On 6/17/2022 9:54 AM, Das, Nirmoy wrote:
On 6/16/2022 5:12 PM, priyanka.dandamudi@xxxxxxxxx wrote:From: Priyanka Dandamudi <priyanka.dandamudi@xxxxxxxxx> For testing purposes, support forcing the lmem_bar_size through a new modparam. In CI we only have a limited number of configurations for DG2, but we still need to be reasonably sure we get a usable device (also verifying we report the correct values for things like probed_cpu_visible_size etc) with all the potential lmem_bar sizes that we might expect see in the wild. v2: Update commit message and a minor modification.(Matt) Cc: Matthew Auld <matthew.auld@xxxxxxxxx> Signed-off-by: Priyanka Dandamudi <priyanka.dandamudi@xxxxxxxxx> --- drivers/gpu/drm/i915/gt/intel_region_lmem.c | 4 +++ drivers/gpu/drm/i915/i915_driver.c | 28 ++++++++++++++++++++- drivers/gpu/drm/i915/i915_params.c | 2 ++ drivers/gpu/drm/i915/i915_params.h | 1 + 4 files changed, 34 insertions(+), 1 deletion(-)diff --git a/drivers/gpu/drm/i915/gt/intel_region_lmem.c b/drivers/gpu/drm/i915/gt/intel_region_lmem.cindex e9c12e0d6f59..4614c30f878f 100644 --- a/drivers/gpu/drm/i915/gt/intel_region_lmem.c +++ b/drivers/gpu/drm/i915/gt/intel_region_lmem.c@@ -111,6 +111,10 @@ static struct intel_memory_region *setup_lmem(struct intel_gt *gt) flat_ccs_base = intel_gt_read_register(gt, XEHPSDV_FLAT_CCS_BASE_ADDR); flat_ccs_base = (flat_ccs_base >> XEHPSDV_CCS_BASE_SHIFT) * SZ_64K;+ /* XXX: Remove this once we have small-bar uapi bits */ + if (i915->params.lmem_bar_size > 0) + lmem_size = pci_resource_len(pdev, 2); + /* FIXME: Remove this when we have small-bar enabled */ if (pci_resource_len(pdev, 2) < lmem_size) {drm_err(&i915->drm, "System requires small-BAR support, which is currently unsupported on this kernel\n"); diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.cindex 4bdb471cb2e2..b2763b032012 100644 --- a/drivers/gpu/drm/i915/i915_driver.c +++ b/drivers/gpu/drm/i915/i915_driver.c@@ -362,8 +362,34 @@ static void i915_resize_lmem_bar(struct drm_i915_private *i915)u32 pci_cmd; int i; - if (!rebar_size) + if (i915->params.lmem_bar_size > 0) { + u32 lmem_bar_size; + u32 set_bit; + u32 rebar; + u32 msb; + int k; + + lmem_bar_size = i915->params.lmem_bar_size; + rebar = pci_rebar_get_possible_sizes(pdev, LMEM_BAR_NUM); + msb = __fls(rebar); + + for (k = msb; k >= 0; k--) { + set_bit = (1 << k); + + if (set_bit & rebar) { + if (set_bit == lmem_bar_size) { + rebar_size = 1ULL << (__fls(lmem_bar_size) + + BAR_SIZE_SHIFT);We have pci_rebar_bytes_to_size() helper function for this please use that.
What I mean is: these calculations are confusing(at-least for me). You could do: if (i915->params.lmem_bar_size) rebar_size = i915->params.lmem_bar_size (in bytes) elserebar_size = device lmem_size; --> we need this to make sure we only rebar till roundup_pow_of_two(), not max of pci_rebar_get_possible_sizes().
Now validate that pci_rebar_bytes_to_size(rebar_size) is within pci_rebar_get_possible_sizes() range.
Regards, Nirmoy
Nirmoy++ if (rebar_size == pci_resource_len(pdev, LMEM_BAR_NUM))+ return; + break; + } + } + } + } else if (!rebar_size) { return; + } /* Find out if root bus contains 64bit memory addressing */ while (root->parent)diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.cindex 701fbc98afa0..6fc475a5db61 100644 --- a/drivers/gpu/drm/i915/i915_params.c +++ b/drivers/gpu/drm/i915/i915_params.c@@ -204,6 +204,8 @@ i915_param_named_unsafe(request_timeout_ms, uint, 0600,i915_param_named_unsafe(lmem_size, uint, 0400,"Set the lmem size(in MiB) for each region. (default: 0, all memory)");+i915_param_named_unsafe(lmem_bar_size, uint, 0400, + "Set the lmem bar size(in MiB)."); static __always_inline void _print_param(struct drm_printer *p, const char *name,diff --git a/drivers/gpu/drm/i915/i915_params.h b/drivers/gpu/drm/i915/i915_params.hindex b5e7ea45d191..2733cb6cfe09 100644 --- a/drivers/gpu/drm/i915/i915_params.h +++ b/drivers/gpu/drm/i915/i915_params.h @@ -74,6 +74,7 @@ struct drm_printer; param(char *, force_probe, CONFIG_DRM_I915_FORCE_PROBE, 0400) \param(unsigned int, request_timeout_ms, CONFIG_DRM_I915_REQUEST_TIMEOUT, CONFIG_DRM_I915_REQUEST_TIMEOUT ? 0600 : 0) \param(unsigned int, lmem_size, 0, 0400) \ + param(unsigned int, lmem_bar_size, 0, 0400) \ /* leave bools at the end to not create holes */ \ param(bool, enable_hangcheck, true, 0600) \ param(bool, load_detect_test, false, 0600) \
