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SubjectRe: [PATCH 2/2 v3] dma/amba-pl08x: add support for the Nomadik variant
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On Thu, 2012-04-12 at 09:01 +0200, Linus Walleij wrote:
> The Nomadik PL080 variant has some extra protection bits that
> may be set, so we need to check these bits to see if the
> channels are actually available for the DMAengine to use.
>
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: Alim Akhtar <alim.akhtar@gmail.com>
> Cc: Alessandro Rubini <rubini@gnudd.com>
> Reviewed-by: Viresh Kumar <viresh.kumar@st.com>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Applied both thanks
> ---
> ChangeLog v1->v2:
> - Fixed these review comments from Viresh Kumar
> - Use kzalloc to allocate the physical channel structs so
> we don't have to assign values to everything and can assume
> booleans are default false
> - unbreak long error message.
> ChangeLog v2->v3:
> - Remove an extraneous NULL assignment now that we have
> kzalloc for the physical channel info.
> ---
> arch/arm/include/asm/hardware/pl080.h | 2 +
> drivers/dma/amba-pl08x.c | 44 +++++++++++++++++++++++++++-----
> include/linux/amba/pl08x.h | 3 ++
> 3 files changed, 42 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm/include/asm/hardware/pl080.h b/arch/arm/include/asm/hardware/pl080.h
> index 33c78d7..4eea210 100644
> --- a/arch/arm/include/asm/hardware/pl080.h
> +++ b/arch/arm/include/asm/hardware/pl080.h
> @@ -102,6 +102,8 @@
> #define PL080_WIDTH_16BIT (0x1)
> #define PL080_WIDTH_32BIT (0x2)
>
> +#define PL080N_CONFIG_ITPROT (1 << 20)
> +#define PL080N_CONFIG_SECPROT (1 << 19)
> #define PL080_CONFIG_HALT (1 << 18)
> #define PL080_CONFIG_ACTIVE (1 << 17) /* RO */
> #define PL080_CONFIG_LOCK (1 << 16)
> diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
> index 08589c6..629250e 100644
> --- a/drivers/dma/amba-pl08x.c
> +++ b/drivers/dma/amba-pl08x.c
> @@ -95,10 +95,14 @@ static struct amba_driver pl08x_amba_driver;
> * struct vendor_data - vendor-specific config parameters for PL08x derivatives
> * @channels: the number of channels available in this variant
> * @dualmaster: whether this version supports dual AHB masters or not.
> + * @nomadik: whether the channels have Nomadik security extension bits
> + * that need to be checked for permission before use and some registers are
> + * missing
> */
> struct vendor_data {
> u8 channels;
> bool dualmaster;
> + bool nomadik;
> };
>
> /*
> @@ -385,7 +389,7 @@ pl08x_get_phy_channel(struct pl08x_driver_data *pl08x,
>
> spin_lock_irqsave(&ch->lock, flags);
>
> - if (!ch->serving) {
> + if (!ch->locked && !ch->serving) {
> ch->serving = virt_chan;
> ch->signal = -1;
> spin_unlock_irqrestore(&ch->lock, flags);
> @@ -1483,6 +1487,9 @@ bool pl08x_filter_id(struct dma_chan *chan, void *chan_id)
> */
> static void pl08x_ensure_on(struct pl08x_driver_data *pl08x)
> {
> + /* The Nomadik variant does not have the config register */
> + if (pl08x->vd->nomadik)
> + return;
> writel(PL080_CONFIG_ENABLE, pl08x->base + PL080_CONFIG);
> }
>
> @@ -1772,8 +1779,10 @@ static int pl08x_debugfs_show(struct seq_file *s, void *data)
> spin_lock_irqsave(&ch->lock, flags);
> virt_chan = ch->serving;
>
> - seq_printf(s, "%d\t\t%s\n",
> - ch->id, virt_chan ? virt_chan->name : "(none)");
> + seq_printf(s, "%d\t\t%s%s\n",
> + ch->id,
> + virt_chan ? virt_chan->name : "(none)",
> + ch->locked ? " LOCKED" : "");
>
> spin_unlock_irqrestore(&ch->lock, flags);
> }
> @@ -1917,7 +1926,7 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
> }
>
> /* Initialize physical channels */
> - pl08x->phy_chans = kmalloc((vd->channels * sizeof(*pl08x->phy_chans)),
> + pl08x->phy_chans = kzalloc((vd->channels * sizeof(*pl08x->phy_chans)),
> GFP_KERNEL);
> if (!pl08x->phy_chans) {
> dev_err(&adev->dev, "%s failed to allocate "
> @@ -1932,8 +1941,23 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
> ch->id = i;
> ch->base = pl08x->base + PL080_Cx_BASE(i);
> spin_lock_init(&ch->lock);
> - ch->serving = NULL;
> ch->signal = -1;
> +
> + /*
> + * Nomadik variants can have channels that are locked
> + * down for the secure world only. Lock up these channels
> + * by perpetually serving a dummy virtual channel.
> + */
> + if (vd->nomadik) {
> + u32 val;
> +
> + val = readl(ch->base + PL080_CH_CONFIG);
> + if (val & (PL080N_CONFIG_ITPROT | PL080N_CONFIG_SECPROT)) {
> + dev_info(&adev->dev, "physical channel %d reserved for secure access only\n", i);
> + ch->locked = true;
> + }
> + }
> +
> dev_dbg(&adev->dev, "physical channel %d is %s\n",
> i, pl08x_phy_channel_busy(ch) ? "BUSY" : "FREE");
> }
> @@ -2016,6 +2040,12 @@ static struct vendor_data vendor_pl080 = {
> .dualmaster = true,
> };
>
> +static struct vendor_data vendor_nomadik = {
> + .channels = 8,
> + .dualmaster = true,
> + .nomadik = true,
> +};
> +
> static struct vendor_data vendor_pl081 = {
> .channels = 2,
> .dualmaster = false,
> @@ -2036,9 +2066,9 @@ static struct amba_id pl08x_ids[] = {
> },
> /* Nomadik 8815 PL080 variant */
> {
> - .id = 0x00280880,
> + .id = 0x00280080,
> .mask = 0x00ffffff,
> - .data = &vendor_pl080,
> + .data = &vendor_nomadik,
> },
> { 0, 0 },
> };
> diff --git a/include/linux/amba/pl08x.h b/include/linux/amba/pl08x.h
> index e64ce2c..0254901 100644
> --- a/include/linux/amba/pl08x.h
> +++ b/include/linux/amba/pl08x.h
> @@ -92,6 +92,8 @@ struct pl08x_bus_data {
> * right now
> * @serving: the virtual channel currently being served by this physical
> * channel
> + * @locked: channel unavailable for the system, e.g. dedicated to secure
> + * world
> */
> struct pl08x_phy_chan {
> unsigned int id;
> @@ -99,6 +101,7 @@ struct pl08x_phy_chan {
> spinlock_t lock;
> int signal;
> struct pl08x_dma_chan *serving;
> + bool locked;
> };
>
> /**


--
~Vinod



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