s390/pci: base support

Add PCI support for s390, (only 64 bit mode is supported by hardware):
- PCI facility tests
- PCI instructions: pcilg, pcistg, pcistb, stpcifc, mpcifc, rpcit
- map readb/w/l/q and writeb/w/l/q to pcilg and pcistg instructions
- pci_iomap implementation
- memcpy_fromio/toio
- pci_root_ops using special pcilg/pcistg
- device, bus and domain allocation

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 194 insertions, 0 deletions

diff --git a/arch/s390/include/asm/pci_io.h b/arch/s390/include/asm/pci_io.h
new file mode 100644
index 000000000000..5fd81f31d6c7
--- /dev/null
+++ b/arch/s390/include/asm/pci_io.h
@@ -0,0 +1,194 @@
+#ifndef _ASM_S390_PCI_IO_H
+#define _ASM_S390_PCI_IO_H
+
+#ifdef CONFIG_PCI
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <asm/pci_insn.h>
+
+/* I/O Map */
+#define ZPCI_IOMAP_MAX_ENTRIES		0x7fff
+#define ZPCI_IOMAP_ADDR_BASE		0x8000000000000000ULL
+#define ZPCI_IOMAP_ADDR_IDX_MASK	0x7fff000000000000ULL
+#define ZPCI_IOMAP_ADDR_OFF_MASK	0x0000ffffffffffffULL
+
+struct zpci_iomap_entry {
+	u32 fh;
+	u8 bar;
+};
+
+extern struct zpci_iomap_entry *zpci_iomap_start;
+
+#define ZPCI_IDX(addr)								\
+	(((__force u64) addr & ZPCI_IOMAP_ADDR_IDX_MASK) >> 48)
+#define ZPCI_OFFSET(addr)							\
+	((__force u64) addr & ZPCI_IOMAP_ADDR_OFF_MASK)
+
+#define ZPCI_CREATE_REQ(handle, space, len)					\
+	((u64) handle << 32 | space << 16 | len)
+
+#define zpci_read(LENGTH, RETTYPE)						\
+static inline RETTYPE zpci_read_##RETTYPE(const volatile void __iomem *addr)	\
+{										\
+	struct zpci_iomap_entry *entry = &zpci_iomap_start[ZPCI_IDX(addr)];	\
+	u64 req = ZPCI_CREATE_REQ(entry->fh, entry->bar, LENGTH);		\
+	u64 data;								\
+	int rc;									\
+										\
+	rc = pcilg_instr(&data, req, ZPCI_OFFSET(addr));			\
+	if (rc)									\
+		data = -1ULL;							\
+	return (RETTYPE) data;							\
+}
+
+#define zpci_write(LENGTH, VALTYPE)						\
+static inline void zpci_write_##VALTYPE(VALTYPE val,				\
+					const volatile void __iomem *addr)	\
+{										\
+	struct zpci_iomap_entry *entry = &zpci_iomap_start[ZPCI_IDX(addr)];	\
+	u64 req = ZPCI_CREATE_REQ(entry->fh, entry->bar, LENGTH);		\
+	u64 data = (VALTYPE) val;						\
+										\
+	pcistg_instr(data, req, ZPCI_OFFSET(addr));				\
+}
+
+zpci_read(8, u64)
+zpci_read(4, u32)
+zpci_read(2, u16)
+zpci_read(1, u8)
+zpci_write(8, u64)
+zpci_write(4, u32)
+zpci_write(2, u16)
+zpci_write(1, u8)
+
+static inline int zpci_write_single(u64 req, const u64 *data, u64 offset, u8 len)
+{
+	u64 val;
+
+	switch (len) {
+	case 1:
+		val = (u64) *((u8 *) data);
+		break;
+	case 2:
+		val = (u64) *((u16 *) data);
+		break;
+	case 4:
+		val = (u64) *((u32 *) data);
+		break;
+	case 8:
+		val = (u64) *((u64 *) data);
+		break;
+	default:
+		val = 0;		/* let FW report error */
+		break;
+	}
+	return pcistg_instr(val, req, offset);
+}
+
+static inline int zpci_read_single(u64 req, u64 *dst, u64 offset, u8 len)
+{
+	u64 data;
+	u8 cc;
+
+	cc = pcilg_instr(&data,	 req, offset);
+	switch (len) {
+	case 1:
+		*((u8 *) dst) = (u8) data;
+		break;
+	case 2:
+		*((u16 *) dst) = (u16) data;
+		break;
+	case 4:
+		*((u32 *) dst) = (u32) data;
+		break;
+	case 8:
+		*((u64 *) dst) = (u64) data;
+		break;
+	}
+	return cc;
+}
+
+static inline int zpci_write_block(u64 req, const u64 *data, u64 offset)
+{
+	return pcistb_instr(data, req, offset);
+}
+
+static inline u8 zpci_get_max_write_size(u64 src, u64 dst, int len, int max)
+{
+	int count = len > max ? max : len, size = 1;
+
+	while (!(src & 0x1) && !(dst & 0x1) && ((size << 1) <= count)) {
+		dst = dst >> 1;
+		src = src >> 1;
+		size = size << 1;
+	}
+	return size;
+}
+
+static inline int zpci_memcpy_fromio(void *dst,
+				     const volatile void __iomem *src,
+				     unsigned long n)
+{
+	struct zpci_iomap_entry *entry = &zpci_iomap_start[ZPCI_IDX(src)];
+	u64 req, offset = ZPCI_OFFSET(src);
+	int size, rc = 0;
+
+	while (n > 0) {
+		size = zpci_get_max_write_size((u64) src, (u64) dst, n, 8);
+		req = ZPCI_CREATE_REQ(entry->fh, entry->bar, size);
+		rc = zpci_read_single(req, dst, offset, size);
+		if (rc)
+			break;
+		offset += size;
+		dst += size;
+		n -= size;
+	}
+	return rc;
+}
+
+static inline int zpci_memcpy_toio(volatile void __iomem *dst,
+				   const void *src, unsigned long n)
+{
+	struct zpci_iomap_entry *entry = &zpci_iomap_start[ZPCI_IDX(dst)];
+	u64 req, offset = ZPCI_OFFSET(dst);
+	int size, rc = 0;
+
+	if (!src)
+		return -EINVAL;
+
+	while (n > 0) {
+		size = zpci_get_max_write_size((u64) dst, (u64) src, n, 128);
+		req = ZPCI_CREATE_REQ(entry->fh, entry->bar, size);
+
+		if (size > 8) /* main path */
+			rc = zpci_write_block(req, src, offset);
+		else
+			rc = zpci_write_single(req, src, offset, size);
+		if (rc)
+			break;
+		offset += size;
+		src += size;
+		n -= size;
+	}
+	return rc;
+}
+
+static inline int zpci_memset_io(volatile void __iomem *dst,
+				 unsigned char val, size_t count)
+{
+	u8 *src = kmalloc(count, GFP_KERNEL);
+	int rc;
+
+	if (src == NULL)
+		return -ENOMEM;
+	memset(src, val, count);
+
+	rc = zpci_memcpy_toio(dst, src, count);
+	kfree(src);
+	return rc;
+}
+
+#endif /* CONFIG_PCI */
+
+#endif /* _ASM_S390_PCI_IO_H */