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Subject[ 04/44] pcdp: use early_ioremap/early_iounmap to access pcdp table
Date
From: Greg KH <gregkh@linuxfoundation.org>

3.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: Greg Pearson <greg.pearson@hp.com>

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/firmware/pcdp.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- 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;
}



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