[PATCH v2] powerpc/xive: Add some error handling code to 'xive_spapr_init()'

From: Christophe JAILLET
Date: Tue Feb 01 2022 - 07:31:27 EST


'xive_irq_bitmap_add()' can return -ENOMEM.
In this case, we should free the memory already allocated and return
'false' to the caller.

Also add an error path which undoes the 'tima = ioremap(...)'

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
NOT compile tested (I don't have a cross compiler and won't install one).
So if some correction or improvement are needed, feel free to propose and
commit it directly.

v2: rebase with latest -next
---
arch/powerpc/sysdev/xive/spapr.c | 36 +++++++++++++++++++++++++-------
1 file changed, 28 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/sysdev/xive/spapr.c b/arch/powerpc/sysdev/xive/spapr.c
index 928f95004501..29456c255f9f 100644
--- a/arch/powerpc/sysdev/xive/spapr.c
+++ b/arch/powerpc/sysdev/xive/spapr.c
@@ -67,6 +67,17 @@ static int __init xive_irq_bitmap_add(int base, int count)
return 0;
}

+static void xive_irq_bitmap_remove_all(void)
+{
+ struct xive_irq_bitmap *xibm, *tmp;
+
+ list_for_each_entry_safe(xibm, tmp, &xive_irq_bitmaps, list) {
+ list_del(&xibm->list);
+ kfree(xibm->bitmap);
+ kfree(xibm);
+ }
+}
+
static int __xive_irq_bitmap_alloc(struct xive_irq_bitmap *xibm)
{
int irq;
@@ -803,7 +814,7 @@ bool __init xive_spapr_init(void)
u32 val;
u32 len;
const __be32 *reg;
- int i;
+ int i, err;

if (xive_spapr_disabled())
return false;
@@ -828,23 +839,26 @@ bool __init xive_spapr_init(void)
}

if (!xive_get_max_prio(&max_prio))
- return false;
+ goto err_unmap;

/* Feed the IRQ number allocator with the ranges given in the DT */
reg = of_get_property(np, "ibm,xive-lisn-ranges", &len);
if (!reg) {
pr_err("Failed to read 'ibm,xive-lisn-ranges' property\n");
- return false;
+ goto err_unmap;
}

if (len % (2 * sizeof(u32)) != 0) {
pr_err("invalid 'ibm,xive-lisn-ranges' property\n");
- return false;
+ goto err_unmap;
}

- for (i = 0; i < len / (2 * sizeof(u32)); i++, reg += 2)
- xive_irq_bitmap_add(be32_to_cpu(reg[0]),
- be32_to_cpu(reg[1]));
+ for (i = 0; i < len / (2 * sizeof(u32)); i++, reg += 2) {
+ err = xive_irq_bitmap_add(be32_to_cpu(reg[0]),
+ be32_to_cpu(reg[1]));
+ if (err < 0)
+ goto err_mem_free;
+ }

/* Iterate the EQ sizes and pick one */
of_property_for_each_u32(np, "ibm,xive-eq-sizes", prop, reg, val) {
@@ -855,10 +869,16 @@ bool __init xive_spapr_init(void)

/* Initialize XIVE core with our backend */
if (!xive_core_init(np, &xive_spapr_ops, tima, TM_QW1_OS, max_prio))
- return false;
+ goto err_mem_free;

pr_info("Using %dkB queues\n", 1 << (xive_queue_shift - 10));
return true;
+
+err_mem_free:
+ xive_irq_bitmap_remove_all();
+err_unmap:
+ iounmap(tima);
+ return false;
}

machine_arch_initcall(pseries, xive_core_debug_init);
--
2.32.0