From 6778948f9de86c3cfaf36725a7c87dcff9ba247f Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 08:20:59 +0000
Subject: [PATCH] kernel_5.10 no rt
---
kernel/arch/arm/mach-rpc/dma.c | 101 +++++++++++++++++++++++++-------------------------
1 files changed, 51 insertions(+), 50 deletions(-)
diff --git a/kernel/arch/arm/mach-rpc/dma.c b/kernel/arch/arm/mach-rpc/dma.c
index c4c9666..50e0f97 100644
--- a/kernel/arch/arm/mach-rpc/dma.c
+++ b/kernel/arch/arm/mach-rpc/dma.c
@@ -1,11 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/mach-rpc/dma.c
*
* Copyright (C) 1998 Russell King
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
*
* DMA functions specific to RiscPC architecture
*/
@@ -27,10 +24,11 @@
struct iomd_dma {
struct dma_struct dma;
- unsigned int state;
- unsigned long base; /* Controller base address */
+ void __iomem *base; /* Controller base address */
int irq; /* Controller IRQ */
- struct scatterlist cur_sg; /* Current controller buffer */
+ unsigned int state;
+ dma_addr_t cur_addr;
+ unsigned int cur_len;
dma_addr_t dma_addr;
unsigned int dma_len;
};
@@ -53,13 +51,13 @@
#define CR (IOMD_IO0CR - IOMD_IO0CURA)
#define ST (IOMD_IO0ST - IOMD_IO0CURA)
-static void iomd_get_next_sg(struct scatterlist *sg, struct iomd_dma *idma)
+static void iomd_get_next_sg(struct iomd_dma *idma)
{
unsigned long end, offset, flags = 0;
if (idma->dma.sg) {
- sg->dma_address = idma->dma_addr;
- offset = sg->dma_address & ~PAGE_MASK;
+ idma->cur_addr = idma->dma_addr;
+ offset = idma->cur_addr & ~PAGE_MASK;
end = offset + idma->dma_len;
@@ -69,7 +67,7 @@
if (offset + TRANSFER_SIZE >= end)
flags |= DMA_END_L;
- sg->length = end - TRANSFER_SIZE;
+ idma->cur_len = end - TRANSFER_SIZE;
idma->dma_len -= end - offset;
idma->dma_addr += end - offset;
@@ -87,52 +85,49 @@
}
} else {
flags = DMA_END_S | DMA_END_L;
- sg->dma_address = 0;
- sg->length = 0;
+ idma->cur_addr = 0;
+ idma->cur_len = 0;
}
- sg->length |= flags;
+ idma->cur_len |= flags;
}
static irqreturn_t iomd_dma_handle(int irq, void *dev_id)
{
struct iomd_dma *idma = dev_id;
- unsigned long base = idma->base;
+ void __iomem *base = idma->base;
+ unsigned int state = idma->state;
+ unsigned int status, cur, end;
do {
- unsigned int status;
-
- status = iomd_readb(base + ST);
+ status = readb(base + ST);
if (!(status & DMA_ST_INT))
- return IRQ_HANDLED;
+ goto out;
- if ((idma->state ^ status) & DMA_ST_AB)
- iomd_get_next_sg(&idma->cur_sg, idma);
+ if ((state ^ status) & DMA_ST_AB)
+ iomd_get_next_sg(idma);
- switch (status & (DMA_ST_OFL | DMA_ST_AB)) {
- case DMA_ST_OFL: /* OIA */
- case DMA_ST_AB: /* .IB */
- iomd_writel(idma->cur_sg.dma_address, base + CURA);
- iomd_writel(idma->cur_sg.length, base + ENDA);
- idma->state = DMA_ST_AB;
- break;
-
- case DMA_ST_OFL | DMA_ST_AB: /* OIB */
- case 0: /* .IA */
- iomd_writel(idma->cur_sg.dma_address, base + CURB);
- iomd_writel(idma->cur_sg.length, base + ENDB);
- idma->state = 0;
- break;
