[PATCH 2/3] ntb_hw_switchtec: Added support of >=4G memory windows

[Wesley Sheng]

From: Paul Selles <paul.sel...@microchip.com>

Current Switchtec's BAR setup registers are limited to 32bits,
corresponding to the maximum MW (memory window) size is <4G.

Increase the MW sizes with the addition of the BAR Setup Extension
Register for the upper 32bits of a 64bits MW size. This increases the MW
range to between 4K and 2^63.

Reported-by: Boris Glimcher <boris.glimc...@emc.com>
Signed-off-by: Paul Selles <paul.sel...@microchip.com>
Signed-off-by: Wesley Sheng <wesley.sh...@microchip.com>
---
 drivers/ntb/hw/mscc/ntb_hw_switchtec.c | 9 +++++++--
 include/linux/switchtec.h              | 6 +++++-
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c 
b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
index 9916bc5..32850fb 100644
--- a/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
+++ b/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
@@ -264,6 +264,7 @@ static void switchtec_ntb_mw_clr_direct(struct 
switchtec_ntb *sndev, int idx)
        ctl_val &= ~NTB_CTRL_BAR_DIR_WIN_EN;
        iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
        iowrite32(0, &ctl->bar_entry[bar].win_size);
+       iowrite32(0, &ctl->bar_ext_entry[bar].win_size);
        iowrite64(sndev->self_partition, &ctl->bar_entry[bar].xlate_addr);
 }
 
@@ -286,7 +287,9 @@ static void switchtec_ntb_mw_set_direct(struct 
switchtec_ntb *sndev, int idx,
        ctl_val |= NTB_CTRL_BAR_DIR_WIN_EN;
 
        iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
-       iowrite32(xlate_pos | size, &ctl->bar_entry[bar].win_size);
+       iowrite32(xlate_pos | (size & 0xFFFFF000),
+                 &ctl->bar_entry[bar].win_size);
+       iowrite32(size >> 32, &ctl->bar_ext_entry[bar].win_size);
        iowrite64(sndev->self_partition | addr,
                  &ctl->bar_entry[bar].xlate_addr);
 }
@@ -1053,7 +1056,9 @@ static int crosslink_setup_mws(struct switchtec_ntb 
*sndev, int ntb_lut_idx,
                ctl_val |= NTB_CTRL_BAR_DIR_WIN_EN;
 
                iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
-               iowrite32(xlate_pos | size, &ctl->bar_entry[bar].win_size);
+               iowrite32(xlate_pos | (size & 0xFFFFF000),
+                         &ctl->bar_entry[bar].win_size);
+               iowrite32(size >> 32, &ctl->bar_ext_entry[bar].win_size);
                iowrite64(sndev->peer_partition | addr,
                          &ctl->bar_entry[bar].xlate_addr);
        }
diff --git a/include/linux/switchtec.h b/include/linux/switchtec.h
index eee0412..1e6e333 100644
--- a/include/linux/switchtec.h
+++ b/include/linux/switchtec.h
@@ -248,7 +248,11 @@ struct ntb_ctrl_regs {
                u32 win_size;
                u64 xlate_addr;
        } bar_entry[6];
-       u32 reserved2[216];
+       struct {
+               u32 win_size;
+               u32 reserved[3];
+       } bar_ext_entry[6];
+       u32 reserved2[192];
        u32 req_id_table[256];
        u32 reserved3[512];
        u64 lut_entry[512];
-- 
2.7.4