On Mon, 4 Sep 2017 15:20:11 +0530 Anup Patel <anup.patel@xxxxxxxxxxxx> wrote: > Sorry for delayed response... > > On Tue, Aug 29, 2017 at 7:39 PM, Konrad Rzeszutek Wilk > <konrad.wilk@xxxxxxxxxx> wrote: > > On Tue, Aug 29, 2017 at 09:34:46AM +0530, Anup Patel wrote: > >> This patch adds Broadcom FlexRM low-level reset for > >> VFIO platform. > >> > > > > Is there an document that explains and /or details the various > > registers? > > Yes, there is a document but its not publicly accessible. > > >> It will do the following: > >> 1. Disable/Deactivate each FlexRM ring > >> 2. Flush each FlexRM ring > >> > >> The cleanup sequence for FlexRM rings is adapted from > >> Broadcom FlexRM mailbox driver. > >> > >> Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxxxx> > >> Reviewed-by: Oza Oza <oza.oza@xxxxxxxxxxxx> > >> Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx> > >> Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx> > >> --- > >> drivers/vfio/platform/reset/Kconfig | 9 ++ > >> drivers/vfio/platform/reset/Makefile | 1 + > >> .../vfio/platform/reset/vfio_platform_bcmflexrm.c | 100 +++++++++++++++++++++ > >> 3 files changed, 110 insertions(+) > >> create mode 100644 drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c > >> > >> diff --git a/drivers/vfio/platform/reset/Kconfig b/drivers/vfio/platform/reset/Kconfig > >> index 70cccc5..392e3c0 100644 > >> --- a/drivers/vfio/platform/reset/Kconfig > >> +++ b/drivers/vfio/platform/reset/Kconfig > >> @@ -13,3 +13,12 @@ config VFIO_PLATFORM_AMDXGBE_RESET > >> Enables the VFIO platform driver to handle reset for AMD XGBE > >> > >> If you don't know what to do here, say N. > >> + > >> +config VFIO_PLATFORM_BCMFLEXRM_RESET > >> + tristate "VFIO support for Broadcom FlexRM reset" > >> + depends on VFIO_PLATFORM && (ARCH_BCM_IPROC || COMPILE_TEST) > >> + default ARCH_BCM_IPROC > >> + help > >> + Enables the VFIO platform driver to handle reset for Broadcom FlexRM > >> + > >> + If you don't know what to do here, say N. > >> diff --git a/drivers/vfio/platform/reset/Makefile b/drivers/vfio/platform/reset/Makefile > >> index 93f4e23..8d9874b 100644 > >> --- a/drivers/vfio/platform/reset/Makefile > >> +++ b/drivers/vfio/platform/reset/Makefile > >> @@ -5,3 +5,4 @@ ccflags-y += -Idrivers/vfio/platform > >> > >> obj-$(CONFIG_VFIO_PLATFORM_CALXEDAXGMAC_RESET) += vfio-platform-calxedaxgmac.o > >> obj-$(CONFIG_VFIO_PLATFORM_AMDXGBE_RESET) += vfio-platform-amdxgbe.o > >> +obj-$(CONFIG_VFIO_PLATFORM_BCMFLEXRM_RESET) += vfio_platform_bcmflexrm.o > >> diff --git a/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c b/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c > >> new file mode 100644 > >> index 0000000..966a813 > >> --- /dev/null > >> +++ b/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c > >> @@ -0,0 +1,100 @@ > >> +/* > >> + * Copyright (C) 2017 Broadcom > >> + * > >> + * This program is free software; you can redistribute it and/or modify > >> + * it under the terms of the GNU General Public License version 2 as > >> + * published by the Free Software Foundation. > >> + * > >> + * This program is distributed in the hope that it will be useful, > >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of > >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > >> + * GNU General Public License for more details. > >> + * > >> + * You should have received a copy of the GNU General Public License > >> + * along with this program. If not, see <http://www.gnu.org/licenses/>. > >> + */ > >> + > >> +/* > >> + * This driver provides reset support for Broadcom FlexRM ring manager > >> + * to VFIO platform. > >> + */ > >> + > >> +#include <linux/delay.h> > >> +#include <linux/init.h> > >> +#include <linux/io.h> > >> +#include <linux/kernel.h> > >> +#include <linux/module.h> > >> + > >> +#include "vfio_platform_private.h" > >> + > >> +/* FlexRM configuration */ > >> +#define RING_REGS_SIZE 0x10000 > >> +#define RING_VER_MAGIC 0x76303031 > >> + > >> +/* Per-Ring register offsets */ > >> +#define RING_VER 0x000 > >> +#define RING_CONTROL 0x034 > >> +#define RING_FLUSH_DONE 0x038 > >> + > >> +/* Register RING_CONTROL fields */ > >> +#define CONTROL_FLUSH_SHIFT 5 > >> + > >> +/* Register RING_FLUSH_DONE fields */ > >> +#define FLUSH_DONE_MASK 0x1 > >> + > >> +static int vfio_platform_bcmflexrm_shutdown(void __iomem *ring) > >> +{ > >> + unsigned int timeout; > >> + > >> + /* Disable/inactivate ring */ > >> + writel_relaxed(0x0, ring + RING_CONTROL); > >> + > >> + /* Flush ring with timeout of 1s */ > >> + timeout = 1000; > > > > Perhaps a #define for this value? > > This magic value 1000 makes it explicit that we try till 1 second > because inside the loop we have mdelay(1). > > > > >> + writel_relaxed(BIT(CONTROL_FLUSH_SHIFT), ring + RING_CONTROL); > >> + do { > >> + if (readl_relaxed(ring + RING_FLUSH_DONE) & FLUSH_DONE_MASK) > >> + break; > >> + mdelay(1); > >> + } while (--timeout); > >> + > >> + if (!timeout) { > >> + pr_warn("VFIO FlexRM shutdown timeout\n"); Since you're planning a new version anyway, perhaps we could also pass the device through and use a dev_warn here so we can associate this error to a specific device. Perhaps even knowing which ring on the device encountered the timeout would be useful. Thanks, Alex > >> + return -ETIMEDOUT; > >> + } > >> + > >> + return 0; > >> +} > > There is a correction in the sequence suggested by HW folks. > > After above, we need to clear the FLUSH bit in RING_CONTROL > register and then wait for FLUSH_DONE bit to be cleared in > RING_FLUSH_DONE register. > > This was missed out previously due to incomplete documentation. > > >> + > >> +static int vfio_platform_bcmflexrm_reset(struct vfio_platform_device *vdev) > >> +{ > >> + int rc = 0; > >> + void __iomem *ring; > >> + struct vfio_platform_region *reg = &vdev->regions[0]; > >> + > >> + /* Map FlexRM ring registers if not mapped */ > >> + if (!reg->ioaddr) { > >> + reg->ioaddr = ioremap_nocache(reg->addr, reg->size); > >> + if (!reg->ioaddr) > >> + return -ENOMEM; > >> + } > >> + > >> + /* Discover and shutdown each FlexRM ring */ > >> + for (ring = reg->ioaddr; > >> + ring < (reg->ioaddr + reg->size); ring += RING_REGS_SIZE) { > >> + if (readl_relaxed(ring + RING_VER) == RING_VER_MAGIC) { > >> + rc = vfio_platform_bcmflexrm_shutdown(ring); > >> + if (rc) > >> + break; > > > > You sure? Don't you want to continue trying to reset all of them and > > then return rc at the end? > > Yes, I think its better to reset all even if few fail. I will update this > accordingly. > > Thanks, > Anup
