce struct dw_pcie_outbound_atu and change
> > the argument. No behavior changes.
> 
> The change now looks much more coherent than before. Though it still looks
> as an incomplete measure. The core driver still have two global outbound
> ATU windows config methods which basically cause the same update
> (performed by the same backend function), but which prototypes are
> completely different. What about dropping the separate
> dw_pcie_prog_outbound_atu() and dw_pcie_prog_outbound_atu() methods,
> convert __dw_pcie_prog_outbound_atu() to dw_pcie_prog_outbound_atu(pci, atu)
> and use it in both RP and EP drivers instead?
> 
> As a result we would have got a single outbound ATUs config method with
> the next prototype:
> int dw_pcie_prog_outbound_atu(struct dw_pcie *pci, struct dw_pcie_ob_atu_cfg *atu);
> Thus we would have reduced a number of the globally defined methods,
> would have got a more unified outbound ATU setup interface which
> by its nature would imply that the OB ATU entries setup is almost the
> same for both RP and EP platforms.

Thank you for your comments! I understood it. I'll modify this patch on v15.

> Please see a few more comments below.
> 
> >
> > Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
> > ---
> >  .../pci/controller/dwc/pcie-designware-ep.c   | 21 ++++---
> >  drivers/pci/controller/dwc/pcie-designware.c  | 63 ++++++++++---------
> >  drivers/pci/controller/dwc/pcie-designware.h  | 13 +++-
> >  3 files changed, 57 insertions(+), 40 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > index a80b9fd03638..96375b0aba82 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware-ep.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
> > @@ -183,9 +183,8 @@ static int dw_pcie_ep_inbound_atu(struct dw_pcie_ep *ep, u8 func_no, int type,
> >  	return 0;
> >  }
> >
> > -static int dw_pcie_ep_outbound_atu(struct dw_pcie_ep *ep, u8 func_no,
> > -				   phys_addr_t phys_addr,
> > -				   u64 pci_addr, size_t size)
> > +static int dw_pcie_ep_outbound_atu(struct dw_pcie_ep *ep,
> > +				   struct dw_pcie_outbound_atu *atu)
> >  {
> >  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> >  	u32 free_win;
> > @@ -197,13 +196,13 @@ static int dw_pcie_ep_outbound_atu(struct dw_pcie_ep *ep, u8 func_no,
> >  		return -EINVAL;
> >  	}
> >
> > -	ret = dw_pcie_prog_ep_outbound_atu(pci, func_no, free_win, PCIE_ATU_TYPE_MEM,
> > -					   phys_addr, pci_addr, size);
> > +	atu->index = free_win;
> > +	ret = dw_pcie_prog_ep_outbound_atu(pci, atu);
> >  	if (ret)
> >  		return ret;
> >
> >  	set_bit(free_win, ep->ob_window_map);
> > -	ep->outbound_addr[free_win] = phys_addr;
> > +	ep->outbound_addr[free_win] = atu->cpu_addr;
> >
> >  	return 0;
> >  }
> > @@ -306,8 +305,14 @@ static int dw_pcie_ep_map_addr(struct pci_epc *epc, u8 func_no, u8 vfunc_no,
> >  	int ret;
> >  	struct dw_pcie_ep *ep = epc_get_drvdata(epc);
> >  	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
> > -
> > -	ret = dw_pcie_ep_outbound_atu(ep, func_no, addr, pci_addr, size);
> > +	struct dw_pcie_outbound_atu atu = { 0 };
> > +
> > +	atu.func_no = func_no;
> > +	atu.type = PCIE_ATU_TYPE_MEM;
> > +	atu.cpu_addr = addr;
> > +	atu.pci_addr = pci_addr;
> > +	atu.size = size;
> > +	ret = dw_pcie_ep_outbound_atu(ep, &atu);
> >  	if (ret) {
> >  		dev_err(pci->dev, "Failed to enable address\n");
> >  		return ret;
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> > index ede166645289..782c4b34d0a3 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.c
> > +++ b/drivers/pci/controller/dwc/pcie-designware.c
> > @@ -464,56 +464,55 @@ static inline u32 dw_pcie_enable_ecrc(u32 val)
> >  	return val | PCIE_ATU_TD;
> >  }
> >
> 
> > -static int __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
> > -				       int index, int type, u64 cpu_addr,
> > -				       u64 pci_addr, u64 size)
> > +static int __dw_pcie_prog_outbound_atu(struct dw_pcie *pci,
> > +				       struct dw_pcie_outbound_atu *atu)
> >  {
> >  	u32 retries, val;
> >  	u64 limit_addr;
> >
> >  	if (pci->ops && pci->ops->cpu_addr_fixup)
> > -		cpu_addr = pci->ops->cpu_addr_fixup(pci, cpu_addr);
> > +		atu->cpu_addr = pci->ops->cpu_addr_fixup(pci, atu->cpu_addr);
> 
> This changes the method semantic a bit. The passed structure will be
> updated meanwhile the former semantic implies the locally defined
> variable modification. Please define a local var "cpu_addr" initialized
> with the atu->cpu_addr field by default.

I'll fix it.

> >
> > -	limit_addr = cpu_addr + size - 1;
> > +	limit_addr = atu->cpu_addr + atu->size - 1;
> >
> > -	if ((limit_addr & ~pci->region_limit) != (cpu_addr & ~pci->region_limit) ||
> > -	    !IS_ALIGNED(cpu_addr, pci->region_align) ||
> > -	    !IS_ALIGNED(pci_addr, pci->region_align) || !size) {
> > +	if ((limit_addr & ~pci->region_limit) != (atu->cpu_addr & ~pci->region_limit) ||
> > +	    !IS_ALIGNED(atu->cpu_addr, pci->region_align) ||
> > +	    !IS_ALIGNED(atu->pci_addr, pci->region_align) || !atu->size) {
> >  		return -EINVAL;
> >  	}
> >
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_LOWER_BASE,
> > -			      lower_32_bits(cpu_addr));
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_UPPER_BASE,
> > -			      upper_32_bits(cpu_addr));
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_LOWER_BASE,
> > +			      lower_32_bits(atu->cpu_addr));
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_UPPER_BASE,
> > +			      upper_32_bits(atu->cpu_addr));
> >
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_LIMIT,
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_LIMIT,
> >  			      lower_32_bits(limit_addr));
> >  	if (dw_pcie_ver_is_ge(pci, 460A))
> > -		dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_UPPER_LIMIT,
> > +		dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_UPPER_LIMIT,
> >  				      upper_32_bits(limit_addr));
> >
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_LOWER_TARGET,
> > -			      lower_32_bits(pci_addr));
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_UPPER_TARGET,
> > -			      upper_32_bits(pci_addr));
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_LOWER_TARGET,
> > +			      lower_32_bits(atu->pci_addr));
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_UPPER_TARGET,
> > +			      upper_32_bits(atu->pci_addr));
> >
> > -	val = type | PCIE_ATU_FUNC_NUM(func_no);
> > -	if (upper_32_bits(limit_addr) > upper_32_bits(cpu_addr) &&
> > +	val = atu->type | PCIE_ATU_FUNC_NUM(atu->func_no);
> > +	if (upper_32_bits(limit_addr) > upper_32_bits(atu->cpu_addr) &&
> >  	    dw_pcie_ver_is_ge(pci, 460A))
> >  		val |= PCIE_ATU_INCREASE_REGION_SIZE;
> >  	if (dw_pcie_ver_is(pci, 490A))
> >  		val = dw_pcie_enable_ecrc(val);
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_REGION_CTRL1, val);
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_REGION_CTRL1, val);
> >
> > -	dw_pcie_writel_atu_ob(pci, index, PCIE_ATU_REGION_CTRL2, PCIE_ATU_ENABLE);
> > +	dw_pcie_writel_atu_ob(pci, atu->index, PCIE_ATU_REGION_CTRL2, PCIE_ATU_ENABLE);
> >
> >  	/*
> >  	 * Make sure ATU enable takes effect before any subsequent config
> >  	 * and I/O accesses.
> >  	 */
> >  	for (retries = 0; retries < LINK_WAIT_MAX_IATU_RETRIES; retries++) {
> > -		val = dw_pcie_readl_atu_ob(pci, index, PCIE_ATU_REGION_CTRL2);
> > +		val = dw_pcie_readl_atu_ob(pci, atu->index, PCIE_ATU_REGION_CTRL2);
> >  		if (val & PCIE_ATU_ENABLE)
> >  			return 0;
> >
> > @@ -528,16 +527,20 @@ static int __dw_pcie_prog_outbound_atu(struct dw_pcie *pci, u8 func_no,
> 
> >  int dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
> >  			      u64 cpu_addr, u64 pci_addr, u64 size)
> >  {
> > -	return __dw_pcie_prog_outbound_atu(pci, 0, index, type,
> > -					   cpu_addr, pci_addr, size);
> > +	struct dw_pcie_outbound_atu atu = { 0 };
> > +
> > +	atu.index = index;
> > +	atu.type = type;
> > +	atu.cpu_addr = cpu_addr;
> > +	atu.pci_addr = pci_addr;
> > +	atu.size = size;
> > +	return __dw_pcie_prog_outbound_atu(pci, &atu);
> >  }
> >
> > -int dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci, u8 func_no, int index,
> > -				 int type, u64 cpu_addr, u64 pci_addr,
> > -				 u64 size)
> > +int dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci,
> > +				 struct dw_pcie_outbound_atu *atu)
> >  {
> > -	return __dw_pcie_prog_outbound_atu(pci, func_no, index, type,
> > -					   cpu_addr, pci_addr, size);
> > +	return __dw_pcie_prog_outbound_atu(pci, atu);
> >  }
> 
> This could have been dropped if you got to implement what I suggested in
> the head of the message.

