Re: [PATCH v3 13/34] m68k: Implement the new page table range API

Geert Uytterhoeven
2023-03-05T10:16:34Z

Hi Willy,

On Tue, Feb 28, 2023 at 10:37 PM Matthew Wilcox (Oracle)
<willy@infradead.org> wrote:
> Add set_ptes(), update_mmu_cache_range(), flush_icache_pages() and
> flush_dcache_folio().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Thanks for your patch!

> --- a/arch/m68k/include/asm/cacheflush_mm.h
> +++ b/arch/m68k/include/asm/cacheflush_mm.h
> @@ -220,24 +220,28 @@ static inline void flush_cache_page(struct vm_area_struct *vma, unsigned long vm
>
> /* Push the page at kernel virtual address and clear the icache */
> /* RZ: use cpush %bc instead of cpush %dc, cinv %ic */
> -static inline void __flush_page_to_ram(void *vaddr)
> +static inline void __flush_pages_to_ram(void *vaddr, unsigned int nr)
> {
> if (CPU_IS_COLDFIRE) {
> unsigned long addr, start, end;
> addr = ((unsigned long) vaddr) & ~(PAGE_SIZE - 1);
> start = addr & ICACHE_SET_MASK;
> - end = (addr + PAGE_SIZE - 1) & ICACHE_SET_MASK;
> + end = (addr + nr * PAGE_SIZE - 1) & ICACHE_SET_MASK;
> if (start > end) {
> flush_cf_bcache(0, end);
> end = ICACHE_MAX_ADDR;
> }
> flush_cf_bcache(start, end);
> } else if (CPU_IS_040_OR_060) {
> - __asm__ __volatile__("nop\n\t"
> - ".chip 68040\n\t"
> - "cpushp %%bc,(%0)\n\t"
> - ".chip 68k"
> - : : "a" (__pa(vaddr)));
> + unsigned long paddr = __pa(vaddr);
> +
> + while (nr--) {
> + __asm__ __volatile__("nop\n\t"
> + ".chip 68040\n\t"
> + "cpushp %%bc,(%0)\n\t"
> + ".chip 68k"
> + : : "a" (paddr + nr * PAGE_SIZE));

As gcc (9.5.0) keeps on calculating "paddr + nr * PAGE_SIZE"
inside the loop (albeit using a shift instead of a multiplication),
please use "paddr" here, followed by "paddr += PAGE_SIZE;".

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds