| Message ID | 20190725192552.24295-1-sumit.saxena@broadcom.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | [V2] PCI: set BAR size bits correctly in Resize BAR control register | expand |
Am 25.07.19 um 21:25 schrieb Sumit Saxena: > In Resize BAR control register, bits[8:12] represents size of BAR. > As per PCIe specification, below is encoded values in register bits > to actual BAR size table: > > Bits BAR size > 0 1 MB > 1 2 MB > 2 4 MB > 3 8 MB > -- > > For 1 MB BAR size, BAR size bits should be set to 0 but incorrectly > these bits are set to "1f". Latest megaraid_sas and mpt3sas adapters > which support Resizable BAR with 1 MB BAR size fails to initialize > during system resume from S3 sleep. > > Fix: Correctly calculate BAR size bits for Resize BAR control register. > > V2: > -Simplified calculation of BAR size bits as suggested by Christian Koenig. > > CC: stable@vger.kernel.org # v4.16+ > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203939 > Fixes: d3252ace0bc652a1a244455556b6a549f969bf99 ("PCI: Restore resized BAR state on resume") > Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> Reviewed-by: Christian König <christian.koenig@amd.com> > --- > drivers/pci/pci.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 29ed5ec1ac27..e59921296125 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -1438,7 +1438,7 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) > pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); > bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; > res = pdev->resource + bar_idx; > - size = order_base_2((resource_size(res) >> 20) | 1) - 1; > + size = order_base_2(resource_size(res) >> 20); > ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; > ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; > pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
On Fri, Jul 26, 2019 at 12:55:52AM +0530, Sumit Saxena wrote: > In Resize BAR control register, bits[8:12] represents size of BAR. > As per PCIe specification, below is encoded values in register bits > to actual BAR size table: > > Bits BAR size > 0 1 MB > 1 2 MB > 2 4 MB > 3 8 MB > -- > > For 1 MB BAR size, BAR size bits should be set to 0 but incorrectly > these bits are set to "1f". Latest megaraid_sas and mpt3sas adapters > which support Resizable BAR with 1 MB BAR size fails to initialize > during system resume from S3 sleep. > > Fix: Correctly calculate BAR size bits for Resize BAR control register. > > V2: > -Simplified calculation of BAR size bits as suggested by Christian Koenig. > > CC: stable@vger.kernel.org # v4.16+ > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203939 > Fixes: d3252ace0bc652a1a244455556b6a549f969bf99 ("PCI: Restore resized BAR state on resume") > Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> > --- > drivers/pci/pci.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 29ed5ec1ac27..e59921296125 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -1438,7 +1438,7 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) > pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); > bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; > res = pdev->resource + bar_idx; > - size = order_base_2((resource_size(res) >> 20) | 1) - 1; > + size = order_base_2(resource_size(res) >> 20); Since BAR sizes are always powers of 2, wouldn't this be simpler as: size = ilog2(resource_size(res)) - 20; which nicely matches the table in PCIe r5.0, sec 7.8.6.3? > ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; > ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; > pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl); > -- > 2.18.1 >
On Fri, Jul 26, 2019 at 12:55:52AM +0530, Sumit Saxena wrote: > In Resize BAR control register, bits[8:12] represents size of BAR. > As per PCIe specification, below is encoded values in register bits > to actual BAR size table: > > Bits BAR size > 0 1 MB > 1 2 MB > 2 4 MB > 3 8 MB > -- > > For 1 MB BAR size, BAR size bits should be set to 0 but incorrectly > these bits are set to "1f". Latest megaraid_sas and mpt3sas adapters > which support Resizable BAR with 1 MB BAR size fails to initialize > during system resume from S3 sleep. > > Fix: Correctly calculate BAR size bits for Resize BAR control register. > > V2: > -Simplified calculation of BAR size bits as suggested by Christian Koenig. > > CC: stable@vger.kernel.org # v4.16+ Also, d3252ace0bc6 ("PCI: Restore resized BAR state on resume") didn't appear until v4.19. I updated this to "v4.19+"; let me know if that's wrong. > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203939 > Fixes: d3252ace0bc652a1a244455556b6a549f969bf99 ("PCI: Restore resized BAR state on resume") I updated this to conventional format as above (12-char SHA1). > Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> > --- > drivers/pci/pci.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 29ed5ec1ac27..e59921296125 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -1438,7 +1438,7 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) > pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); > bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; > res = pdev->resource + bar_idx; > - size = order_base_2((resource_size(res) >> 20) | 1) - 1; > + size = order_base_2(resource_size(res) >> 20); > ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; > ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; > pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl); > -- > 2.18.1 >
