On 14.10.2022 16:02, Matt Roper wrote:
> MTL's graphics IP (Xe_LPG) once again changes the multicast register
> types and steering details. Key changes from past platforms:
> * The number of instances of some MCR types (NODE, OAAL2, and GAM) vary
> according to the MTL subplatform and cannot be read from fuse
> registers. However steering to instance #0 will always provided a
> non-terminated value, so we can lump these all into a single
> "instance0" table.
> * The MCR steering register (and its bitfields) has changed.
>
> Unlike past platforms, we will be explicitly steering all types of MCR
> accesses, including those for "SLICE" and "DSS" ranges; we no longer
> rely on implicit steering. On previous platforms, various
> hardware/firmware agents that needed to access registers typically had
> their own steering control registers, allowing them to perform multicast
> steering without clobbering the CPU/kernel steering. Starting with MTL,
> more of these agents now share a single steering register (0xFD4) and it
> is no longer safe for us to assume that the value will remain unchanged
> from how we initialized it during startup. There is also a slight
> chance of race conditions between the driver and a hardware/firmware
> agent, so the hardware provides a semaphore register that can be used to
> coordinate access to the steering register. Support for the semaphore
> register will be introduced in a future patch.
>
> v2:
> - Use Xe_LPG terminology instead of "MTL 3D" since it's the IP version
> we're matching on now rather than the platform.
> - Don't combine l3bank and mslice masks into a union. It's not related
> to the other changes here and we might still need both of them on
> some future platform.
> - Separate debug dumping of steering settings to a separate helper
> function. (Tvrtko)
> - Update debug dumping to include DSS ranges (and future-proof it so
> that any new ranges added on future platforms will also be dumped).
> - Restore MULTICAST bit at the end of rw_with_mcr_steering_fw() if we
> cleared it. Also force the MULTICAST bit to true at the beginning of
> multicast writes just to be safe. (Bala)
>
> Bspec: 67788, 67112
> Cc: Radhakrishna Sripada <radhakrishna.sripada@xxxxxxxxx>
> Cc: Balasubramani Vivekanandan <balasubramani.vivekanandan@xxxxxxxxx>
> Signed-off-by: Matt Roper <matthew.d.roper@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/gt/intel_gt_mcr.c | 135 +++++++++++++++++---
> drivers/gpu/drm/i915/gt/intel_gt_regs.h | 5 +
> drivers/gpu/drm/i915/gt/intel_gt_types.h | 1 +
> drivers/gpu/drm/i915/gt/intel_workarounds.c | 33 ++++-
> drivers/gpu/drm/i915/i915_pci.c | 1 +
> 5 files changed, 154 insertions(+), 21 deletions(-)
Reviewed-by: Balasubramani Vivekanandan <balasubramani.vivekanandan@xxxxxxxxx>
Regards,
Bala
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c
> index 349074bf365f..23a1ef9659bf 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_mcr.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_mcr.c
