On 9/12/22 13:39, Vadym Kochan wrote:
> Hi Adrian,
>
> On Fri, 9 Dec 2022 09:23:05 +0200, Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:
>> On 5/12/22 12:59, Vadym Kochan wrote:
>>> There is a limitation on AC5 SoC that mmc controller
>>> can't have DMA access over 2G memory, so use SDMA with
>>> a bounce buffer. Swiotlb can't help because on arm64 arch
>>> it reserves memblock's at the end of the memory.
>>>
>>> Additionally set mask to 34 bit since on AC5 SoC RAM starts
>>> at 0x2_00000000.
>>
>> Can you explain more about how a 34-bit DMA mask works when
>> SDMA only supports 32-bit addresses?
>>
>
> So, after I set
>
>>> + host->flags &= ~SDHCI_USE_64_BIT_DMA;
>
> then sdhc core sets mask to 32 bit, but then dma_map fails to map
> bounce buffer because the base address is higher than 32bit - 0x2_00000000,
> and 34bit mask fixed it.
What happens if the bounce buffer gets mapped in the range
0x1_00000000 to 0x1_ffffffff ?
>
>>>
>>> Co-developed-by: Elad Nachman <enachman@xxxxxxxxxxx>
>>> Signed-off-by: Elad Nachman <enachman@xxxxxxxxxxx>
>>> Signed-off-by: Vadym Kochan <vadym.kochan@xxxxxxxxxxx>
>>> ---
>>> drivers/mmc/host/sdhci-xenon.c | 38 ++++++++++++++++++++++++++++++++++
>>> drivers/mmc/host/sdhci-xenon.h | 3 ++-
>>> 2 files changed, 40 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci-xenon.c b/drivers/mmc/host/sdhci-xenon.c
>>> index 08e838400b52..5f3db0425674 100644
>>> --- a/drivers/mmc/host/sdhci-xenon.c
>>> +++ b/drivers/mmc/host/sdhci-xenon.c
>>> @@ -13,7 +13,9 @@
>>>
>>> #include <linux/acpi.h>
>>> #include <linux/delay.h>
>>> +#include <linux/dma-mapping.h>
>>> #include <linux/ktime.h>
>>> +#include <linux/mm.h>
>>> #include <linux/module.h>
>>> #include <linux/of.h>
>>> #include <linux/pm.h>
>>> @@ -253,6 +255,22 @@ static unsigned int xenon_get_max_clock(struct sdhci_host *host)
>>> return pltfm_host->clock;
>>> }
>>>
>>> +static int xenon_set_dma_mask(struct sdhci_host *host)
>>> +{
>>> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>> + struct xenon_priv *priv = sdhci_pltfm_priv(pltfm_host);
>>> + struct mmc_host *mmc = host->mmc;
>>> + struct device *dev = mmc_dev(mmc);
>>> +
>>> + if (priv->hw_version == XENON_AC5) {
>>> + host->flags &= ~SDHCI_USE_64_BIT_DMA;
>>> +
>>> + return dma_set_mask_and_coherent(dev, DMA_BIT_MASK(34));
>>> + }
>>> +
>>> + return sdhci_set_dma_mask(host);
>>> +}
>>> +
>>> static const struct sdhci_ops sdhci_xenon_ops = {
>>> .voltage_switch = xenon_voltage_switch,
>>> .set_clock = sdhci_set_clock,
>>> @@ -261,6 +279,7 @@ static const struct sdhci_ops sdhci_xenon_ops = {
>>> .reset = xenon_reset,
>>> .set_uhs_signaling = xenon_set_uhs_signaling,
>>> .get_max_clock = xenon_get_max_clock,
>>> + .set_dma_mask = xenon_set_dma_mask,
>>> };
>>>
>>> static const struct sdhci_pltfm_data sdhci_xenon_pdata = {
>>> @@ -486,6 +505,18 @@ 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 sysinfo si;
>>> +
>>> + si_meminfo(&si);
>>> +
>>> + if ((si.totalram * si.mem_unit) > SZ_2G)
>>> + host->quirks |= SDHCI_QUIRK_BROKEN_ADMA;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> static int xenon_probe(struct platform_device *pdev)
>>> {
>>> struct sdhci_pltfm_host *pltfm_host;
>>> @@ -533,6 +564,12 @@ static int xenon_probe(struct platform_device *pdev)
>>> }
>>> }
>>>
>>> + if (priv->hw_version == XENON_AC5) {
>>> + err = xenon_ac5_probe(host);
>>> + if (err)
>>> + goto err_clk_axi;
>>> + }
>>> +
>>> err = mmc_of_parse(host->mmc);
>>> if (err)
>>> goto err_clk_axi;
>>> @@ -682,6 +719,7 @@ 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_AC5},
>>> {}
>>> };
>>> MODULE_DEVICE_TABLE(of, sdhci_xenon_dt_ids);
>>> diff --git a/drivers/mmc/host/sdhci-xenon.h b/drivers/mmc/host/sdhci-xenon.h
>>> index 3e9c6c908a79..0460d97aad26 100644
>>> --- a/drivers/mmc/host/sdhci-xenon.h
>>> +++ b/drivers/mmc/host/sdhci-xenon.h
>>> @@ -57,7 +57,8 @@ enum xenon_variant {
>>> XENON_A3700,
>>> XENON_AP806,
>>> XENON_AP807,
>>> - XENON_CP110
>>> + XENON_CP110,
>>> + XENON_AC5
>>> };
>>>
>>> struct xenon_priv {
>>
>
> Regards,