On Fri, Jul 26, 2019 at 12:55:52AM +0530, Sumit Saxena wrote: > In Resize BAR control register, bits[8:12] represents size of BAR. > As per PCIe specification, below is encoded values in register bits > to actual BAR size table: > > Bits BAR size > 0 1 MB > 1 2 MB > 2 4 MB > 3 8 MB > -- > > For 1 MB BAR size, BAR size bits should be set to 0 but incorrectly > these bits are set to "1f". Latest megaraid_sas and mpt3sas adapters > which support Resizable BAR with 1 MB BAR size fails to initialize > during system resume from S3 sleep. > > Fix: Correctly calculate BAR size bits for Resize BAR control register. > > V2: > -Simplified calculation of BAR size bits as suggested by Christian Koenig. > > CC: stable@vger.kernel.org # v4.16+ > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203939 > Fixes: d3252ace0bc652a1a244455556b6a549f969bf99 ("PCI: Restore resized BAR state on resume") > Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> I applied this to pci/misc for v5.4 with the tweaks I mentioned (see below). Christian, I didn't add your Reviewed-by since I changed the patch, but I'll be glad to update the branch if you take another look. > --- > drivers/pci/pci.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 29ed5ec1ac27..e59921296125 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -1438,7 +1438,7 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) > pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); > bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; > res = pdev->resource + bar_idx; > - size = order_base_2((resource_size(res) >> 20) | 1) - 1; > + size = order_base_2(resource_size(res) >> 20); > ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; > ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; > pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl); commit 614b04644b57 Author: Sumit Saxena <sumit.saxena@broadcom.com> Date: Fri Jul 26 00:55:52 2019 +0530 PCI: Set BAR size bits correctly in Resize BAR control register In a Resizable BAR Control Register, bits 13:8 control the size of the BAR. The encoded values of these bits are as follows (see PCIe r5.0, sec 7.8.6.3): Value BAR size 0 1 MB (2^20 bytes) 1 2 MB (2^21 bytes) 2 4 MB (2^22 bytes) ... 43 8 EB (2^63 bytes) Previously we incorrectly set the BAR size bits for a 1 MB BAR to 0x1f instead of 0, so devices that support that size, e.g., new megaraid_sas and mpt3sas adapters, fail to initialize during resume from S3 sleep. Correctly calculate the BAR size bits for Resizable BAR control registers. Link: https://lore.kernel.org/r/20190725192552.24295-1-sumit.saxena@broadcom.com Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203939 Fixes: d3252ace0bc6 ("PCI: Restore resized BAR state on resume") Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: stable@vger.kernel.org # v4.19+ diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index da3241bb4479..5836eb576d96 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1438,7 +1438,7 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; res = pdev->resource + bar_idx; - size = order_base_2((resource_size(res) >> 20) | 1) - 1; + size = ilog2(resource_size(res)) - 20; ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
Am 08.08.19 um 01:01 schrieb Bjorn Helgaas: > On Fri, Jul 26, 2019 at 12:55:52AM +0530, Sumit Saxena wrote: >> In Resize BAR control register, bits[8:12] represents size of BAR. >> As per PCIe specification, below is encoded values in register bits >> to actual BAR size table: >> >> Bits BAR size >> 0 1 MB >> 1 2 MB >> 2 4 MB >> 3 8 MB >> -- >> >> For 1 MB BAR size, BAR size bits should be set to 0 but incorrectly >> these bits are set to "1f". Latest megaraid_sas and mpt3sas adapters >> which support Resizable BAR with 1 MB BAR size fails to initialize >> during system resume from S3 sleep. >> >> Fix: Correctly calculate BAR size bits for Resize BAR control register. >> >> V2: >> -Simplified calculation of BAR size bits as suggested by Christian Koenig. >> >> CC: stable@vger.kernel.org # v4.16+ >> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203939 >> Fixes: d3252ace0bc652a1a244455556b6a549f969bf99 ("PCI: Restore resized BAR state on resume") >> Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> >> --- >> drivers/pci/pci.