On Fri, 11 Apr 2025 16:17:56 +0100
Karunika Choo <karunika.c...@arm.com> wrote:
> On 10/04/2025 17:46, Boris Brezillon wrote:
> > On Thu, 10 Apr 2025 17:35:46 +0100
> > Karunika Choo <karunika.c...@arm.com> wrote:
> >
> >> This patch adds 64-bit register accessors to simplify register access in
> >> Panthor. It also adds 32-bit and 64-bit variants for read_poll_timeout.
> >>
> >> This patch also updates Panthor to use the new 64-bit accessors and poll
> >> functions.
> >>
> >> Signed-off-by: Karunika Choo <karunika.c...@arm.com>
> >> ---
> >> drivers/gpu/drm/panthor/panthor_device.h | 71 ++++++++++++
> >> drivers/gpu/drm/panthor/panthor_fw.c | 9 +-
> >> drivers/gpu/drm/panthor/panthor_gpu.c | 142 ++++++-----------------
> >> drivers/gpu/drm/panthor/panthor_mmu.c | 34 ++----
> >> drivers/gpu/drm/panthor/panthor_regs.h | 6 -
> >> 5 files changed, 124 insertions(+), 138 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/panthor/panthor_device.h
> >> b/drivers/gpu/drm/panthor/panthor_device.h
> >> index da6574021664..5028e25f5e0d 100644
> >> --- a/drivers/gpu/drm/panthor/panthor_device.h
> >> +++ b/drivers/gpu/drm/panthor/panthor_device.h
> >> @@ -428,4 +428,75 @@ static int panthor_request_ ## __name ## _irq(struct
> >> panthor_device *ptdev, \
> >>
> >> extern struct workqueue_struct *panthor_cleanup_wq;
> >>
> >> +static inline void gpu_write(struct panthor_device *ptdev, u32 reg, u32
> >> data)
> >> +{
> >> + writel(data, ptdev->iomem + reg);
> >> +}
> >> +
> >> +static inline u32 gpu_read(struct panthor_device *ptdev, u32 reg)
> >> +{
> >> + return readl(ptdev->iomem + reg);
> >> +}
> >> +
> >> +static inline u32 gpu_read_relaxed(struct panthor_device *ptdev, u32 reg)
> >> +{
> >> + return readl_relaxed(ptdev->iomem + reg);
> >> +}
> >> +
> >> +static inline void gpu_write64(struct panthor_device *ptdev, u32 reg, u64
> >> data)
> >> +{
> >> + gpu_write(ptdev, reg, lower_32_bits(data));
> >> + gpu_write(ptdev, reg + 4, upper_32_bits(data));
> >> +}
> >> +
> >> +static inline u64 gpu_read64(struct panthor_device *ptdev, u32 reg)
> >> +{
> >> + return (gpu_read(ptdev, reg) | ((u64)gpu_read(ptdev, reg + 4) << 32));
> >> +}
> >> +
> >> +static inline u64 gpu_read64_relaxed(struct panthor_device *ptdev, u32
> >> reg)
> >> +{
> >> + return (gpu_read_relaxed(ptdev, reg) |
> >> + ((u64)gpu_read_relaxed(ptdev, reg + 4) << 32));
> >> +}
> >> +
> >> +static inline u64 gpu_read64_counter(struct panthor_device *ptdev, u32
> >> reg)
> >> +{
> >> + u32 lo, hi1, hi2;
> >> + do {
> >> + hi1 = gpu_read(ptdev, reg + 4);
> >> + lo = gpu_read(ptdev, reg);
> >> + hi2 = gpu_read(ptdev, reg + 4);
> >> + } while (hi1 != hi2);
> >> + return lo | ((u64)hi2 << 32);
> >> +}
> >> +
> >> +#define gpu_read_poll_timeout(dev, reg, val, cond, delay_us, timeout_us)
> >> \
> >> + read_poll_timeout(gpu_read, val, cond, delay_us, timeout_us, false, \
> >> + dev, reg)
> >
> > nit: can use use tabs to pad till the '\' at the end of the line so we
> > can have a consistent formatting across these definitions?
