[PATCH V4 2/3] ARM64 LPC: Add missing range exception for special ISA

[zhichang.yuan]

Currently if the range property is not specified of_translate_one
returns an error. There are some special devices that work on a
range of I/O ports where it's is not correct to specify a range
property as the cpu addresses are used by special accessors.
Here we add a new exception in of_translate_one to return
the cpu address if the range property is not there. The exception
checks if the parent bus is ISA and if the special accessors are
defined.

Signed-off-by: zhichang.yuan <yuanzhichang@xxxxxxxxxxxxx>
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx>
---
 arch/arm64/include/asm/io.h |  7 +++++++
 arch/arm64/kernel/extio.c   | 24 +++++++++++++++++++++++
 drivers/of/address.c        | 47 +++++++++++++++++++++++++++++++++++++++++++--
 drivers/pci/pci.c           |  6 +++---
 include/linux/of_address.h  | 17 ++++++++++++++++
 5 files changed, 96 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index 136735d..e480199 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -175,6 +175,13 @@ static inline u64 __raw_readq(const volatile void __iomem *addr)
 #define outsl outsl
 
 DECLARE_EXTIO(l, u32)
+
+
+#define indirect_io_ison indirect_io_ison
+extern int indirect_io_ison(void);
+
+#define chk_indirect_range chk_indirect_range
+extern int chk_indirect_range(u64 taddr);
 #endif
 
 
diff --git a/arch/arm64/kernel/extio.c b/arch/arm64/kernel/extio.c
index 80cafd5..55df8dc 100644
--- a/arch/arm64/kernel/extio.c
+++ b/arch/arm64/kernel/extio.c
@@ -19,6 +19,30 @@
 
 struct extio_ops *arm64_extio_ops;
 
+/**
+ * indirect_io_ison - check whether indirectIO can work well. This function only call
+ *		before the target I/O address was obtained.
+ *
+ * Returns 1 when indirectIO can work.
+ */
+int indirect_io_ison()
+{
+	return arm64_extio_ops ? 1 : 0;
+}
+
+/**
+ * check_indirect_io - check whether the input taddr is for indirectIO.
+ * @taddr: the io address to be checked.
+ *
+ * Returns 1 when taddr is in the range; otherwise return 0.
+ */
+int chk_indirect_range(u64 taddr)
+{
+	if (arm64_extio_ops->start > taddr || arm64_extio_ops->end < taddr)
+		return 0;
+
+	return 1;
+}
 
 BUILD_EXTIO(b, u8)
 
diff --git a/drivers/of/address.c b/drivers/of/address.c
index 02b2903..0bee822 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -479,6 +479,39 @@ static int of_empty_ranges_quirk(struct device_node *np)
 	return false;
 }
 
+
+/*
+ * Check whether the current device being translating use indirectIO.
+ *
+ * return 1 if the check is past, or 0 represents fail checking.
+ */
+static int of_isa_indirect_io(struct device_node *parent,
+				struct of_bus *bus, __be32 *addr,
+				int na, u64 *presult)
+{
+	unsigned int flags;
+	unsigned int rlen;
+
+	/* whether support indirectIO */
+	if (!indirect_io_ison())
+		return 0;
+
+	if (!of_bus_isa_match(parent))
+		return 0;
+
+	flags = bus->get_flags(addr);
+	if (!(flags & IORESOURCE_IO))
+		return 0;
+
+	/* there is ranges property, apply the normal translation directly. */
+	if (of_get_property(parent, "ranges", &rlen))
+		return 0;
+
+	*presult = of_read_number(addr + 1, na - 1);
+
+	return chk_indirect_range(*presult);
+}
+
 static int of_translate_one(struct device_node *parent, struct of_bus *bus,
 			    struct of_bus *pbus, __be32 *addr,
 			    int na, int ns, int pna, const char *rprop)
@@ -532,7 +565,7 @@ static int of_translate_one(struct device_node *parent, struct of_bus *bus,
 	}
 	memcpy(addr, ranges + na, 4 * pna);
 
- finish:
+finish:
 	of_dump_addr("parent translation for:", addr, pna);
 	pr_debug("with offset: %llx\n", (unsigned long long)offset);
 
@@ -595,6 +628,15 @@ static u64 __of_translate_address(struct device_node *dev,
 			result = of_read_number(addr, na);
 			break;
 		}
+		/*
+		 * For indirectIO device which has no ranges property, get
+		 * the address from reg directly.
+		 */
+		if (of_isa_indirect_io(dev, bus, addr, na, &result)) {
+			pr_info("isa indirectIO matched(%s)..addr = 0x%llx\n",
+				of_node_full_name(dev), result);
+			break;
+		}
 
 		/* Get new parent bus and counts */
 		pbus = of_match_bus(parent);
@@ -688,8 +730,9 @@ static int __of_address_to_resource(struct device_node *dev,
 	if (taddr == OF_BAD_ADDR)
 		return -EINVAL;
 	memset(r, 0, sizeof(struct resource));
-	if (flags & IORESOURCE_IO) {
+	if (flags & IORESOURCE_IO && taddr >= PCIBIOS_MIN_IO) {
 		unsigned long port;
+
 		port = pci_address_to_pio(taddr);
 		if (port == (unsigned long)-1)
 			return -EINVAL;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ba34907..1a08511 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3263,7 +3263,7 @@ int __weak pci_register_io_range(phys_addr_t addr, resource_size_t size)
 
 #ifdef PCI_IOBASE
 	struct io_range *range;
-	resource_size_t allocated_size = 0;
+	resource_size_t allocated_size = PCIBIOS_MIN_IO;
 
 	/* check if the range hasn't been previously recorded */
 	spin_lock(&io_range_lock);
@@ -3312,7 +3312,7 @@ phys_addr_t pci_pio_to_address(unsigned long pio)
 
 #ifdef PCI_IOBASE
 	struct io_range *range;
-	resource_size_t allocated_size = 0;
+	resource_size_t allocated_size = PCIBIOS_MIN_IO;
 
 	if (pio > IO_SPACE_LIMIT)
 		return address;
@@ -3335,7 +3335,7 @@ unsigned long __weak pci_address_to_pio(phys_addr_t address)
 {
 #ifdef PCI_IOBASE
 	struct io_range *res;
-	resource_size_t offset = 0;
+	resource_size_t offset = PCIBIOS_MIN_IO;
 	unsigned long addr = -1;
 
 	spin_lock(&io_range_lock);
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 3786473..0ba7e21 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -24,6 +24,23 @@ struct of_pci_range {
 #define for_each_of_pci_range(parser, range) \
 	for (; of_pci_range_parser_one(parser, range);)
 
+
+#ifndef indirect_io_ison
+#define indirect_io_ison indirect_io_ison
+static inline int indirect_io_ison(void)
+{
+	return 0;
+}
+#endif
+
+#ifndef chk_indirect_range
+#define chk_indirect_range chk_indirect_range
+static inline int chk_indirect_range(u64 taddr)
+{
+	return 0;
+}
+#endif
+
 /* Translate a DMA address from device space to CPU space */
 extern u64 of_translate_dma_address(struct device_node *dev,
 				    const __be32 *in_addr);
-- 
1.9.1