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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
PCI: endpoint: Add helper API to get the 'next' unreserved BAR
Add an API to get the next unreserved BAR starting from a given BAR number
that can be used by the endpoint function.
Link: https://lore.kernel.org/r/20210201195809.7342-4-kishon@ti.com
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
authored by
Kishon Vijay Abraham I
and committed by
Bjorn Helgaas
fa8fef0e
959a48d0
+24
-4
+22
-4
drivers/pci/endpoint/pci-epc-core.c
+22
-4
drivers/pci/endpoint/pci-epc-core.c
···
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* pci_epc_get_first_free_bar() - helper to get first unreserved BAR
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* @epc_features: pci_epc_features structure that holds the reserved bar bitmap
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*
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-
* Invoke to get the first unreserved BAR that can be used for endpoint
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* Invoke to get the first unreserved BAR that can be used by the endpoint
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* function. For any incorrect value in reserved_bar return '0'.
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*/
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unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
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*epc_features)
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{
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return pci_epc_get_next_free_bar(epc_features, BAR_0);
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}
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EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
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/**
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* pci_epc_get_next_free_bar() - helper to get unreserved BAR starting from @bar
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* @epc_features: pci_epc_features structure that holds the reserved bar bitmap
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* @bar: the starting BAR number from where unreserved BAR should be searched
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*
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* Invoke to get the next unreserved BAR starting from @bar that can be used
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* for endpoint function. For any incorrect value in reserved_bar return '0'.
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*/
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unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
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*epc_features, enum pci_barno bar)
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{
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unsigned long free_bar;
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if (!epc_features)
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return 0;
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+
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/* If 'bar - 1' is a 64-bit BAR, move to the next BAR */
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if ((epc_features->bar_fixed_64bit << 1) & 1 << bar)
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bar++;
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/* Find if the reserved BAR is also a 64-bit BAR */
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free_bar = epc_features->reserved_bar & epc_features->bar_fixed_64bit;
···
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free_bar <<= 1;
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free_bar |= epc_features->reserved_bar;
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-
/* Now find the free BAR */
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free_bar = ffz(free_bar);
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free_bar = find_next_zero_bit(&free_bar, 6, bar);
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if (free_bar > 5)
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return 0;
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return free_bar;
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}
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-
EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
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EXPORT_SYMBOL_GPL(pci_epc_get_next_free_bar);
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/**
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* pci_epc_get_features() - get the features supported by EPC
+2
include/linux/pci-epc.h
+2
include/linux/pci-epc.h
···
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u8 func_no);
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unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
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*epc_features);
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unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
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*epc_features, enum pci_barno bar);
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struct pci_epc *pci_epc_get(const char *epc_name);
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void pci_epc_put(struct pci_epc *epc);
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