> @@ -41,6 +41,7 @@ static const char * const intel_steering_types[] = {
> "MSLICE",
> "LNCF",
> "GAM",
> + "DSS",
> "INSTANCE 0",
> };
>
> @@ -99,9 +100,40 @@ static const struct intel_mmio_range pvc_instance0_steering_table[] = {
> {},
> };
>
> +static const struct intel_mmio_range xelpg_instance0_steering_table[] = {
> + { 0x000B00, 0x000BFF }, /* SQIDI */
> + { 0x001000, 0x001FFF }, /* SQIDI */
> + { 0x004000, 0x0048FF }, /* GAM */
> + { 0x008700, 0x0087FF }, /* SQIDI */
> + { 0x00B000, 0x00B0FF }, /* NODE */
> + { 0x00C800, 0x00CFFF }, /* GAM */
> + { 0x00D880, 0x00D8FF }, /* NODE */
> + { 0x00DD00, 0x00DDFF }, /* OAAL2 */
> + {},
> +};
> +
> +static const struct intel_mmio_range xelpg_l3bank_steering_table[] = {
> + { 0x00B100, 0x00B3FF },
> + {},
> +};
> +
> +/* DSS steering is used for SLICE ranges as well */
> +static const struct intel_mmio_range xelpg_dss_steering_table[] = {
> + { 0x005200, 0x0052FF }, /* SLICE */
> + { 0x005500, 0x007FFF }, /* SLICE */
> + { 0x008140, 0x00815F }, /* SLICE (0x8140-0x814F), DSS (0x8150-0x815F) */
> + { 0x0094D0, 0x00955F }, /* SLICE (0x94D0-0x951F), DSS (0x9520-0x955F) */
> + { 0x009680, 0x0096FF }, /* DSS */
> + { 0x00D800, 0x00D87F }, /* SLICE */
> + { 0x00DC00, 0x00DCFF }, /* SLICE */
> + { 0x00DE80, 0x00E8FF }, /* DSS (0xE000-0xE0FF reserved) */
> +};
> +
> void intel_gt_mcr_init(struct intel_gt *gt)
> {
> struct drm_i915_private *i915 = gt->i915;
> + unsigned long fuse;
> + int i;
>
> /*
> * An mslice is unavailable only if both the meml3 for the slice is
> @@ -119,7 +151,22 @@ void intel_gt_mcr_init(struct intel_gt *gt)
> drm_warn(&i915->drm, "mslice mask all zero!\n");
> }
>
> - if (IS_PONTEVECCHIO(i915)) {
> + if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70) &&
> + gt->type == GT_PRIMARY) {
> + fuse = REG_FIELD_GET(GT_L3_EXC_MASK,
> + intel_uncore_read(gt->uncore, XEHP_FUSE4));
> +
> + /*
> + * Despite the register field being named "exclude mask" the
> + * bits actually represent enabled banks (two banks per bit).
> + */
> + for_each_set_bit(i, &fuse, 3)
> + gt->info.l3bank_mask |= 0x3 << 2 * i;
> +
> + gt->steering_table[INSTANCE0] = xelpg_instance0_steering_table;
> + gt->steering_table[L3BANK] = xelpg_l3bank_steering_table;
> + gt->steering_table[DSS] = xelpg_dss_steering_table;
> + } else if (IS_PONTEVECCHIO(i915)) {
> gt->steering_table[INSTANCE0] = pvc_instance0_steering_table;
> } else if (IS_DG2(i915)) {
> gt->steering_table[MSLICE] = xehpsdv_mslice_steering_table;
> @@ -184,7 +231,19 @@ static u32 rw_with_mcr_steering_fw(struct intel_uncore *uncore,
>
> lockdep_assert_held(&uncore->lock);
>
> - if (GRAPHICS_VER(uncore->i915) >= 11) {
> + if (GRAPHICS_VER_FULL(uncore->i915) >= IP_VER(12, 70)) {
> + /*
> + * Always leave the hardware in multicast mode when doing reads
> + * (see comment about Wa_22013088509 below) and only change it
> + * to unicast mode when doing writes of a specific instance.
> + *
> + * No need to save old steering reg value.
