Re: [PATCH v5 RESEND 09/17] openrisc: mm: Convert to GENERIC_IOREMAP

Mike Rapoport
2023-05-16T06:50:40Z

Hi,

On Mon, May 15, 2023 at 05:08:40PM +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.
>
> Here, add wrapper function iounmap() for openrisc's special operation
> when iounmap().
>
> Signed-off-by: Baoquan He <bhe@redhat.com>
> 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 | 46 +---------------------------------
> 3 files changed, 9 insertions(+), 49 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..e640960c26c2 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 +29,12 @@
> #define PIO_OFFSET 0
> #define PIO_MASK 0
>
> -#define ioremap ioremap
> -void __iomem *ioremap(phys_addr_t offset, unsigned long size);
> -
> +/*
> + * I/O memory mapping functions.
> + */
> #define iounmap iounmap
> -extern void iounmap(volatile void __iomem *addr);
> +
> +#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 90b59bc53c8c..9f9941df7d4c 100644
> --- a/arch/openrisc/mm/ioremap.c
> +++ b/arch/openrisc/mm/ioremap.c
> @@ -22,49 +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)
> {
> /* If the page is from the fixmap pool then we just clear out

The page cannot be from fixmap pool since we removed fixmap support from
ioremap in an earlier patch.
I believe that patch should also remove special casing of fixmap in
iounmap() and then openrisc does not need to override any of ioremap
methods.

> @@ -88,9 +45,8 @@ void iounmap(volatile void __iomem *addr)
> return;
> }
>
> - return vfree((void *)(PAGE_MASK & (unsigned long)addr));
> + generic_iounmap(addr);
> }
> -EXPORT_SYMBOL(iounmap);
>
> /**
> * OK, this one's a bit tricky... ioremap can get called before memory is
> --
> 2.34.1
>
>

--
Sincerely yours,
Mike.