I got it. I'll modify this patch on v15.

> >
> >  static inline u32 dw_pcie_readl_atu_ib(struct dw_pcie *pci, u32 index, u32 reg)
> > diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
> > index 9acf6c40d252..81c7558a4718 100644
> > --- a/drivers/pci/controller/dwc/pcie-designware.h
> > +++ b/drivers/pci/controller/dwc/pcie-designware.h
> > @@ -291,6 +291,15 @@ enum dw_pcie_core_rst {
> >  	DW_PCIE_NUM_CORE_RSTS
> >  };
> >
> 
> > +struct dw_pcie_outbound_atu {
> 
> what about using the name "dw_pcie_ob_atu_cfg" instead?

It looks better than dw_pcie_outbound_atu. I'll change the name.

> > +	u64 cpu_addr;
> > +	u64 pci_addr;
> > +	u64 size;
> > +	int index;
> > +	int type;
> > +	u8 func_no;
> 
> The structure will be padded by 7 bytes anyway. Let's move the "index",
> "type" and "func_no" group to the head of the structure declaration.

I got it.

> > +};
> > +
> >  struct dw_pcie_host_ops {
> >  	int (*host_init)(struct dw_pcie_rp *pp);
> >  	void (*host_deinit)(struct dw_pcie_rp *pp);
> > @@ -421,8 +430,8 @@ void dw_pcie_upconfig_setup(struct dw_pcie *pci);
> >  int dw_pcie_wait_for_link(struct dw_pcie *pci);
> 
> >  int dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index, int type,
> >  			      u64 cpu_addr, u64 pci_addr, u64 size);
> > -int dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci, u8 func_no, int index,
> > -				 int type, u64 cpu_addr, u64 pci_addr, u64 size);
> > +int dw_pcie_prog_ep_outbound_atu(struct dw_pcie *pci,
> > +				 struct dw_pcie_outbound_atu *atu);
> 
> What about converting it to just a single:
> dw_pcie_prog_outbound_atu(struct dw_pcie *pci, const struct dw_pcie_ob_atu_cfg *atu);
> ?

I got it. I will use dw_pcie_prog_outbound_atu() only. I also think that using
"const struct dw_pcie_ob_atu_cfg *atu" is better.

Best regards,
Yoshihiro Shimoda

> -Serge(y)
> 
> >  int dw_pcie_prog_inbound_atu(struct dw_pcie *pci, int index, int type,
> >  			     u64 cpu_addr, u64 pci_addr, u64 size);
> >  int dw_pcie_prog_ep_inbound_atu(struct dw_pcie *pci, u8 func_no, int index,
> > --
> > 2.25.1
> >




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