> + */
> + intel_uncore_write_fw(uncore, MTL_MCR_SELECTOR,
> + REG_FIELD_PREP(MTL_MCR_GROUPID, group) |
> + REG_FIELD_PREP(MTL_MCR_INSTANCEID, instance) |
> + (rw_flag == FW_REG_READ) ? GEN11_MCR_MULTICAST : 0);
> + } else if (GRAPHICS_VER(uncore->i915) >= 11) {
> mcr_mask = GEN11_MCR_SLICE_MASK | GEN11_MCR_SUBSLICE_MASK;
> mcr_ss = GEN11_MCR_SLICE(group) | GEN11_MCR_SUBSLICE(instance);
>
> @@ -202,26 +261,40 @@ static u32 rw_with_mcr_steering_fw(struct intel_uncore *uncore,
> */
> if (rw_flag == FW_REG_WRITE)
> mcr_mask |= GEN11_MCR_MULTICAST;
> +
> + mcr = intel_uncore_read_fw(uncore, GEN8_MCR_SELECTOR);
> + old_mcr = mcr;
> +
> + mcr &= ~mcr_mask;
> + mcr |= mcr_ss;
> + intel_uncore_write_fw(uncore, GEN8_MCR_SELECTOR, mcr);
> } else {
> mcr_mask = GEN8_MCR_SLICE_MASK | GEN8_MCR_SUBSLICE_MASK;
> mcr_ss = GEN8_MCR_SLICE(group) | GEN8_MCR_SUBSLICE(instance);
> - }
>
> - old_mcr = mcr = intel_uncore_read_fw(uncore, GEN8_MCR_SELECTOR);
> + mcr = intel_uncore_read_fw(uncore, GEN8_MCR_SELECTOR);
> + old_mcr = mcr;
>
> - mcr &= ~mcr_mask;
> - mcr |= mcr_ss;
> - intel_uncore_write_fw(uncore, GEN8_MCR_SELECTOR, mcr);
> + mcr &= ~mcr_mask;
> + mcr |= mcr_ss;
> + intel_uncore_write_fw(uncore, GEN8_MCR_SELECTOR, mcr);
> + }
>
> if (rw_flag == FW_REG_READ)
> val = intel_uncore_read_fw(uncore, mcr_reg_cast(reg));
> else
> intel_uncore_write_fw(uncore, mcr_reg_cast(reg), value);
>
> - mcr &= ~mcr_mask;
> - mcr |= old_mcr & mcr_mask;
> -
> - intel_uncore_write_fw(uncore, GEN8_MCR_SELECTOR, mcr);
> + /*
> + * For pre-MTL platforms, we need to restore the old value of the
> + * steering control register to ensure that implicit steering continues
> + * to behave as expected. For MTL and beyond, we need only reinstate
> + * the 'multicast' bit (and only if we did a write that cleared it).
> + */
> + if (GRAPHICS_VER_FULL(uncore->i915) >= IP_VER(12, 70) && rw_flag == FW_REG_WRITE)
> + intel_uncore_write_fw(uncore, MTL_MCR_SELECTOR, GEN11_MCR_MULTICAST);
> + else if (GRAPHICS_VER_FULL(uncore->i915) < IP_VER(12, 70))
> + intel_uncore_write_fw(uncore, GEN8_MCR_SELECTOR, old_mcr);
>
> return val;
> }
> @@ -296,6 +369,13 @@ void intel_gt_mcr_unicast_write(struct intel_gt *gt, i915_mcr_reg_t reg, u32 val
> void intel_gt_mcr_multicast_write(struct intel_gt *gt,
> i915_mcr_reg_t reg, u32 value)
> {
> + /*
> + * Ensure we have multicast behavior, just in case some non-i915 agent
> + * left the hardware in unicast mode.
> + */
> + if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70))
> + intel_uncore_write_fw(gt->uncore, MTL_MCR_SELECTOR, GEN11_MCR_MULTICAST);
> +
> intel_uncore_write(gt->uncore, mcr_reg_cast(reg), value);
> }
>
> @@ -312,6 +392,13 @@ void intel_gt_mcr_multicast_write(struct intel_gt *gt,
> */
> void intel_gt_mcr_multicast_write_fw(struct intel_gt *gt, i915_mcr_reg_t reg, u32 value)
> {
> + /*
> + * Ensure we have multicast behavior, just in case some non-i915 agent
> + * left the hardware in unicast mode.
