Am Mon, Oct 04, 2021 at 01:42:48PM +0000 schrieb Visa Hankala:
> On the Zynq-7000, the lowest 512KiB of physical address space usually
> contains RAM that is usable by the CPUs. However, many other bus
> masters, such as the Ethernet and SDIO controllers, are not able to
> access the 256KiB range that starts at physical address 0x40000.
>
> So far I have used a device tree that says that RAM starts at 0x80000,
> to avoid the DMA hole. This is unconventional, though. Typically the
> memory node for Zynq-7000 specifies 0x0 as the starting address for RAM.
>
> I think armv7 DMA constraint should be adjusted on the Zynq-7000 so that
> less device tree customization would be needed.
>
> This diff makes armv7 efiboot and kernel handle the
> openbsd,dma-constraint device tree property, with a tweak for the Zynq.
> The code is similar to what is already present on arm64 and riscv64.
>
> OK?
Heh, I just saw that the dma constraint range is paddr_t, so on ARMv7
it's 32-bit values. Hence it makes sense that you're not using sizeof(
dma_constraint).
Using the same size in the openbsd,dma-constrant API as arm64 does make
sense to me, so while it might looks less nice than on arm64, I feel it
is the sane way.
Might want to see if kettenis agrees, since he built it, but otherwise
ok patrick@.
> Index: arch/armv7/armv7/armv7_machdep.c
> ===================================================================
> RCS file: src/sys/arch/armv7/armv7/armv7_machdep.c,v
> retrieving revision 1.63
> diff -u -p -r1.63 armv7_machdep.c
> --- arch/armv7/armv7/armv7_machdep.c 25 Mar 2021 04:12:01 -0000 1.63
> +++ arch/armv7/armv7/armv7_machdep.c 4 Oct 2021 13:32:11 -0000
> @@ -453,6 +453,12 @@ initarm(void *arg0, void *arg1, void *ar
> len = fdt_node_property(node, "openbsd,uefi-mmap-desc-ver",
> &prop);
> if (len == sizeof(mmap_desc_ver))
> mmap_desc_ver = bemtoh32((uint32_t *)prop);
> +
> + len = fdt_node_property(node, "openbsd,dma-constraint", &prop);
> + if (len == sizeof(uint64_t[2])) {
> + dma_constraint.ucr_low = bemtoh64((uint64_t *)prop);
> + dma_constraint.ucr_high = bemtoh64((uint64_t *)prop +
> 1);
> + }
> }
>
> process_kernel_args();
> Index: arch/armv7/stand/efiboot/conf.c
> ===================================================================
> RCS file: src/sys/arch/armv7/stand/efiboot/conf.c,v
> retrieving revision 1.31
> diff -u -p -r1.31 conf.c
> --- arch/armv7/stand/efiboot/conf.c 10 Jun 2021 22:17:58 -0000 1.31
> +++ arch/armv7/stand/efiboot/conf.c 4 Oct 2021 13:32:11 -0000
> @@ -42,7 +42,7 @@
> #include "efidev.h"
> #include "efipxe.h"
>
> -const char version[] = "1.18";
> +const char version[] = "1.19";
> int debug = 0;
>
> struct fs_ops file_system[] = {
> Index: arch/armv7/stand/efiboot/efiboot.c
> ===================================================================
> RCS file: src/sys/arch/armv7/stand/efiboot/efiboot.c,v
> retrieving revision 1.34
> diff -u -p -r1.34 efiboot.c
> --- arch/armv7/stand/efiboot/efiboot.c 7 Jun 2021 21:18:31 -0000
> 1.34
> +++ arch/armv7/stand/efiboot/efiboot.c 4 Oct 2021 13:32:11 -0000
> @@ -435,6 +435,28 @@ efi_framebuffer(void)
> sizeof(framebuffer_path));
> }
>
> +uint64_t dma_constraint[2] = { 0, -1 };
> +
> +void
> +efi_dma_constraint(void)
> +{
> + void *node;
> +
> + /* Raspberry Pi 4 is "special". */
> + node = fdt_find_node("/");
> + if (fdt_node_is_compatible(node, "brcm,bcm2711"))
> + dma_constraint[1] = htobe64(0x3bffffff);
> +
> + /* Not all bus masters can access 0x40000-0x7ffff on Zynq-7000. */
> + if (fdt_node_is_compatible(node, "xlnx,zynq-7000"))
> + dma_constraint[0] = htobe64(0x00080000);
> +
> + /* Pass DMA constraint. */
> + node = fdt_find_node("/chosen");
> + fdt_node_add_property(node, "openbsd,dma-constraint",
> + dma_constraint, sizeof(dma_constraint));
> +}
> +
> void
> efi_console(void)
> {
> @@ -515,6 +537,7 @@ efi_makebootargs(char *bootargs, int how
>
> efi_framebuffer();
> efi_console();
> + efi_dma_constraint();
>
> fdt_finalize();
>
>
