Re: [Intel-gfx] [PATCH] drm/i915/dmc: Add MMIO range restrictions

["Srivatsa, Anusha" <anusha.srivatsa@intel.com>]

> -----Original Message-----
> From: De Marchi, Lucas <lucas.demarchi@intel.com>
> Sent: Tuesday, April 5, 2022 11:03 AM
> To: Srivatsa, Anusha <anusha.srivatsa@intel.com>
> Cc: intel-gfx@lists.freedesktop.org
> Subject: Re: [Intel-gfx] [PATCH] drm/i915/dmc: Add MMIO range restrictions
> 
> On Tue, Apr 05, 2022 at 10:14:29AM -0700, Anusha Srivatsa wrote:
> >Bspec has added some steps that check for DMC MMIO range before
> >programming them.
> >
> >v2: Fix for CI failure for v1
> >
> >Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> >Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
> >---
> > drivers/gpu/drm/i915/display/intel_dmc.c | 42
> ++++++++++++++++++++++++
> > 1 file changed, 42 insertions(+)
> >
> >diff --git a/drivers/gpu/drm/i915/display/intel_dmc.c
> >b/drivers/gpu/drm/i915/display/intel_dmc.c
> >index 257cf662f9f4..05d8e90854ec 100644
> >--- a/drivers/gpu/drm/i915/display/intel_dmc.c
> >+++ b/drivers/gpu/drm/i915/display/intel_dmc.c
> >@@ -103,6 +103,18 @@ MODULE_FIRMWARE(BXT_DMC_PATH);
> > #define DMC_V1_MAX_MMIO_COUNT		8
> > #define DMC_V3_MAX_MMIO_COUNT		20
> > #define DMC_V1_MMIO_START_RANGE		0x80000
> >+#define TGL_MAIN_MMIO_START		0x8F000
> >+#define TGL_MAIN_MMIO_END		0x8FFFF
> >+#define TGL_PIPEA_MMIO_START		0x92000
> >+#define TGL_PIPEA_MMIO_END		0x93FFF
> >+#define TGL_PIPEB_MMIO_START		0x96000
> >+#define TGL_PIPEB_MMIO_END		0x97FFF
> >+#define TGL_PIPEC_MMIO_START		0x9A000
> >+#define TGL_PIPEC_MMIO_END		0x9BFFF
> >+#define TGL_PIPED_MMIO_START		0x9E000
> >+#define TGL_PIPED_MMIO_END		0x9FFFF
> >+#define ADLP_PIPE_MMIO_START		0x5F000
> >+#define ADLP_PIPE_MMIO_END		0x5FFFF
> >
> > struct intel_css_header {
> > 	/* 0x09 for DMC */
> >@@ -374,6 +386,30 @@ static void dmc_set_fw_offset(struct intel_dmc
> *dmc,
> > 	}
> > }
> >
> >+static bool dmc_mmio_addr_sanity_check(struct intel_dmc *dmc, const
> >+u32 *mmioaddr,
> >+u32 mmio_count)
> >+{
> >+	struct drm_i915_private *i915 = container_of(dmc, typeof(*i915),
> dmc);
> >+	int i;
> >+
> >+	if (IS_DG2(i915) || IS_ALDERLAKE_P(i915)) {
> >+		for (i = 0; i < mmio_count; i++) {
> >+			if (!((mmioaddr[i] >= TGL_MAIN_MMIO_START &&
> mmioaddr[i] <= TGL_MAIN_MMIO_END) ||
> >+			      (mmioaddr[i] >= ADLP_PIPE_MMIO_START &&
> mmioaddr[i] <= ADLP_PIPE_MMIO_END)))
> >+				return false;
> >+		}
> >+	} else if (IS_TIGERLAKE(i915) || IS_DG1(i915) ||
> IS_ALDERLAKE_S(i915))
> >+		for (i = 0; i < mmio_count; i++) {
> >+			if (!((mmioaddr[i] >= TGL_MAIN_MMIO_START &&
> mmioaddr[i] <= TGL_MAIN_MMIO_END) ||
> >+			      (mmioaddr[i] >= TGL_PIPEA_MMIO_START &&
> mmioaddr[i] <= TGL_PIPEA_MMIO_END) ||
> >+			      (mmioaddr[i] >= TGL_PIPEB_MMIO_START &&
> mmioaddr[i] <= TGL_PIPEB_MMIO_END) ||
> >+			      (mmioaddr[i] >= TGL_PIPEC_MMIO_START &&
> mmioaddr[i] <= TGL_PIPEC_MMIO_END) ||
> >+			      (mmioaddr[i] >= TGL_PIPED_MMIO_START &&
> mmioaddr[i] <= TGL_PIPEC_MMIO_END)))
> >+				return false;
> 
> wonder if we should check for each pipe DMC range independently rather
> than just checking all the ranges.
 Can convert this to a switch case in that scenario. "If it is PIPE A then it must be within this range". But it will be 2 switches one for DG2 and ADLP and one for TGL and the rest which have individual ranges for every pipe. 

> >+	}
> >+	return true;
> >+}
> >+
> > static u32 parse_dmc_fw_header(struct intel_dmc *dmc,
> > 			       const struct intel_dmc_header_base
> *dmc_header,
> > 			       size_t rem_size, u8 dmc_id)
> >@@ -443,6 +479,12 @@ static u32 parse_dmc_fw_header(struct intel_dmc
> *dmc,
> > 		return 0;
> > 	}
> >
> >+	if (dmc_header->header_ver == 3) {
> 
> this also needs to be done for ver 2
For v2 though there has been no update about the start range. As in this mmio range is different from the RAM_MMIO_START range.

Anusha 
 
> Lucas De Marchi