The reset driver subsystem does not need any extra data, so it can use
`struct fdt_driver` directly. The generic fdt_reset_init() performs a
best-effort initialization of all matching DT nodes. Platform-specific
logic expects exactly one DT node to match a single driver. This is
accomplished by using fdt_driver_init_one() with a local list containing
that one driver.
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Several of these override functions access the FDT blob. Explicitly
indicate which callbacks are allowed to modify the FDT blob by passing
the parameter as a possibly-const pointer. This also reduces code size
by deduplicating the call to fdt_get_address().
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
This reverts commit 6966ad0abe ("platform/lib: Allow the OS to map the
regions that are protected by PMP").
It was thought at the time of this commit that allowing the kernel to map
PMP protected regions was safe but it is actually not: for example, the
hibernation process will try to access any linear mapping page and then
will fault on such mapped PMP regions [1]. Another issue is that the
device tree specification [2] states that a !no-map region must be
declared as EfiBootServicesData/Code in the EFI memory map which would make
the PMP protected regions reclaimable by the kernel. And to circumvent
this, RISC-V edk2 diverges from the DT specification to declare those
regions as EfiReserved.
The no-map attribute was removed to allow the kernel to use hugepages
larger than 2MB to map the linear mapping to improve the performance but
actually a recent talk from Mike Rapoport [3] stated that the
performance benefit was marginal.
For all those reasons, let's mark all the PMP protected regions as "no-map".
[1] https://lore.kernel.org/linux-riscv/CAAYs2=gQvkhTeioMmqRDVGjdtNF_vhB+vm_1dHJxPNi75YDQ_Q@mail.gmail.com/
[2] "3.5.4 /reserved-memory and UEFI" https://github.com/devicetree-org/devicetree-specification/releases/download/v0.4-rc1/devicetree-specification-v0.4-rc1.pdf
[3] https://lwn.net/Articles/931406/
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Xiang W <wxjstz@126.com>
C language standard uses true/false for the boolean type.
Let's switch to that for better language compatibility.
Signed-off-by: Bin Meng <bmeng@tinylab.org>
Reviewed-by: Anup Patel <anup@brainfault.org>
Reviewed-by: Samuel Holland <samuel@sholland.org>
Tested-by: Samuel Holland <samuel@sholland.org>
We update generic platform to use kconfig for enabling/disabling
platform overrides. We also enable all platform overrides in generic
platform defconfig.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Tested-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Atish Patra <atishp@rivosinc.com>
Tested-by: Atish Patra <atishp@rivosinc.com>
Let us move SiFive platform overrides for FU540 and FU740 into a separate
directory so better maintainability. Other SoC vendors can also create
their own directory under platform/generic.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
