Re: [PATCH v4 6/8] hw/ppc: Pass dump-sizes property for fadump in device tree

[Sourabh Jain]

On 20/10/25 01:00, Aditya Gupta wrote:

On 25/10/18 04:50PM, Sourabh Jain wrote:

<...snip...>
+    uint32_t fadump_rgn_sizes[2][3] = {
+        {
+            cpu_to_be32(FADUMP_CPU_STATE_DATA),
+            0, 0 /* Calculated later */
+        },
+        {
+            cpu_to_be32(FADUMP_HPTE_REGION),
+            0, 0 /* HPTE region not implemented */
+        }

#nit-pick
Why to advertise if we don't support it? Kernel anyways ignores this for
now.

Nice catch.
PAPR doesn't seem to say about HPTE being optional anywhere, nor being
mandatory, so to be on safe side, exported it with 0 size until/if
it's implemented.

PAPR R1–7.3.30–7 says this (trimmed, emphasis mine):

        The platform 'must' present the RTAS property,
        “ibm,configure-kernel-dump-sizes” in the OF device tree, which
        describes space required for 'firmware defined dump sections', where
        the 'firmware defined dump sections' are:
                0x0001 = CPU State Data
                0x0002 = Hardware Page Table for Real Mode Region

Yeah lets advertise HPTE with zero size.

- Sourabh