ata: ahci allow 64-bit DMA for SATA

Allow 64-bit DMA on AHCI. If not supported by the host controller, at
least print a message and fail.

Signed-off-by: Roman Kapl <rka@sysgo.com>

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 21a89eba5af5b1dab0fa766e3c961b1d7754c238..d10f9f0bf8c1a36a787296a37f556daebbc02a1e 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -50,6 +50,8 @@ struct ahci_uc_priv *probe_ent = NULL;
 #define WAIT_MS_FLUSH  5000
 #define WAIT_MS_LINKUP 200
 
+#define AHCI_CAP_S64A BIT(31)
+
 __weak void __iomem *ahci_port_base(void __iomem *base, u32 port)
 {
        return base + 0x100 + (port * 0x80);
@@ -503,9 +505,15 @@ static int ahci_fill_sg(struct ahci_uc_priv *uc_priv, u8 port,
        }
 
        for (i = 0; i < sg_count; i++) {
-               ahci_sg->addr =
-                   cpu_to_le32((unsigned long) buf + i * MAX_DATA_BYTE_COUNT);
-               ahci_sg->addr_hi = 0;
+               /* We assume virt=phys */
+               phys_addr_t pa = (unsigned long)buf + i * MAX_DATA_BYTE_COUNT;
+
+               ahci_sg->addr = cpu_to_le32(lower_32_bits(pa));
+               ahci_sg->addr_hi = cpu_to_le32(upper_32_bits(pa));
+               if (ahci_sg->addr_hi && !(uc_priv->cap & AHCI_CAP_S64A)) {
+                       printf("Error: DMA address too high\n");
+                       return -1;
+               }
                ahci_sg->flags_size = cpu_to_le32(0x3fffff &
                                          (buf_len < MAX_DATA_BYTE_COUNT
                                           ? (buf_len - 1)