Re: [PATCHv2 6/7] ARM: socfpga: Enable Arria10 OCRAM ECC on startup

[Thor Thayer]

Hi,

On 03/31/2016 01:48 PM, tthayer@xxxxxxxxxxxxxxxxxxxxx wrote:
> From: Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx>
>
> Enable ECC for Arria10 On-Chip RAM on machine startup. The ECC has to
> be enabled and memory initialized before data is stored in memory
> otherwise the ECC will fail on reads.
>
> Signed-off-by: Thor Thayer <tthayer@xxxxxxxxxxxxxxxxxxxxx>
> ---
> v2: Add Arria10 ECC block initialization locally.
> ---
>   arch/arm/mach-socfpga/ocram.c |  128 +++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 128 insertions(+)
>
> diff --git a/arch/arm/mach-socfpga/ocram.c b/arch/arm/mach-socfpga/ocram.c
> index 60ec643..d4a524c 100644
> --- a/arch/arm/mach-socfpga/ocram.c
> +++ b/arch/arm/mach-socfpga/ocram.c
> @@ -13,12 +13,15 @@
>    * You should have received a copy of the GNU General Public License along with
>    * this program.  If not, see <http://www.gnu.org/licenses/>.
>    */
> +#include <linux/delay.h>
>   #include <linux/io.h>
>   #include <linux/genalloc.h>
>   #include <linux/module.h>
>   #include <linux/of_address.h>
>   #include <linux/of_platform.h>
>
> +#include "core.h"
> +
>   #define ALTR_OCRAM_CLEAR_ECC          0x00000018
>   #define ALTR_OCRAM_ECC_EN             0x00000019
>
> @@ -47,3 +50,128 @@ void socfpga_init_ocram_ecc(void)
>
>   	iounmap(mapped_ocr_edac_addr);
>   }
> +
> +/* Arria10 OCRAM Section */
> +#define ALTR_A10_ECC_CTRL_OFST          0x08
> +#define ALTR_A10_OCRAM_ECC_EN_CTL       (BIT(1) | BIT(0))
> +#define ALTR_A10_ECC_INITA              BIT(16)
> +
> +#define ALTR_A10_ECC_INITSTAT_OFST      0x0C
> +#define ALTR_A10_ECC_INITCOMPLETEA      BIT(0)
> +#define ALTR_A10_ECC_INITCOMPLETEB      BIT(8)
> +
> +#define ALTR_A10_ECC_ERRINTEN_OFST      0x10
> +#define ALTR_A10_ECC_SERRINTEN          BIT(0)
> +
> +#define ALTR_A10_ECC_INTSTAT_OFST       0x20
> +#define ALTR_A10_ECC_SERRPENA           BIT(0)
> +#define ALTR_A10_ECC_DERRPENA           BIT(8)
> +#define ALTR_A10_ECC_ERRPENA_MASK       (ALTR_A10_ECC_SERRPENA | \
> +					 ALTR_A10_ECC_DERRPENA)
> +/* ECC Manager Defines */
> +#define A10_SYSMGR_ECC_INTMASK_SET_OFST   0x94
> +#define A10_SYSMGR_ECC_INTMASK_CLR_OFST   0x98
> +#define A10_SYSMGR_ECC_INTMASK_OCRAM      BIT(1)
> +
> +#define ALTR_A10_ECC_INIT_WATCHDOG_10US   10000
> +
> +static void ecc_set_bits(u32 bit_mask, void __iomem *ioaddr)
> +{
> +	u32 value = readl(ioaddr);
> +
> +	value |= bit_mask;
> +	writel(value, ioaddr);
> +}
> +
> +static void ecc_clear_bits(u32 bit_mask, void __iomem *ioaddr)
> +{
> +	u32 value = readl(ioaddr);
> +
> +	value &= ~bit_mask;