> + */
> + if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70))
> + intel_uncore_write_fw(gt->uncore, MTL_MCR_SELECTOR, GEN11_MCR_MULTICAST);
> +
> intel_uncore_write_fw(gt->uncore, mcr_reg_cast(reg), value);
> }
>
> @@ -389,6 +476,8 @@ static void get_nonterminated_steering(struct intel_gt *gt,
> enum intel_steering_type type,
> u8 *group, u8 *instance)
> {
> + u32 dss;
> +
> switch (type) {
> case L3BANK:
> *group = 0; /* unused */
> @@ -412,6 +501,11 @@ static void get_nonterminated_steering(struct intel_gt *gt,
> *group = IS_DG2(gt->i915) ? 1 : 0;
> *instance = 0;
> break;
> + case DSS:
> + dss = intel_sseu_find_first_xehp_dss(>->info.sseu, 0, 0);
> + *group = dss / GEN_DSS_PER_GSLICE;
> + *instance = dss % GEN_DSS_PER_GSLICE;
> + break;
> case INSTANCE0:
> /*
> * There are a lot of MCR types for which instance (0, 0)
> @@ -544,11 +638,20 @@ static void report_steering_type(struct drm_printer *p,
> void intel_gt_mcr_report_steering(struct drm_printer *p, struct intel_gt *gt,
> bool dump_table)
> {
> - drm_printf(p, "Default steering: group=0x%x, instance=0x%x\n",
> - gt->default_steering.groupid,
> - gt->default_steering.instanceid);
> -
> - if (IS_PONTEVECCHIO(gt->i915)) {
> + /*
> + * Starting with MTL we no longer have default steering;
> + * all ranges are explicitly steered.
> + */
> + if (GRAPHICS_VER_FULL(gt->i915) < IP_VER(12, 70))
> + drm_printf(p, "Default steering: group=0x%x, instance=0x%x\n",
> + gt->default_steering.groupid,
> + gt->default_steering.instanceid);
> +
> + if (GRAPHICS_VER_FULL(gt->i915) >= IP_VER(12, 70)) {
> + for (int i = 0; i < NUM_STEERING_TYPES; i++)
> + if (gt->steering_table[i])
> + report_steering_type(p, gt, i, dump_table);
> + } else if (IS_PONTEVECCHIO(gt->i915)) {
> report_steering_type(p, gt, INSTANCE0, dump_table);
> } else if (HAS_MSLICE_STEERING(gt->i915)) {
> report_steering_type(p, gt, MSLICE, dump_table);
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> index 754c27dd1e82..810283131f0a 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> @@ -59,6 +59,7 @@
> #define GMD_ID_MEDIA _MMIO(MTL_MEDIA_GSI_BASE + 0xd8c)
>
> #define MCFG_MCR_SELECTOR _MMIO(0xfd0)
> +#define MTL_MCR_SELECTOR _MMIO(0xfd4)
> #define SF_MCR_SELECTOR _MMIO(0xfd8)
> #define GEN8_MCR_SELECTOR _MMIO(0xfdc)
> #define GAM_MCR_SELECTOR _MMIO(0xfe0)
> @@ -71,6 +72,8 @@
> #define GEN11_MCR_SLICE_MASK GEN11_MCR_SLICE(0xf)
> #define GEN11_MCR_SUBSLICE(subslice) (((subslice) & 0x7) << 24)
> #define GEN11_MCR_SUBSLICE_MASK GEN11_MCR_SUBSLICE(0x7)
> +#define MTL_MCR_GROUPID REG_GENMASK(11, 8)
> +#define MTL_MCR_INSTANCEID REG_GENMASK(3, 0)
>
> #define IPEIR_I965 _MMIO(0x2064)
> #define IPEHR_I965 _MMIO(0x2068)
> @@ -531,6 +534,8 @@
> #define GEN6_MBCTL_BOOT_FETCH_MECH (1 << 0)
>
> /* Fuse readout registers for GT */
> +#define XEHP_FUSE4 _MMIO(0x9114)
> +#define GT_L3_EXC_MASK REG_GENMASK(6, 4)
> #define GEN10_MIRROR_FUSE3 _MMIO(0x9118)
> #define GEN10_L3BANK_PAIR_COUNT 4
> #define GEN10_L3BANK_MASK 0x0F
