PCI: Add pci_irq_type() to query the allocated interrupt typegrafted

Add a helper that returns PCI_IRQ_MSIX, PCI_IRQ_MSI, or PCI_IRQ_INTX
based on the interrupt type the PCI core selected after
pci_alloc_irq_vectors().

Several drivers already open-code this check against pdev->msix_enabled
and pdev->msi_enabled, or even open code this helper [1].

A common helper avoids the duplication and keeps drivers from accessing
the bitfield directly (see also [2]).

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Link: https://elixir.bootlin.com/linux/v7.1/source/drivers/net/ethernet/aquantia/atlantic/aq_pci_func.c#L196 [1]
Inspired-by: John Hubbard <jhubbard@nvidia.com>
Link: https://lore.kernel.org/all/DKKG2QM3YJYB.Z2H2B2UXJ75N@kernel.org/ [2]
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260813165234.620555-5-dakr@kernel.org
[ Add missing pci_irq_type() stub for CONFIG_PCI=n. ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

1 files changed, 76 insertions, 0 deletions

diff --git a/sound/soc/sof/sof-utils.c b/sound/soc/sof/sof-utils.c
new file mode 100644
index 000000000..f70089317
--- /dev/null
+++ b/sound/soc/sof/sof-utils.c
@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
+//
+// This file is provided under a dual BSD/GPLv2 license.  When using or
+// redistributing this file, you may do so under either license.
+//
+// Copyright(c) 2018-2022 Intel Corporation
+//
+// Author: Keyon Jie <yang.jie@linux.intel.com>
+//
+
+#include <linux/unaligned.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/device.h>
+#include <sound/memalloc.h>
+#include <linux/module.h>
+#include "sof-utils.h"
+
+/*
+ * Generic buffer page table creation.
+ * Take the each physical page address and drop the least significant unused
+ * bits from each (based on PAGE_SIZE). Then pack valid page address bits
+ * into compressed page table.
+ */
+
+int snd_sof_create_page_table(struct device *dev,
+			      struct snd_dma_buffer *dmab,
+			      unsigned char *page_table, size_t size)
+{
+	int i, pages;
+
+	pages = snd_sgbuf_aligned_pages(size);
+
+	dev_dbg(dev, "generating page table for %p size 0x%zx pages %d\n",
+		dmab->area, size, pages);
+
+	for (i = 0; i < pages; i++) {
+		/*
+		 * The number of valid address bits for each page is 20.
+		 * idx determines the byte position within page_table
+		 * where the current page's address is stored
+		 * in the compressed page_table.
+		 * This can be calculated by multiplying the page number by 2.5.
+		 */
+		u32 idx = (5 * i) >> 1;
+		u32 pfn = snd_sgbuf_get_addr(dmab, i * PAGE_SIZE) >> PAGE_SHIFT;
+		u8 *pg_table;
+
+		pg_table = (u8 *)(page_table + idx);
+
+		/*
+		 * pagetable compression:
+		 * byte 0     byte 1     byte 2     byte 3     byte 4     byte 5
+		 * ___________pfn 0__________ __________pfn 1___________  _pfn 2...
+		 * .... ....  .... ....  .... ....  .... ....  .... ....  ....
+		 * It is created by:
+		 * 1. set current location to 0, PFN index i to 0
+		 * 2. put pfn[i] at current location in Little Endian byte order
+		 * 3. calculate an intermediate value as
+		 *    x = (pfn[i+1] << 4) | (pfn[i] & 0xf)
+		 * 4. put x at offset (current location + 2) in LE byte order
+		 * 5. increment current location by 5 bytes, increment i by 2
+		 * 6. continue to (2)
+		 */
+		if (i & 1)
+			put_unaligned_le32((pg_table[0] & 0xf) | pfn << 4,
+					   pg_table);
+		else
+			put_unaligned_le32(pfn, pg_table);
+	}
+
+	return pages;
+}
+EXPORT_SYMBOL(snd_sof_create_page_table);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("SOF utils");