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authorChristoph Hellwig <hch@lst.de>2020-07-14 15:18:51 +0300
committerRich Felker <dalias@libc.org>2020-08-15 05:05:15 +0300
commit13f1fc870dd747131f21ba6f20dc0d81cc5d4474 (patch)
tree4d5d6ebb959a02d29f91753442c7a28cc2ac597b /arch/sh/mm
parent3eef6b74d9fecf18b03db26584cc66928972a60b (diff)
downloadlinux-13f1fc870dd747131f21ba6f20dc0d81cc5d4474.tar.xz
sh: move the ioremap implementation out of line
Move the internal implementation details of ioremap out of line, no need to expose any of this to drivers for a slow path API. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Rich Felker <dalias@libc.org>
Diffstat (limited to 'arch/sh/mm')
-rw-r--r--arch/sh/mm/ioremap.c53
1 files changed, 53 insertions, 0 deletions
diff --git a/arch/sh/mm/ioremap.c b/arch/sh/mm/ioremap.c
index d9ec85b6bb21..69e55939e48a 100644
--- a/arch/sh/mm/ioremap.c
+++ b/arch/sh/mm/ioremap.c
@@ -27,6 +27,51 @@
#include "ioremap.h"
/*
+ * On 32-bit SH, we traditionally have the whole physical address space mapped
+ * at all times (as MIPS does), so "ioremap()" and "iounmap()" do not need to do
+ * anything but place the address in the proper segment. This is true for P1
+ * and P2 addresses, as well as some P3 ones. However, most of the P3 addresses
+ * and newer cores using extended addressing need to map through page tables, so
+ * the ioremap() implementation becomes a bit more complicated.
+ */
+#ifdef CONFIG_29BIT
+static void __iomem *
+__ioremap_29bit(phys_addr_t offset, unsigned long size, pgprot_t prot)
+{
+ phys_addr_t last_addr = offset + size - 1;
+
+ /*
+ * For P1 and P2 space this is trivial, as everything is already
+ * mapped. Uncached access for P1 addresses are done through P2.
+ * In the P3 case or for addresses outside of the 29-bit space,
+ * mapping must be done by the PMB or by using page tables.
+ */
+ if (likely(PXSEG(offset) < P3SEG && PXSEG(last_addr) < P3SEG)) {
+ u64 flags = pgprot_val(prot);
+
+ /*
+ * Anything using the legacy PTEA space attributes needs
+ * to be kicked down to page table mappings.
+ */
+ if (unlikely(flags & _PAGE_PCC_MASK))
+ return NULL;
+ if (unlikely(flags & _PAGE_CACHABLE))
+ return (void __iomem *)P1SEGADDR(offset);
+
+ return (void __iomem *)P2SEGADDR(offset);
+ }
+
+ /* P4 above the store queues are always mapped. */
+ if (unlikely(offset >= P3_ADDR_MAX))
+ return (void __iomem *)P4SEGADDR(offset);
+
+ return NULL;
+}
+#else
+#define __ioremap_29bit(offset, size, prot) NULL
+#endif /* CONFIG_29BIT */
+
+/*
* Remap an arbitrary physical address space into the kernel virtual
* address space. Needed when the kernel wants to access high addresses
* directly.
@@ -43,6 +88,14 @@ __ioremap_caller(phys_addr_t phys_addr, unsigned long size,
unsigned long offset, last_addr, addr, orig_addr;
void __iomem *mapped;
+ mapped = __ioremap_trapped(phys_addr, size);
+ if (mapped)
+ return mapped;
+
+ mapped = __ioremap_29bit(phys_addr, size, pgprot);
+ if (mapped)
+ return mapped;
+
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)