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_types.h b/drivers/gpu/drm/i915/gt/intel_gt_types.h
> index 30003d68fd51..0bb73d110a84 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_types.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_types.h
> @@ -60,6 +60,7 @@ enum intel_steering_type {
> MSLICE,
> LNCF,
> GAM,
> + DSS,
>
> /*
> * On some platforms there are multiple types of MCR registers that
> diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> index dadb60e6a58f..711a31935857 100644
> --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> @@ -1128,18 +1128,23 @@ static void __set_mcr_steering(struct i915_wa_list *wal,
> wa_write_clr_set(wal, steering_reg, mcr_mask, mcr);
> }
>
> -static void __add_mcr_wa(struct intel_gt *gt, struct i915_wa_list *wal,
> - unsigned int slice, unsigned int subslice)
> +static void debug_dump_steering(struct intel_gt *gt)
> {
> struct drm_printer p = drm_debug_printer("MCR Steering:");
>
> + if (drm_debug_enabled(DRM_UT_DRIVER))
> + intel_gt_mcr_report_steering(&p, gt, false);
> +}
> +
> +static void __add_mcr_wa(struct intel_gt *gt, struct i915_wa_list *wal,
> + unsigned int slice, unsigned int subslice)
> +{
> __set_mcr_steering(wal, GEN8_MCR_SELECTOR, slice, subslice);
>
> gt->default_steering.groupid = slice;
> gt->default_steering.instanceid = subslice;
>
> - if (drm_debug_enabled(DRM_UT_DRIVER))
> - intel_gt_mcr_report_steering(&p, gt, false);
> + debug_dump_steering(gt);
> }
>
> static void
> @@ -1581,12 +1586,30 @@ pvc_gt_workarounds_init(struct intel_gt *gt, struct i915_wa_list *wal)
> wa_mcr_write_clr(wal, GEN8_MISCCPCTL, GEN12_DOP_CLOCK_GATE_RENDER_ENABLE);
> }
>
> +static void
> +xelpg_gt_workarounds_init(struct intel_gt *gt, struct i915_wa_list *wal)
> +{
> + /* FIXME: Actual workarounds will be added in future patch(es) */
> +
> + /*
> + * Unlike older platforms, we no longer setup implicit steering here;
> + * all MCR accesses are explicitly steered.
> + */
> + debug_dump_steering(gt);
> +}
> +
> static void
> gt_init_workarounds(struct intel_gt *gt, struct i915_wa_list *wal)
> {
> struct drm_i915_private *i915 = gt->i915;
>
> - if (IS_PONTEVECCHIO(i915))
> + /* FIXME: Media GT handling will be added in an upcoming patch */
> + if (gt->type == GT_MEDIA)
> + return;
> +
> + if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70))
> + xelpg_gt_workarounds_init(gt, wal);
> + else if (IS_PONTEVECCHIO(i915))
> pvc_gt_workarounds_init(gt, wal);
> else if (IS_DG2(i915))
> dg2_gt_workarounds_init(gt, wal);
> diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c
> index 40bb06c5cdc0..496df0f547f4 100644
> --- a/drivers/gpu/drm/i915/i915_pci.c
> +++ b/drivers/gpu/drm/i915/i915_pci.c
> @@ -1143,6 +1143,7 @@ static const struct intel_device_info mtl_info = {
> .extra_gt_list = xelpmp_extra_gt,
> .has_flat_ccs = 0,
> .has_gmd_id = 1,
> + .has_mslice_steering = 0,
> .has_snoop = 1,
> .__runtime.memory_regions = REGION_SMEM | REGION_STOLEN_LMEM,
> .__runtime.platform_engine_mask = BIT(RCS0) | BIT(BCS0) | BIT(CCS0),
> --
> 2.37.3
>
