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authorKyösti Mälkki <kyosti.malkki@gmail.com>2019-03-05 07:56:38 +0200
committerKyösti Mälkki <kyosti.malkki@gmail.com>2019-04-07 02:31:36 +0000
commitd2cdfff63b6e2376fad729252a57acfd2b4418ea (patch)
tree01d0ccd1e0826c9449a6c4f1781e7feb813fe537 /src/device
parentbf0970e762a6611cef06af761bc2dec068d439bb (diff)
downloadcoreboot-d2cdfff63b6e2376fad729252a57acfd2b4418ea.tar.xz
device/pci: Rewrite PCI MMCONF with symbol reference
The effect of pointer aliasing on writes is that any data on CPU registers that has been resolved from (non-const and non-volatile) memory objects has to be discarded and resolved. In other words, the compiler assumes that a pointer that does not have an absolute value at build-time, and is of type 'void *' or 'char *', may write over any memory object. Using a unique datatype for MMIO writes makes the pointer to _not_ qualify for pointer aliasing with any other objects in memory. This avoid constantly resolving the PCI MMCONF address, which is a derived value from a 'struct device *'. Change-Id: Id112aa5e729ffd8015bb806786bdee38783b7ea9 Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/31752 Reviewed-by: Aaron Durbin <adurbin@chromium.org> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Diffstat (limited to 'src/device')
-rw-r--r--src/device/Makefile.inc8
-rw-r--r--src/device/pci_ops.c4
2 files changed, 11 insertions, 1 deletions
diff --git a/src/device/Makefile.inc b/src/device/Makefile.inc
index 711a403353..baa45bec3e 100644
--- a/src/device/Makefile.inc
+++ b/src/device/Makefile.inc
@@ -26,9 +26,15 @@ postcar-y += pci_early.c
ramstage-y += pci_class.c
ramstage-y += pci_device.c
-ramstage-y += pci_ops.c
ramstage-y += pci_rom.c
+bootblock-y += pci_ops.c
+verstage-y += pci_ops.c
+romstage-y += pci_ops.c
+postcar-y += pci_ops.c
+ramstage-y += pci_ops.c
+smm-y += pci_ops.c
+
ramstage-$(CONFIG_HYPERTRANSPORT_PLUGIN_SUPPORT) += hypertransport.c
ramstage-$(CONFIG_PCIX_PLUGIN_SUPPORT) += pcix_device.c
ramstage-$(CONFIG_PCIEXP_PLUGIN_SUPPORT) += pciexp_device.c
diff --git a/src/device/pci_ops.c b/src/device/pci_ops.c
index bdf8ec4584..34f9d1e5b5 100644
--- a/src/device/pci_ops.c
+++ b/src/device/pci_ops.c
@@ -10,3 +10,7 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
+
+#include <stdint.h>
+
+u8 *const pci_mmconf = (void *)(uintptr_t)CONFIG_MMCONF_BASE_ADDRESS;