+ // This efficiently implements state = OFL != AB ? AB : 0
+ state = ((status >> 2) ^ status) & DMA_ST_AB;
+ if (state) {
+ cur = CURA;
+ end = ENDA;
+ } else {
+ cur = CURB;
+ end = ENDB;
}
+ writel(idma->cur_addr, base + cur);
+ writel(idma->cur_len, base + end);
if (status & DMA_ST_OFL &&
- idma->cur_sg.length == (DMA_END_S|DMA_END_L))
+ idma->cur_len == (DMA_END_S|DMA_END_L))
break;
} while (1);
- idma->state = ~DMA_ST_AB;
+ state = ~DMA_ST_AB;
disable_irq_nosync(irq);
-
+out:
+ idma->state = state;
return IRQ_HANDLED;
}
@@ -151,10 +146,16 @@
free_irq(idma->irq, idma);
}
+static struct device isa_dma_dev = {
+ .init_name = "fallback device",
+ .coherent_dma_mask = ~(dma_addr_t)0,
+ .dma_mask = &isa_dma_dev.coherent_dma_mask,
+};
+
static void iomd_enable_dma(unsigned int chan, dma_t *dma)
{
struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma);
- unsigned long dma_base = idma->base;
+ void __iomem *base = idma->base;
unsigned int ctrl = TRANSFER_SIZE | DMA_CR_E;
if (idma->dma.invalid) {
@@ -168,7 +169,7 @@
idma->dma.sg = &idma->dma.buf;
idma->dma.sgcount = 1;
idma->dma.buf.length = idma->dma.count;
- idma->dma.buf.dma_address = dma_map_single(NULL,
+ idma->dma.buf.dma_address = dma_map_single(&isa_dma_dev,
idma->dma.addr, idma->dma.count,
idma->dma.dma_mode == DMA_MODE_READ ?
DMA_FROM_DEVICE : DMA_TO_DEVICE);
@@ -177,27 +178,27 @@
idma->dma_addr = idma->dma.sg->dma_address;
idma->dma_len = idma->dma.sg->length;
- iomd_writeb(DMA_CR_C, dma_base + CR);
+ writeb(DMA_CR_C, base + CR);
idma->state = DMA_ST_AB;
}
if (idma->dma.dma_mode == DMA_MODE_READ)
ctrl |= DMA_CR_D;
- iomd_writeb(ctrl, dma_base + CR);
+ writeb(ctrl, base + CR);
enable_irq(idma->irq);
}
static void iomd_disable_dma(unsigned int chan, dma_t *dma)
{
struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma);
- unsigned long dma_base = idma->base;
+ void __iomem *base = idma->base;
unsigned long flags;
local_irq_save(flags);
if (idma->state != ~DMA_ST_AB)
disable_irq(idma->irq);
- iomd_writeb(0, dma_base + CR);
+ writeb(0, base + CR);
local_irq_restore(flags);
}
@@ -360,17 +361,17 @@
*/
iomd_writeb(DMA_EXT_IO3|DMA_EXT_IO2, IOMD_DMAEXT);
- iomd_dma[DMA_0].base = IOMD_IO0CURA;
+ iomd_dma[DMA_0].base = IOMD_BASE + IOMD_IO0CURA;
iomd_dma[DMA_0].irq = IRQ_DMA0;
- iomd_dma[DMA_1].base = IOMD_IO1CURA;
+ iomd_dma[DMA_1].base = IOMD_BASE + IOMD_IO1CURA;
iomd_dma[DMA_1].irq = IRQ_DMA1;
- iomd_dma[DMA_2].base = IOMD_IO2CURA;
+ iomd_dma[DMA_2].base = IOMD_BASE + IOMD_IO2CURA;
iomd_dma[DMA_2].irq = IRQ_DMA2;
- iomd_dma[DMA_3].base = IOMD_IO3CURA;
+ iomd_dma[DMA_3].base = IOMD_BASE + IOMD_IO3CURA;
iomd_dma[DMA_3].irq = IRQ_DMA3;
- iomd_dma[DMA_S0].base = IOMD_SD0CURA;
+ iomd_dma[DMA_S0].base = IOMD_BASE + IOMD_SD0CURA;
iomd_dma[DMA_S0].irq = IRQ_DMAS0;
- iomd_dma[DMA_S1].base = IOMD_SD1CURA;
+ iomd_dma[DMA_S1].base = IOMD_BASE + IOMD_SD1CURA;
iomd_dma[DMA_S1].irq = IRQ_DMAS1;
for (i = DMA_0; i <= DMA_S1; i++) {
--
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