libpayload: xhci: Make XHCI stack usable on ARM

This patch updates the libpayload XHCI stack to run on ARM CPUs (tested
with the DWC3 controller on an Exynos5420). Firstly, it adds support for
64-byte Slot/Endpoint Context sizes. Since the existing context handling
code represented the whole device context as a C struct (whose size has
to be known at compile time), it was necessary to refactor the input and
device context structures to consist of pointers to the actual contexts
instead.

Secondly, it moves all data structures that the xHC accesses through DMA
to cache-coherent memory. With a similar rationale as in the ARM patches
for EHCI, using explicit cache maintenance functions to correctly handle
the actual transfer buffers in all cases is presumably impossible.
Instead this patch also chooses to create a DMA bounce buffer in the
XHCI stack where transfer buffers which are not already cache-coherent
will be copied to/from.

Change-Id: I14e82fffb43b4d52d687b65415f2e33920e088de
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/169453
Reviewed-by: Stefan Reinauer <reinauer@google.com>
(cherry picked from commit 1fa9964063cce6cbd87ba68334806dde8aa2354c)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6643
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

1 files changed, 32 insertions, 25 deletions

diff --git a/payloads/libpayload/drivers/usb/xhci_private.h b/payloads/libpayload/drivers/usb/xhci_private.h
index c7048f494e..a851d8ec57 100644
--- a/payloads/libpayload/drivers/usb/xhci_private.h
+++ b/payloads/libpayload/drivers/usb/xhci_private.h
@@ -198,13 +198,13 @@ typedef transfer_ring_t command_ring_t;
 #define SC_STATE_START		27
 #define SC_STATE_LEN		8
 #define SC_MASK(tok)		MASK(SC_##tok##_START, SC_##tok##_LEN)
-#define SC_GET(tok, sc)		(((sc).SC_##tok##_FIELD & SC_MASK(tok)) \
+#define SC_GET(tok, sc)		(((sc)->SC_##tok##_FIELD & SC_MASK(tok)) \
 				 >> SC_##tok##_START)
-#define SC_SET(tok, sc, to)	(sc).SC_##tok##_FIELD = \
-				(((sc).SC_##tok##_FIELD & ~SC_MASK(tok)) | \
+#define SC_SET(tok, sc, to)	(sc)->SC_##tok##_FIELD = \
+				(((sc)->SC_##tok##_FIELD & ~SC_MASK(tok)) | \
 				 (((to) << SC_##tok##_START) & SC_MASK(tok)))
 #define SC_DUMP(tok, sc)	usb_debug(" "#tok"\t0x%04"PRIx32"\n", SC_GET(tok, sc))
-typedef struct slotctx {
+typedef volatile struct slotctx {
 	u32 f1;
 	u32 f2;
 	u32 f3;
@@ -240,15 +240,15 @@ typedef struct slotctx {
 #define EC_MXESIT_START		16
 #define EC_MXESIT_LEN		16
 #define EC_MASK(tok)		MASK(EC_##tok##_START, EC_##tok##_LEN)
-#define EC_GET(tok, ec)		(((ec).EC_##tok##_FIELD & EC_MASK(tok)) \
+#define EC_GET(tok, ec)		(((ec)->EC_##tok##_FIELD & EC_MASK(tok)) \
 				 >> EC_##tok##_START)
-#define EC_SET(tok, ec, to)	(ec).EC_##tok##_FIELD = \
-				(((ec).EC_##tok##_FIELD & ~EC_MASK(tok)) | \
+#define EC_SET(tok, ec, to)	(ec)->EC_##tok##_FIELD = \
+				(((ec)->EC_##tok##_FIELD & ~EC_MASK(tok)) | \
 				 (((to) << EC_##tok##_START) & EC_MASK(tok)))
 #define EC_DUMP(tok, ec)	usb_debug(" "#tok"\t0x%04"PRIx32"\n", EC_GET(tok, ec))
 enum { EP_ISOC_OUT = 1, EP_BULK_OUT = 2, EP_INTR_OUT = 3,
 	EP_CONTROL = 4, EP_ISOC_IN = 5, EP_BULK_IN = 6, EP_INTR_IN = 7 };
-typedef struct epctx {
+typedef volatile struct epctx {
 	u32 f1;
 	u32 f2;
 	u32 tr_dq_low;
@@ -257,23 +257,30 @@ typedef struct epctx {
 	u32 rsvd[3];
 } epctx_t;
 
+#define NUM_EPS 32
+#define CTXSIZE(xhci) ((xhci)->capreg->csz ? 64 : 32)
+
 typedef union devctx {
+	/* set of pointers, so we can dynamically adjust Slot/EP context size */
 	struct {
-		slotctx_t slot;
-		epctx_t ep0;
-		epctx_t eps1_30[30];
+		union {
+			slotctx_t *slot;
+			void *raw;	/* Pointer to the whole dev context. */
+		};
+		epctx_t *ep0;
+		epctx_t *eps1_30[NUM_EPS - 2];
 	};
-	epctx_t eps[32]; /* At index 0 it's actually the slotctx,
-			    we have it like that so we can use
-			    the ep_id directly as index. */
+	epctx_t *ep[NUM_EPS];	/* At index 0 it's actually the slotctx,
+					we have it like that so we can use
+					the ep_id directly as index. */
 } devctx_t;
 
 typedef struct inputctx {
-	struct {
-		u32 drop;
-		u32 add;
-		u32 reserved[6];
-	} control;
+	union {		    /* The drop flags are located at the start of the */
+		u32 *drop;  /* structure, so a pointer to them is equivalent */
+		void *raw;  /* to a pointer to the whole (raw) input context. */
+	};
+	u32 *add;
 	devctx_t dev;
 } inputctx_t;
 
@@ -286,14 +293,10 @@ typedef struct intrq {
 } intrq_t;
 
 typedef struct devinfo {
-	volatile devctx_t devctx;
-	transfer_ring_t *transfer_rings[32];
+	devctx_t ctx;
+	transfer_ring_t *transfer_rings[NUM_EPS];
 	intrq_t *interrupt_queues[32];
 } devinfo_t;
-#define DEVINFO_FROM_XHCI(xhci, slot_id) \
-	(((xhci)->dcbaa[slot_id]) \
-	 ? phys_to_virt((xhci)->dcbaa[slot_id] - offsetof(devinfo_t, devctx)) \
-	 : NULL)
 
 typedef struct erst_entry {
 	u32 seg_base_lo;
@@ -459,6 +462,10 @@ typedef struct xhci {
 	usbdev_t *roothub;
 
 	u8 max_slots_en;
+	devinfo_t *dev;	/* array of devinfos by slot_id */
+
+#define DMA_SIZE (64 * 1024)
+	void *dma_buffer;
 } xhci_t;
 
 #define XHCI_INST(controller) ((xhci_t*)((controller)->instance))