[PATCH v2 04/11] arc: mm: Convert to GENERIC_IOREMAP

Baoquan He
2022-08-20T00:31:57Z

Add hooks arch_ioremap() and arch_iounmap() for arc's special
operation when ioremap_prot() and iounmap(). Meanwhile define and
implement arc's own ioremap() because arc has some special handling
in ioremap() than standard ioremap().

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: linux-snps-arc@lists.infradead.org
---
arch/arc/Kconfig | 1 +
arch/arc/include/asm/io.h | 19 +++++++++----
arch/arc/mm/ioremap.c | 60 ++++++---------------------------------
3 files changed, 23 insertions(+), 57 deletions(-)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 9e3653253ef2..a08d2abfaf61 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 8f777d6441a5..af88a2c5550e 100644
--- a/arch/arc/include/asm/io.h
+++ b/arch/arc/include/asm/io.h
@@ -20,9 +20,20 @@
#define __iowmb() do { } while (0)
#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);
+/*
+ * 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
+
+void __iomem *ioremap(phys_addr_t paddr, unsigned long size);
+#define ioremap ioremap
+
static inline void __iomem *ioport_map(unsigned long port, unsigned int nr)
{
return (void __iomem *)port;
@@ -32,8 +43,6 @@ static inline void ioport_unmap(void __iomem *addr)
{
}

-extern void iounmap(const 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 0ee75aca6e10..72b01da31ea1 100644
--- a/arch/arc/mm/ioremap.c
+++ b/arch/arc/mm/ioremap.c
@@ -25,13 +25,6 @@ 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
@@ -44,62 +37,25 @@ void __iomem *ioremap(phys_addr_t paddr, unsigned long size)
}
EXPORT_SYMBOL(ioremap);

-/*
- * ioremap with access flags
- * Cache semantics wise it is same as ioremap - "forced" uncached.
- * However unlike vanilla ioremap which bypasses ARC MMU for addresses in
- * 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,
- unsigned long flags)
+void __iomem *
+arch_ioremap(phys_addr_t *paddr, size_t size, unsigned long *prot_val)
{
- 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;
+ return IOMEM_ERR_PTR(-EINVAL);

/* force uncached */
- prot = pgprot_noncached(prot);
+ *prot_val = pgprot_val(pgprot_noncached(__pgprot(*prot_val)));

- /* Mappings have to be page-aligned */
- off = paddr & ~PAGE_MASK;
- paddr &= PAGE_MASK_PHYS;
- size = PAGE_ALIGN(end + 1) - paddr;
+ return NULL;

- /*
- * 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);
}
-EXPORT_SYMBOL(ioremap_prot);
-

-void iounmap(const void __iomem *addr)
+int arch_iounmap(void __iomem *addr)
{
/* weird double cast to handle phys_addr_t > 32 bits */
if (arc_uncached_addr_space((phys_addr_t)(u32)addr))
- return;
+ return -EINVAL;

- vfree((void *)(PAGE_MASK & (unsigned long __force)addr));
+ return 0;
}
-EXPORT_SYMBOL(iounmap);
--
2.34.1