diff options
Diffstat (limited to 'arch/s390/include/asm/pci_io.h')
| -rw-r--r-- | arch/s390/include/asm/pci_io.h | 32 |
1 files changed, 18 insertions, 14 deletions
diff --git a/arch/s390/include/asm/pci_io.h b/arch/s390/include/asm/pci_io.h index 287bb88f7698..2686bee800e3 100644 --- a/arch/s390/include/asm/pci_io.h +++ b/arch/s390/include/asm/pci_io.h @@ -11,6 +11,8 @@ /* I/O size constraints */ #define ZPCI_MAX_READ_SIZE 8 #define ZPCI_MAX_WRITE_SIZE 128 +#define ZPCI_BOUNDARY_SIZE (1 << 12) +#define ZPCI_BOUNDARY_MASK (ZPCI_BOUNDARY_SIZE - 1) /* I/O Map */ #define ZPCI_IOMAP_SHIFT 48 @@ -125,16 +127,18 @@ out: int zpci_write_block(volatile void __iomem *dst, const void *src, unsigned long len); -static inline u8 zpci_get_max_write_size(u64 src, u64 dst, int len, int max) +static inline int zpci_get_max_io_size(u64 src, u64 dst, int len, int max) { - int count = len > max ? max : len, size = 1; + int offset = dst & ZPCI_BOUNDARY_MASK; + int size; - while (!(src & 0x1) && !(dst & 0x1) && ((size << 1) <= count)) { - dst = dst >> 1; - src = src >> 1; - size = size << 1; - } - return size; + size = min3(len, ZPCI_BOUNDARY_SIZE - offset, max); + if (IS_ALIGNED(src, 8) && IS_ALIGNED(dst, 8) && IS_ALIGNED(size, 8)) + return size; + + if (size >= 8) + return 8; + return rounddown_pow_of_two(size); } static inline int zpci_memcpy_fromio(void *dst, @@ -144,9 +148,9 @@ static inline int zpci_memcpy_fromio(void *dst, int size, rc = 0; while (n > 0) { - size = zpci_get_max_write_size((u64 __force) src, - (u64) dst, n, - ZPCI_MAX_READ_SIZE); + size = zpci_get_max_io_size((u64 __force) src, + (u64) dst, n, + ZPCI_MAX_READ_SIZE); rc = zpci_read_single(dst, src, size); if (rc) break; @@ -166,9 +170,9 @@ static inline int zpci_memcpy_toio(volatile void __iomem *dst, return -EINVAL; while (n > 0) { - size = zpci_get_max_write_size((u64 __force) dst, - (u64) src, n, - ZPCI_MAX_WRITE_SIZE); + size = zpci_get_max_io_size((u64 __force) dst, + (u64) src, n, + ZPCI_MAX_WRITE_SIZE); if (size > 8) /* main path */ rc = zpci_write_block(dst, src, size); else |