Hi Simon, Thanks for your comments!
> -----Original Message----- > From: s...@google.com [mailto:s...@google.com] On Behalf Of Simon Glass > Sent: 2016年11月28日 1:02 > To: Z.Q. Hou <zhiqiang....@nxp.com> > Cc: U-Boot Mailing List <u-boot@lists.denx.de>; Albert ARIBAUD > <albert.u.b...@aribaud.net>; Prabhakar Kushwaha > <prabhakar.kushw...@nxp.com>; Huan Wang-B18965 > <alison.w...@freescale.com>; Sumit Garg <sumit.g...@nxp.com>; Ruchika > Gupta <ruchika.gu...@nxp.com>; Saksham Jain > <saksham.j...@nxp.freescale.com>; york sun <york....@nxp.com>; M.H. Lian > <minghuan.l...@nxp.com>; Bin Meng <bmeng...@gmail.com>; Mingkai Hu > <mingkai...@nxp.com> > Subject: Re: [PATCHv3 09/15] pci: layerscape: add pci driver based on DM > > Hi, > > On 24 November 2016 at 02:28, Z.Q. Hou <zhiqiang....@nxp.com> wrote: > > Hi Simon, > > > > Thanks for your comments! > > > >> -----Original Message----- > >> From: s...@google.com [mailto:s...@google.com] On Behalf Of Simon Glass > >> Sent: 2016年11月24日 10:21 > >> To: Z.Q. Hou <zhiqiang....@nxp.com> > >> Cc: U-Boot Mailing List <u-boot@lists.denx.de>; Albert ARIBAUD > >> <albert.u.b...@aribaud.net>; Prabhakar Kushwaha > >> <prabhakar.kushw...@nxp.com>; Huan Wang-B18965 > >> <alison.w...@freescale.com>; Sumit Garg <sumit.g...@nxp.com>; > Ruchika > >> Gupta <ruchika.gu...@nxp.com>; Saksham Jain > >> <saksham.j...@nxp.freescale.com>; york sun <york....@nxp.com>; M.H. > >> Lian <minghuan.l...@nxp.com>; Bin Meng <bmeng...@gmail.com>; > Mingkai > >> Hu <mingkai...@nxp.com> > >> Subject: Re: [PATCHv3 09/15] pci: layerscape: add pci driver based on > >> DM > >> > >> Hi, > >> > >> On 22 November 2016 at 02:25, Z.Q. Hou <zhiqiang....@nxp.com> wrote: > >> > Hi Simon, > >> > > >> > Sorry for my delay respond due to out of the office several days, > >> > and thanks > >> a lot for your comments! > >> > > >> >> -----Original Message----- > >> >> From: s...@google.com [mailto:s...@google.com] On Behalf Of Simon > >> >> Glass > >> >> Sent: 2016年11月18日 9:15 > >> >> To: Z.Q. Hou <zhiqiang....@nxp.com> > >> >> Cc: U-Boot Mailing List <u-boot@lists.denx.de>; Albert ARIBAUD > >> >> <albert.u.b...@aribaud.net>; Prabhakar Kushwaha > >> >> <prabhakar.kushw...@nxp.com>; Huan Wang-B18965 > >> >> <alison.w...@freescale.com>; Sumit Garg <sumit.g...@nxp.com>; > >> Ruchika > >> >> Gupta <ruchika.gu...@nxp.com>; Saksham Jain > >> >> <saksham.j...@nxp.freescale.com>; york sun <york....@nxp.com>; > M.H. > >> >> Lian <minghuan.l...@nxp.com>; Bin Meng <bmeng...@gmail.com>; > >> Mingkai > >> >> Hu <mingkai...@nxp.com> > >> >> Subject: Re: [PATCHv3 09/15] pci: layerscape: add pci driver based > >> >> on DM > >> >> > >> >> Hi, > >> >> > >> >> On 16 November 2016 at 02:48, Zhiqiang Hou <zhiqiang....@nxp.com> > >> >> wrote: > >> >> > From: Minghuan Lian <minghuan.l...@nxp.com> > >> >> > > >> >> > There are more than five kinds of Layerscape SoCs. > >> >> > unfortunately, PCIe controller of each SoC is a little bit > >> >> > different. In order to avoid too many macro definitions, the > >> >> > patch addes a new implementation of PCIe driver based on DM. > >> >> > PCIe dts node is used to describe the difference. > >> >> > > >> >> > Signed-off-by: Minghuan Lian <minghuan.l...@nxp.com> > >> >> > Signed-off-by: Hou Zhiqiang <zhiqiang....@nxp.com> > >> >> > --- > >> >> > V3: > >> >> > - No change > >> >> > > >> >> > drivers/pci/Kconfig | 8 + > >> >> > drivers/pci/pcie_layerscape.c | 761 > >> >> > ++++++++++++++++++++++++++++++++++++++++++ > >> >> > 2 files changed, 769 insertions(+) > >> >> > > >> > >> >> > +#ifdef CONFIG_FSL_LSCH3 > >> >> > >> >> Can this be a run-time check? > >> > > >> > No, it is for Linux DT fixup and these functions is needed only by > >> > FSL_LSCH3 > >> SoCs. > >> > >> I mean that you cannot have an #ifdef in a driver - it should be done > >> at run-time by looking at the compatible