> >
> >> +
> >> +#define gpu_read_poll_timeout_atomic(dev, reg, val, cond, delay_us,
> >> \
> >> + timeout_us) \
> >> + read_poll_timeout_atomic(gpu_read, val, cond, delay_us, timeout_us, \
> >> + false, dev, reg)
> >> +
> >> +#define gpu_read64_poll_timeout(dev, reg, val, cond, delay_us,
> >> timeout_us) \
> >> + read_poll_timeout(gpu_read64, val, cond, delay_us, timeout_us, false, \
> >> + dev, reg)
> >> +
> >> +#define gpu_read64_poll_timeout_atomic(dev, reg, val, cond, delay_us,
> >> \
> >> + timeout_us) \
> >> + read_poll_timeout_atomic(gpu_read64, val, cond, delay_us, timeout_us, \
> >> + false, dev, reg)
> >> +
> >> +#define gpu_read_relaxed_poll_timeout_atomic(dev, reg, val, cond,
> >> delay_us, \
> >> + timeout_us) \
> >> + read_poll_timeout_atomic(gpu_read_relaxed, val, cond, delay_us, \
> >> + timeout_us, false, dev, reg)
> >> +
> >> +#define gpu_read64_relaxed_poll_timeout(dev, reg, val, cond, delay_us,
> >> \
> >> + timeout_us) \
> >> + read_poll_timeout(gpu_read64_relaxed, val, cond, delay_us, timeout_us, \
> >> + false, dev, reg)
> >> +
> >> #endif
> >> diff --git a/drivers/gpu/drm/panthor/panthor_fw.c
> >> b/drivers/gpu/drm/panthor/panthor_fw.c
> >> index 0f52766a3120..ecfbe0456f89 100644
> >> --- a/drivers/gpu/drm/panthor/panthor_fw.c
> >> +++ b/drivers/gpu/drm/panthor/panthor_fw.c
> >> @@ -1059,8 +1059,8 @@ static void panthor_fw_stop(struct panthor_device
> >> *ptdev)
> >> u32 status;
> >>
> >> gpu_write(ptdev, MCU_CONTROL, MCU_CONTROL_DISABLE);
> >> - if (readl_poll_timeout(ptdev->iomem + MCU_STATUS, status,
> >> - status == MCU_STATUS_DISABLED, 10, 100000))
> >> + if (gpu_read_poll_timeout(ptdev, MCU_STATUS, status,
> >> + status == MCU_STATUS_DISABLED, 10, 100000))
> >> drm_err(&ptdev->base, "Failed to stop MCU");
> >> }
> >>
> >> @@ -1085,8 +1085,9 @@ void panthor_fw_pre_reset(struct panthor_device
> >> *ptdev, bool on_hang)
> >>
> >> panthor_fw_update_reqs(glb_iface, req, GLB_HALT, GLB_HALT);
> >> gpu_write(ptdev, CSF_DOORBELL(CSF_GLB_DOORBELL_ID), 1);
> >> - if (!readl_poll_timeout(ptdev->iomem + MCU_STATUS, status,
> >> - status == MCU_STATUS_HALT, 10, 100000))
> >> {
> >> + if (!gpu_read_poll_timeout(ptdev, MCU_STATUS, status,
> >> + status == MCU_STATUS_HALT, 10,
> >> + 100000)) {
> >> ptdev->reset.fast = true;
> >> } else {
> >> drm_warn(&ptdev->base, "Failed to cleanly suspend MCU");
> >> diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c
> >> b/drivers/gpu/drm/panthor/panthor_gpu.c
> >> index 671049020afa..fd09f0928019 100644
> >> --- a/drivers/gpu/drm/panthor/panthor_gpu.c
> >> +++ b/drivers/gpu/drm/panthor/panthor_gpu.c
> >> @@ -108,14 +108,9 @@ static void panthor_gpu_init_info(struct
> >> panthor_device *ptdev)
> >>
> >> ptdev->gpu_info.as_present = gpu_read(ptdev, GPU_AS_PRESENT);
> >>
> >> - ptdev->gpu_info.shader_present = gpu_read(ptdev, GPU_SHADER_PRESENT_LO);
> >> - ptdev->gpu_info.shader_present |= (u64)gpu_read(ptdev,
> >> GPU_SHADER_PRESENT_HI) << 32;
> >> -
> >> - ptdev->gpu_info.tiler_present = gpu_read(ptdev, GPU_TILER_PRESENT_LO);
> >> - ptdev->gpu_info.tiler_present |= (u64)gpu_read(ptdev,
> >> GPU_TILER_PRESENT_HI) << 32;
> >> -
> >> - ptdev->gpu_info.l2_present = gpu_read(ptdev, GPU_L2_PRESENT_LO);
> >> - ptdev->gpu_info.l2_present |= (u64)gpu_read(ptdev, GPU_L2_PRESENT_HI)
> >> << 32;
> >> + ptdev->gpu_info.shader_present = gpu_read64(ptdev,
> >> GPU_SHADER_PRESENT_LO);
> >> + ptdev->gpu_info.tiler_present = gpu_read64(ptdev, GPU_TILER_PRESENT_LO);
> >> + ptdev->gpu_info.l2_present = gpu_read64(ptdev, GPU_L2_PRESENT_LO);
> >
> > Now that we have proper 64-bit accessors, I think I would drop the
> > _LO/_HI definitions and just go a single def per register that replaces
> > the _LO one.
>
> Hello,
>
> please find a link to v2 below that addresses your comments.
>
> -
> https://lore.kernel.org/dri-devel/20250411151140.1815435-1-karunika.c...@arm.com/
Looks all good now.
Thanks!
Boris
