Re: [PATCH v5 RESEND 07/17] arc: mm: Convert to GENERIC_IOREMAP

Mike Rapoport
2023-05-16T06:49:36Z

On Mon, May 15, 2023 at 05:08:38PM +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 functions ioremap_prot() and iounmap() for arc's
> special operation when ioremap_prot() and iounmap().
>
> Signed-off-by: Baoquan He <bhe@redhat.com>
> Cc: Vineet Gupta <vgupta@kernel.org>
> Cc: linux-snps-arc@lists.infradead.org

Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
> arch/arc/Kconfig | 1 +
> arch/arc/include/asm/io.h | 7 +++---
> arch/arc/mm/ioremap.c | 49 ++++-----------------------------------
> 3 files changed, 8 insertions(+), 49 deletions(-)
>
> diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
> index ab6d701365bb..3a666ee0c0bc 100644
> --- a/arch/arc/Kconfig
> +++ b/arch/arc/Kconfig
> @@ -26,6 +26,7 @@ config ARC
> select GENERIC_PENDING_IRQ if SMP
> select GENERIC_SCHED_CLOCK
> select GENERIC_SMP_IDLE_THREAD
> + select GENERIC_IOREMAP
> select HAVE_ARCH_KGDB
> select HAVE_ARCH_TRACEHOOK
> select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARC_MMU_V4
> diff --git a/arch/arc/include/asm/io.h b/arch/arc/include/asm/io.h
> index 80347382a380..4fdb7350636c 100644
> --- a/arch/arc/include/asm/io.h
> +++ b/arch/arc/include/asm/io.h
> @@ -21,8 +21,9 @@
> #endif
>
> extern void __iomem *ioremap(phys_addr_t paddr, unsigned long size);
> -extern void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
> - unsigned long flags);
> +#define ioremap ioremap
> +#define ioremap_prot ioremap_prot
> +#define iounmap iounmap
> static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
> {
> return (void __iomem *)port;
> @@ -32,8 +33,6 @@ static inline void ioport_unmap(void __iomem *addr)
> {
> }
>
> -extern void iounmap(const volatile void __iomem *addr);
> -
> /*
> * io{read,write}{16,32}be() macros
> */
> diff --git a/arch/arc/mm/ioremap.c b/arch/arc/mm/ioremap.c
> index 712c2311daef..b07004d53267 100644
> --- a/arch/arc/mm/ioremap.c
> +++ b/arch/arc/mm/ioremap.c
> @@ -8,7 +8,6 @@
> #include <linux/module.h>
> #include <linux/io.h>
> #include <linux/mm.h>
> -#include <linux/slab.h>
> #include <linux/cache.h>
>
> static inline bool arc_uncached_addr_space(phys_addr_t paddr)
> @@ -25,13 +24,6 @@ static inline bool arc_uncached_addr_space(phys_addr_t paddr)
>
> void __iomem *ioremap(phys_addr_t paddr, unsigned long size)
> {
> - phys_addr_t end;
> -
> - /* Don't allow wraparound or zero size */
> - end = paddr + size - 1;
> - if (!size || (end < paddr))
> - return NULL;
> -
> /*
> * If the region is h/w uncached, MMU mapping can be elided as optim
> * The cast to u32 is fine as this region can only be inside 4GB
> @@ -51,55 +43,22 @@ EXPORT_SYMBOL(ioremap);
> * ARC hardware uncached region, this one still goes thru the MMU as caller
> * might need finer access control (R/W/X)
> */
> -void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
> +void __iomem *ioremap_prot(phys_addr_t paddr, size_t size,
> unsigned long flags)
> {
> - unsigned int off;
> - unsigned long vaddr;
> - struct vm_struct *area;
> - phys_addr_t end;
> pgprot_t prot = __pgprot(flags);
>
> - /* Don't allow wraparound, zero size */
> - end = paddr + size - 1;
> - if ((!size) || (end < paddr))
> - return NULL;
> -
> - /* An early platform driver might end up here */
> - if (!slab_is_available())
> - return NULL;
> -
> /* force uncached */
> - prot = pgprot_noncached(prot);
> -
> - /* Mappings have to be page-aligned */
> - off = paddr & ~PAGE_MASK;
> - paddr &= PAGE_MASK_PHYS;
> - size = PAGE_ALIGN(end + 1) - paddr;
> -
> - /*
> - * Ok, go for it..
> - */
> - area = get_vm_area(size, VM_IOREMAP);
> - if (!area)
> - return NULL;
> - area->phys_addr = paddr;
> - vaddr = (unsigned long)area->addr;
> - if (ioremap_page_range(vaddr, vaddr + size, paddr, prot)) {
> - vunmap((void __force *)vaddr);
> - return NULL;
> - }
> - return (void __iomem *)(off + (char __iomem *)vaddr);
> + return generic_ioremap_prot(paddr, size, pgprot_noncached(prot));
> }
> EXPORT_SYMBOL(ioremap_prot);
>
> -
> -void iounmap(const volatile void __iomem *addr)
> +void iounmap(volatile void __iomem *addr)
> {
> /* weird double cast to handle phys_addr_t > 32 bits */
> if (arc_uncached_addr_space((phys_addr_t)(u32)addr))
> return;
>
> - vfree((void *)(PAGE_MASK & (unsigned long __force)addr));
> + generic_iounmap(addr);
> }
> EXPORT_SYMBOL(iounmap);
> --
> 2.34.1
>
>

--
Sincerely yours,
Mike.