Re: [PATCH v7 09/19] openrisc: mm: Convert to GENERIC_IOREMAP

Baoquan He
2023-07-09T10:12:04Z

On 07/08/23 at 01:33am, Stafford Horne wrote:
> On Tue, Jun 20, 2023 at 09:13:46PM +0800, Baoquan He wrote:
> > By taking GENERIC_IOREMAP method, the generic generic_ioremap_prot(),
> > generic_iounmap(), and their generic wrapper ioremap_prot(), ioremap()
> > and iounmap() are all visible and available to arch. Arch needs to
> > provide wrapper functions to override the generic versions if there's
> > arch specific handling in its ioremap_prot(), ioremap() or iounmap().
> > This change will simplify implementation by removing duplicated codes
> > with generic_ioremap_prot() and generic_iounmap(), and has the equivalent
> > functioality as before.
> >
> > For openrisc, the current ioremap() and iounmap() are the same as
> > generic version. After taking GENERIC_IOREMAP way, the old ioremap()
> > and iounmap() can be completely removed.
> >
> > Signed-off-by: Baoquan He <bhe@redhat.com>
> > Reviewed-by: Christoph Hellwig <hch@lst.de>
> > Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
> > Cc: Stafford Horne <shorne@gmail.com>
> > Cc: Jonas Bonn <jonas@southpole.se>
> > Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
> > Cc: openrisc@lists.librecores.org
> > ---
> > arch/openrisc/Kconfig | 1 +
> > arch/openrisc/include/asm/io.h | 11 ++++----
> > arch/openrisc/mm/ioremap.c | 49 ----------------------------------
> > 3 files changed, 7 insertions(+), 54 deletions(-)
> >
> > diff --git a/arch/openrisc/Kconfig b/arch/openrisc/Kconfig
> > index c7f282f60f64..fd9bb76a610b 100644
> > --- a/arch/openrisc/Kconfig
> > +++ b/arch/openrisc/Kconfig
> > @@ -21,6 +21,7 @@ config OPENRISC
> > select GENERIC_IRQ_PROBE
> > select GENERIC_IRQ_SHOW
> > select GENERIC_PCI_IOMAP
> > + select GENERIC_IOREMAP
> > select GENERIC_CPU_DEVICES
> > select HAVE_PCI
> > select HAVE_UID16
> > diff --git a/arch/openrisc/include/asm/io.h b/arch/openrisc/include/asm/io.h
> > index ee6043a03173..5a6f0f16a5ce 100644
> > --- a/arch/openrisc/include/asm/io.h
> > +++ b/arch/openrisc/include/asm/io.h
> > @@ -15,6 +15,8 @@
> > #define __ASM_OPENRISC_IO_H
> >
> > #include <linux/types.h>
> > +#include <asm/pgalloc.h>
> > +#include <asm/pgtable.h>
> >
> > /*
> > * PCI: We do not use IO ports in OpenRISC
> > @@ -27,11 +29,10 @@
> > #define PIO_OFFSET 0
> > #define PIO_MASK 0
> >
> > -#define ioremap ioremap
> > -void __iomem *ioremap(phys_addr_t offset, unsigned long size);
> > -
> > -#define iounmap iounmap
> > -extern void iounmap(volatile void __iomem *addr);
> > +/*
> > + * I/O memory mapping functions.
> > + */
> > +#define _PAGE_IOREMAP (pgprot_val(PAGE_KERNEL) | _PAGE_CI)
> >
> > #include <asm-generic/io.h>
> >
> > diff --git a/arch/openrisc/mm/ioremap.c b/arch/openrisc/mm/ioremap.c
> > index cdbcc7e73684..91c8259d4b7e 100644
> > --- a/arch/openrisc/mm/ioremap.c
> > +++ b/arch/openrisc/mm/ioremap.c
> > @@ -22,55 +22,6 @@
> >
> > extern int mem_init_done;
> >
> > -/*
> > - * Remap an arbitrary physical address space into the kernel virtual
> > - * address space. Needed when the kernel wants to access high addresses
> > - * directly.
> > - *
> > - * NOTE! We need to allow non-page-aligned mappings too: we will obviously
> > - * have to convert them into an offset in a page-aligned mapping, but the
> > - * caller shouldn't need to know that small detail.
> > - */
> > -void __iomem *__ref ioremap(phys_addr_t addr, unsigned long size)
> > -{
> > - phys_addr_t p;
> > - unsigned long v;
> > - unsigned long offset, last_addr;
> > - struct vm_struct *area = NULL;
> > -
> > - /* Don't allow wraparound or zero size */
> > - last_addr = addr + size - 1;
> > - if (!size || last_addr < addr)
> > - return NULL;
> > -
> > - /*
> > - * Mappings have to be page-aligned
> > - */
> > - offset = addr & ~PAGE_MASK;
> > - p = addr & PAGE_MASK;
> > - size = PAGE_ALIGN(last_addr + 1) - p;
> > -
> > - area = get_vm_area(size, VM_IOREMAP);
> > - if (!area)
> > - return NULL;
> > - v = (unsigned long)area->addr;
> > -
> > - if (ioremap_page_range(v, v + size, p,
> > - __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_CI))) {
> > - vfree(area->addr);
> > - return NULL;
> > - }
> > -
> > - return (void __iomem *)(offset + (char *)v);
> > -}
> > -EXPORT_SYMBOL(ioremap);
> > -
> > -void iounmap(volatile void __iomem *addr)
> > -{
> > - return vfree((void *)(PAGE_MASK & (unsigned long)addr));
> > -}
> > -EXPORT_SYMBOL(iounmap);
> > -
>
> Hello,
>
> Thanks for the patch, I was able to test this booting openrisc and running a few
> glibc tests and see no issues. Also the code cleanup looks good to me.
>
> Acked-by: Stafford Horne <shorne@gmail.com>

Thanks a lot, Stafford.

I later posted v8 to add update for hexagon and s390, this is the link:
https://lore.kernel.org/all/20230706154520.11257-10-bhe@redhat.com/T/#u

Thanks