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c >> index 29ed5ec1ac27..e59921296125 100644 >> --- a/drivers/pci/pci.c >> +++ b/drivers/pci/pci.c >> @@ -1438,7 +1438,7 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) >> pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); >> bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; >> res = pdev->resource + bar_idx; >> - size = order_base_2((resource_size(res) >> 20) | 1) - 1; >> + size = order_base_2(resource_size(res) >> 20); > Since BAR sizes are always powers of 2, wouldn't this be simpler as: > > size = ilog2(resource_size(res)) - 20; > > which nicely matches the table in PCIe r5.0, sec 7.8.6.3? Yeah, that should obviously work as well. We would have a serious problem in the resource management if the resource size is smaller than 1MB or not a power of two. Feel free to add my r-b. Regards, Christian. > >> ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; >> ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; >> pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl); >> -- >> 2.18.1 >>
On Thu, Aug 08, 2019 at 07:01:03AM +0000, Koenig, Christian wrote: > Am 08.08.19 um 01:01 schrieb Bjorn Helgaas: > > On Fri, Jul 26, 2019 at 12:55:52AM +0530, Sumit Saxena wrote: > >> In Resize BAR control register, bits[8:12] represents size of BAR. > >> As per PCIe specification, below is encoded values in register bits > >> to actual BAR size table: > >> > >> Bits BAR size > >> 0 1 MB > >> 1 2 MB > >> 2 4 MB > >> 3 8 MB > >> -- > >> > >> For 1 MB BAR size, BAR size bits should be set to 0 but incorrectly > >> these bits are set to "1f". Latest megaraid_sas and mpt3sas adapters > >> which support Resizable BAR with 1 MB BAR size fails to initialize > >> during system resume from S3 sleep. > >> > >> Fix: Correctly calculate BAR size bits for Resize BAR control register. > >> > >> V2: > >> -Simplified calculation of BAR size bits as suggested by Christian Koenig. > >> > >> CC: stable@vger.kernel.org # v4.16+ > >> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203939 > >> Fixes: d3252ace0bc652a1a244455556b6a549f969bf99 ("PCI: Restore resized BAR state on resume") > >> Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> > >> --- > >> drivers/pci/pci.c | 2 +- > >> 1 file changed, 1 insertion(+), 1 deletion(-) > >> > >> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > >> index 29ed5ec1ac27..e59921296125 100644 > >> --- a/drivers/pci/pci.c > >> +++ b/drivers/pci/pci.c > >> @@ -1438,7 +1438,7 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) > >> pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); > >> bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; > >> res = pdev->resource + bar_idx; > >> - size = order_base_2((resource_size(res) >> 20) | 1) - 1; > >> + size = order_base_2(resource_size(res) >> 20); > > Since BAR sizes are always powers of 2, wouldn't this be simpler as: > > > > size = ilog2(resource_size(res)) - 20; > > > > which nicely matches the table in PCIe r5.0, sec 7.8.6.3? > > Yeah, that should obviously work as well. > > We would have a serious problem in the resource management if the > resource size is smaller than 1MB or not a power of two. Yes, definitely. Resizable BARs are required by spec to be 1MB or larger, but this does niggle at me a little bit, too. It probably saves a few bits in pci_dev to recompute this at restore-time, but honestly, I think it would be more obviously correct to just do the simple-minded thing of saving and restoring the entire register. > Feel free to add my r-b. Done, thanks! > Regards, > Christian. > > > > >> ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; > >> ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; > >> pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl); > >> -- > >> 2.18.1 > >> >
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 29ed5ec1ac27..e59921296125 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1438,7 +1438,7 @@ static void pci_restore_rebar_state(struct pci_dev *pdev) pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; res = pdev->resource + bar_idx; - size = order_base_2((resource_size(res) >> 20) | 1) - 1; + size = order_base_2(resource_size(res) >> 20); ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl);
In Resize BAR control register, bits[8:12] represents size of BAR. As per PCIe specification, below is encoded values in register bits to actual BAR size table: Bits BAR size 0 1 MB 1 2 MB 2 4 MB 3 8 MB -- For 1 MB BAR size, BAR size bits should be set to 0 but incorrectly these bits are set to "1f". Latest megaraid_sas and mpt3sas adapters which support Resizable BAR with 1 MB BAR size fails to initialize during system resume from S3 sleep. Fix: Correctly calculate BAR size bits for Resize BAR control register. V2: -Simplified calculation of BAR size bits as suggested by Christian Koenig. CC: stable@vger.kernel.org # v4.16+ Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203939 Fixes: d3252ace0bc652a1a244455556b6a549f969bf99 ("PCI: Restore resized BAR state on resume") Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> --- drivers/pci/pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)