> +	writel(value, ioaddr);
> +}
> +
> +static int ecc_test_bits(u32 bit_mask, void __iomem *ioaddr)
> +{
> +	u32 value = readl(ioaddr);
> +
> +	return (value & bit_mask) ? 1 : 0;
> +}
> +
> +/*
> + * This function uses the memory initialization block in the Arria10 ECC
> + * controller to initialize/clear the entire memory data and ECC data.
> + */
> +static int altr_init_memory_port(void __iomem *ioaddr)
> +{
> +	int limit = ALTR_A10_ECC_INIT_WATCHDOG_10US;
> +
> +	ecc_set_bits(ALTR_A10_ECC_INITA, (ioaddr + ALTR_A10_ECC_CTRL_OFST));
> +	while (limit--) {
> +		if (ecc_test_bits(ALTR_A10_ECC_INITCOMPLETEA,
> +				  (ioaddr + ALTR_A10_ECC_INITSTAT_OFST)))
> +			break;
> +		udelay(1);
> +	}
> +	if (limit < 0)
> +		return -EBUSY;
> +
> +	/* Clear any pending ECC interrupts */
> +	writel(ALTR_A10_ECC_ERRPENA_MASK,
> +	       (ioaddr + ALTR_A10_ECC_INTSTAT_OFST));
> +
> +	return 0;
> +}
> +
> +void socfpga_init_arria10_ocram_ecc(void)
> +{
> +	struct device_node *np;
> +	int ret = 0;
> +	void __iomem *ecc_block_base;
> +
> +	if (!sys_manager_base_addr) {
> +		pr_err("SOCFPGA: sys-mgr is not initialized\n");
> +		return;
> +	}
> +
> +	/* Find the OCRAM EDAC device tree node */
> +	np = of_find_compatible_node(NULL, NULL, "altr,socfpga-a10-ocram-ecc");
> +	if (!np) {
> +		pr_err("Unable to find socfpga-a10-ocram-ecc\n");
> +		return;
> +	}
> +
> +	/* Map the ECC Block */
> +	ecc_block_base = of_iomap(np, 0);
> +	of_node_put(np);
> +	if (!ecc_block_base) {
> +		pr_err("Unable to map OCRAM ECC block\n");
> +		return;
> +	}
> +
> +	/* Disable ECC */
> +	writel(ALTR_A10_OCRAM_ECC_EN_CTL,
> +	       sys_manager_base_addr + A10_SYSMGR_ECC_INTMASK_SET_OFST);
> +	ecc_clear_bits(ALTR_A10_ECC_SERRINTEN,
> +		       (ecc_block_base + ALTR_A10_ECC_ERRINTEN_OFST));
> +	ecc_clear_bits(ALTR_A10_OCRAM_ECC_EN_CTL,
> +		       (ecc_block_base + ALTR_A10_ECC_CTRL_OFST));
> +
> +	/* Use HW initialization block to initialize memory for ECC */
> +	ret = altr_init_memory_port(ecc_block_base);
> +	if (ret) {
> +		pr_err("ECC: cannot init OCRAM PORTA memory\n");
> +		return;

I realize that I'm not calling iounmap(ecc_block_base) and I'll fix that 
in the next revision with a goto.

> +	}
> +
> +	/* Enable ECC */
> +	ecc_set_bits(ALTR_A10_OCRAM_ECC_EN_CTL,
> +		     (ecc_block_base + ALTR_A10_ECC_CTRL_OFST));
> +	ecc_set_bits(ALTR_A10_ECC_SERRINTEN,
> +		     (ecc_block_base + ALTR_A10_ECC_ERRINTEN_OFST));
> +	writel(ALTR_A10_OCRAM_ECC_EN_CTL,
> +	       sys_manager_base_addr + A10_SYSMGR_ECC_INTMASK_CLR_OFST);
> +

The iounmap() will go here. I'd still like to hear review comments for 
the rest.

Thanks for reviewing.

> +	/* Ensure all writes complete */
> +	wmb();
> +}