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Commit | Line | Data |
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2cb7cef9 BS |
1 | From: Milton Miller <miltonm@bga.com> |
2 | Subject: powerpc/xics: EOI unmapped irqs after disabling them | |
3 | Date: Fri Oct 10 01:56:23 2008 +0000 | |
4 | X-Git-Tag: v2.6.28-rc1~569^2~27 | |
5 | X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=8767e9badca7cdf0adc2564d7524092d47ababf3 | |
6 | Patch-mainline: v2.6.28-rc1 | |
7 | References: bnc#459065 | |
8 | ||
9 | When reciving an irq vector that does not have a linux mapping, the kernel | |
10 | prints a message and calls RTAS to disable the irq source. Previously | |
11 | the kernel did not EOI the interrupt, causing the source to think it is | |
12 | still being processed by software. While this does add an additional | |
13 | layer of protection against interrupt storms had RTAS failed to disable | |
14 | the source, it also prevents the interrupt from working when a driver | |
15 | later enables it. (We could alternatively send an EOI on startup, but | |
16 | that strategy would likely fail on an emulated xics.) | |
17 | ||
18 | All interrupts should be disabled when the kernel starts, but this can | |
19 | be observed if a driver does not shutdown an interrupt in its reboot | |
20 | hook before starting a new kernel with kexec. | |
21 | ||
22 | Michael reports this can be reproduced trivially by banging the keyboard | |
23 | while kexec'ing on a P5 LPAR: even though the hvc_console driver request's | |
24 | the console irq later in boot, the console is non-functional because | |
25 | we're receiving no console interrupts. | |
26 | ||
27 | Reported-By: Michael Ellerman | |
28 | Signed-off-by: Milton Miller <miltonm@bga.com> | |
29 | Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> | |
30 | Acked-by: Petr Tesarik <ptesarik@suse.cz> | |
31 | ||
32 | --- | |
33 | arch/powerpc/platforms/pseries/xics.c | 53 ++++++++++++++++++++++++++-------- | |
34 | 1 file changed, 41 insertions(+), 12 deletions(-) | |
35 | ||
36 | --- linux-2.6.27-SLE11_BRANCH.orig/arch/powerpc/platforms/pseries/xics.c 2009-04-16 10:33:47.000000000 +0200 | |
37 | +++ linux-2.6.27-SLE11_BRANCH/arch/powerpc/platforms/pseries/xics.c 2009-04-16 10:52:29.000000000 +0200 | |
38 | @@ -335,32 +335,61 @@ static void xics_eoi_lpar(unsigned int v | |
39 | lpar_xirr_info_set((0xff << 24) | irq); | |
40 | } | |
41 | ||
42 | -static inline unsigned int xics_remap_irq(unsigned int vec) | |
43 | +static inline unsigned int xics_xirr_vector(unsigned int xirr) | |
44 | { | |
45 | - unsigned int irq; | |
46 | + /* | |
47 | + * The top byte is the old cppr, to be restored on EOI. | |
48 | + * The remaining 24 bits are the vector. | |
49 | + */ | |
50 | + return xirr & 0x00ffffff; | |
51 | +} | |
52 | ||
53 | - vec &= 0x00ffffff; | |
54 | +static void xics_mask_unknown_vec(unsigned int vec) | |
55 | +{ | |
56 | + printk(KERN_ERR "Interrupt %u (real) is invalid, disabling it.\n", vec); | |
57 | + xics_mask_real_irq(vec); | |
58 | +} | |
59 | + | |
60 | +static unsigned int xics_get_irq_direct(void) | |
61 | +{ | |
62 | + unsigned int xirr = direct_xirr_info_get(); | |
63 | + unsigned int vec = xics_xirr_vector(xirr); | |
64 | + unsigned int irq; | |
65 | ||
66 | if (vec == XICS_IRQ_SPURIOUS) | |
67 | return NO_IRQ; | |
68 | + | |
69 | irq = irq_radix_revmap(xics_host, vec); | |
70 | if (likely(irq != NO_IRQ)) | |
71 | return irq; | |
72 | ||
73 | - printk(KERN_ERR "Interrupt %u (real) is invalid," | |
74 | - " disabling it.\n", vec); | |
75 | - xics_mask_real_irq(vec); | |
76 | - return NO_IRQ; | |
77 | -} | |
78 | + /* We don't have a linux mapping, so have rtas mask it. */ | |
79 | + xics_mask_unknown_vec(vec); | |
80 | ||
81 | -static unsigned int xics_get_irq_direct(void) | |
82 | -{ | |
83 | - return xics_remap_irq(direct_xirr_info_get()); | |
84 | + /* We might learn about it later, so EOI it */ | |
85 | + direct_xirr_info_set(xirr); | |
86 | + return NO_IRQ; | |
87 | } | |
88 | ||
89 | static unsigned int xics_get_irq_lpar(void) | |
90 | { | |
91 | - return xics_remap_irq(lpar_xirr_info_get()); | |
92 | + unsigned int xirr = lpar_xirr_info_get(); | |
93 | + unsigned int vec = xics_xirr_vector(xirr); | |
94 | + unsigned int irq; | |
95 | + | |
96 | + if (vec == XICS_IRQ_SPURIOUS) | |
97 | + return NO_IRQ; | |
98 | + | |
99 | + irq = irq_radix_revmap(xics_host, vec); | |
100 | + if (likely(irq != NO_IRQ)) | |
101 | + return irq; | |
102 | + | |
103 | + /* We don't have a linux mapping, so have RTAS mask it. */ | |
104 | + xics_mask_unknown_vec(vec); | |
105 | + | |
106 | + /* We might learn about it later, so EOI it */ | |
107 | + lpar_xirr_info_set(xirr); | |
108 | + return NO_IRQ; | |
109 | } | |
110 | ||
111 | #ifdef CONFIG_SMP |