Re: [PATCH v6 14/19] parisc: mm: Convert to GENERIC_IOREMAP

Helge Deller
2023-06-19T05:48:12Z

On 6/9/23 09:55, 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 ioremap_prot() for parisc's special operation
> when iounmap().
>
> Signed-off-by: Baoquan He <bhe@redhat.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
> Cc: Helge Deller <deller@gmx.de>
> Cc: linux-parisc@vger.kernel.org

Acked-by: Helge Deller <deller@gmx.de> # parisc

Thanks!
Helge

> ---
> v5->v6:
> Remove the stale paragraph related to ARCH_HAS_IOREMAP_WC adding in
> log - Mike
>
> arch/parisc/Kconfig | 1 +
> arch/parisc/include/asm/io.h | 15 ++++++---
> arch/parisc/mm/ioremap.c | 62 +++---------------------------------
> 3 files changed, 15 insertions(+), 63 deletions(-)
>
> diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
> index 967bde65dd0e..315cc42b1a2c 100644
> --- a/arch/parisc/Kconfig
> +++ b/arch/parisc/Kconfig
> @@ -36,6 +36,7 @@ config PARISC
> select GENERIC_ATOMIC64 if !64BIT
> select GENERIC_IRQ_PROBE
> select GENERIC_PCI_IOMAP
> + select GENERIC_IOREMAP
> select ARCH_HAVE_NMI_SAFE_CMPXCHG
> select GENERIC_SMP_IDLE_THREAD
> select GENERIC_ARCH_TOPOLOGY if SMP
> diff --git a/arch/parisc/include/asm/io.h b/arch/parisc/include/asm/io.h
> index c05e781be2f5..366537042465 100644
> --- a/arch/parisc/include/asm/io.h
> +++ b/arch/parisc/include/asm/io.h
> @@ -125,12 +125,17 @@ static inline void gsc_writeq(unsigned long long val, unsigned long addr)
> /*
> * The standard PCI ioremap interfaces
> */
> -void __iomem *ioremap(unsigned long offset, unsigned long size);
> -#define ioremap_wc ioremap
> -#define ioremap_uc ioremap
> -#define pci_iounmap pci_iounmap
> +#define ioremap_prot ioremap_prot
> +
> +#define _PAGE_IOREMAP (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | \
> + _PAGE_ACCESSED | _PAGE_NO_CACHE)
>
> -extern void iounmap(const volatile void __iomem *addr);
> +#define ioremap_wc(addr, size) \
> + ioremap_prot((addr), (size), _PAGE_IOREMAP)
> +#define ioremap_uc(addr, size) \
> + ioremap_prot((addr), (size), _PAGE_IOREMAP)
> +
> +#define pci_iounmap pci_iounmap
>
> void memset_io(volatile void __iomem *addr, unsigned char val, int count);
> void memcpy_fromio(void *dst, const volatile void __iomem *src, int count);
> diff --git a/arch/parisc/mm/ioremap.c b/arch/parisc/mm/ioremap.c
> index 345ff0b66499..fd996472dfe7 100644
> --- a/arch/parisc/mm/ioremap.c
> +++ b/arch/parisc/mm/ioremap.c
> @@ -13,25 +13,9 @@
> #include <linux/io.h>
> #include <linux/mm.h>
>
> -/*
> - * Generic mapping function (not visible outside):
> - */
> -
> -/*
> - * Remap an arbitrary physical address space into the kernel virtual
> - * address space.
> - *
> - * 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 *ioremap(unsigned long phys_addr, unsigned long size)
> +void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
> + unsigned long prot)
> {
> - void __iomem *addr;
> - struct vm_struct *area;
> - unsigned long offset, last_addr;
> - pgprot_t pgprot;
> -
> #ifdef CONFIG_EISA
> unsigned long end = phys_addr + size - 1;
> /* Support EISA addresses */
> @@ -40,11 +24,6 @@ void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
> phys_addr |= F_EXTEND(0xfc000000);
> #endif
>
> - /* Don't allow wraparound or zero size */
> - last_addr = phys_addr + size - 1;
> - if (!size || last_addr < phys_addr)
> - return NULL;
> -
> /*
> * Don't allow anybody to remap normal RAM that we're using..
> */
> @@ -62,39 +41,6 @@ void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
> }
> }
>
> - pgprot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY |
> - _PAGE_ACCESSED | _PAGE_NO_CACHE);
> -
> - /*
> - * Mappings have to be page-aligned
> - */
> - offset = phys_addr & ~PAGE_MASK;
> - phys_addr &= PAGE_MASK;
> - size = PAGE_ALIGN(last_addr + 1) - phys_addr;
> -
> - /*
> - * Ok, go for it..
> - */
> - area = get_vm_area(size, VM_IOREMAP);
> - if (!area)
> - return NULL;
> -
> - addr = (void __iomem *) area->addr;
> - if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
> - phys_addr, pgprot)) {
> - vunmap(addr);
> - return NULL;
> - }
> -
> - return (void __iomem *) (offset + (char __iomem *)addr);
> -}
> -EXPORT_SYMBOL(ioremap);
> -
> -void iounmap(const volatile void __iomem *io_addr)
> -{
> - unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
> -
> - if (is_vmalloc_addr((void *)addr))
> - vunmap((void *)addr);
> + return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
> }
> -EXPORT_SYMBOL(iounmap);
> +EXPORT_SYMBOL(ioremap_prot);