| From | Paul Gortmaker <> | Subject | [v2.6.34-stable 199/213] pcdp: use early_ioremap/early_iounmap to access pcdp table | Date | Wed, 5 Feb 2014 15:02:34 -0500 |
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From: Greg Pearson <greg.pearson@hp.com>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. -------------------
commit 6c4088ac3a4d82779903433bcd5f048c58fb1aca upstream.
efi_setup_pcdp_console() is called during boot to parse the HCDP/PCDP EFI system table and setup an early console for printk output. The routine uses ioremap/iounmap to setup access to the HCDP/PCDP table information.
The call to ioremap is happening early in the boot process which leads to a panic on x86_64 systems:
panic+0x01ca do_exit+0x043c oops_end+0x00a7 no_context+0x0119 __bad_area_nosemaphore+0x0138 bad_area_nosemaphore+0x000e do_page_fault+0x0321 page_fault+0x0020 reserve_memtype+0x02a1 __ioremap_caller+0x0123 ioremap_nocache+0x0012 efi_setup_pcdp_console+0x002b setup_arch+0x03a9 start_kernel+0x00d4 x86_64_start_reservations+0x012c x86_64_start_kernel+0x00fe
This replaces the calls to ioremap/iounmap in efi_setup_pcdp_console() with calls to early_ioremap/early_iounmap which can be called during early boot.
This patch was tested on an x86_64 prototype system which uses the HCDP/PCDP table for early console setup.
Signed-off-by: Greg Pearson <greg.pearson@hp.com> Acked-by: Khalid Aziz <khalid.aziz@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> --- drivers/firmware/pcdp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/firmware/pcdp.c b/drivers/firmware/pcdp.c index 51e0e2d8fac6..a330492e06f9 100644 --- a/drivers/firmware/pcdp.c +++ b/drivers/firmware/pcdp.c @@ -95,7 +95,7 @@ efi_setup_pcdp_console(char *cmdline) if (efi.hcdp == EFI_INVALID_TABLE_ADDR) return -ENODEV; - pcdp = ioremap(efi.hcdp, 4096); + pcdp = early_ioremap(efi.hcdp, 4096); printk(KERN_INFO "PCDP: v%d at 0x%lx\n", pcdp->rev, efi.hcdp); if (strstr(cmdline, "console=hcdp")) { @@ -131,6 +131,6 @@ efi_setup_pcdp_console(char *cmdline) } out: - iounmap(pcdp); + early_iounmap(pcdp, 4096); return rc; } -- 1.8.5.2
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