USB: use genalloc for USB HCs with local memory

For HCs that have local memory, replace the current DMA API usage with
a genalloc generic allocator to manage the mappings for these devices.
To help users, introduce a new HCD API, usb_hcd_setup_local_mem() that
will setup up the genalloc backing up the device local memory. It will
be used in subsequent patches.  This is in preparation for dropping
the existing "coherent" dma mem declaration APIs.  The current
implementation was relying on a short circuit in the DMA API that in
the end, was acting as an allocator for these type of devices.

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Tested-by: Fredrik Noring <noring@nocrew.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>

3 files changed, 51 insertions, 9 deletions

diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 210181fd98d2..b200b19b44fa 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -40,6 +40,7 @@
 #include <linux/dmapool.h>
 #include <linux/workqueue.h>
 #include <linux/debugfs.h>
+#include <linux/genalloc.h>
 
 #include <asm/io.h>
 #include <asm/irq.h>
@@ -505,8 +506,15 @@ static int ohci_init (struct ohci_hcd *ohci)
 	timer_setup(&ohci->io_watchdog, io_watchdog_func, 0);
 	ohci->prev_frame_no = IO_WATCHDOG_OFF;
 
-	ohci->hcca = dma_alloc_coherent (hcd->self.controller,
-			sizeof(*ohci->hcca), &ohci->hcca_dma, GFP_KERNEL);
+	if (hcd->localmem_pool)
+		ohci->hcca = gen_pool_dma_alloc(hcd->localmem_pool,
+						sizeof(*ohci->hcca),
+						&ohci->hcca_dma);
+	else
+		ohci->hcca = dma_alloc_coherent(hcd->self.controller,
+						sizeof(*ohci->hcca),
+						&ohci->hcca_dma,
+						GFP_KERNEL);
 	if (!ohci->hcca)
 		return -ENOMEM;
 
@@ -990,9 +998,14 @@ static void ohci_stop (struct usb_hcd *hcd)
 	remove_debug_files (ohci);
 	ohci_mem_cleanup (ohci);
 	if (ohci->hcca) {
-		dma_free_coherent (hcd->self.controller,
-				sizeof *ohci->hcca,
-				ohci->hcca, ohci->hcca_dma);
+		if (hcd->localmem_pool)
+			gen_pool_free(hcd->localmem_pool,
+				      (unsigned long)ohci->hcca,
+				      sizeof(*ohci->hcca));
+		else
+			dma_free_coherent(hcd->self.controller,
+					  sizeof(*ohci->hcca),
+					  ohci->hcca, ohci->hcca_dma);
 		ohci->hcca = NULL;
 		ohci->hcca_dma = 0;
 	}
diff --git a/drivers/usb/host/ohci-mem.c b/drivers/usb/host/ohci-mem.c
index 3965ac0341eb..4afe27cc7e46 100644
--- a/drivers/usb/host/ohci-mem.c
+++ b/drivers/usb/host/ohci-mem.c
@@ -36,6 +36,13 @@ static void ohci_hcd_init (struct ohci_hcd *ohci)
 
 static int ohci_mem_init (struct ohci_hcd *ohci)
 {
+	/*
+	 * HCs with local memory allocate from localmem_pool so there's
+	 * no need to create the below dma pools.
+	 */
+	if (ohci_to_hcd(ohci)->localmem_pool)
+		return 0;
+
 	ohci->td_cache = dma_pool_create ("ohci_td",
 		ohci_to_hcd(ohci)->self.controller,
 		sizeof (struct td),
@@ -84,8 +91,12 @@ td_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
 {
 	dma_addr_t	dma;
 	struct td	*td;
+	struct usb_hcd	*hcd = ohci_to_hcd(hc);
 
-	td = dma_pool_zalloc (hc->td_cache, mem_flags, &dma);
+	if (hcd->localmem_pool)
+		td = gen_pool_dma_zalloc(hcd->localmem_pool, sizeof(*td), &dma);
+	else
+		td = dma_pool_zalloc(hc->td_cache, mem_flags, &dma);
 	if (td) {
 		/* in case hc fetches it, make it look dead */
 		td->hwNextTD = cpu_to_hc32 (hc, dma);
@@ -99,6 +110,7 @@ static void
 td_free (struct ohci_hcd *hc, struct td *td)
 {
 	struct td	**prev = &hc->td_hash [TD_HASH_FUNC (td->td_dma)];
+	struct usb_hcd	*hcd = ohci_to_hcd(hc);
 
 	while (*prev && *prev != td)
 		prev = &(*prev)->td_hash;
@@ -106,7 +118,12 @@ td_free (struct ohci_hcd *hc, struct td *td)
 		*prev = td->td_hash;
 	else if ((td->hwINFO & cpu_to_hc32(hc, TD_DONE)) != 0)
 		ohci_dbg (hc, "no hash for td %p\n", td);
-	dma_pool_free (hc->td_cache, td, td->td_dma);
+
+	if (hcd->localmem_pool)
+		gen_pool_free(hcd->localmem_pool, (unsigned long)td,
+			      sizeof(*td));
+	else
+		dma_pool_free(hc->td_cache, td, td->td_dma);
 }
 
 /*-------------------------------------------------------------------------*/
@@ -117,8 +134,12 @@ ed_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
 {
 	dma_addr_t	dma;
 	struct ed	*ed;
+	struct usb_hcd	*hcd = ohci_to_hcd(hc);
 
-	ed = dma_pool_zalloc (hc->ed_cache, mem_flags, &dma);
+	if (hcd->localmem_pool)
+		ed = gen_pool_dma_zalloc(hcd->localmem_pool, sizeof(*ed), &dma);
+	else
+		ed = dma_pool_zalloc(hc->ed_cache, mem_flags, &dma);
 	if (ed) {
 		INIT_LIST_HEAD (&ed->td_list);
 		ed->dma = dma;
@@ -129,6 +150,12 @@ ed_alloc (struct ohci_hcd *hc, gfp_t mem_flags)
 static void
 ed_free (struct ohci_hcd *hc, struct ed *ed)
 {
-	dma_pool_free (hc->ed_cache, ed, ed->dma);
+	struct usb_hcd	*hcd = ohci_to_hcd(hc);
+
+	if (hcd->localmem_pool)
+		gen_pool_free(hcd->localmem_pool, (unsigned long)ed,
+			      sizeof(*ed));
+	else
+		dma_pool_free(hc->ed_cache, ed, ed->dma);
 }
 
diff --git a/drivers/usb/host/ohci.h b/drivers/usb/host/ohci.h
index ef4813bfc5bf..b015b00774b2 100644
--- a/drivers/usb/host/ohci.h
+++ b/drivers/usb/host/ohci.h
@@ -385,6 +385,8 @@ struct ohci_hcd {
 
 	/*
 	 * memory management for queue data structures
+	 *
+	 * @td_cache and @ed_cache are %NULL if &usb_hcd.localmem_pool is used.
 	 */
 	struct dma_pool		*td_cache;
 	struct dma_pool		*ed_cache;