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MIPS: refactor the runtime coherent vs noncoherent DMA indicators
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Replace the global coherentio enum, and the hw_coherentio (fake) boolean
variables with a single boolean dma_default_coherent flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
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Christoph Hellwig authored and tsbogend committed Feb 13, 2021
1 parent 3440caf commit 14ac09a
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Showing 6 changed files with 16 additions and 40 deletions.
3 changes: 1 addition & 2 deletions arch/mips/alchemy/common/setup.c
Original file line number Diff line number Diff line change
Expand Up @@ -65,8 +65,7 @@ void __init plat_mem_setup(void)
/* Clear to obtain best system bus performance */
clear_c0_config(1 << 19); /* Clear Config[OD] */

coherentio = alchemy_dma_coherent() ?
IO_COHERENCE_ENABLED : IO_COHERENCE_DISABLED;
dma_default_coherent = alchemy_dma_coherent();

board_setup(); /* board specific setup */

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24 changes: 4 additions & 20 deletions arch/mips/include/asm/dma-coherence.h
Original file line number Diff line number Diff line change
Expand Up @@ -9,30 +9,14 @@
#ifndef __ASM_DMA_COHERENCE_H
#define __ASM_DMA_COHERENCE_H

enum coherent_io_user_state {
IO_COHERENCE_DEFAULT,
IO_COHERENCE_ENABLED,
IO_COHERENCE_DISABLED,
};

#if defined(CONFIG_DMA_PERDEV_COHERENT)
/* Don't provide (hw_)coherentio to avoid misuse */
#elif defined(CONFIG_DMA_MAYBE_COHERENT)
extern enum coherent_io_user_state coherentio;
extern int hw_coherentio;

#ifdef CONFIG_DMA_MAYBE_COHERENT
extern bool dma_default_coherent;
static inline bool dev_is_dma_coherent(struct device *dev)
{
return coherentio == IO_COHERENCE_ENABLED ||
(coherentio == IO_COHERENCE_DEFAULT && hw_coherentio);
return dma_default_coherent;
}
#else
#ifdef CONFIG_DMA_NONCOHERENT
#define coherentio IO_COHERENCE_DISABLED
#else
#define coherentio IO_COHERENCE_ENABLED
#define dma_default_coherent (!IS_ENABLED(CONFIG_DMA_NONCOHERENT))
#endif
#define hw_coherentio 0
#endif /* CONFIG_DMA_MAYBE_COHERENT */

#endif
10 changes: 4 additions & 6 deletions arch/mips/kernel/setup.c
Original file line number Diff line number Diff line change
Expand Up @@ -803,22 +803,20 @@ arch_initcall(debugfs_mips);
#endif

#ifdef CONFIG_DMA_MAYBE_COHERENT
/* User defined DMA coherency from command line. */
enum coherent_io_user_state coherentio = IO_COHERENCE_DEFAULT;
EXPORT_SYMBOL_GPL(coherentio);
int hw_coherentio; /* Actual hardware supported DMA coherency setting. */
bool dma_default_coherent;
EXPORT_SYMBOL_GPL(dma_default_coherent);

static int __init setcoherentio(char *str)
{
coherentio = IO_COHERENCE_ENABLED;
dma_default_coherent = true;
pr_info("Hardware DMA cache coherency (command line)\n");
return 0;
}
early_param("coherentio", setcoherentio);

static int __init setnocoherentio(char *str)
{
coherentio = IO_COHERENCE_DISABLED;
dma_default_coherent = true;
pr_info("Software DMA cache coherency (command line)\n");
return 0;
}
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8 changes: 2 additions & 6 deletions arch/mips/mm/c-r4k.c
Original file line number Diff line number Diff line change
Expand Up @@ -1914,15 +1914,11 @@ void r4k_cache_init(void)
__local_flush_icache_user_range = local_r4k_flush_icache_user_range;

#ifdef CONFIG_DMA_NONCOHERENT
#ifdef CONFIG_DMA_MAYBE_COHERENT
if (coherentio == IO_COHERENCE_ENABLED ||
(coherentio == IO_COHERENCE_DEFAULT && hw_coherentio)) {
if (dma_default_coherent) {
_dma_cache_wback_inv = (void *)cache_noop;
_dma_cache_wback = (void *)cache_noop;
_dma_cache_inv = (void *)cache_noop;
} else
#endif /* CONFIG_DMA_MAYBE_COHERENT */
{
} else {
_dma_cache_wback_inv = r4k_dma_cache_wback_inv;
_dma_cache_wback = r4k_dma_cache_wback_inv;
_dma_cache_inv = r4k_dma_cache_inv;
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6 changes: 3 additions & 3 deletions arch/mips/mti-malta/malta-setup.c
Original file line number Diff line number Diff line change
Expand Up @@ -98,7 +98,7 @@ static void __init plat_setup_iocoherency(void)
if (BONITO_PCICACHECTRL & BONITO_PCICACHECTRL_CPUCOH_PRES) {
BONITO_PCICACHECTRL |= BONITO_PCICACHECTRL_CPUCOH_EN;
pr_info("Enabled Bonito CPU coherency\n");
hw_coherentio = 1;
dma_default_coherent = true;
}
if (strstr(fw_getcmdline(), "iobcuncached")) {
BONITO_PCICACHECTRL &= ~BONITO_PCICACHECTRL_IOBCCOH_EN;
Expand All @@ -118,12 +118,12 @@ static void __init plat_setup_iocoherency(void)
pr_info("CMP IOCU detected\n");
cfg = __raw_readl((u32 *)CKSEG1ADDR(ROCIT_CONFIG_GEN0));
if (cfg & ROCIT_CONFIG_GEN0_PCI_IOCU)
hw_coherentio = 1;
dma_default_coherent = true;
else
pr_crit("IOCU OPERATION DISABLED BY SWITCH - DEFAULTING TO SW IO COHERENCY\n");
}

if (hw_coherentio)
if (dma_default_coherent)
pr_info("Hardware DMA cache coherency enabled\n");
else
pr_info("Software DMA cache coherency enabled\n");
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5 changes: 2 additions & 3 deletions arch/mips/pci/pci-alchemy.c
Original file line number Diff line number Diff line change
Expand Up @@ -429,9 +429,8 @@ static int alchemy_pci_probe(struct platform_device *pdev)
ctx->alchemy_pci_ctrl.io_map_base = (unsigned long)virt_io;

/* Au1500 revisions older than AD have borked coherent PCI */
if ((alchemy_get_cputype() == ALCHEMY_CPU_AU1500) &&
(read_c0_prid() < 0x01030202) &&
(coherentio == IO_COHERENCE_DISABLED)) {
if (alchemy_get_cputype() == ALCHEMY_CPU_AU1500 &&
read_c0_prid() < 0x01030202 && !dma_default_coherent) {
val = __raw_readl(ctx->regs + PCI_REG_CONFIG);
val |= PCI_CONFIG_NC;
__raw_writel(val, ctx->regs + PCI_REG_CONFIG);
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