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Message-Id: <20220806085818.9873-3-vadym.kochan@plvision.eu>
Date: Sat, 6 Aug 2022 11:58:13 +0300
From: Vadym Kochan <vadym.kochan@...ision.eu>
To: Hu Ziji <huziji@...vell.com>, Ulf Hansson <ulf.hansson@...aro.org>,
Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Adrian Hunter <adrian.hunter@...el.com>,
Vadym Kochan <vadym.kochan@...ision.eu>,
linux-mmc@...r.kernel.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org
Cc: Elad Nachman <enachman@...vell.com>
Subject: [PATCH 2/3] mmc: sdhci-xenon: Try to fix 2G address limitation on AC5 SoC
There is a limitation on AC5 SoC that Xenon SDHC can address only
first 2GB of memory. Turning to the SDMA mode to use the bounce_buffer
causes ext_csd recognition to fail on init.
Using of swiotlb=force also does not help as it is allocated at the
end of the memory.
So it was decided to use reserved-memory as a bounce buffer in case
if the board has more than 2G of memory, or turn on the PIO
mode if such memory region does not exist in the device-tree.
It was tested that this approach is 1.5 times faster than PIO.
Signed-off-by: Vadym Kochan <vadym.kochan@...ision.eu>
---
drivers/mmc/host/sdhci-xenon.c | 36 ++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c
index 08e838400b52..fbbd1a045002 100644
--- a/drivers/mmc/host/sdhci-xenon.c
+++ b/drivers/mmc/host/sdhci-xenon.c
@@ -14,8 +14,10 @@
#include <linux/acpi.h>
#include <linux/delay.h>
#include <linux/ktime.h>
+#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_reserved_mem.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
@@ -486,6 +488,31 @@ static void xenon_sdhc_unprepare(struct sdhci_host *host)
xenon_disable_sdhc(host, sdhc_id);
}
+static int xenon_ac5_probe(struct sdhci_host *host)
+{
+ struct device *dev = mmc_dev(host->mmc);
+ struct sysinfo si;
+ int err;
+
+ si_meminfo(&si);
+
+ if ((si.totalram * si.mem_unit) > SZ_2G) {
+ struct device_node *dma_bounce_np;
+
+ dma_bounce_np = of_parse_phandle(dev->of_node,
+ "marvell,ac5-sdhci-dma-bounce-pool", 0);
+ err = of_reserved_mem_device_init_by_idx(dev, dma_bounce_np, 0);
+ of_node_put(dma_bounce_np);
+ if (err) {
+ dev_warn(dev, "Disabling DMA because of 2GB DMA access limit and missing DMA bounce region\n");
+ host->quirks |= SDHCI_QUIRK_BROKEN_ADMA;
+ host->quirks |= SDHCI_QUIRK_BROKEN_DMA;
+ }
+ }
+
+ return 0;
+}
+
static int xenon_probe(struct platform_device *pdev)
{
struct sdhci_pltfm_host *pltfm_host;
@@ -531,6 +558,12 @@ static int xenon_probe(struct platform_device *pdev)
if (err)
goto err_clk;
}
+
+ if (of_device_is_compatible(dev->of_node, "marvell,ac5-sdhci")) {
+ err = xenon_ac5_probe(host);
+ if (err)
+ goto err_clk_axi;
+ }
}
err = mmc_of_parse(host->mmc);
@@ -570,6 +603,7 @@ static int xenon_probe(struct platform_device *pdev)
pm_runtime_put_noidle(&pdev->dev);
xenon_sdhc_unprepare(host);
err_clk_axi:
+ of_reserved_mem_device_release(&pdev->dev);
clk_disable_unprepare(priv->axi_clk);
err_clk:
clk_disable_unprepare(pltfm_host->clk);
@@ -591,6 +625,7 @@ static int xenon_remove(struct platform_device *pdev)
sdhci_remove_host(host, 0);
xenon_sdhc_unprepare(host);
+ of_reserved_mem_device_release(&pdev->dev);
clk_disable_unprepare(priv->axi_clk);
clk_disable_unprepare(pltfm_host->clk);
@@ -682,6 +717,7 @@ static const struct of_device_id sdhci_xenon_dt_ids[] = {
{ .compatible = "marvell,armada-ap807-sdhci", .data = (void *)XENON_AP807},
{ .compatible = "marvell,armada-cp110-sdhci", .data = (void *)XENON_CP110},
{ .compatible = "marvell,armada-3700-sdhci", .data = (void *)XENON_A3700},
+ { .compatible = "marvell,ac5-sdhci", .data = (void *)XENON_AP806},
{}
};
MODULE_DEVICE_TABLE(of, sdhci_xenon_dt_ids);
--
2.17.1
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