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PCI: endpoint: Add helper API to get the 'next' unreserved BAR

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[ Upstream commit fa8fef0e10 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Kishon Vijay Abraham I 2021-02-02 01:27:55 +05:30 committed by Greg Kroah-Hartman
parent 5974766170
commit d98bfd4cc2
2 changed files with 24 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
drivers/pci/endpoint/pci-epc-core.c
View File

@ -87,17 +87,36 @@ EXPORT_SYMBOL_GPL(pci_epc_get);
* pci_epc_get_first_free_bar() - helper to get first unreserved BAR * pci_epc_get_first_free_bar() - helper to get first unreserved BAR
* @epc_features: pci_epc_features structure that holds the reserved bar bitmap * @epc_features: pci_epc_features structure that holds the reserved bar bitmap
* *
* Invoke to get the first unreserved BAR that can be used for endpoint * Invoke to get the first unreserved BAR that can be used by the endpoint
* function. For any incorrect value in reserved_bar return '0'. * function. For any incorrect value in reserved_bar return '0'.
*/ */
unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
*epc_features) *epc_features)
{
return pci_epc_get_next_free_bar(epc_features, BAR_0);
}
EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar);
/**
* pci_epc_get_next_free_bar() - helper to get unreserved BAR starting from @bar
* @epc_features: pci_epc_features structure that holds the reserved bar bitmap
* @bar: the starting BAR number from where unreserved BAR should be searched
*
* Invoke to get the next unreserved BAR starting from @bar that can be used
* for endpoint function. For any incorrect value in reserved_bar return '0'.
*/
unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
*epc_features, enum pci_barno bar)
{ {
unsigned long free_bar; unsigned long free_bar;
if (!epc_features) if (!epc_features)
return 0; return 0;
/* If 'bar - 1' is a 64-bit BAR, move to the next BAR */
if ((epc_features->bar_fixed_64bit << 1) & 1 << bar)
bar++;
/* Find if the reserved BAR is also a 64-bit BAR */ /* Find if the reserved BAR is also a 64-bit BAR */
free_bar = epc_features->reserved_bar & epc_features->bar_fixed_64bit; free_bar = epc_features->reserved_bar & epc_features->bar_fixed_64bit;
@ -105,14 +124,13 @@ unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
free_bar <<= 1; free_bar <<= 1;
free_bar |= epc_features->reserved_bar; free_bar |= epc_features->reserved_bar;
/* Now find the free BAR */ free_bar = find_next_zero_bit(&free_bar, 6, bar);
free_bar = ffz(free_bar);
if (free_bar > 5) if (free_bar > 5)
return 0; return 0;
return free_bar; return free_bar;
} }
EXPORT_SYMBOL_GPL(pci_epc_get_first_free_bar); EXPORT_SYMBOL_GPL(pci_epc_get_next_free_bar);
/** /**
* pci_epc_get_features() - get the features supported by EPC * pci_epc_get_features() - get the features supported by EPC

2
include/linux/pci-epc.h
View File

@ -203,6 +203,8 @@ const struct pci_epc_features *pci_epc_get_features(struct pci_epc *epc,
u8 func_no); u8 func_no);
unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features unsigned int pci_epc_get_first_free_bar(const struct pci_epc_features
*epc_features); *epc_features);
unsigned int pci_epc_get_next_free_bar(const struct pci_epc_features
*epc_features, enum pci_barno bar);
struct pci_epc *pci_epc_get(const char *epc_name); struct pci_epc *pci_epc_get(const char *epc_name);
void pci_epc_put(struct pci_epc *epc); void pci_epc_put(struct pci_epc *epc);