spi-geni-qcom: Add new interfaces and utilise them

Merge series from Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com>:

A "known issue" during implementation of SE DMA for spi geni driver was
that it does DMA map/unmap internally instead of in spi framework.
Current patches remove this hiccup and also clean up code a bit.

Testing revealed no regressions and results with 1000 iterations of
reading from EC showed no loss of performance.
Results
=======
Before - Iteration 999, min=5.10, max=5.17, avg=5.14, ints=25129
After  - Iteration 999, min=5.10, max=5.20, avg=5.15, ints=25153

1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
index fbb087b728dc..268ccbec88f9 100644
--- a/drivers/usb/core/buffer.c
+++ b/drivers/usb/core/buffer.c
@@ -172,3 +172,44 @@ void hcd_buffer_free(
 	}
 	dma_free_coherent(hcd->self.sysdev, size, addr, dma);
 }
+
+void *hcd_buffer_alloc_pages(struct usb_hcd *hcd,
+		size_t size, gfp_t mem_flags, dma_addr_t *dma)
+{
+	if (size == 0)
+		return NULL;
+
+	if (hcd->localmem_pool)
+		return gen_pool_dma_alloc_align(hcd->localmem_pool,
+				size, dma, PAGE_SIZE);
+
+	/* some USB hosts just use PIO */
+	if (!hcd_uses_dma(hcd)) {
+		*dma = DMA_MAPPING_ERROR;
+		return (void *)__get_free_pages(mem_flags,
+				get_order(size));
+	}
+
+	return dma_alloc_coherent(hcd->self.sysdev,
+			size, dma, mem_flags);
+}
+
+void hcd_buffer_free_pages(struct usb_hcd *hcd,
+		size_t size, void *addr, dma_addr_t dma)
+{
+	if (!addr)
+		return;
+
+	if (hcd->localmem_pool) {
+		gen_pool_free(hcd->localmem_pool,
+				(unsigned long)addr, size);
+		return;
+	}
+
+	if (!hcd_uses_dma(hcd)) {
+		free_pages((unsigned long)addr, get_order(size));
+		return;
+	}
+
+	dma_free_coherent(hcd->self.sysdev, size, addr, dma);
+}