RE: [PATCH V4 2/2] PCI: rcar: Recalculate inbound range alignment for each controller entry

[Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>]

Hi Lorenzo,

> From: Lorenzo Pieralisi, Sent: Monday, October 28, 2019 7:21 PM
> 
> On Mon, Oct 28, 2019 at 08:35:32AM +0000, Yoshihiro Shimoda wrote:
> > Hi Marek-san.
> >
> > > From: Marek Vasut, Sent: Sunday, October 27, 2019 3:27 AM
> > >
> > > Due to hardware constraints, the size of each inbound range entry
> > > populated into the controller cannot be larger than the alignment
> > > of the entry's start address. Currently, the alignment for each
> > > "dma-ranges" inbound range is calculated only once for each range
> > > and the increment for programming the controller is also derived
> > > from it only once. Thus, a "dma-ranges" entry describing a memory
> > > at 0x48000000 and size 0x38000000 would lead to multiple controller
> > > entries, each 0x08000000 long.
> >
> > I added a debug code [1] and I confirmed that each entry is not 0x08000000 long [2].
> >
> > After fixed the commit log above,
> 
> So what does this mean in practice ? Does it mean that the commit log is
> wrong or that the issue is not present as described, in the mainline
> code ?

I meant the commit log is wrong. In such the case, the multiple controller
entries has 3 kind of size like below.

> > +		dev_dbg(pcie->dev, "idx%d: 0x%016llx..0x%016llx -> 0x%016llx\n",
> > +			idx, cpu_addr, size, pci_addr);
<snip>
> > [    0.374771] rcar-pcie fe000000.pcie: idx0: 0x0000000048000000..0x0000000008000000 -> 0x0000000048000000

The first entry's size is 0x08000000.

> > [    0.374777] rcar-pcie fe000000.pcie: idx2: 0x0000000050000000..0x0000000010000000 -> 0x0000000050000000

The second one's size is 0x10000000.

> > [    0.374782] rcar-pcie fe000000.pcie: idx4: 0x0000000060000000..0x0000000020000000 -> 0x0000000060000000

The third one's size is 0x20000000.

> Please clarify and send a v5 accordingly.

Marek-san, would you send a v5 patch series?

Best regards,
Yoshihiro Shimoda

> Thanks,
> Lorenzo
> 
> > Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> >
> > And I tested on r8a7795-salvator-xs with my debug code. So,
> >
> > Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> >
> > Best regards,
> > Yoshihiro Shimoda
> >
> > ---
> > [1] Based on next-20191025 with this patch series:
> > diff --git a/arch/arm64/boot/dts/renesas/r8a7795.dtsi b/arch/arm64/boot/dts/renesas/r8a7795.dtsi
> > index fde6ec1..9bdd39e 100644
> > --- a/arch/arm64/boot/dts/renesas/r8a7795.dtsi
> > +++ b/arch/arm64/boot/dts/renesas/r8a7795.dtsi
> > @@ -2684,7 +2684,7 @@
> >  				0x02000000 0 0x30000000 0 0x30000000 0 0x08000000
> >  				0x42000000 0 0x38000000 0 0x38000000 0 0x08000000>;
> >  			/* Map all possible DDR as inbound ranges */
> > -			dma-ranges = <0x42000000 0 0x40000000 0 0x40000000 0 0x40000000>;
> > +			dma-ranges = <0x42000000 0 0x48000000 0 0x48000000 0 0x38000000>;
> >  			interrupts = <GIC_SPI 116 IRQ_TYPE_LEVEL_HIGH>,
> >  				<GIC_SPI 117 IRQ_TYPE_LEVEL_HIGH>,
> >  				<GIC_SPI 118 IRQ_TYPE_LEVEL_HIGH>;
> > diff --git a/drivers/pci/controller/pcie-rcar.c b/drivers/pci/controller/pcie-rcar.c
> > index 0dadccb..54ad977 100644
> > --- a/drivers/pci/controller/pcie-rcar.c
> > +++ b/drivers/pci/controller/pcie-rcar.c
> > @@ -11,6 +11,8 @@
> >   * Author: Phil Edworthy <phil.edworthy@renesas.com>
> >   */
> >
> > +#define DEBUG
> > +
> >  #include <linux/bitops.h>
> >  #include <linux/clk.h>
> >  #include <linux/delay.h>
> > @@ -1054,6 +1056,8 @@ static int rcar_pcie_inbound_ranges(struct rcar_pcie *pcie,
> >  		mask = roundup_pow_of_two(size) - 1;
> >  		mask &= ~0xf;
> >
> > +		dev_dbg(pcie->dev, "idx%d: 0x%016llx..0x%016llx -> 0x%016llx\n",
> > +			idx, cpu_addr, size, pci_addr);
> >  		/*
> >  		 * Set up 64-bit inbound regions as the range parser doesn't
> >  		 * distinguish between 32 and 64-bit types.
> > ---
> > [2]
> > [    0.374771] rcar-pcie fe000000.pcie: idx0: 0x0000000048000000..0x0000000008000000 -> 0x0000000048000000
> > [    0.374777] rcar-pcie fe000000.pcie: idx2: 0x0000000050000000..0x0000000010000000 -> 0x0000000050000000
> > [    0.374782] rcar-pcie fe000000.pcie: idx4: 0x0000000060000000..0x0000000020000000 -> 0x0000000060000000
> > ---
> >