From: Raju Rangoju <Raju.Rangoju@amd.com>
Date: Fri, 16 May 2025 10:06:56 +0000 (+0530)
Subject: spi: spi_amd: Remove read{q,b} usage on DMA buffer
X-Git-Tag: v6.16-rc1~166^2~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8cd079e69dc51e707b0a7ce105b01f6dbb66ddc1;p=thirdparty%2Fkernel%2Flinux.git

spi: spi_amd: Remove read{q,b} usage on DMA buffer

Add changes to replace the usage of read{q,b} MMIO accessors with direct
memory copy logic for reading data from DMA buffer.

Co-developed-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Signed-off-by: Krishnamoorthi M <krishnamoorthi.m@amd.com>
Signed-off-by: Raju Rangoju <Raju.Rangoju@amd.com>
Link: https://patch.msgid.link/20250516100658.585654-2-Raju.Rangoju@amd.com
Signed-off-by: Mark Brown <broonie@kernel.org>
---

diff --git a/drivers/spi/spi-amd.c b/drivers/spi/spi-amd.c
index 90b1f7daa072c..52d893d41b128 100644
--- a/drivers/spi/spi-amd.c
+++ b/drivers/spi/spi-amd.c
@@ -590,15 +590,21 @@ static void amd_spi_mem_data_in(struct amd_spi *amd_spi,
 	 * Use index mode otherwise.
 	 */
 	if (amd_spi->version == AMD_HID2_SPI && amd_is_spi_read_cmd(op->cmd.opcode)) {
+		u64 *dma_buf64 = (u64 *)amd_spi->dma_virt_addr;
+		u8 *dma_buf;
+
 		amd_spi_hiddma_read(amd_spi, op);
 
-		for (i = 0; left_data >= 8; i++, left_data -= 8)
-			*buf_64++ = readq((u8 __iomem *)amd_spi->dma_virt_addr + (i * 8));
+		/* Copy data from DMA buffer */
+		while (left_data >= 8) {
+			*buf_64++ = *dma_buf64++;
+			left_data -= 8;
+		}
 
 		buf = (u8 *)buf_64;
-		for (i = 0; i < left_data; i++)
-			buf[i] = readb((u8 __iomem *)amd_spi->dma_virt_addr +
-				       (nbytes - left_data + i));
+		dma_buf = (u8 *)dma_buf64;
+		while (left_data--)
+			*buf++ = *dma_buf++;
 
 		/* Reset HID RX memory logic */
 		data = amd_spi_readreg32(amd_spi, AMD_SPI_HID2_CNTRL);