On 5/27/21 3:32 PM, Rob Herring wrote: > Reserved memory regions can be used for more than just DMA regions, so > only enabling on DMA_DECLARE_COHERENT (via HAS_DMA) or DMA_CMA is wrong. > This effectively doesn't matter except for the few cases arches select > NO_DMA. > > At least, these users of RESERVEDMEM_OF_DECLARE depend on reserved memory > support: > > arch/riscv/mm/init.c:RESERVEDMEM_OF_DECLARE(elfcorehdr, "linux,elfcorehdr", elfcore_hdr_setup); > drivers/memory/tegra/tegra210-emc-table.c:RESERVEDMEM_OF_DECLARE(tegra210_emc_table, "nvidia,tegra210-emc-table", > drivers/soc/fsl/qbman/bman_ccsr.c:RESERVEDMEM_OF_DECLARE(bman_fbpr, "fsl,bman-fbpr", bman_fbpr); > drivers/soc/fsl/qbman/qman_ccsr.c:RESERVEDMEM_OF_DECLARE(qman_fqd, "fsl,qman-fqd", qman_fqd); > drivers/soc/fsl/qbman/qman_ccsr.c:RESERVEDMEM_OF_DECLARE(qman_pfdr, "fsl,qman-pfdr", qman_pfdr); > > Let's simplify things and enable OF_RESERVED_MEM when OF_EARLY_FLATTREE is > enabled. > > Cc: Christoph Hellwig <hch@xxxxxx> > Signed-off-by: Rob Herring <robh@xxxxxxxxxx> Hi Rob, I'm OK with this patch, but with or without this patch, compiling kernel/dma/coherent.c without HAS_IOMEM (!) has build errors: s390-linux-ld: kernel/dma/coherent.o: in function `dma_init_coherent_memory': coherent.c:(.text+0x5ae): undefined reference to `memremap' s390-linux-ld: coherent.c:(.text+0x7a4): undefined reference to `memunmap' s390-linux-ld: kernel/dma/coherent.o: in function `dma_declare_coherent_memory': coherent.c:(.text+0xd84): undefined reference to `memunmap' along with a slew of other build errors (arch/s390/, CONFIG_PCI is not set, CONFIG_HAS_IOMEM is not set): s390-linux-ld: drivers/irqchip/irq-al-fic.o: in function `al_fic_init_dt': irq-al-fic.c:(.init.text+0x6a0): undefined reference to `iounmap' s390-linux-ld: drivers/char/xillybus/xillybus_of.o: in function `xilly_drv_probe': xillybus_of.c:(.text+0x2c8): undefined reference to `devm_platform_ioremap_resource' s390-linux-ld: drivers/pcmcia/cistpl.o: in function `set_cis_map': cistpl.c:(.text+0x87a): undefined reference to `ioremap' s390-linux-ld: cistpl.c:(.text+0x99a): undefined reference to `iounmap' s390-linux-ld: cistpl.c:(.text+0xa34): undefined reference to `iounmap' s390-linux-ld: cistpl.c:(.text+0xaa6): undefined reference to `ioremap' s390-linux-ld: drivers/pcmcia/cistpl.o: in function `release_cis_mem': cistpl.c:(.text+0x2976): undefined reference to `iounmap' s390-linux-ld: drivers/of/address.o: in function `of_iomap': address.c:(.text+0x1f02): undefined reference to `ioremap' s390-linux-ld: drivers/of/address.o: in function `of_io_request_and_map': address.c:(.text+0x2030): undefined reference to `ioremap' > --- > This is needed to prevent build break on UML with this patch: > > https://lore.kernel.org/lkml/20210527193841.1284169-1-robh@xxxxxxxxxx/ > > drivers/of/Kconfig | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig > index 18450437d5d5..3dfeae8912df 100644 > --- a/drivers/of/Kconfig > +++ b/drivers/of/Kconfig > @@ -75,9 +75,7 @@ config OF_NET > def_bool y > > config OF_RESERVED_MEM > - bool > - depends on OF_EARLY_FLATTREE > - default y if DMA_DECLARE_COHERENT || DMA_CMA > + def_bool OF_EARLY_FLATTREE > > config OF_RESOLVE > bool > -- ~Randy
