On Tue, Aug 05, 2025 at 11:38:07AM +0200, Geert Uytterhoeven wrote: > Hi Stafford, > > On Tue, 5 Aug 2025 at 11:15, Stafford Horne <[email protected]> wrote: > > On Tue, Aug 05, 2025 at 08:40:57AM +0000, ChenMiao wrote: > > > From: chenmiao <[email protected]> > > > > > > We need a text patching mechanism to ensure that in the subsequent > > > implementation of jump_label, the code can be modified to the correct > > > location. Therefore, FIX_TEXT_POKE0 has been added as a mapping area. > > > > > > And, I create a new file named insn-def.h to define the or1k insn macro > > > size and more define in the future. > > > > > > Among these changes, we implement patch_map and support the > > > patch_insn_write API for single instruction writing. > > > > > > Signed-off-by: chenmiao <[email protected]> > > > > --- /dev/null > > > +++ b/arch/openrisc/include/asm/insn-def.h > > > > +/* or1k instructions are always 32 bits. */ > > > +#define OPENRISC_INSN_SIZE 4 > > > > --- /dev/null > > > +++ b/arch/openrisc/kernel/patching.c > > > > +static int __patch_insn_write(void *addr, const void *insn) > > > +{ > > > + void *waddr = addr; > > > + unsigned long flags = 0; > > > + int ret; > > > + > > > + raw_spin_lock_irqsave(&patch_lock, flags); > > > + > > > + waddr = patch_map(addr, FIX_TEXT_POKE0); > > > + > > > + ret = copy_to_kernel_nofault(waddr, insn, OPENRISC_INSN_SIZE); > > > > If you change *insn to unsigned long insn, you can do: > > > > ret = copy_to_kernel_nofault(waddr, &insn, iszeof(insn)); > > sizeof(*insn)?
Yes, typo, thanks. > > > > > + local_icache_range_inv((unsigned long)waddr, > > > + (unsigned long)waddr + OPENRISC_INSN_SIZE); > > > + > > > + patch_unmap(FIX_TEXT_POKE0); > > > + > > > + raw_spin_unlock_irqrestore(&patch_lock, flags); > > > + > > > + return ret; > > > +} > > > + > > > +int patch_insn_write(void *addr, const void *insn) > > > > Does insn need to be void *? It think it could be just unsigned long. See > > comment above. > > u32? > > unsigned long would be 64-bit on 64-bit platforms. Thanks, yes for us it's more correct to use u32. I always thing unsigned long is OK in openrisc as we have no 64-bit implementations. But might as well have it correct in case we ever add the 64-bit implementation. -Stafford
