From d0c72d6e399e88691ae978f997bd72a9f1ccf129 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ilpo=20J=C3=A4rvinen?= Date: Fri, 19 Dec 2025 19:40:19 +0200 Subject: [PATCH] PCI: Push realloc check into pbus_size_mem() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit pbus_size_mem() and calculate_memsize() input both min_size and add_size. They are given the same value if realloc_head is NULL and min_size is 0 otherwise. Both are used in calculate_memsize() to enforce a lower bound to the size. The interface between __pci_bus_size_bridges() and the forementioned functions can be simplied by pushing the realloc check into pbus_size_mem(). There are only two possible cases: 1) when calculating size0, add_size parameter given to calculate_memsize() is always 0 which implies only min_size matters. 2) when calculating size1, realloc_head is not NULL which implies min_size=0 so only add_size matters. Drop min_size parameter from pbus_size_mem() and check realloc_head when calling calculate_memsize(). Drop add_size from calculate_memsize() and use only min_size within max() to enforce the lower bound. calculate_iosize() is a bit more complicated than calculate_memsize() and is therefore left as is, but pbus_size_io() can still input only min_size similar to pbus_size_mem(). Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Link: https://patch.msgid.link/20251219174036.16738-7-ilpo.jarvinen@linux.intel.com --- drivers/pci/setup-bus.c | 34 ++++++++++++---------------------- 1 file changed, 12 insertions(+), 22 deletions(-) diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 8660449f59bd..f85ae20dc894 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1069,14 +1069,10 @@ static resource_size_t calculate_iosize(resource_size_t size, static resource_size_t calculate_memsize(resource_size_t size, resource_size_t min_size, - resource_size_t add_size, resource_size_t children_add_size, resource_size_t align) { - if (size < min_size) - size = min_size; - - size = max(size, add_size) + children_add_size; + size = max(size, min_size) + children_add_size; return ALIGN(size, align); } @@ -1115,8 +1111,7 @@ static resource_size_t window_alignment(struct pci_bus *bus, unsigned long type) * pbus_size_io() - Size the I/O window of a given bus * * @bus: The bus - * @min_size: The minimum I/O window that must be allocated - * @add_size: Additional optional I/O window + * @add_size: Additional I/O window * @realloc_head: Track the additional I/O window on this list * * Sizing the I/O windows of the PCI-PCI bridge is trivial, since these @@ -1124,8 +1119,7 @@ static resource_size_t window_alignment(struct pci_bus *bus, unsigned long type) * devices are limited to 256 bytes. We must be careful with the ISA * aliasing though. */ -static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, - resource_size_t add_size, +static void pbus_size_io(struct pci_bus *bus, resource_size_t add_size, struct list_head *realloc_head) { struct pci_dev *dev; @@ -1170,7 +1164,7 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, } } - size0 = calculate_iosize(size, min_size, size1, 0, 0, + size0 = calculate_iosize(size, realloc_head ? 0 : add_size, size1, 0, 0, resource_size(b_res), min_align); if (size0) @@ -1178,7 +1172,7 @@ static void pbus_size_io(struct pci_bus *bus, resource_size_t min_size, size1 = size0; if (realloc_head && (add_size > 0 || children_add_size > 0)) { - size1 = calculate_iosize(size, min_size, size1, add_size, + size1 = calculate_iosize(size, 0, size1, add_size, children_add_size, resource_size(b_res), min_align); } @@ -1269,8 +1263,7 @@ static resource_size_t calculate_head_align(resource_size_t *aligns, * * @bus: The bus * @type: The type of bridge resource - * @min_size: The minimum memory window that must be allocated - * @add_size: Additional optional memory window + * @add_size: Additional memory window * @realloc_head: Track the additional memory window on this list * * Calculate the size of the bus resource for @type and minimal alignment @@ -1283,7 +1276,6 @@ static resource_size_t calculate_head_align(resource_size_t *aligns, * supplied. */ static void pbus_size_mem(struct pci_bus *bus, unsigned long type, - resource_size_t min_size, resource_size_t add_size, struct list_head *realloc_head) { @@ -1363,7 +1355,8 @@ static void pbus_size_mem(struct pci_bus *bus, unsigned long type, win_align = window_alignment(bus, b_res->flags); min_align = calculate_head_align(aligns, max_order); min_align = max(min_align, win_align); - size0 = calculate_memsize(size, min_size, 0, 0, win_align); + size0 = calculate_memsize(size, realloc_head ? 0 : add_size, + 0, win_align); if (size0) { resource_set_range(b_res, min_align, size0); @@ -1372,7 +1365,7 @@ static void pbus_size_mem(struct pci_bus *bus, unsigned long type, if (realloc_head && (add_size > 0 || children_add_size > 0)) { add_align = max(min_align, add_align); - size1 = calculate_memsize(size, min_size, add_size, children_add_size, + size1 = calculate_memsize(size, add_size, children_add_size, win_align); } @@ -1550,20 +1543,17 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head) } fallthrough; default: - pbus_size_io(bus, realloc_head ? 0 : additional_io_size, - additional_io_size, realloc_head); + pbus_size_io(bus, additional_io_size, realloc_head); if (pref && (pref->flags & IORESOURCE_PREFETCH)) { pbus_size_mem(bus, IORESOURCE_MEM | IORESOURCE_PREFETCH | (pref->flags & IORESOURCE_MEM_64), - realloc_head ? 0 : additional_mmio_pref_size, additional_mmio_pref_size, realloc_head); } - pbus_size_mem(bus, IORESOURCE_MEM, - realloc_head ? 0 : additional_mmio_size, - additional_mmio_size, realloc_head); + pbus_size_mem(bus, IORESOURCE_MEM, additional_mmio_size, + realloc_head); break; } } -- 2.47.3