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From:   Baoquan He <bhe@redhat.com>
To:     linux-kernel@vger.kernel.org
Cc:     linux-mm@kvack.org, akpm@linux-foundation.org, hch@infradead.org,
        agordeev@linux.ibm.com, wangkefeng.wang@huawei.com,
        linux-arm-kernel@lists.infradead.org, Baoquan He <bhe@redhat.com>,
        "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
        Helge Deller <deller@gmx.de>, linux-parisc@vger.kernel.org
Subject: [PATCH v2 08/11] parisc: mm: Convert to GENERIC_IOREMAP
Date:   Sat, 20 Aug 2022 08:31:22 +0800
Message-Id: <20220820003125.353570-9-bhe@redhat.com>
In-Reply-To: <20220820003125.353570-1-bhe@redhat.com>
References: <20220820003125.353570-1-bhe@redhat.com>
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Add hook arch_ioremap() for parisc's special operation when ioremap(),
then ioremap_[wc|uc]() are converted to use ioremap_prot() from
GENERIC_IOREMAP.

Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
---
 arch/parisc/Kconfig          |  1 +
 arch/parisc/include/asm/io.h | 16 ++++++---
 arch/parisc/mm/ioremap.c     | 65 ++++--------------------------------
 3 files changed, 18 insertions(+), 64 deletions(-)

diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 7f059cd1196a..5fed465c9b83 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 42ffb60a6ea9..614e21d9749f 100644
--- a/arch/parisc/include/asm/io.h
+++ b/arch/parisc/include/asm/io.h
@@ -123,13 +123,19 @@ static inline void gsc_writeq(unsigned long long val, unsigned long addr)
 }
 
 /*
- * The standard PCI ioremap interfaces
+ * I/O memory mapping functions.
  */
-void __iomem *ioremap(unsigned long offset, unsigned long size);
-#define ioremap_wc			ioremap
-#define ioremap_uc			ioremap
+void __iomem *
+arch_ioremap(phys_addr_t *paddr, size_t size, unsigned long prot);
+#define arch_ioremap arch_ioremap
 
-extern void iounmap(const volatile void __iomem *addr);
+#define _PAGE_IOREMAP (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | \
+		       _PAGE_ACCESSED | _PAGE_NO_CACHE)
+
+#define ioremap_wc(addr, size)  \
+	ioremap_prot((addr), (size), _PAGE_IOREMAP)
+#define ioremap_uc(addr, size)  \
+	ioremap_prot((addr), (size), _PAGE_IOREMAP)
 
 static inline unsigned char __raw_readb(const volatile void __iomem *addr)
 {
diff --git a/arch/parisc/mm/ioremap.c b/arch/parisc/mm/ioremap.c
index 345ff0b66499..28884757fad0 100644
--- a/arch/parisc/mm/ioremap.c
+++ b/arch/parisc/mm/ioremap.c
@@ -13,38 +13,19 @@
 #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 *
+arch_ioremap(phys_addr_t *paddr, size_t size, unsigned long *prot_val)
 {
-	void __iomem *addr;
-	struct vm_struct *area;
-	unsigned long offset, last_addr;
-	pgprot_t pgprot;
+	phys_addr_t phys_addr = *paddr;
 
 #ifdef CONFIG_EISA
 	unsigned long end = phys_addr + size - 1;
 	/* Support EISA addresses */
 	if ((phys_addr >= 0x00080000 && end < 0x000fffff) ||
 	    (phys_addr >= 0x00500000 && end < 0x03bfffff))
-		phys_addr |= F_EXTEND(0xfc000000);
+		*paddr = 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..
 	 */
@@ -58,43 +39,9 @@ void __iomem *ioremap(unsigned long phys_addr, unsigned long size)
 		for (page = virt_to_page(t_addr); 
 		     page <= virt_to_page(t_end); page++) {
 			if(!PageReserved(page))
-				return NULL;
+				return IOMEM_ERR_PTR(-EINVAL);
 		}
 	}
 
-	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 NULL;
 }
-EXPORT_SYMBOL(iounmap);
-- 
2.34.1