strings. > > > > This driver work for many platforms, but this fixup is only used by > > FSL_LSCH3 SoCs, if check the compatible string at run-time, the fixup will > > be > still compiled for the platform which doesn't need it. > > Why compile it into the binary for the platform which doesn't need it? > > Because that's how it works. Drivers are drivers for their hardware. > We cannot compile them differently depending on who might use them... > > If this is a big problem you could split the driver into multiple parts > perhaps. But > what exactly is the problem here? It isn't a big problem, actually it is just kernel DT fixup function, and it doesn't affect the u-boot pcie driver. But the fixup is LSCH3 SoC special, and some macros are only defined in header file of LSCH3, e.g. FSL_PEX_STREAM_ID_*. So cannot removed the #ifdef CONFIG_FSL_LSCH3. > > > > >> > > >> >> > >> >> > +/* > >> >> > + * Return next available LUT index. > >> >> > + */ > >> >> > +static int ls_pcie_next_lut_index(struct ls_pcie *pcie) { > >> >> > + if (pcie->next_lut_index < PCIE_LUT_ENTRY_COUNT) > >> >> > + return pcie->next_lut_index++; > >> >> > + else > >> >> > + return -1; /* LUT is full */ > >> >> > >> >> -ENOSPC? > >> > > >> > Yes, ENOSPC is more reasonable. > >> > > >> >> > >> >> > +} > >> >> > + > >> >> > +/* > >> >> > + * Program a single LUT entry > >> >> > + */ > >> >> > +static void ls_pcie_lut_set_mapping(struct ls_pcie *pcie, int > >> >> > +index, u32 > >> >> devid, > >> >> > + u32 streamid) { > >> >> > + /* leave mask as all zeroes, want to match all bits */ > >> >> > + lut_writel(pcie, devid << 16, PCIE_LUT_UDR(index)); > >> >> > + lut_writel(pcie, streamid | PCIE_LUT_ENABLE, > >> >> > +PCIE_LUT_LDR(index)); } > >> >> > + > >> >> > +/* returns the next available streamid */ static u32 > >> >> > +ls_pcie_next_streamid(void) { > >> >> > + static int next_stream_id = FSL_PEX_STREAM_ID_START; > >> >> > + > >> >> > + if (next_stream_id > FSL_PEX_STREAM_ID_END) > >> >> > + return 0xffffffff; > >> >> > >> >> Is FSL_PEX_STREAM_ID_END the maximum value, or the number of > values? > >> > > >> > The maximum value for PCIe. > >> > > >> >> > + > >> >> > + return next_stream_id++; } > >> >> > + > >> >> > +/* > >> >> > + * An msi-map is a property to be added to the pci controller > >> >> > + * node. It is a table, where each entry consists of 4 fields > >> >> > + * e.g.: > >> >> > + * > >> >> > + * msi-map = <[devid] [phandle-to-msi-ctrl] [stream-id] [count] > >> >> > + * [devid] [phandle-to-msi-ctrl] [stream-id] > [count]>; > >> >> > + */ > >> >> > +static void fdt_pcie_set_msi_map_entry(void *blob, struct ls_pcie > *pcie, > >> >> > + u32 devid, u32 > streamid) { > >> >> > + u32 *prop; > >> >> > + u32 phandle; > >> >> > + int nodeoffset; > >> >> > + > >> >> > + /* find pci controller node */ > >> >> > + nodeoffset = fdt_node_offset_by_compat_reg(blob, > >> >> > + "fsl,ls-pcie", > >> >> > + > >> >> > + pcie->dbi_res.start); > >> >> > >> >> At this point I'm a bit lost, but if this is using driver model, > >> >> you can use > >> >> dev->of_offset > >> > > >> > This function is used to fixup Linux Kernel DT instead of u-boot DT. > >> > >> They should use the same DT. > > > > Yes, Ideally they should, but up to now actually Kernel does not use > > the one u-boot used, so we cannot make sure the offset of the nodes are the > same. > > So to ensure the fixup work, get the node offset from kernel DT. > > Is it not possible to change U-Boot to use the kernel DT? It might be less > work. Since this is used to fixup Kernel DT, and u-boot and Kernel use two copies of DT, until the u-boot and kernel use one copy of DT, we must fixup the one works for Kernel. > > > > >> > >> > > >> >> > >> >> > + if (nodeoffset < 0) { > >> >> > + #ifdef FSL_PCIE_COMPAT /* Compatible with older version > >> >> > + of dts node */ > >> >> > >> >> Eek! Can't you detect this at run-time? > >> >> > >> > > >> > No, it's Kernel DT fixup, we plan to refactor Layerscape PCIe Linux > >> > driver using the compatible "fsl,ls-pcie", but for now the macro > >> FSL_PCIE_COMPAT must be defined to fixup Linux DT. > >> > >> I'm still confused by this. I don't see it defined anywhere and it is not a > CONFIG. > >> Can you not detect at run-time when you need to do the fix-up? > > > > Ok, the process is find the node offset by "fsl,ls-pcie" first, if failed, > > find it > again by FSL_PCIE_COMPAT. > > But in the current kernel DT the name of PCIe controller node is NOT > > the "fsl,ls-pcie" which we will refactor layerscape pcie kernel driver > > to use, so far it is the FSL_PCIE_COMPAT which is defined according to the > current kernel DT in header file include/configs/ls*.h. > > So it is unable to be detected at run-time, but it will be removed when the > kernel driver refactored. > > OK, so how about making this a new CONFIG which you can turn on/off? Yes, will move it to CONFIG_ FSL_PCIE_COMPAT. > > > >> > >> > > >> >> > + nodeoffset = > fdt_node_offset_by_compat_reg(blob, > >> >> > + > >> >> FSL_PCIE_COMPAT, > >> >> > + > >> >> pcie->dbi_res.start); > >> >> > + if (nodeoffset < 0) > >> >> > + return; > >> >> > + #else > >> >> > + return; > >> >> > + #endif > >> >> > + } > >> >> > + > >> >> > + /* get phandle to MSI controller */ > >> >> > + prop = (u32 *)fdt_getprop(blob, nodeoffset, > >> >> > + "msi-parent", 0); > >> >> > >> >> fdtdec_getint() > >> > > >> > The fdtdec_get_int() is not suit for this case, because the value > >> > of > >> "msi-parent" is an index of gic-its, so there isn't a default value. > >> > >> Try: > >> > >> val = fdtdec_get_int(blob, nodeoffset, "msi-parent", -1) > >> if (val == -1) { > >> debug(...); > >> return -EINVAL; > >> } > >> > > > > Any benefit compared with fdt_getprop? I'm confused by this function, what > if the correct value equal to the given default value? > > You choose an invalid default. If there isn't one then you cannot use this > function. The benefit is that it avoids the be32_to_cpu(). The value of this property is a reference of other node and don't know which is the invalid value. Do you have any suggestion about this case? > > > >> > > >> >> > >> >> > + if (prop == NULL) { > >> >> > + printf("\n%s: ERROR: missing msi-parent: > PCIe%d\n", > >> >> > + __func__, pcie->idx); > >> >> > + return; > >> >> > >> >> Return an error error and check it. > >> > > >> > This function is used to fixup Linux DT, so this error won't block > >> > the u-boot > >> process, and I think an error message is enough. > >> > >> If it is an error it should return an error. If it is just a warning > >> it should say so, ideally using debug(). As it is, it is very > >> confusing for the user to get this message. > > > > Will replace with debug(). > > > >> > > >> >> > + } > >> >> > + phandle = be32_to_cpu(*prop); > >> >> > >> >> fdt32_to_cpu() > >> >> > >> > > >> > Yes, better to use fdt32_to_cpu. > >> > >> But where do you use that value? Also. consider fdtdec_lookup_phandle(). > > > > Thanks for your tip, just the value of this phandle is used, see the lines > > below. > > OK I see. > > > > >> > > >> >> > + > >> >> > + /* set one msi-map row */ > >> >> > + fdt_appendprop_u32(blob, nodeoffset, "msi-map", devid); > >> >> > + fdt_appendprop_u32(blob, nodeoffset, "msi-map", phandle); > >> >> > + fdt_appendprop_u32(blob, nodeoffset, "msi-map", > streamid); > >> >> > + fdt_appendprop_u32(blob, nodeoffset, "msi-map", 1); } > >> >> > + > >> >> > +static void fdt_fixup_pcie(void *blob) > >> >> > >> >> This is a pretty horrible function. What is it for? > >> > > >> > Kernel DT fixup. > >> > >> OK, well please add some comments! > > > > Will comment it. Regards, Zhiqiang _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
