[U-Boot] [PATCH v3] ata: ahci allow 64-bit DMA for SATA

Roman Kapl
2019-10-14T09:21:09Z

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>
---
v1 -> v2: v1 was a mistake
v2 -> v3: suppress warning on 32-bit phys addr platforms by using the
upper/lower 32 bits macros

drivers/ata/ahci.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 21a89eba5a..d10f9f0bf8 100644
--- 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)
--
2.22.0