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linux-2.4.36

linux-2.4.36: Commit

2.4.36-stable kernel tree

[PATCH] sym53c8xx_2 SMP deadlock on driver load

This patch fixes two problems with sym53c8xx_2.o in 2.4.x kernels:

1) A system hang when loading sym53c8xx_2.o on a SMP system with two
dual-channel LSI HBAs (http://bugzilla.kernel.org/show_bug.cgi?id=3680)

2) A function improperly marked init.

Comment from Matthew Wilcox:
" This is a pretty ugly patch, but I think the three alternatives are

worse:

- Drop the iorl at the beginning of ->detect and reacquire it at exit.

We don't know what else the iorl might be protecting. Probably
nothing, but I don't want to audit it.

- Convert sym2 back to old error handling so the midlayer doesn't

acquire the iorl for us in ->detect.

- Acquire the iorl in ->release. We might deadlock on something.

So, sure, apply this patch. "

Signed-off-by: Tony Battersby <tonyb@cybernetics.com>

--- a/drivers/scsi/sym53c8xx_2/sym_glue.c

+++ b/drivers/scsi/sym53c8xx_2/sym_glue.c

		@@ -224,15 +224,26 @@ static u_long __init pci_map_mem(u_long base, u_long size)
224	224	{
225	225	u_long page_base = ((u_long) base) & PAGE_MASK;
226	226	u_long page_offs = ((u_long) base) - page_base;
227		- u_long page_remapped = (u_long) ioremap(page_base, page_offs+size);
	227	+ u_long page_remapped;
	228	+
	229	+ spin_unlock_irq(&io_request_lock);
	230	+ page_remapped = (u_long) ioremap(page_base, page_offs+size);
	231	+ spin_lock_irq(&io_request_lock);
228	232
229	233	return page_remapped? (page_remapped + page_offs) : 0UL;
230	234	}
231	235
232		-static void __init pci_unmap_mem(u_long vaddr, u_long size)
	236	+static void pci_unmap_mem(u_long vaddr,
	237	+ u_long size,
	238	+ int holding_io_request_lock)
233	239	{
234		- if (vaddr)
	240	+ if (vaddr) {
	241	+ if (holding_io_request_lock)
	242	+ spin_unlock_irq(&io_request_lock);
235	243	iounmap((void *) (vaddr & PAGE_MASK));
	244	+ if (holding_io_request_lock)
	245	+ spin_lock_irq(&io_request_lock);
	246	+ }
236	247	}
237	248	#endif
238	249

		@@ -1840,7 +1851,7 @@ static int sym53c8xx_proc_info(char buffer, char *start, off_t offset,
1840	1851	/*
1841	1852	* Free controller resources.
1842	1853	*/
1843		-static void sym_free_resources(hcb_p np)
	1854	+static void sym_free_resources(hcb_p np, int holding_io_request_lock)
1844	1855	{
1845	1856	/*
1846	1857	* Free O/S specific resources.

		@@ -1851,9 +1862,13 @@ static void sym_free_resources(hcb_p np)
1851	1862	release_region(np->s.io_port, np->s.io_ws);
1852	1863	#ifndef SYM_OPT_NO_BUS_MEMORY_MAPPING
1853	1864	if (np->s.mmio_va)
1854		- pci_unmap_mem(np->s.mmio_va, np->s.io_ws);
	1865	+ pci_unmap_mem(np->s.mmio_va,
	1866	+ np->s.io_ws,
	1867	+ holding_io_request_lock);
1855	1868	if (np->s.ram_va)
1856		- pci_unmap_mem(np->s.ram_va, np->ram_ws);
	1869	+ pci_unmap_mem(np->s.ram_va,
	1870	+ np->ram_ws,
	1871	+ holding_io_request_lock);
1857	1872	#endif
1858	1873	/*
1859	1874	* Free O/S independant resources.

		@@ -2155,7 +2170,7 @@ attach_failed:
2155	2170	if (!instance) return -1;
2156	2171	printf_info("%s: giving up ...\n", sym_name(np));
2157	2172	if (np)
2158		- sym_free_resources(np);
	2173	+ sym_free_resources(np, 1);
2159	2174	scsi_unregister(instance);
2160	2175
2161	2176	return -1;

		@@ -2197,7 +2212,7 @@ static void __init sym_get_nvram(sym_device devp, sym_nvram nvp)
2197	2212	#ifdef SYM_CONF_IOMAPPED
2198	2213	release_region(devp->s.io_port, 128);
2199	2214	#else
2200		- pci_unmap_mem((u_long) devp->s.mmio_va, 128ul);
	2215	+ pci_unmap_mem((u_long) devp->s.mmio_va, 128ul, 1);
2201	2216	#endif
2202	2217	}
2203	2218	#endif /* SYM_CONF_NVRAM_SUPPORT */

		@@ -2551,7 +2566,7 @@ sym53c8xx_pci_init(Scsi_Host_Template tpnt, pcidev_t pdev, sym_device device)
2551	2566	ram_ptr = pci_map_mem(base_2_c, ram_size);
2552	2567	if (ram_ptr) {
2553	2568	ram_val = readl_raw(ram_ptr + ram_size - 16);
2554		- pci_unmap_mem(ram_ptr, ram_size);
	2569	+ pci_unmap_mem(ram_ptr, ram_size, 1);
2555	2570	if (ram_val == 0x52414944) {
2556	2571	printf_info("%s: not initializing, "
2557	2572	"driven by RAID controller.\n",