Re: [PATCH v2 07/11] openrisc: mm: Convert to GENERIC_IOREMAP

Stafford Horne
2022-08-29T06:32:38Z

On Sat, Aug 20, 2022 at 08:31:21AM +0800, Baoquan He wrote:
> Add hooks arch_ioremap() and arch_iounmap() for operisc's special
> operation when ioremap() and iounmap.
>
> Signed-off-by: Baoquan He <bhe@redhat.com>
> Cc: Jonas Bonn <jonas@southpole.se>
> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
> Cc: Stafford Horne <shorne@gmail.com>
> Cc: openrisc@lists.librecores.org
> ---
> arch/openrisc/Kconfig | 1 +
> arch/openrisc/include/asm/io.h | 16 ++++++++---
> arch/openrisc/mm/ioremap.c | 51 +++++++++++-----------------------
> 3 files changed, 29 insertions(+), 39 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..9db67938bfc4 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/pgtable.h>
> +#include <asm/pgalloc.h>

This seems to cause a compilation issue when building virt_defconig:

CC kernel/irq/generic-chip.o
In file included from ./include/asm-generic/pgtable-nopud.h:7,
from ./include/asm-generic/pgtable-nopmd.h:7,
from ./arch/openrisc/include/asm/pgtable.h:24,
from ./arch/openrisc/include/asm/io.h:18,
from ./include/linux/io.h:13,
from kernel/irq/generic-chip.c:7:
./include/asm-generic/pgtable-nop4d.h:9:18: error: unknown type name 'pgd_t'
9 | typedef struct { pgd_t pgd; } p4d_t;
| ^~~~~

It works if we swap the order arround:

+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>

Otherwise we need to add an asm/page.h include to asm/pgtable.h (which is more
correct) but means you would touch more files.

> /*
> * PCI: We do not use IO ports in OpenRISC
> @@ -27,11 +29,17 @@
> #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.
> + */
> +void __iomem *
> +arch_ioremap(phys_addr_t *paddr, size_t size, unsigned long *prot_val);
> +#define arch_ioremap arch_ioremap
> +
> +int arch_iounmap(void __iomem *addr);
> +#define arch_iounmap arch_iounmap
>
> -#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 8ec0dafecf25..bc41660e1fb0 100644
> --- a/arch/openrisc/mm/ioremap.c
> +++ b/arch/openrisc/mm/ioremap.c
> @@ -24,26 +24,18 @@ extern int mem_init_done;
>
> static unsigned int fixmaps_used __initdata;
>
> -/*
> - * 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)
> +void __iomem *
> +arch_ioremap(phys_addr_t *paddr, size_t size, unsigned long *prot_val)
> {
> phys_addr_t p;
> unsigned long v;
> - unsigned long offset, last_addr;
> - struct vm_struct *area = NULL;
> + unsigned long offset, last_addr, addr = *paddr;
> + int ret = -EINVAL;
>
> /* Don't allow wraparound or zero size */
> last_addr = addr + size - 1;
> if (!size || last_addr < addr)
> - return NULL;
> + return IOMEM_ERR_PTR(ret);
>
> /*
> * Mappings have to be page-aligned
> @@ -52,32 +44,24 @@ void __iomem *__ref ioremap(phys_addr_t addr, unsigned long size)
> p = addr & PAGE_MASK;
> size = PAGE_ALIGN(last_addr + 1) - p;
>
> - if (likely(mem_init_done)) {
> - area = get_vm_area(size, VM_IOREMAP);
> - if (!area)
> - return NULL;
> - v = (unsigned long)area->addr;
> - } else {
> + if (unlikely(!mem_init_done)) {
> if ((fixmaps_used + (size >> PAGE_SHIFT)) > FIX_N_IOREMAPS)
> - return NULL;
> + return IOMEM_ERR_PTR(ret);
> v = fix_to_virt(FIX_IOREMAP_BEGIN + fixmaps_used);
> fixmaps_used += (size >> PAGE_SHIFT);
> - }
>
> - if (ioremap_page_range(v, v + size, p,
> - __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_CI))) {
> - if (likely(mem_init_done))
> - vfree(area->addr);
> - else
> + if (ioremap_page_range(v, v + size, p, __pgprot(*prot_val))) {
> fixmaps_used -= (size >> PAGE_SHIFT);
> - return NULL;
> + return IOMEM_ERR_PTR(ret);
> + }
> +
> + return (void __iomem *)(offset + (char *)v);
> }
>
> - return (void __iomem *)(offset + (char *)v);
> + return NULL;
> }
> -EXPORT_SYMBOL(ioremap);
>
> -void iounmap(volatile void __iomem *addr)
> +int arch_iounmap(void __iomem *addr)
> {
> /* If the page is from the fixmap pool then we just clear out
> * the fixmap mapping.
> @@ -97,13 +81,10 @@ void iounmap(volatile void __iomem *addr)
> * ii) invalid accesses to the freed areas aren't made
> */
> flush_tlb_all();
> - return;
> + return -EINVAL;
> }
> -
> - return vfree((void *)(PAGE_MASK & (unsigned long)addr));
> + return 0;
> }
> -EXPORT_SYMBOL(iounmap);
> -
> /**
> * OK, this one's a bit tricky... ioremap can get called before memory is
> * initialized (early serial console does this) and will want to alloc a page
> --
> 2.34.1

Other than that compiler issue, I fixed it and test booted this and it works
well.

Acked-by: Stafford Horne <shorne@gmail.com>