Subject: Re: [PATCH] ppc440spe-adma: adds updated ppc440spe adma driver

From: Anatolij Gustschin <[email-masked]>
Date: Mon, 23 Nov 2009 11:23:01 +0100

On Fri, 20 Nov 2009 08:00:26 -0500
Josh Boyer <[email-masked]> wrote:

> On Tue, Nov 17, 2009 at 03:17:05PM +0100, Anatolij Gustschin wrote:
> >This patch adds new version of the PPC440SPe ADMA driver.
> >
> >Signed-off-by: Anatolij Gustschin <[email-masked]>
> 
> The driver author is listed as Yuri Tikhonov <[email-masked]>.  Shouldn't
> this include a sign-off from Yuri, or perhaps even a From?

Yuri is the author of the previous driver version but he didn't
have time to rework the driver and prepare it for submission.
I will CC him and ask for his sign-off when submitting next
patch version.

> >Before applying this patch the following patch to katmai.dts
> >should be applied first: http://patchwork.ozlabs.org/patch/36768/
> 
> For the linux-raid people's benefit, I have that patch queued up in my next
> branch.

Thanks!

> > arch/powerpc/include/asm/async_tx.h                |   47 +
> > arch/powerpc/include/asm/ppc440spe_adma.h          |  195 +
> > arch/powerpc/include/asm/ppc440spe_dma.h           |  224 +
> > arch/powerpc/include/asm/ppc440spe_xor.h           |  110 +
> 
> Why are these header files in the asm directory?  They seem to be only used
> by your new driver, so why not have them under the drivers/dma or if you want
> to be neat, drivers/dma/ppc440spe/ dirs?  I really don't think they should
> be in asm at all.

async_tx layer expects async_tx.h to be in the asm directory if
the architecture provides async_tx_find_channel(). I will move
other header files and the driver file to drivers/dma/ppc440spe/
directory.

> >diff --git a/arch/powerpc/include/asm/dcr-regs.h b/arch/powerpc/include/asm/dcr-regs.h
> >index 828e3aa..67d4069 100644
> >--- a/arch/powerpc/include/asm/dcr-regs.h
> >+++ b/arch/powerpc/include/asm/dcr-regs.h
> >@@ -157,4 +157,30 @@
> > #define  L2C_SNP_SSR_32G	0x0000f000
> > #define  L2C_SNP_ESR		0x00000800
> >
> >+#define DCRN_SDR_CONFIG_ADDR	0xe
> >+#define DCRN_SDR_CONFIG_DATA	0xf
> 
> These #defines already exist as DCRN_SDR0_CONFIG_{ADDR,DATA}.  We don't need
> them defined again.

OK, I'll remove them.

<snip>
> >+ * Common initialisation for RAID engines; allocate memory for
> >+ * DMAx FIFOs, perform configuration common for all DMA engines.
> >+ * Further DMA engine specific configuration is done at probe time.
> >+ */
> >+static int ppc440spe_configure_raid_devices(void)
> >+{
> >+	struct device_node *np;
> >+	struct resource i2o_res;
> >+	i2o_regs_t __iomem *i2o_reg;
> >+	const u32 *dcrreg;
> >+	u32 dcrbase_i2o;
> >+	int i, len, ret;
> >+
> >+	np = of_find_compatible_node(NULL, NULL, "ibm,i2o-440spe");
> >+	if (!np) {
> >+		pr_err("%s: can't find I2O device tree node\n",
> >+			__func__);
> >+		return -ENODEV;
> >+	}
> >+
> >+	if (of_address_to_resource(np, 0, &i2o_res)) {
> >+		of_node_put(np);
> >+		return -EINVAL;
> >+	}
> >+
> >+	i2o_reg = of_iomap(np, 0);
> >+	if (!i2o_reg) {
> >+		pr_err("%s: failed to map I2O registers\n", __func__);
> >+		of_node_put(np);
> >+		return -EINVAL;
> >+	}
> >+
> >+	/* Get I2O DCRs base */
> >+	dcrreg = of_get_property(np, "dcr-reg", &len);
> >+	if (!dcrreg || (len != 2 * sizeof(u32))) {
> >+		pr_err("%s: can't get DCR register base!\n",
> >+			np->full_name);
> >+		of_node_put(np);
> >+		iounmap(i2o_reg);
> >+		return -ENODEV;
> >+	}
> >+	of_node_put(np);
> >+	dcrbase_i2o = dcrreg[0];
> >+
> >+	/* Provide memory regions for DMA's FIFOs: I2O, DMA0 and DMA1 share
> >+	 * the base address of FIFO memory space.
> >+	 * Actually we need twice more physical memory than programmed in the
> >+	 * <fsiz> register (because there are two FIFOs for each DMA: CP and CS)
> >+	 */
> >+	ppc440spe_dma_fifo_buf = kmalloc((DMA0_FIFO_SIZE + DMA1_FIFO_SIZE) << 1,
> >+					 GFP_KERNEL);
> >+	if (!ppc440spe_dma_fifo_buf) {
> >+		pr_err("%s: DMA FIFO buffer allocation failed.\n", __func__);
> >+		iounmap(i2o_reg);
> >+		return -ENOMEM;
> >+	}
> >+v
> >+	/*
> >+	 * Configure h/w
> >+	 */
> >+	/* Reset I2O/DMA */
> >+	mtdcri(SDR, DCRN_SDR0_SRST, DCRN_SDR0_SRST_I2ODMA);
> >+	mtdcri(SDR, DCRN_SDR0_SRST, 0);
> >+
> >+	/* Setup the base address of mmaped registers */
> >+	mtdcr(dcrbase_i2o + DCRN_I2O0_IBAH, (u32)(i2o_res.start >> 32));
> >+	mtdcr(dcrbase_i2o + DCRN_I2O0_IBAL, (u32)(i2o_res.start) |
> >+					    I2O_REG_ENABLE);
> 
> It would be cleaner if you used the dcr_read/dcr_write functions instead
> of the open coded mtdcr/mfdcr.  I don't think it's required though.
> 
> >+
> >+	/* Setup FIFO memory space base address */
> >+	out_le32(&i2o_reg->ifbah, 0);
> >+	out_le32(&i2o_reg->ifbal, ((u32)__pa(ppc440spe_dma_fifo_buf)));
> 
> Similarly ioread32/iowrite32 instead of {out,in}_.

OK, I'll fix this.

Thanks!

Anatolij