LinuxPPC-Dev Archive on lore.kernel.org
 help / color / Atom feed
From: Greg Kurz <groug@kaod.org>
To: Sasha Levin <sashal@kernel.org>
Cc: Greg KH <greg@kroah.com>,
	linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Subject: [PATCH] powerpc/xive: Fix bogus error code returned by OPAL
Date: Mon, 23 Sep 2019 08:29:40 +0200
Message-ID: <156922009207.910857.10785273696571088534.stgit@bahia.lan> (raw)

There's a bug in skiboot that causes the OPAL_XIVE_ALLOCATE_IRQ call
to return the 32-bit value 0xffffffff when OPAL has run out of IRQs.
Unfortunatelty, OPAL return values are signed 64-bit entities and
errors are supposed to be negative. If that happens, the linux code
confusingly treats 0xffffffff as a valid IRQ number and panics at some
point.

A fix was recently merged in skiboot:

e97391ae2bb5 ("xive: fix return value of opal_xive_allocate_irq()")

but we need a workaround anyway to support older skiboots already
in the field.

Internally convert 0xffffffff to OPAL_RESOURCE which is the usual error
returned upon resource exhaustion.

Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821713818.1985334.14123187368108582810.stgit@bahia.lan
(cherry picked from commit 6ccb4ac2bf8a35c694ead92f8ac5530a16e8f2c8,
 groug: fix arch/powerpc/platforms/powernv/opal-wrappers.S instead of
        non-existing arch/powerpc/platforms/powernv/opal-call.c)
Signed-off-by: Greg Kurz <groug@kaod.org>
---

This is for 4.14 and 4.19.

 arch/powerpc/include/asm/opal.h                |    2 +-
 arch/powerpc/platforms/powernv/opal-wrappers.S |    2 +-
 arch/powerpc/sysdev/xive/native.c              |   11 +++++++++++
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 8eb3ebca02df..163970c56e2f 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -266,7 +266,7 @@ int64_t opal_xive_get_vp_info(uint64_t vp,
 int64_t opal_xive_set_vp_info(uint64_t vp,
 			      uint64_t flags,
 			      uint64_t report_cl_pair);
-int64_t opal_xive_allocate_irq(uint32_t chip_id);
+int64_t opal_xive_allocate_irq_raw(uint32_t chip_id);
 int64_t opal_xive_free_irq(uint32_t girq);
 int64_t opal_xive_sync(uint32_t type, uint32_t id);
 int64_t opal_xive_dump(uint32_t type, uint32_t id);
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index 8c1ede2d3f7e..b12a75a0ee8b 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -301,7 +301,7 @@ OPAL_CALL(opal_xive_set_queue_info,		OPAL_XIVE_SET_QUEUE_INFO);
 OPAL_CALL(opal_xive_donate_page,		OPAL_XIVE_DONATE_PAGE);
 OPAL_CALL(opal_xive_alloc_vp_block,		OPAL_XIVE_ALLOCATE_VP_BLOCK);
 OPAL_CALL(opal_xive_free_vp_block,		OPAL_XIVE_FREE_VP_BLOCK);
-OPAL_CALL(opal_xive_allocate_irq,		OPAL_XIVE_ALLOCATE_IRQ);
+OPAL_CALL(opal_xive_allocate_irq_raw,		OPAL_XIVE_ALLOCATE_IRQ);
 OPAL_CALL(opal_xive_free_irq,			OPAL_XIVE_FREE_IRQ);
 OPAL_CALL(opal_xive_get_vp_info,		OPAL_XIVE_GET_VP_INFO);
 OPAL_CALL(opal_xive_set_vp_info,		OPAL_XIVE_SET_VP_INFO);
diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c
index 0f89ee557b04..aac61374afeb 100644
--- a/arch/powerpc/sysdev/xive/native.c
+++ b/arch/powerpc/sysdev/xive/native.c
@@ -234,6 +234,17 @@ static bool xive_native_match(struct device_node *node)
 	return of_device_is_compatible(node, "ibm,opal-xive-vc");
 }
 
+static s64 opal_xive_allocate_irq(u32 chip_id)
+{
+	s64 irq = opal_xive_allocate_irq_raw(chip_id);
+
+	/*
+	 * Old versions of skiboot can incorrectly return 0xffffffff to
+	 * indicate no space, fix it up here.
+	 */
+	return irq == 0xffffffff ? OPAL_RESOURCE : irq;
+}
+
 #ifdef CONFIG_SMP
 static int xive_native_get_ipi(unsigned int cpu, struct xive_cpu *xc)
 {


             reply index

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-23  6:29 Greg Kurz [this message]
2019-09-23  7:31 ` Greg KH
  -- strict thread matches above, loose matches on Subject: below --
2019-09-10 13:53 Greg Kurz
2019-09-10 13:59 ` Cédric Le Goater
2019-09-11 14:26 ` Michael Ellerman
2019-09-11 14:40   ` Greg Kurz

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=156922009207.910857.10785273696571088534.stgit@bahia.lan \
    --to=groug@kaod.org \
    --cc=greg@kroah.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=sashal@kernel.org \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LinuxPPC-Dev Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linuxppc-dev/0 linuxppc-dev/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linuxppc-dev linuxppc-dev/ https://lore.kernel.org/linuxppc-dev \
		linuxppc-dev@lists.ozlabs.org linuxppc-dev@ozlabs.org
	public-inbox-index linuxppc-dev

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.ozlabs.lists.linuxppc-dev


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git