drm/msm: Allocate memory for disp snapshot with kvzalloc()

With the "drm/msm: add a display mmu fault handler" series [1] we saw
issues in the field where memory allocation was failing when
allocating space for registers in msm_disp_state_dump_regs().
Specifically we were seeing an order 5 allocation fail. It's not
surprising that order 5 allocations will sometimes fail after the
system has been up and running for a while.

There's no need here for contiguous memory. Change the allocation to
kvzalloc() which should make it much less likely to fail.

[1] https://lore.kernel.org/r/20240628214848.4075651-1-quic_abhinavk@quicinc.com/

Fixes: 98659487b845 ("drm/msm: add support to take dpu snapshot")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/619658/
Link: https://lore.kernel.org/r/20241014093605.2.I72441365ffe91f3dceb17db0a8ec976af8139590@changeid
Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>

diff --git a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c
index bb149281d31faac7b7099bb997f8ab1f6a0255ed..4d55e3cf570f0b818b9387f3e7763294e1f8e0f4 100644 (file)
--- a/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c
+++ b/drivers/gpu/drm/msm/disp/msm_disp_snapshot_util.c
@@ -26,7 +26,7 @@ static void msm_disp_state_dump_regs(u32 **reg, u32 aligned_len, void __iomem *b
        end_addr = base_addr + aligned_len;
 
        if (!(*reg))
-               *reg = kzalloc(len_padded, GFP_KERNEL);
+               *reg = kvzalloc(len_padded, GFP_KERNEL);
 
        if (*reg)
                dump_addr = *reg;
@@ -162,7 +162,7 @@ void msm_disp_state_free(void *data)
 
        list_for_each_entry_safe(block, tmp, &disp_state->blocks, node) {
                list_del(&block->node);
-               kfree(block->state);
+               kvfree(block->state);
                kfree(block);
        }